1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The top-level routing/network map tracking logic lives here.
12 //! You probably want to create a P2PGossipSync and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::gossip::{DirectedChannelInfoWithUpdate, EffectiveCapacity, ReadOnlyNetworkGraph, NodeId, RoutingFees};
21 use routing::scoring::{ChannelUsage, Score};
22 use util::ser::{Writeable, Readable, Writer};
23 use util::logger::{Level, Logger};
24 use util::chacha20::ChaCha20;
28 use alloc::collections::BinaryHeap;
33 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
35 /// The node_id of the node at this hop.
36 pub pubkey: PublicKey,
37 /// The node_announcement features of the node at this hop. For the last hop, these may be
38 /// amended to match the features present in the invoice this node generated.
39 pub node_features: NodeFeatures,
40 /// The channel that should be used from the previous hop to reach this node.
41 pub short_channel_id: u64,
42 /// The channel_announcement features of the channel that should be used from the previous hop
43 /// to reach this node.
44 pub channel_features: ChannelFeatures,
45 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
46 /// For the last hop, this should be the full value of the payment (might be more than
47 /// requested if we had to match htlc_minimum_msat).
49 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
50 /// expected at the destination, in excess of the current block height.
51 pub cltv_expiry_delta: u32,
54 impl_writeable_tlv_based!(RouteHop, {
55 (0, pubkey, required),
56 (2, node_features, required),
57 (4, short_channel_id, required),
58 (6, channel_features, required),
59 (8, fee_msat, required),
60 (10, cltv_expiry_delta, required),
63 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
64 /// it can take multiple paths. Each path is composed of one or more hops through the network.
65 #[derive(Clone, Hash, PartialEq, Eq)]
67 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
68 /// last RouteHop in each path must be the same. Each entry represents a list of hops, NOT
69 /// INCLUDING our own, where the last hop is the destination. Thus, this must always be at
70 /// least length one. While the maximum length of any given path is variable, keeping the length
71 /// of any path less or equal to 19 should currently ensure it is viable.
72 pub paths: Vec<Vec<RouteHop>>,
73 /// The `payment_params` parameter passed to [`find_route`].
74 /// This is used by `ChannelManager` to track information which may be required for retries,
75 /// provided back to you via [`Event::PaymentPathFailed`].
77 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
78 pub payment_params: Option<PaymentParameters>,
81 pub(crate) trait RoutePath {
82 /// Gets the fees for a given path, excluding any excess paid to the recipient.
83 fn get_path_fees(&self) -> u64;
85 impl RoutePath for Vec<RouteHop> {
86 fn get_path_fees(&self) -> u64 {
87 // Do not count last hop of each path since that's the full value of the payment
88 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
89 .iter().map(|hop| &hop.fee_msat)
95 /// Returns the total amount of fees paid on this [`Route`].
97 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
98 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
99 pub fn get_total_fees(&self) -> u64 {
100 self.paths.iter().map(|path| path.get_path_fees()).sum()
103 /// Returns the total amount paid on this [`Route`], excluding the fees.
104 pub fn get_total_amount(&self) -> u64 {
105 return self.paths.iter()
106 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
111 const SERIALIZATION_VERSION: u8 = 1;
112 const MIN_SERIALIZATION_VERSION: u8 = 1;
114 impl Writeable for Route {
115 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
116 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
117 (self.paths.len() as u64).write(writer)?;
118 for hops in self.paths.iter() {
119 (hops.len() as u8).write(writer)?;
120 for hop in hops.iter() {
124 write_tlv_fields!(writer, {
125 (1, self.payment_params, option),
131 impl Readable for Route {
132 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
133 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
134 let path_count: u64 = Readable::read(reader)?;
135 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
136 for _ in 0..path_count {
137 let hop_count: u8 = Readable::read(reader)?;
138 let mut hops = Vec::with_capacity(hop_count as usize);
139 for _ in 0..hop_count {
140 hops.push(Readable::read(reader)?);
144 let mut payment_params = None;
145 read_tlv_fields!(reader, {
146 (1, payment_params, option),
148 Ok(Route { paths, payment_params })
152 /// Parameters needed to find a [`Route`].
154 /// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
155 /// [`Event::PaymentPathFailed`] for retrying a failed payment path.
157 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
158 #[derive(Clone, Debug)]
159 pub struct RouteParameters {
160 /// The parameters of the failed payment path.
161 pub payment_params: PaymentParameters,
163 /// The amount in msats sent on the failed payment path.
164 pub final_value_msat: u64,
166 /// The CLTV on the final hop of the failed payment path.
167 pub final_cltv_expiry_delta: u32,
170 impl_writeable_tlv_based!(RouteParameters, {
171 (0, payment_params, required),
172 (2, final_value_msat, required),
173 (4, final_cltv_expiry_delta, required),
176 /// Maximum total CTLV difference we allow for a full payment path.
177 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
179 // The median hop CLTV expiry delta currently seen in the network.
180 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
182 // During routing, we only consider paths shorter than our maximum length estimate.
183 // In the legacy onion format, the maximum number of hops used to be a fixed value of 20.
184 // However, in the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
185 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
186 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
188 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
189 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
190 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
191 // (payment_secret and total_msat) = 93 bytes for the final hop.
192 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
193 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
194 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
196 /// The recipient of a payment.
197 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
198 pub struct PaymentParameters {
199 /// The node id of the payee.
200 pub payee_pubkey: PublicKey,
202 /// Features supported by the payee.
204 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
205 /// does not contain any features.
207 /// [`for_keysend`]: Self::for_keysend
208 pub features: Option<InvoiceFeatures>,
210 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
211 pub route_hints: Vec<RouteHint>,
213 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
214 pub expiry_time: Option<u64>,
216 /// The maximum total CLTV delta we accept for the route.
217 pub max_total_cltv_expiry_delta: u32,
220 impl_writeable_tlv_based!(PaymentParameters, {
221 (0, payee_pubkey, required),
222 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
223 (2, features, option),
224 (4, route_hints, vec_type),
225 (6, expiry_time, option),
228 impl PaymentParameters {
229 /// Creates a payee with the node id of the given `pubkey`.
230 pub fn from_node_id(payee_pubkey: PublicKey) -> Self {
236 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
240 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
241 pub fn for_keysend(payee_pubkey: PublicKey) -> Self {
242 Self::from_node_id(payee_pubkey).with_features(InvoiceFeatures::for_keysend())
245 /// Includes the payee's features.
247 /// (C-not exported) since bindings don't support move semantics
248 pub fn with_features(self, features: InvoiceFeatures) -> Self {
249 Self { features: Some(features), ..self }
252 /// Includes hints for routing to the payee.
254 /// (C-not exported) since bindings don't support move semantics
255 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
256 Self { route_hints, ..self }
259 /// Includes a payment expiration in seconds relative to the UNIX epoch.
261 /// (C-not exported) since bindings don't support move semantics
262 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
263 Self { expiry_time: Some(expiry_time), ..self }
266 /// Includes a limit for the total CLTV expiry delta which is considered during routing
268 /// (C-not exported) since bindings don't support move semantics
269 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
270 Self { max_total_cltv_expiry_delta, ..self }
274 /// A list of hops along a payment path terminating with a channel to the recipient.
275 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
276 pub struct RouteHint(pub Vec<RouteHintHop>);
278 impl Writeable for RouteHint {
279 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
280 (self.0.len() as u64).write(writer)?;
281 for hop in self.0.iter() {
288 impl Readable for RouteHint {
289 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
290 let hop_count: u64 = Readable::read(reader)?;
291 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
292 for _ in 0..hop_count {
293 hops.push(Readable::read(reader)?);
299 /// A channel descriptor for a hop along a payment path.
300 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
301 pub struct RouteHintHop {
302 /// The node_id of the non-target end of the route
303 pub src_node_id: PublicKey,
304 /// The short_channel_id of this channel
305 pub short_channel_id: u64,
306 /// The fees which must be paid to use this channel
307 pub fees: RoutingFees,
308 /// The difference in CLTV values between this node and the next node.
309 pub cltv_expiry_delta: u16,
310 /// The minimum value, in msat, which must be relayed to the next hop.
311 pub htlc_minimum_msat: Option<u64>,
312 /// The maximum value in msat available for routing with a single HTLC.
313 pub htlc_maximum_msat: Option<u64>,
316 impl_writeable_tlv_based!(RouteHintHop, {
317 (0, src_node_id, required),
318 (1, htlc_minimum_msat, option),
319 (2, short_channel_id, required),
320 (3, htlc_maximum_msat, option),
322 (6, cltv_expiry_delta, required),
325 #[derive(Eq, PartialEq)]
326 struct RouteGraphNode {
328 lowest_fee_to_peer_through_node: u64,
329 lowest_fee_to_node: u64,
330 total_cltv_delta: u32,
331 // The maximum value a yet-to-be-constructed payment path might flow through this node.
332 // This value is upper-bounded by us by:
333 // - how much is needed for a path being constructed
334 // - how much value can channels following this node (up to the destination) can contribute,
335 // considering their capacity and fees
336 value_contribution_msat: u64,
337 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
338 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
339 path_htlc_minimum_msat: u64,
340 /// All penalties incurred from this hop on the way to the destination, as calculated using
342 path_penalty_msat: u64,
343 /// The number of hops walked up to this node.
344 path_length_to_node: u8,
347 impl cmp::Ord for RouteGraphNode {
348 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
349 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat)
350 .saturating_add(other.path_penalty_msat);
351 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat)
352 .saturating_add(self.path_penalty_msat);
353 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
357 impl cmp::PartialOrd for RouteGraphNode {
358 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
359 Some(self.cmp(other))
363 /// A wrapper around the various hop representations.
365 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
366 #[derive(Clone, Debug)]
367 enum CandidateRouteHop<'a> {
368 /// A hop from the payer, where the outbound liquidity is known.
370 details: &'a ChannelDetails,
372 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
374 info: DirectedChannelInfoWithUpdate<'a>,
375 short_channel_id: u64,
377 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
379 hint: &'a RouteHintHop,
383 impl<'a> CandidateRouteHop<'a> {
384 fn short_channel_id(&self) -> u64 {
386 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
387 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
388 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
392 // NOTE: This may alloc memory so avoid calling it in a hot code path.
393 fn features(&self) -> ChannelFeatures {
395 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
396 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
397 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
401 fn cltv_expiry_delta(&self) -> u32 {
403 CandidateRouteHop::FirstHop { .. } => 0,
404 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
405 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
409 fn htlc_minimum_msat(&self) -> u64 {
411 CandidateRouteHop::FirstHop { .. } => 0,
412 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
413 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
417 fn htlc_maximum_msat(&self) -> u64 {
419 CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_limit_msat,
420 CandidateRouteHop::PublicHop { info, .. } => info.htlc_maximum_msat(),
421 CandidateRouteHop::PrivateHop { hint } => {
422 hint.htlc_maximum_msat.unwrap_or(u64::max_value())
427 fn fees(&self) -> RoutingFees {
429 CandidateRouteHop::FirstHop { .. } => RoutingFees {
430 base_msat: 0, proportional_millionths: 0,
432 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
433 CandidateRouteHop::PrivateHop { hint } => hint.fees,
437 fn effective_capacity(&self) -> EffectiveCapacity {
439 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
440 liquidity_msat: details.next_outbound_htlc_limit_msat,
442 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
443 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
448 /// It's useful to keep track of the hops associated with the fees required to use them,
449 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
450 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
451 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
453 struct PathBuildingHop<'a> {
454 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
455 // is a larger refactor and will require careful performance analysis.
457 candidate: CandidateRouteHop<'a>,
460 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
461 src_lowest_inbound_fees: RoutingFees,
462 /// All the fees paid *after* this channel on the way to the destination
463 next_hops_fee_msat: u64,
464 /// Fee paid for the use of the current channel (see candidate.fees()).
465 /// The value will be actually deducted from the counterparty balance on the previous link.
466 hop_use_fee_msat: u64,
467 /// Used to compare channels when choosing the for routing.
468 /// Includes paying for the use of a hop and the following hops, as well as
469 /// an estimated cost of reaching this hop.
470 /// Might get stale when fees are recomputed. Primarily for internal use.
472 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
473 /// walk and may be invalid thereafter.
474 path_htlc_minimum_msat: u64,
475 /// All penalties incurred from this channel on the way to the destination, as calculated using
477 path_penalty_msat: u64,
478 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
479 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
480 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
481 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
482 /// avoid processing them again.
484 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
485 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
486 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
487 // value_contribution_msat, which requires tracking it here. See comments below where it is
488 // used for more info.
489 value_contribution_msat: u64,
492 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
493 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
494 let mut debug_struct = f.debug_struct("PathBuildingHop");
496 .field("node_id", &self.node_id)
497 .field("short_channel_id", &self.candidate.short_channel_id())
498 .field("total_fee_msat", &self.total_fee_msat)
499 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
500 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
501 .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)))
502 .field("path_penalty_msat", &self.path_penalty_msat)
503 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
504 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
505 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
506 let debug_struct = debug_struct
507 .field("value_contribution_msat", &self.value_contribution_msat);
508 debug_struct.finish()
512 // Instantiated with a list of hops with correct data in them collected during path finding,
513 // an instance of this struct should be further modified only via given methods.
515 struct PaymentPath<'a> {
516 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
519 impl<'a> PaymentPath<'a> {
520 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
521 fn get_value_msat(&self) -> u64 {
522 self.hops.last().unwrap().0.fee_msat
525 fn get_path_penalty_msat(&self) -> u64 {
526 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
529 fn get_total_fee_paid_msat(&self) -> u64 {
530 if self.hops.len() < 1 {
534 // Can't use next_hops_fee_msat because it gets outdated.
535 for (i, (hop, _)) in self.hops.iter().enumerate() {
536 if i != self.hops.len() - 1 {
537 result += hop.fee_msat;
543 fn get_cost_msat(&self) -> u64 {
544 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
547 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
548 // to change fees may result in an inconsistency.
550 // Sometimes we call this function right after constructing a path which is inconsistent in
551 // that it the value being transferred has decreased while we were doing path finding, leading
552 // to the fees being paid not lining up with the actual limits.
554 // Note that this function is not aware of the available_liquidity limit, and thus does not
555 // support increasing the value being transferred.
556 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
557 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
559 let mut total_fee_paid_msat = 0 as u64;
560 for i in (0..self.hops.len()).rev() {
561 let last_hop = i == self.hops.len() - 1;
563 // For non-last-hop, this value will represent the fees paid on the current hop. It
564 // will consist of the fees for the use of the next hop, and extra fees to match
565 // htlc_minimum_msat of the current channel. Last hop is handled separately.
566 let mut cur_hop_fees_msat = 0;
568 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
571 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
572 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
573 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
574 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
575 // set it too high just to maliciously take more fees by exploiting this
576 // match htlc_minimum_msat logic.
577 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
578 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
579 // Note that there is a risk that *previous hops* (those closer to us, as we go
580 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
582 // This might make us end up with a broken route, although this should be super-rare
583 // in practice, both because of how healthy channels look like, and how we pick
584 // channels in add_entry.
585 // Also, this can't be exploited more heavily than *announce a free path and fail
587 cur_hop_transferred_amount_msat += extra_fees_msat;
588 total_fee_paid_msat += extra_fees_msat;
589 cur_hop_fees_msat += extra_fees_msat;
593 // Final hop is a special case: it usually has just value_msat (by design), but also
594 // it still could overpay for the htlc_minimum_msat.
595 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
597 // Propagate updated fees for the use of the channels to one hop back, where they
598 // will be actually paid (fee_msat). The last hop is handled above separately.
599 cur_hop.fee_msat = cur_hop_fees_msat;
602 // Fee for the use of the current hop which will be deducted on the previous hop.
603 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
604 // this channel is free for us.
606 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
607 cur_hop.hop_use_fee_msat = new_fee;
608 total_fee_paid_msat += new_fee;
610 // It should not be possible because this function is called only to reduce the
611 // value. In that case, compute_fee was already called with the same fees for
612 // larger amount and there was no overflow.
620 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
621 let proportional_fee_millions =
622 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
623 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
624 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
628 // This function may be (indirectly) called without any verification,
629 // with channel_fees provided by a caller. We should handle it gracefully.
634 /// The default `features` we assume for a node in a route, when no `features` are known about that
637 /// Default features are:
638 /// * variable_length_onion_optional
639 fn default_node_features() -> NodeFeatures {
640 let mut features = NodeFeatures::empty();
641 features.set_variable_length_onion_optional();
645 /// Finds a route from us (payer) to the given target node (payee).
647 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
648 /// Without this, MPP will only be used if the payee's features are available in the network graph.
650 /// Private routing paths between a public node and the target may be included in `params.payee`.
652 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
653 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
654 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
656 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
657 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
658 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
662 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
663 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
668 /// Panics if first_hops contains channels without short_channel_ids;
669 /// [`ChannelManager::list_usable_channels`] will never include such channels.
671 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
672 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
673 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
674 pub fn find_route<L: Deref, S: Score>(
675 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
676 network_graph: &ReadOnlyNetworkGraph, first_hops: Option<&[&ChannelDetails]>, logger: L,
677 scorer: &S, random_seed_bytes: &[u8; 32]
678 ) -> Result<Route, LightningError>
679 where L::Target: Logger {
680 let mut route = get_route(our_node_pubkey, &route_params.payment_params, network_graph, first_hops,
681 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, scorer,
683 add_random_cltv_offset(&mut route, &route_params.payment_params, network_graph, random_seed_bytes);
687 pub(crate) fn get_route<L: Deref, S: Score>(
688 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
689 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
690 logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
691 ) -> Result<Route, LightningError>
692 where L::Target: Logger {
693 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
694 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
696 if payee_node_id == our_node_id {
697 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
700 if final_value_msat > MAX_VALUE_MSAT {
701 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
704 if final_value_msat == 0 {
705 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
708 for route in payment_params.route_hints.iter() {
709 for hop in &route.0 {
710 if hop.src_node_id == payment_params.payee_pubkey {
711 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
715 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
716 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});
719 // The general routing idea is the following:
720 // 1. Fill first/last hops communicated by the caller.
721 // 2. Attempt to construct a path from payer to payee for transferring
722 // any ~sufficient (described later) value.
723 // If succeed, remember which channels were used and how much liquidity they have available,
724 // so that future paths don't rely on the same liquidity.
725 // 3. Proceed to the next step if:
726 // - we hit the recommended target value;
727 // - OR if we could not construct a new path. Any next attempt will fail too.
728 // Otherwise, repeat step 2.
729 // 4. See if we managed to collect paths which aggregately are able to transfer target value
730 // (not recommended value).
731 // 5. If yes, proceed. If not, fail routing.
732 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
733 // 7. Of all the found paths, select only those with the lowest total fee.
734 // 8. The last path in every selected route is likely to be more than we need.
735 // Reduce its value-to-transfer and recompute fees.
736 // 9. Choose the best route by the lowest total fee.
738 // As for the actual search algorithm,
739 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
740 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
742 // We are not a faithful Dijkstra's implementation because we can change values which impact
743 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
744 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
745 // the value we are currently attempting to send over a path, we simply reduce the value being
746 // sent along the path for any hops after that channel. This may imply that later fees (which
747 // we've already tabulated) are lower because a smaller value is passing through the channels
748 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
749 // channels which were selected earlier (and which may still be used for other paths without a
750 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
753 // One potentially problematic case for this algorithm would be if there are many
754 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
755 // graph walking), we may never find a path which is not liquidity-limited and has lower
756 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
757 // Because we only consider paths with at least 5% of the total value being sent, the damage
758 // from such a case should be limited, however this could be further reduced in the future by
759 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
760 // limits for the purposes of fee calculation.
762 // Alternatively, we could store more detailed path information in the heap (targets, below)
763 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
764 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
765 // and practically (as we would need to store dynamically-allocated path information in heap
766 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
767 // results of such an algorithm would likely be biased towards lower-value paths.
769 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
770 // outside of our current search value, running a path search more times to gather candidate
771 // paths at different values. While this may be acceptable, further path searches may increase
772 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
773 // graph for candidate paths, calculating the maximum value which can realistically be sent at
774 // the same time, remaining generic across different payment values.
776 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
777 // to use as the A* heuristic beyond just the cost to get one node further than the current
780 let network_channels = network_graph.channels();
781 let network_nodes = network_graph.nodes();
783 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
784 // it. If the payee supports it they're supposed to include it in the invoice, so that should
786 let allow_mpp = if let Some(features) = &payment_params.features {
787 features.supports_basic_mpp()
788 } else if let Some(node) = network_nodes.get(&payee_node_id) {
789 if let Some(node_info) = node.announcement_info.as_ref() {
790 node_info.features.supports_basic_mpp()
793 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
794 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
795 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
798 // Prepare the data we'll use for payee-to-payer search by
799 // inserting first hops suggested by the caller as targets.
800 // Our search will then attempt to reach them while traversing from the payee node.
801 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
802 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
803 if let Some(hops) = first_hops {
805 if chan.get_outbound_payment_scid().is_none() {
806 panic!("first_hops should be filled in with usable channels, not pending ones");
808 if chan.counterparty.node_id == *our_node_pubkey {
809 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
812 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
813 .or_insert(Vec::new())
816 if first_hop_targets.is_empty() {
817 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
821 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
822 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
823 // adding duplicate entries when we find a better path to a given node.
824 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
826 // Map from node_id to information about the best current path to that node, including feerate
828 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
830 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
831 // indicating that we may wish to try again with a higher value, potentially paying to meet an
832 // htlc_minimum with extra fees while still finding a cheaper path.
833 let mut hit_minimum_limit;
835 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
836 // We start with a path_value of the exact amount we want, and if that generates a route we may
837 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
838 // amount we want in total across paths, selecting the best subset at the end.
839 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
840 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
841 let mut path_value_msat = final_value_msat;
843 // Keep track of how much liquidity has been used in selected channels. Used to determine
844 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
845 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
846 // liquidity used in one direction will not offset any used in the opposite direction.
847 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
848 HashMap::with_capacity(network_nodes.len());
850 // Keeping track of how much value we already collected across other paths. Helps to decide:
851 // - how much a new path should be transferring (upper bound);
852 // - whether a channel should be disregarded because
853 // it's available liquidity is too small comparing to how much more we need to collect;
854 // - when we want to stop looking for new paths.
855 let mut already_collected_value_msat = 0;
857 for (_, channels) in first_hop_targets.iter_mut() {
858 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
861 // First, if channels are below `recommended_value_msat`, sort them in descending order,
862 // preferring larger channels to avoid splitting the payment into more MPP parts than is
865 // Second, because simply always sorting in descending order would always use our largest
866 // available outbound capacity, needlessly fragmenting our available channel capacities,
867 // sort channels above `recommended_value_msat` in ascending order, preferring channels
868 // which have enough, but not too much, capacity for the payment.
869 channels.sort_unstable_by(|chan_a, chan_b| {
870 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
871 // Sort in descending order
872 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
874 // Sort in ascending order
875 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
880 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
882 macro_rules! add_entry {
883 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
884 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
885 // since that value has to be transferred over this channel.
886 // Returns whether this channel caused an update to `targets`.
887 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
888 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
889 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
890 // We "return" whether we updated the path at the end, via this:
891 let mut did_add_update_path_to_src_node = false;
892 // Channels to self should not be used. This is more of belt-and-suspenders, because in
893 // practice these cases should be caught earlier:
894 // - for regular channels at channel announcement (TODO)
895 // - for first and last hops early in get_route
896 if $src_node_id != $dest_node_id {
897 let short_channel_id = $candidate.short_channel_id();
898 let htlc_maximum_msat = $candidate.htlc_maximum_msat();
900 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
901 // It may be misleading because we might later choose to reduce the value transferred
902 // over these channels, and the channel which was insufficient might become sufficient.
903 // Worst case: we drop a good channel here because it can't cover the high following
904 // fees caused by one expensive channel, but then this channel could have been used
905 // if the amount being transferred over this path is lower.
906 // We do this for now, but this is a subject for removal.
907 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
908 let used_liquidity_msat = used_channel_liquidities
909 .get(&(short_channel_id, $src_node_id < $dest_node_id))
910 .map_or(0, |used_liquidity_msat| {
911 available_value_contribution_msat = available_value_contribution_msat
912 .saturating_sub(*used_liquidity_msat);
916 // Routing Fragmentation Mitigation heuristic:
918 // Routing fragmentation across many payment paths increases the overall routing
919 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
920 // Taking too many smaller paths also increases the chance of payment failure.
921 // Thus to avoid this effect, we require from our collected links to provide
922 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
924 // This requirement is currently 5% of the remaining-to-be-collected value.
925 // This means as we successfully advance in our collection,
926 // the absolute liquidity contribution is lowered,
927 // thus increasing the number of potential channels to be selected.
929 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
930 // or 100% if we're not allowed to do multipath payments.
931 let minimal_value_contribution_msat: u64 = if allow_mpp {
932 (recommended_value_msat - already_collected_value_msat + 19) / 20
936 // Verify the liquidity offered by this channel complies to the minimal contribution.
937 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
938 // Do not consider candidate hops that would exceed the maximum path length.
939 let path_length_to_node = $next_hops_path_length + 1;
940 let doesnt_exceed_max_path_length = path_length_to_node <= MAX_PATH_LENGTH_ESTIMATE;
942 // Do not consider candidates that exceed the maximum total cltv expiry limit.
943 // In order to already account for some of the privacy enhancing random CLTV
944 // expiry delta offset we add on top later, we subtract a rough estimate
945 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
946 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
947 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
948 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
949 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
950 .saturating_add($candidate.cltv_expiry_delta());
951 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
953 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
954 // Includes paying fees for the use of the following channels.
955 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
956 Some(result) => result,
957 // Can't overflow due to how the values were computed right above.
958 None => unreachable!(),
960 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
961 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
962 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
964 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
965 let may_overpay_to_meet_path_minimum_msat =
966 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
967 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
968 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
969 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
971 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
972 // bother considering this channel. If retrying with recommended_value_msat may
973 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
974 // around again with a higher amount.
975 if contributes_sufficient_value && doesnt_exceed_max_path_length &&
976 doesnt_exceed_cltv_delta_limit && may_overpay_to_meet_path_minimum_msat {
977 hit_minimum_limit = true;
978 } else if contributes_sufficient_value && doesnt_exceed_max_path_length &&
979 doesnt_exceed_cltv_delta_limit && over_path_minimum_msat {
980 // Note that low contribution here (limited by available_liquidity_msat)
981 // might violate htlc_minimum_msat on the hops which are next along the
982 // payment path (upstream to the payee). To avoid that, we recompute
983 // path fees knowing the final path contribution after constructing it.
984 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
985 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
986 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
987 .unwrap_or_else(|| u64::max_value());
988 let hm_entry = dist.entry($src_node_id);
989 let old_entry = hm_entry.or_insert_with(|| {
990 // If there was previously no known way to access the source node
991 // (recall it goes payee-to-payer) of short_channel_id, first add a
992 // semi-dummy record just to compute the fees to reach the source node.
993 // This will affect our decision on selecting short_channel_id
994 // as a way to reach the $dest_node_id.
995 let mut fee_base_msat = 0;
996 let mut fee_proportional_millionths = 0;
997 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
998 fee_base_msat = fees.base_msat;
999 fee_proportional_millionths = fees.proportional_millionths;
1002 node_id: $dest_node_id.clone(),
1003 candidate: $candidate.clone(),
1005 src_lowest_inbound_fees: RoutingFees {
1006 base_msat: fee_base_msat,
1007 proportional_millionths: fee_proportional_millionths,
1009 next_hops_fee_msat: u64::max_value(),
1010 hop_use_fee_msat: u64::max_value(),
1011 total_fee_msat: u64::max_value(),
1012 path_htlc_minimum_msat,
1013 path_penalty_msat: u64::max_value(),
1014 was_processed: false,
1015 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1016 value_contribution_msat,
1020 #[allow(unused_mut)] // We only use the mut in cfg(test)
1021 let mut should_process = !old_entry.was_processed;
1022 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1024 // In test/fuzzing builds, we do extra checks to make sure the skipping
1025 // of already-seen nodes only happens in cases we expect (see below).
1026 if !should_process { should_process = true; }
1030 let mut hop_use_fee_msat = 0;
1031 let mut total_fee_msat = $next_hops_fee_msat;
1033 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1034 // will have the same effective-fee
1035 if $src_node_id != our_node_id {
1036 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
1037 // max_value means we'll always fail
1038 // the old_entry.total_fee_msat > total_fee_msat check
1039 None => total_fee_msat = u64::max_value(),
1041 hop_use_fee_msat = fee_msat;
1042 total_fee_msat += hop_use_fee_msat;
1043 // When calculating the lowest inbound fees to a node, we
1044 // calculate fees here not based on the actual value we think
1045 // will flow over this channel, but on the minimum value that
1046 // we'll accept flowing over it. The minimum accepted value
1047 // is a constant through each path collection run, ensuring
1048 // consistent basis. Otherwise we may later find a
1049 // different path to the source node that is more expensive,
1050 // but which we consider to be cheaper because we are capacity
1051 // constrained and the relative fee becomes lower.
1052 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
1053 .map(|a| a.checked_add(total_fee_msat)) {
1058 total_fee_msat = u64::max_value();
1065 let channel_usage = ChannelUsage {
1066 amount_msat: amount_to_transfer_over_msat,
1067 inflight_htlc_msat: used_liquidity_msat,
1068 effective_capacity: $candidate.effective_capacity(),
1070 let channel_penalty_msat = scorer.channel_penalty_msat(
1071 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage
1073 let path_penalty_msat = $next_hops_path_penalty_msat
1074 .saturating_add(channel_penalty_msat);
1075 let new_graph_node = RouteGraphNode {
1076 node_id: $src_node_id,
1077 lowest_fee_to_peer_through_node: total_fee_msat,
1078 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1079 total_cltv_delta: hop_total_cltv_delta,
1080 value_contribution_msat: value_contribution_msat,
1081 path_htlc_minimum_msat,
1083 path_length_to_node,
1086 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1087 // if this way is cheaper than the already known
1088 // (considering the cost to "reach" this channel from the route destination,
1089 // the cost of using this channel,
1090 // and the cost of routing to the source node of this channel).
1091 // Also, consider that htlc_minimum_msat_difference, because we might end up
1092 // paying it. Consider the following exploit:
1093 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1094 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1095 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1096 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1098 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1099 // but it may require additional tracking - we don't want to double-count
1100 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1101 // can't use something that may decrease on future hops.
1102 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1103 .saturating_add(old_entry.path_penalty_msat);
1104 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1105 .saturating_add(path_penalty_msat);
1107 if !old_entry.was_processed && new_cost < old_cost {
1108 targets.push(new_graph_node);
1109 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1110 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1111 old_entry.total_fee_msat = total_fee_msat;
1112 old_entry.node_id = $dest_node_id.clone();
1113 old_entry.candidate = $candidate.clone();
1114 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1115 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1116 old_entry.path_penalty_msat = path_penalty_msat;
1117 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1119 old_entry.value_contribution_msat = value_contribution_msat;
1121 did_add_update_path_to_src_node = true;
1122 } else if old_entry.was_processed && new_cost < old_cost {
1123 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1125 // If we're skipping processing a node which was previously
1126 // processed even though we found another path to it with a
1127 // cheaper fee, check that it was because the second path we
1128 // found (which we are processing now) has a lower value
1129 // contribution due to an HTLC minimum limit.
1131 // e.g. take a graph with two paths from node 1 to node 2, one
1132 // through channel A, and one through channel B. Channel A and
1133 // B are both in the to-process heap, with their scores set by
1134 // a higher htlc_minimum than fee.
1135 // Channel A is processed first, and the channels onwards from
1136 // node 1 are added to the to-process heap. Thereafter, we pop
1137 // Channel B off of the heap, note that it has a much more
1138 // restrictive htlc_maximum_msat, and recalculate the fees for
1139 // all of node 1's channels using the new, reduced, amount.
1141 // This would be bogus - we'd be selecting a higher-fee path
1142 // with a lower htlc_maximum_msat instead of the one we'd
1143 // already decided to use.
1144 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1146 value_contribution_msat + path_penalty_msat <
1147 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1155 did_add_update_path_to_src_node
1159 let default_node_features = default_node_features();
1161 // Find ways (channels with destination) to reach a given node and store them
1162 // in the corresponding data structures (routing graph etc).
1163 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1164 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1165 // This data can later be helpful to optimize routing (pay lower fees).
1166 macro_rules! add_entries_to_cheapest_to_target_node {
1167 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1168 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1169 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1170 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1171 let was_processed = elem.was_processed;
1172 elem.was_processed = true;
1175 // Entries are added to dist in add_entry!() when there is a channel from a node.
1176 // Because there are no channels from payee, it will not have a dist entry at this point.
1177 // If we're processing any other node, it is always be the result of a channel from it.
1178 assert_eq!($node_id, payee_node_id);
1183 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1184 for details in first_channels {
1185 let candidate = CandidateRouteHop::FirstHop { details };
1186 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1187 $next_hops_value_contribution,
1188 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1189 $next_hops_cltv_delta, $next_hops_path_length);
1193 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1196 &default_node_features
1199 if !features.requires_unknown_bits() {
1200 for chan_id in $node.channels.iter() {
1201 let chan = network_channels.get(chan_id).unwrap();
1202 if !chan.features.requires_unknown_bits() {
1203 let (directed_channel, source) =
1204 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1205 if first_hops.is_none() || *source != our_node_id {
1206 if let Some(direction) = directed_channel.direction() {
1207 if direction.enabled {
1208 let candidate = CandidateRouteHop::PublicHop {
1209 info: directed_channel.with_update().unwrap(),
1210 short_channel_id: *chan_id,
1212 add_entry!(candidate, *source, $node_id,
1213 $fee_to_target_msat,
1214 $next_hops_value_contribution,
1215 $next_hops_path_htlc_minimum_msat,
1216 $next_hops_path_penalty_msat,
1217 $next_hops_cltv_delta, $next_hops_path_length);
1228 let mut payment_paths = Vec::<PaymentPath>::new();
1230 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1231 'paths_collection: loop {
1232 // For every new path, start from scratch, except for used_channel_liquidities, which
1233 // helps to avoid reusing previously selected paths in future iterations.
1236 hit_minimum_limit = false;
1238 // If first hop is a private channel and the only way to reach the payee, this is the only
1239 // place where it could be added.
1240 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1241 for details in first_channels {
1242 let candidate = CandidateRouteHop::FirstHop { details };
1243 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat,
1245 log_trace!(logger, "{} direct route to payee via SCID {}",
1246 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1250 // Add the payee as a target, so that the payee-to-payer
1251 // search algorithm knows what to start with.
1252 match network_nodes.get(&payee_node_id) {
1253 // The payee is not in our network graph, so nothing to add here.
1254 // There is still a chance of reaching them via last_hops though,
1255 // so don't yet fail the payment here.
1256 // If not, targets.pop() will not even let us enter the loop in step 2.
1259 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0, 0);
1264 // If a caller provided us with last hops, add them to routing targets. Since this happens
1265 // earlier than general path finding, they will be somewhat prioritized, although currently
1266 // it matters only if the fees are exactly the same.
1267 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1268 let first_hop_in_route = &(route.0)[0];
1269 let have_hop_src_in_graph =
1270 // Only add the hops in this route to our candidate set if either
1271 // we have a direct channel to the first hop or the first hop is
1272 // in the regular network graph.
1273 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1274 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1275 if have_hop_src_in_graph {
1276 // We start building the path from reverse, i.e., from payee
1277 // to the first RouteHintHop in the path.
1278 let hop_iter = route.0.iter().rev();
1279 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1280 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1281 let mut hop_used = true;
1282 let mut aggregate_next_hops_fee_msat: u64 = 0;
1283 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1284 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1285 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1286 let mut aggregate_next_hops_path_length: u8 = 0;
1288 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1289 let source = NodeId::from_pubkey(&hop.src_node_id);
1290 let target = NodeId::from_pubkey(&prev_hop_id);
1291 let candidate = network_channels
1292 .get(&hop.short_channel_id)
1293 .and_then(|channel| channel.as_directed_to(&target))
1294 .and_then(|(channel, _)| channel.with_update())
1295 .map(|info| CandidateRouteHop::PublicHop {
1297 short_channel_id: hop.short_channel_id,
1299 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1301 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
1302 path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
1303 aggregate_next_hops_path_penalty_msat,
1304 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
1305 // If this hop was not used then there is no use checking the preceding
1306 // hops in the RouteHint. We can break by just searching for a direct
1307 // channel between last checked hop and first_hop_targets.
1311 let used_liquidity_msat = used_channel_liquidities
1312 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1313 let channel_usage = ChannelUsage {
1314 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1315 inflight_htlc_msat: used_liquidity_msat,
1316 effective_capacity: candidate.effective_capacity(),
1318 let channel_penalty_msat = scorer.channel_penalty_msat(
1319 hop.short_channel_id, &source, &target, channel_usage
1321 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1322 .saturating_add(channel_penalty_msat);
1324 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1325 .saturating_add(hop.cltv_expiry_delta as u32);
1327 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1330 // Searching for a direct channel between last checked hop and first_hop_targets
1331 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1332 for details in first_channels {
1333 let candidate = CandidateRouteHop::FirstHop { details };
1334 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1335 aggregate_next_hops_fee_msat, path_value_msat,
1336 aggregate_next_hops_path_htlc_minimum_msat,
1337 aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
1338 aggregate_next_hops_path_length);
1346 // In the next values of the iterator, the aggregate fees already reflects
1347 // the sum of value sent from payer (final_value_msat) and routing fees
1348 // for the last node in the RouteHint. We need to just add the fees to
1349 // route through the current node so that the preceding node (next iteration)
1351 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1352 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1353 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1355 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1356 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1357 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1358 .checked_add(hop_htlc_minimum_msat_inc);
1359 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1361 if idx == route.0.len() - 1 {
1362 // The last hop in this iterator is the first hop in
1363 // overall RouteHint.
1364 // If this hop connects to a node with which we have a direct channel,
1365 // ignore the network graph and, if the last hop was added, add our
1366 // direct channel to the candidate set.
1368 // Note that we *must* check if the last hop was added as `add_entry`
1369 // always assumes that the third argument is a node to which we have a
1371 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1372 for details in first_channels {
1373 let candidate = CandidateRouteHop::FirstHop { details };
1374 add_entry!(candidate, our_node_id,
1375 NodeId::from_pubkey(&hop.src_node_id),
1376 aggregate_next_hops_fee_msat, path_value_msat,
1377 aggregate_next_hops_path_htlc_minimum_msat,
1378 aggregate_next_hops_path_penalty_msat,
1379 aggregate_next_hops_cltv_delta,
1380 aggregate_next_hops_path_length);
1388 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1390 // At this point, targets are filled with the data from first and
1391 // last hops communicated by the caller, and the payment receiver.
1392 let mut found_new_path = false;
1395 // If this loop terminates due the exhaustion of targets, two situations are possible:
1396 // - not enough outgoing liquidity:
1397 // 0 < already_collected_value_msat < final_value_msat
1398 // - enough outgoing liquidity:
1399 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1400 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1401 // paths_collection will be stopped because found_new_path==false.
1402 // This is not necessarily a routing failure.
1403 '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() {
1405 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1406 // traversing the graph and arrange the path out of what we found.
1407 if node_id == our_node_id {
1408 let mut new_entry = dist.remove(&our_node_id).unwrap();
1409 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1412 let mut features_set = false;
1413 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1414 for details in first_channels {
1415 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1416 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1417 features_set = true;
1423 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1424 if let Some(node_info) = node.announcement_info.as_ref() {
1425 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1427 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1430 // We can fill in features for everything except hops which were
1431 // provided via the invoice we're paying. We could guess based on the
1432 // recipient's features but for now we simply avoid guessing at all.
1436 // Means we succesfully traversed from the payer to the payee, now
1437 // save this path for the payment route. Also, update the liquidity
1438 // remaining on the used hops, so that we take them into account
1439 // while looking for more paths.
1440 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1444 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1445 Some(payment_hop) => payment_hop,
1446 // We can't arrive at None because, if we ever add an entry to targets,
1447 // we also fill in the entry in dist (see add_entry!).
1448 None => unreachable!(),
1450 // We "propagate" the fees one hop backward (topologically) here,
1451 // so that fees paid for a HTLC forwarding on the current channel are
1452 // associated with the previous channel (where they will be subtracted).
1453 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1454 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1456 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1457 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1459 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1460 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1462 let mut payment_path = PaymentPath {hops: ordered_hops};
1464 // We could have possibly constructed a slightly inconsistent path: since we reduce
1465 // value being transferred along the way, we could have violated htlc_minimum_msat
1466 // on some channels we already passed (assuming dest->source direction). Here, we
1467 // recompute the fees again, so that if that's the case, we match the currently
1468 // underpaid htlc_minimum_msat with fees.
1469 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1471 // Since a path allows to transfer as much value as
1472 // the smallest channel it has ("bottleneck"), we should recompute
1473 // the fees so sender HTLC don't overpay fees when traversing
1474 // larger channels than the bottleneck. This may happen because
1475 // when we were selecting those channels we were not aware how much value
1476 // this path will transfer, and the relative fee for them
1477 // might have been computed considering a larger value.
1478 // Remember that we used these channels so that we don't rely
1479 // on the same liquidity in future paths.
1480 let mut prevented_redundant_path_selection = false;
1481 let prev_hop_iter = core::iter::once(&our_node_id)
1482 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1483 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1484 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1485 let used_liquidity_msat = used_channel_liquidities
1486 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1487 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
1488 .or_insert(spent_on_hop_msat);
1489 if *used_liquidity_msat == hop.candidate.htlc_maximum_msat() {
1490 // If this path used all of this channel's available liquidity, we know
1491 // this path will not be selected again in the next loop iteration.
1492 prevented_redundant_path_selection = true;
1494 debug_assert!(*used_liquidity_msat <= hop.candidate.htlc_maximum_msat());
1496 if !prevented_redundant_path_selection {
1497 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1498 // we'll probably end up picking the same path again on the next iteration.
1499 // Decrease the available liquidity of a hop in the middle of the path.
1500 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1501 let exhausted = u64::max_value();
1502 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1503 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
1504 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
1507 // Track the total amount all our collected paths allow to send so that we:
1508 // - know when to stop looking for more paths
1509 // - know which of the hops are useless considering how much more sats we need
1510 // (contributes_sufficient_value)
1511 already_collected_value_msat += value_contribution_msat;
1513 payment_paths.push(payment_path);
1514 found_new_path = true;
1515 break 'path_construction;
1518 // If we found a path back to the payee, we shouldn't try to process it again. This is
1519 // the equivalent of the `elem.was_processed` check in
1520 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1521 if node_id == payee_node_id { continue 'path_construction; }
1523 // Otherwise, since the current target node is not us,
1524 // keep "unrolling" the payment graph from payee to payer by
1525 // finding a way to reach the current target from the payer side.
1526 match network_nodes.get(&node_id) {
1529 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
1530 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
1531 total_cltv_delta, path_length_to_node);
1537 // If we don't support MPP, no use trying to gather more value ever.
1538 break 'paths_collection;
1542 // Stop either when the recommended value is reached or if no new path was found in this
1544 // In the latter case, making another path finding attempt won't help,
1545 // because we deterministically terminated the search due to low liquidity.
1546 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1547 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1548 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1549 break 'paths_collection;
1550 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1551 // Further, if this was our first walk of the graph, and we weren't limited by an
1552 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1553 // limited by an htlc_minimum_msat value, find another path with a higher value,
1554 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1555 // still keeping a lower total fee than this path.
1556 if !hit_minimum_limit {
1557 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1558 break 'paths_collection;
1560 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1561 path_value_msat = recommended_value_msat;
1566 if payment_paths.len() == 0 {
1567 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1570 if already_collected_value_msat < final_value_msat {
1571 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1574 // Sort by total fees and take the best paths.
1575 payment_paths.sort_unstable_by_key(|path| path.get_total_fee_paid_msat());
1576 if payment_paths.len() > 50 {
1577 payment_paths.truncate(50);
1580 // Draw multiple sufficient routes by randomly combining the selected paths.
1581 let mut drawn_routes = Vec::new();
1582 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 12]);
1583 let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
1585 let num_permutations = payment_paths.len();
1586 for _ in 0..num_permutations {
1587 let mut cur_route = Vec::<PaymentPath>::new();
1588 let mut aggregate_route_value_msat = 0;
1591 // Do a Fisher-Yates shuffle to create a random permutation of the payment paths
1592 for cur_index in (1..payment_paths.len()).rev() {
1593 prng.process_in_place(&mut random_index_bytes);
1594 let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
1595 payment_paths.swap(cur_index, random_index);
1599 for payment_path in &payment_paths {
1600 cur_route.push(payment_path.clone());
1601 aggregate_route_value_msat += payment_path.get_value_msat();
1602 if aggregate_route_value_msat > final_value_msat {
1603 // Last path likely overpaid. Substract it from the most expensive
1604 // (in terms of proportional fee) path in this route and recompute fees.
1605 // This might be not the most economically efficient way, but fewer paths
1606 // also makes routing more reliable.
1607 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1609 // First, we drop some expensive low-value paths entirely if possible, since fewer
1610 // paths is better: the payment is less likely to fail. In order to do so, we sort
1611 // by value and fall back to total fees paid, i.e., in case of equal values we
1612 // prefer lower cost paths.
1613 cur_route.sort_unstable_by(|a, b| {
1614 a.get_value_msat().cmp(&b.get_value_msat())
1615 // Reverse ordering for cost, so we drop higher-cost paths first
1616 .then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
1619 // We should make sure that at least 1 path left.
1620 let mut paths_left = cur_route.len();
1621 cur_route.retain(|path| {
1622 if paths_left == 1 {
1625 let mut keep = true;
1626 let path_value_msat = path.get_value_msat();
1627 if path_value_msat <= overpaid_value_msat {
1629 overpaid_value_msat -= path_value_msat;
1635 if overpaid_value_msat == 0 {
1639 assert!(cur_route.len() > 0);
1642 // Now, subtract the overpaid value from the most-expensive path.
1643 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1644 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1645 cur_route.sort_unstable_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1646 let expensive_payment_path = cur_route.first_mut().unwrap();
1648 // We already dropped all the small value paths above, meaning all the
1649 // remaining paths are larger than remaining overpaid_value_msat.
1650 // Thus, this can't be negative.
1651 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1652 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1656 drawn_routes.push(cur_route);
1660 // Select the best route by lowest total cost.
1661 drawn_routes.sort_unstable_by_key(|paths| paths.iter().map(|path| path.get_cost_msat()).sum::<u64>());
1662 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1663 for payment_path in drawn_routes.first().unwrap() {
1664 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1666 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)})?,
1667 node_features: node_features.clone(),
1668 short_channel_id: payment_hop.candidate.short_channel_id(),
1669 channel_features: payment_hop.candidate.features(),
1670 fee_msat: payment_hop.fee_msat,
1671 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1673 }).collect::<Vec<_>>();
1674 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1675 // applicable for the previous hop.
1676 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1677 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1679 selected_paths.push(path);
1682 if let Some(features) = &payment_params.features {
1683 for path in selected_paths.iter_mut() {
1684 if let Ok(route_hop) = path.last_mut().unwrap() {
1685 route_hop.node_features = features.to_context();
1691 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1692 payment_params: Some(payment_params.clone()),
1694 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1698 // When an adversarial intermediary node observes a payment, it may be able to infer its
1699 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1700 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1701 // payment path by adding a randomized 'shadow route' offset to the final hop.
1702 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
1703 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
1705 let network_channels = network_graph.channels();
1706 let network_nodes = network_graph.nodes();
1708 for path in route.paths.iter_mut() {
1709 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1711 // Remember the last three nodes of the random walk and avoid looping back on them.
1712 // Init with the last three nodes from the actual path, if possible.
1713 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.last().unwrap().pubkey),
1714 NodeId::from_pubkey(&path.get(path.len().saturating_sub(2)).unwrap().pubkey),
1715 NodeId::from_pubkey(&path.get(path.len().saturating_sub(3)).unwrap().pubkey)];
1717 // Choose the last publicly known node as the starting point for the random walk.
1718 let mut cur_hop: Option<NodeId> = None;
1719 let mut path_nonce = [0u8; 12];
1720 if let Some(starting_hop) = path.iter().rev()
1721 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1722 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
1723 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
1726 // Init PRNG with the path-dependant nonce, which is static for private paths.
1727 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1728 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1730 // Pick a random path length in [1 .. 3]
1731 prng.process_in_place(&mut random_path_bytes);
1732 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1734 for random_hop in 0..random_walk_length {
1735 // If we don't find a suitable offset in the public network graph, we default to
1736 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1737 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1739 if let Some(cur_node_id) = cur_hop {
1740 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1741 // Randomly choose the next unvisited hop.
1742 prng.process_in_place(&mut random_path_bytes);
1743 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
1744 .checked_rem(cur_node.channels.len())
1745 .and_then(|index| cur_node.channels.get(index))
1746 .and_then(|id| network_channels.get(id)) {
1747 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1748 if !nodes_to_avoid.iter().any(|x| x == next_id) {
1749 nodes_to_avoid[random_hop] = *next_id;
1750 dir_info.direction().map(|channel_update_info| {
1751 random_hop_offset = channel_update_info.cltv_expiry_delta.into();
1752 cur_hop = Some(*next_id);
1760 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1761 .checked_add(random_hop_offset)
1762 .unwrap_or(shadow_ctlv_expiry_delta_offset);
1765 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1766 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1767 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1769 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1770 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1771 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1772 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1773 max_path_offset = cmp::max(
1774 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1775 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1776 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1778 // Add 'shadow' CLTV offset to the final hop
1779 if let Some(last_hop) = path.last_mut() {
1780 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1781 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1786 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
1787 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
1789 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
1790 pub fn build_route_from_hops<L: Deref>(
1791 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
1792 network_graph: &ReadOnlyNetworkGraph, logger: L, random_seed_bytes: &[u8; 32]
1793 ) -> Result<Route, LightningError>
1794 where L::Target: Logger {
1795 let mut route = build_route_from_hops_internal(
1796 our_node_pubkey, hops, &route_params.payment_params, &network_graph,
1797 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, random_seed_bytes)?;
1798 add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
1802 fn build_route_from_hops_internal<L: Deref>(
1803 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
1804 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
1805 logger: L, random_seed_bytes: &[u8; 32]
1806 ) -> Result<Route, LightningError> where L::Target: Logger {
1809 our_node_id: NodeId,
1810 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
1813 impl Score for HopScorer {
1814 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
1815 _usage: ChannelUsage) -> u64
1817 let mut cur_id = self.our_node_id;
1818 for i in 0..self.hop_ids.len() {
1819 if let Some(next_id) = self.hop_ids[i] {
1820 if cur_id == *source && next_id == *target {
1831 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
1833 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
1836 impl<'a> Writeable for HopScorer {
1838 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
1843 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
1844 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
1847 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
1848 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
1849 for i in 0..hops.len() {
1850 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
1853 let scorer = HopScorer { our_node_id, hop_ids };
1855 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
1856 final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
1861 use routing::gossip::{NetworkGraph, P2PGossipSync, NodeId};
1862 use routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
1863 PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
1864 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
1865 use routing::scoring::{ChannelUsage, Score};
1866 use chain::transaction::OutPoint;
1867 use chain::keysinterface::KeysInterface;
1868 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1869 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1870 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1871 use ln::channelmanager;
1872 use util::test_utils;
1873 use util::chacha20::ChaCha20;
1874 use util::ser::Writeable;
1876 use util::ser::Writer;
1878 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1879 use bitcoin::hashes::Hash;
1880 use bitcoin::network::constants::Network;
1881 use bitcoin::blockdata::constants::genesis_block;
1882 use bitcoin::blockdata::script::Builder;
1883 use bitcoin::blockdata::opcodes;
1884 use bitcoin::blockdata::transaction::TxOut;
1888 use bitcoin::secp256k1::{PublicKey,SecretKey};
1889 use bitcoin::secp256k1::{Secp256k1, All};
1892 use sync::{self, Arc};
1894 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1895 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1896 channelmanager::ChannelDetails {
1897 channel_id: [0; 32],
1898 counterparty: channelmanager::ChannelCounterparty {
1901 unspendable_punishment_reserve: 0,
1902 forwarding_info: None,
1903 outbound_htlc_minimum_msat: None,
1904 outbound_htlc_maximum_msat: None,
1906 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1909 outbound_scid_alias: None,
1910 inbound_scid_alias: None,
1911 channel_value_satoshis: 0,
1914 outbound_capacity_msat,
1915 next_outbound_htlc_limit_msat: outbound_capacity_msat,
1916 inbound_capacity_msat: 42,
1917 unspendable_punishment_reserve: None,
1918 confirmations_required: None,
1919 force_close_spend_delay: None,
1920 is_outbound: true, is_channel_ready: true,
1921 is_usable: true, is_public: true,
1922 inbound_htlc_minimum_msat: None,
1923 inbound_htlc_maximum_msat: None,
1927 // Using the same keys for LN and BTC ids
1929 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1930 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1932 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1933 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1935 let unsigned_announcement = UnsignedChannelAnnouncement {
1937 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1941 bitcoin_key_1: node_id_1,
1942 bitcoin_key_2: node_id_2,
1943 excess_data: Vec::new(),
1946 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1947 let valid_announcement = ChannelAnnouncement {
1948 node_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1949 node_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1950 bitcoin_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1951 bitcoin_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1952 contents: unsigned_announcement.clone(),
1954 match gossip_sync.handle_channel_announcement(&valid_announcement) {
1955 Ok(res) => assert!(res),
1961 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1962 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1964 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1965 let valid_channel_update = ChannelUpdate {
1966 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
1967 contents: update.clone()
1970 match gossip_sync.handle_channel_update(&valid_channel_update) {
1971 Ok(res) => assert!(res),
1976 fn add_or_update_node(
1977 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1978 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1980 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1981 let unsigned_announcement = UnsignedNodeAnnouncement {
1987 addresses: Vec::new(),
1988 excess_address_data: Vec::new(),
1989 excess_data: Vec::new(),
1991 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1992 let valid_announcement = NodeAnnouncement {
1993 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
1994 contents: unsigned_announcement.clone()
1997 match gossip_sync.handle_node_announcement(&valid_announcement) {
2003 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
2004 let privkeys: Vec<SecretKey> = (2..22).map(|i| {
2005 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
2008 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
2010 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
2011 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
2013 (our_privkey, our_id, privkeys, pubkeys)
2016 fn id_to_feature_flags(id: u8) -> Vec<u8> {
2017 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
2018 // test for it later.
2019 let idx = (id - 1) * 2 + 1;
2021 vec![1 << (idx - 8*3), 0, 0, 0]
2022 } else if idx > 8*2 {
2023 vec![1 << (idx - 8*2), 0, 0]
2024 } else if idx > 8*1 {
2025 vec![1 << (idx - 8*1), 0]
2031 fn build_line_graph() -> (
2032 Secp256k1<All>, sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2033 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2034 sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>,
2036 let secp_ctx = Secp256k1::new();
2037 let logger = Arc::new(test_utils::TestLogger::new());
2038 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2039 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2040 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2041 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2043 // Build network from our_id to node 19:
2044 // our_id -1(1)2- node0 -1(2)2- node1 - ... - node19
2045 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2047 for (idx, (cur_privkey, next_privkey)) in core::iter::once(&our_privkey)
2048 .chain(privkeys.iter()).zip(privkeys.iter()).enumerate() {
2049 let cur_short_channel_id = (idx as u64) + 1;
2050 add_channel(&gossip_sync, &secp_ctx, &cur_privkey, &next_privkey,
2051 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), cur_short_channel_id);
2052 update_channel(&gossip_sync, &secp_ctx, &cur_privkey, UnsignedChannelUpdate {
2053 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2054 short_channel_id: cur_short_channel_id,
2055 timestamp: idx as u32,
2057 cltv_expiry_delta: 0,
2058 htlc_minimum_msat: 0,
2059 htlc_maximum_msat: OptionalField::Absent,
2061 fee_proportional_millionths: 0,
2062 excess_data: Vec::new()
2064 update_channel(&gossip_sync, &secp_ctx, &next_privkey, UnsignedChannelUpdate {
2065 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2066 short_channel_id: cur_short_channel_id,
2067 timestamp: (idx as u32)+1,
2069 cltv_expiry_delta: 0,
2070 htlc_minimum_msat: 0,
2071 htlc_maximum_msat: OptionalField::Absent,
2073 fee_proportional_millionths: 0,
2074 excess_data: Vec::new()
2076 add_or_update_node(&gossip_sync, &secp_ctx, next_privkey,
2077 NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2080 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2083 fn build_graph() -> (
2085 sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2086 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2087 sync::Arc<test_utils::TestChainSource>,
2088 sync::Arc<test_utils::TestLogger>,
2090 let secp_ctx = Secp256k1::new();
2091 let logger = Arc::new(test_utils::TestLogger::new());
2092 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2093 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2094 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2095 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2096 // Build network from our_id to node6:
2098 // -1(1)2- node0 -1(3)2-
2100 // our_id -1(12)2- node7 -1(13)2--- node2
2102 // -1(2)2- node1 -1(4)2-
2105 // chan1 1-to-2: disabled
2106 // chan1 2-to-1: enabled, 0 fee
2108 // chan2 1-to-2: enabled, ignored fee
2109 // chan2 2-to-1: enabled, 0 fee
2111 // chan3 1-to-2: enabled, 0 fee
2112 // chan3 2-to-1: enabled, 100 msat fee
2114 // chan4 1-to-2: enabled, 100% fee
2115 // chan4 2-to-1: enabled, 0 fee
2117 // chan12 1-to-2: enabled, ignored fee
2118 // chan12 2-to-1: enabled, 0 fee
2120 // chan13 1-to-2: enabled, 200% fee
2121 // chan13 2-to-1: enabled, 0 fee
2124 // -1(5)2- node3 -1(8)2--
2128 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
2130 // -1(7)2- node5 -1(10)2-
2132 // Channels 5, 8, 9 and 10 are private channels.
2134 // chan5 1-to-2: enabled, 100 msat fee
2135 // chan5 2-to-1: enabled, 0 fee
2137 // chan6 1-to-2: enabled, 0 fee
2138 // chan6 2-to-1: enabled, 0 fee
2140 // chan7 1-to-2: enabled, 100% fee
2141 // chan7 2-to-1: enabled, 0 fee
2143 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
2144 // chan8 2-to-1: enabled, 0 fee
2146 // chan9 1-to-2: enabled, 1001 msat fee
2147 // chan9 2-to-1: enabled, 0 fee
2149 // chan10 1-to-2: enabled, 0 fee
2150 // chan10 2-to-1: enabled, 0 fee
2152 // chan11 1-to-2: enabled, 0 fee
2153 // chan11 2-to-1: enabled, 0 fee
2155 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2157 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
2158 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2159 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2160 short_channel_id: 1,
2163 cltv_expiry_delta: 0,
2164 htlc_minimum_msat: 0,
2165 htlc_maximum_msat: OptionalField::Absent,
2167 fee_proportional_millionths: 0,
2168 excess_data: Vec::new()
2171 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2173 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
2174 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2175 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2176 short_channel_id: 2,
2179 cltv_expiry_delta: (5 << 4) | 3,
2180 htlc_minimum_msat: 0,
2181 htlc_maximum_msat: OptionalField::Absent,
2182 fee_base_msat: u32::max_value(),
2183 fee_proportional_millionths: u32::max_value(),
2184 excess_data: Vec::new()
2186 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2187 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2188 short_channel_id: 2,
2191 cltv_expiry_delta: 0,
2192 htlc_minimum_msat: 0,
2193 htlc_maximum_msat: OptionalField::Absent,
2195 fee_proportional_millionths: 0,
2196 excess_data: Vec::new()
2199 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
2201 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
2202 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2203 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2204 short_channel_id: 12,
2207 cltv_expiry_delta: (5 << 4) | 3,
2208 htlc_minimum_msat: 0,
2209 htlc_maximum_msat: OptionalField::Absent,
2210 fee_base_msat: u32::max_value(),
2211 fee_proportional_millionths: u32::max_value(),
2212 excess_data: Vec::new()
2214 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2215 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2216 short_channel_id: 12,
2219 cltv_expiry_delta: 0,
2220 htlc_minimum_msat: 0,
2221 htlc_maximum_msat: OptionalField::Absent,
2223 fee_proportional_millionths: 0,
2224 excess_data: Vec::new()
2227 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
2229 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
2230 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2231 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2232 short_channel_id: 3,
2235 cltv_expiry_delta: (3 << 4) | 1,
2236 htlc_minimum_msat: 0,
2237 htlc_maximum_msat: OptionalField::Absent,
2239 fee_proportional_millionths: 0,
2240 excess_data: Vec::new()
2242 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2243 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2244 short_channel_id: 3,
2247 cltv_expiry_delta: (3 << 4) | 2,
2248 htlc_minimum_msat: 0,
2249 htlc_maximum_msat: OptionalField::Absent,
2251 fee_proportional_millionths: 0,
2252 excess_data: Vec::new()
2255 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
2256 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2257 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2258 short_channel_id: 4,
2261 cltv_expiry_delta: (4 << 4) | 1,
2262 htlc_minimum_msat: 0,
2263 htlc_maximum_msat: OptionalField::Absent,
2265 fee_proportional_millionths: 1000000,
2266 excess_data: Vec::new()
2268 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2269 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2270 short_channel_id: 4,
2273 cltv_expiry_delta: (4 << 4) | 2,
2274 htlc_minimum_msat: 0,
2275 htlc_maximum_msat: OptionalField::Absent,
2277 fee_proportional_millionths: 0,
2278 excess_data: Vec::new()
2281 add_channel(&gossip_sync, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2282 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2283 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2284 short_channel_id: 13,
2287 cltv_expiry_delta: (13 << 4) | 1,
2288 htlc_minimum_msat: 0,
2289 htlc_maximum_msat: OptionalField::Absent,
2291 fee_proportional_millionths: 2000000,
2292 excess_data: Vec::new()
2294 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2295 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2296 short_channel_id: 13,
2299 cltv_expiry_delta: (13 << 4) | 2,
2300 htlc_minimum_msat: 0,
2301 htlc_maximum_msat: OptionalField::Absent,
2303 fee_proportional_millionths: 0,
2304 excess_data: Vec::new()
2307 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2309 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2310 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2311 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2312 short_channel_id: 6,
2315 cltv_expiry_delta: (6 << 4) | 1,
2316 htlc_minimum_msat: 0,
2317 htlc_maximum_msat: OptionalField::Absent,
2319 fee_proportional_millionths: 0,
2320 excess_data: Vec::new()
2322 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2323 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2324 short_channel_id: 6,
2327 cltv_expiry_delta: (6 << 4) | 2,
2328 htlc_minimum_msat: 0,
2329 htlc_maximum_msat: OptionalField::Absent,
2331 fee_proportional_millionths: 0,
2332 excess_data: Vec::new(),
2335 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2336 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2337 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2338 short_channel_id: 11,
2341 cltv_expiry_delta: (11 << 4) | 1,
2342 htlc_minimum_msat: 0,
2343 htlc_maximum_msat: OptionalField::Absent,
2345 fee_proportional_millionths: 0,
2346 excess_data: Vec::new()
2348 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2349 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2350 short_channel_id: 11,
2353 cltv_expiry_delta: (11 << 4) | 2,
2354 htlc_minimum_msat: 0,
2355 htlc_maximum_msat: OptionalField::Absent,
2357 fee_proportional_millionths: 0,
2358 excess_data: Vec::new()
2361 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2363 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2365 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2366 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2367 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2368 short_channel_id: 7,
2371 cltv_expiry_delta: (7 << 4) | 1,
2372 htlc_minimum_msat: 0,
2373 htlc_maximum_msat: OptionalField::Absent,
2375 fee_proportional_millionths: 1000000,
2376 excess_data: Vec::new()
2378 update_channel(&gossip_sync, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2379 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2380 short_channel_id: 7,
2383 cltv_expiry_delta: (7 << 4) | 2,
2384 htlc_minimum_msat: 0,
2385 htlc_maximum_msat: OptionalField::Absent,
2387 fee_proportional_millionths: 0,
2388 excess_data: Vec::new()
2391 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2393 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2397 fn simple_route_test() {
2398 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2399 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2400 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2401 let scorer = test_utils::TestScorer::with_penalty(0);
2402 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2403 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2405 // Simple route to 2 via 1
2407 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) {
2408 assert_eq!(err, "Cannot send a payment of 0 msat");
2409 } else { panic!(); }
2411 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2412 assert_eq!(route.paths[0].len(), 2);
2414 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2415 assert_eq!(route.paths[0][0].short_channel_id, 2);
2416 assert_eq!(route.paths[0][0].fee_msat, 100);
2417 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2418 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2419 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2421 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2422 assert_eq!(route.paths[0][1].short_channel_id, 4);
2423 assert_eq!(route.paths[0][1].fee_msat, 100);
2424 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2425 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2426 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2430 fn invalid_first_hop_test() {
2431 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2432 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2433 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2434 let scorer = test_utils::TestScorer::with_penalty(0);
2435 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2436 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2438 // Simple route to 2 via 1
2440 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2442 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2443 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) {
2444 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2445 } else { panic!(); }
2447 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2448 assert_eq!(route.paths[0].len(), 2);
2452 fn htlc_minimum_test() {
2453 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2454 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2455 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2456 let scorer = test_utils::TestScorer::with_penalty(0);
2457 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2458 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2460 // Simple route to 2 via 1
2462 // Disable other paths
2463 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2464 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2465 short_channel_id: 12,
2467 flags: 2, // to disable
2468 cltv_expiry_delta: 0,
2469 htlc_minimum_msat: 0,
2470 htlc_maximum_msat: OptionalField::Absent,
2472 fee_proportional_millionths: 0,
2473 excess_data: Vec::new()
2475 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2477 short_channel_id: 3,
2479 flags: 2, // to disable
2480 cltv_expiry_delta: 0,
2481 htlc_minimum_msat: 0,
2482 htlc_maximum_msat: OptionalField::Absent,
2484 fee_proportional_millionths: 0,
2485 excess_data: Vec::new()
2487 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2488 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2489 short_channel_id: 13,
2491 flags: 2, // to disable
2492 cltv_expiry_delta: 0,
2493 htlc_minimum_msat: 0,
2494 htlc_maximum_msat: OptionalField::Absent,
2496 fee_proportional_millionths: 0,
2497 excess_data: Vec::new()
2499 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2500 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2501 short_channel_id: 6,
2503 flags: 2, // to disable
2504 cltv_expiry_delta: 0,
2505 htlc_minimum_msat: 0,
2506 htlc_maximum_msat: OptionalField::Absent,
2508 fee_proportional_millionths: 0,
2509 excess_data: Vec::new()
2511 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2512 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2513 short_channel_id: 7,
2515 flags: 2, // to disable
2516 cltv_expiry_delta: 0,
2517 htlc_minimum_msat: 0,
2518 htlc_maximum_msat: OptionalField::Absent,
2520 fee_proportional_millionths: 0,
2521 excess_data: Vec::new()
2524 // Check against amount_to_transfer_over_msat.
2525 // Set minimal HTLC of 200_000_000 msat.
2526 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2527 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2528 short_channel_id: 2,
2531 cltv_expiry_delta: 0,
2532 htlc_minimum_msat: 200_000_000,
2533 htlc_maximum_msat: OptionalField::Absent,
2535 fee_proportional_millionths: 0,
2536 excess_data: Vec::new()
2539 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2541 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2542 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2543 short_channel_id: 4,
2546 cltv_expiry_delta: 0,
2547 htlc_minimum_msat: 0,
2548 htlc_maximum_msat: OptionalField::Present(199_999_999),
2550 fee_proportional_millionths: 0,
2551 excess_data: Vec::new()
2554 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2555 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) {
2556 assert_eq!(err, "Failed to find a path to the given destination");
2557 } else { panic!(); }
2559 // Lift the restriction on the first hop.
2560 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2561 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2562 short_channel_id: 2,
2565 cltv_expiry_delta: 0,
2566 htlc_minimum_msat: 0,
2567 htlc_maximum_msat: OptionalField::Absent,
2569 fee_proportional_millionths: 0,
2570 excess_data: Vec::new()
2573 // A payment above the minimum should pass
2574 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();
2575 assert_eq!(route.paths[0].len(), 2);
2579 fn htlc_minimum_overpay_test() {
2580 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2581 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2582 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2583 let scorer = test_utils::TestScorer::with_penalty(0);
2584 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2585 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2587 // A route to node#2 via two paths.
2588 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2589 // Thus, they can't send 60 without overpaying.
2590 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2591 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2592 short_channel_id: 2,
2595 cltv_expiry_delta: 0,
2596 htlc_minimum_msat: 35_000,
2597 htlc_maximum_msat: OptionalField::Present(40_000),
2599 fee_proportional_millionths: 0,
2600 excess_data: Vec::new()
2602 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2603 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2604 short_channel_id: 12,
2607 cltv_expiry_delta: 0,
2608 htlc_minimum_msat: 35_000,
2609 htlc_maximum_msat: OptionalField::Present(40_000),
2611 fee_proportional_millionths: 0,
2612 excess_data: Vec::new()
2616 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2617 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2618 short_channel_id: 13,
2621 cltv_expiry_delta: 0,
2622 htlc_minimum_msat: 0,
2623 htlc_maximum_msat: OptionalField::Absent,
2625 fee_proportional_millionths: 0,
2626 excess_data: Vec::new()
2628 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2629 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2630 short_channel_id: 4,
2633 cltv_expiry_delta: 0,
2634 htlc_minimum_msat: 0,
2635 htlc_maximum_msat: OptionalField::Absent,
2637 fee_proportional_millionths: 0,
2638 excess_data: Vec::new()
2641 // Disable other paths
2642 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2643 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2644 short_channel_id: 1,
2646 flags: 2, // to disable
2647 cltv_expiry_delta: 0,
2648 htlc_minimum_msat: 0,
2649 htlc_maximum_msat: OptionalField::Absent,
2651 fee_proportional_millionths: 0,
2652 excess_data: Vec::new()
2655 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2656 // Overpay fees to hit htlc_minimum_msat.
2657 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2658 // TODO: this could be better balanced to overpay 10k and not 15k.
2659 assert_eq!(overpaid_fees, 15_000);
2661 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2662 // while taking even more fee to match htlc_minimum_msat.
2663 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2664 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2665 short_channel_id: 12,
2668 cltv_expiry_delta: 0,
2669 htlc_minimum_msat: 65_000,
2670 htlc_maximum_msat: OptionalField::Present(80_000),
2672 fee_proportional_millionths: 0,
2673 excess_data: Vec::new()
2675 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2676 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2677 short_channel_id: 2,
2680 cltv_expiry_delta: 0,
2681 htlc_minimum_msat: 0,
2682 htlc_maximum_msat: OptionalField::Absent,
2684 fee_proportional_millionths: 0,
2685 excess_data: Vec::new()
2687 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2688 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2689 short_channel_id: 4,
2692 cltv_expiry_delta: 0,
2693 htlc_minimum_msat: 0,
2694 htlc_maximum_msat: OptionalField::Absent,
2696 fee_proportional_millionths: 100_000,
2697 excess_data: Vec::new()
2700 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2701 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2702 assert_eq!(route.paths.len(), 1);
2703 assert_eq!(route.paths[0][0].short_channel_id, 12);
2704 let fees = route.paths[0][0].fee_msat;
2705 assert_eq!(fees, 5_000);
2707 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2708 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2709 // the other channel.
2710 assert_eq!(route.paths.len(), 1);
2711 assert_eq!(route.paths[0][0].short_channel_id, 2);
2712 let fees = route.paths[0][0].fee_msat;
2713 assert_eq!(fees, 5_000);
2717 fn disable_channels_test() {
2718 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2719 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2720 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2721 let scorer = test_utils::TestScorer::with_penalty(0);
2722 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2723 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2725 // // Disable channels 4 and 12 by flags=2
2726 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2727 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2728 short_channel_id: 4,
2730 flags: 2, // to disable
2731 cltv_expiry_delta: 0,
2732 htlc_minimum_msat: 0,
2733 htlc_maximum_msat: OptionalField::Absent,
2735 fee_proportional_millionths: 0,
2736 excess_data: Vec::new()
2738 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2739 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2740 short_channel_id: 12,
2742 flags: 2, // to disable
2743 cltv_expiry_delta: 0,
2744 htlc_minimum_msat: 0,
2745 htlc_maximum_msat: OptionalField::Absent,
2747 fee_proportional_millionths: 0,
2748 excess_data: Vec::new()
2751 // If all the channels require some features we don't understand, route should fail
2752 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) {
2753 assert_eq!(err, "Failed to find a path to the given destination");
2754 } else { panic!(); }
2756 // If we specify a channel to node7, that overrides our local channel view and that gets used
2757 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2758 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();
2759 assert_eq!(route.paths[0].len(), 2);
2761 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2762 assert_eq!(route.paths[0][0].short_channel_id, 42);
2763 assert_eq!(route.paths[0][0].fee_msat, 200);
2764 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2765 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2766 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2768 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2769 assert_eq!(route.paths[0][1].short_channel_id, 13);
2770 assert_eq!(route.paths[0][1].fee_msat, 100);
2771 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2772 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2773 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2777 fn disable_node_test() {
2778 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2779 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2780 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2781 let scorer = test_utils::TestScorer::with_penalty(0);
2782 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2783 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2785 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2786 let mut unknown_features = NodeFeatures::known();
2787 unknown_features.set_unknown_feature_required();
2788 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2789 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2790 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2792 // If all nodes require some features we don't understand, route should fail
2793 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) {
2794 assert_eq!(err, "Failed to find a path to the given destination");
2795 } else { panic!(); }
2797 // If we specify a channel to node7, that overrides our local channel view and that gets used
2798 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2799 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();
2800 assert_eq!(route.paths[0].len(), 2);
2802 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2803 assert_eq!(route.paths[0][0].short_channel_id, 42);
2804 assert_eq!(route.paths[0][0].fee_msat, 200);
2805 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2806 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2807 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2809 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2810 assert_eq!(route.paths[0][1].short_channel_id, 13);
2811 assert_eq!(route.paths[0][1].fee_msat, 100);
2812 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2813 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2814 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2816 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2817 // naively) assume that the user checked the feature bits on the invoice, which override
2818 // the node_announcement.
2822 fn our_chans_test() {
2823 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2824 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2825 let scorer = test_utils::TestScorer::with_penalty(0);
2826 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2827 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2829 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2830 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2831 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2832 assert_eq!(route.paths[0].len(), 3);
2834 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2835 assert_eq!(route.paths[0][0].short_channel_id, 2);
2836 assert_eq!(route.paths[0][0].fee_msat, 200);
2837 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2838 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2839 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2841 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2842 assert_eq!(route.paths[0][1].short_channel_id, 4);
2843 assert_eq!(route.paths[0][1].fee_msat, 100);
2844 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2845 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2846 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2848 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2849 assert_eq!(route.paths[0][2].short_channel_id, 3);
2850 assert_eq!(route.paths[0][2].fee_msat, 100);
2851 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2852 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2853 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2855 // If we specify a channel to node7, that overrides our local channel view and that gets used
2856 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2857 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2858 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();
2859 assert_eq!(route.paths[0].len(), 2);
2861 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2862 assert_eq!(route.paths[0][0].short_channel_id, 42);
2863 assert_eq!(route.paths[0][0].fee_msat, 200);
2864 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2865 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2866 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2868 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2869 assert_eq!(route.paths[0][1].short_channel_id, 13);
2870 assert_eq!(route.paths[0][1].fee_msat, 100);
2871 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2872 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2873 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2876 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2877 let zero_fees = RoutingFees {
2879 proportional_millionths: 0,
2881 vec![RouteHint(vec![RouteHintHop {
2882 src_node_id: nodes[3],
2883 short_channel_id: 8,
2885 cltv_expiry_delta: (8 << 4) | 1,
2886 htlc_minimum_msat: None,
2887 htlc_maximum_msat: None,
2889 ]), RouteHint(vec![RouteHintHop {
2890 src_node_id: nodes[4],
2891 short_channel_id: 9,
2894 proportional_millionths: 0,
2896 cltv_expiry_delta: (9 << 4) | 1,
2897 htlc_minimum_msat: None,
2898 htlc_maximum_msat: None,
2899 }]), RouteHint(vec![RouteHintHop {
2900 src_node_id: nodes[5],
2901 short_channel_id: 10,
2903 cltv_expiry_delta: (10 << 4) | 1,
2904 htlc_minimum_msat: None,
2905 htlc_maximum_msat: None,
2909 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2910 let zero_fees = RoutingFees {
2912 proportional_millionths: 0,
2914 vec![RouteHint(vec![RouteHintHop {
2915 src_node_id: nodes[2],
2916 short_channel_id: 5,
2919 proportional_millionths: 0,
2921 cltv_expiry_delta: (5 << 4) | 1,
2922 htlc_minimum_msat: None,
2923 htlc_maximum_msat: None,
2925 src_node_id: nodes[3],
2926 short_channel_id: 8,
2928 cltv_expiry_delta: (8 << 4) | 1,
2929 htlc_minimum_msat: None,
2930 htlc_maximum_msat: None,
2932 ]), RouteHint(vec![RouteHintHop {
2933 src_node_id: nodes[4],
2934 short_channel_id: 9,
2937 proportional_millionths: 0,
2939 cltv_expiry_delta: (9 << 4) | 1,
2940 htlc_minimum_msat: None,
2941 htlc_maximum_msat: None,
2942 }]), RouteHint(vec![RouteHintHop {
2943 src_node_id: nodes[5],
2944 short_channel_id: 10,
2946 cltv_expiry_delta: (10 << 4) | 1,
2947 htlc_minimum_msat: None,
2948 htlc_maximum_msat: None,
2953 fn partial_route_hint_test() {
2954 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2955 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2956 let scorer = test_utils::TestScorer::with_penalty(0);
2957 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2958 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2960 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2961 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2962 // RouteHint may be partially used by the algo to build the best path.
2964 // First check that last hop can't have its source as the payee.
2965 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2966 src_node_id: nodes[6],
2967 short_channel_id: 8,
2970 proportional_millionths: 0,
2972 cltv_expiry_delta: (8 << 4) | 1,
2973 htlc_minimum_msat: None,
2974 htlc_maximum_msat: None,
2977 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2978 invalid_last_hops.push(invalid_last_hop);
2980 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2981 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) {
2982 assert_eq!(err, "Route hint cannot have the payee as the source.");
2983 } else { panic!(); }
2986 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
2987 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2988 assert_eq!(route.paths[0].len(), 5);
2990 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2991 assert_eq!(route.paths[0][0].short_channel_id, 2);
2992 assert_eq!(route.paths[0][0].fee_msat, 100);
2993 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2994 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2995 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2997 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2998 assert_eq!(route.paths[0][1].short_channel_id, 4);
2999 assert_eq!(route.paths[0][1].fee_msat, 0);
3000 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3001 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3002 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3004 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3005 assert_eq!(route.paths[0][2].short_channel_id, 6);
3006 assert_eq!(route.paths[0][2].fee_msat, 0);
3007 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3008 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3009 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3011 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3012 assert_eq!(route.paths[0][3].short_channel_id, 11);
3013 assert_eq!(route.paths[0][3].fee_msat, 0);
3014 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3015 // If we have a peer in the node map, we'll use their features here since we don't have
3016 // a way of figuring out their features from the invoice:
3017 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3018 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3020 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3021 assert_eq!(route.paths[0][4].short_channel_id, 8);
3022 assert_eq!(route.paths[0][4].fee_msat, 100);
3023 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3024 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3025 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3028 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3029 let zero_fees = RoutingFees {
3031 proportional_millionths: 0,
3033 vec![RouteHint(vec![RouteHintHop {
3034 src_node_id: nodes[3],
3035 short_channel_id: 8,
3037 cltv_expiry_delta: (8 << 4) | 1,
3038 htlc_minimum_msat: None,
3039 htlc_maximum_msat: None,
3040 }]), RouteHint(vec![
3042 ]), RouteHint(vec![RouteHintHop {
3043 src_node_id: nodes[5],
3044 short_channel_id: 10,
3046 cltv_expiry_delta: (10 << 4) | 1,
3047 htlc_minimum_msat: None,
3048 htlc_maximum_msat: None,
3053 fn ignores_empty_last_hops_test() {
3054 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3055 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3056 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
3057 let scorer = test_utils::TestScorer::with_penalty(0);
3058 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3059 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3061 // Test handling of an empty RouteHint passed in Invoice.
3063 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3064 assert_eq!(route.paths[0].len(), 5);
3066 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3067 assert_eq!(route.paths[0][0].short_channel_id, 2);
3068 assert_eq!(route.paths[0][0].fee_msat, 100);
3069 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3070 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3071 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3073 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3074 assert_eq!(route.paths[0][1].short_channel_id, 4);
3075 assert_eq!(route.paths[0][1].fee_msat, 0);
3076 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3077 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3078 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3080 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3081 assert_eq!(route.paths[0][2].short_channel_id, 6);
3082 assert_eq!(route.paths[0][2].fee_msat, 0);
3083 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3084 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3085 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3087 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3088 assert_eq!(route.paths[0][3].short_channel_id, 11);
3089 assert_eq!(route.paths[0][3].fee_msat, 0);
3090 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3091 // If we have a peer in the node map, we'll use their features here since we don't have
3092 // a way of figuring out their features from the invoice:
3093 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3094 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3096 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3097 assert_eq!(route.paths[0][4].short_channel_id, 8);
3098 assert_eq!(route.paths[0][4].fee_msat, 100);
3099 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3100 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3101 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3104 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3106 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3107 let zero_fees = RoutingFees {
3109 proportional_millionths: 0,
3111 vec![RouteHint(vec![RouteHintHop {
3112 src_node_id: hint_hops[0],
3113 short_channel_id: 0xff00,
3116 proportional_millionths: 0,
3118 cltv_expiry_delta: (5 << 4) | 1,
3119 htlc_minimum_msat: None,
3120 htlc_maximum_msat: None,
3122 src_node_id: hint_hops[1],
3123 short_channel_id: 0xff01,
3125 cltv_expiry_delta: (8 << 4) | 1,
3126 htlc_minimum_msat: None,
3127 htlc_maximum_msat: None,
3132 fn multi_hint_last_hops_test() {
3133 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3134 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3135 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3136 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3137 let scorer = test_utils::TestScorer::with_penalty(0);
3138 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3139 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3140 // Test through channels 2, 3, 0xff00, 0xff01.
3141 // Test shows that multiple hop hints are considered.
3143 // Disabling channels 6 & 7 by flags=2
3144 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3145 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3146 short_channel_id: 6,
3148 flags: 2, // to disable
3149 cltv_expiry_delta: 0,
3150 htlc_minimum_msat: 0,
3151 htlc_maximum_msat: OptionalField::Absent,
3153 fee_proportional_millionths: 0,
3154 excess_data: Vec::new()
3156 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3157 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3158 short_channel_id: 7,
3160 flags: 2, // to disable
3161 cltv_expiry_delta: 0,
3162 htlc_minimum_msat: 0,
3163 htlc_maximum_msat: OptionalField::Absent,
3165 fee_proportional_millionths: 0,
3166 excess_data: Vec::new()
3169 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3170 assert_eq!(route.paths[0].len(), 4);
3172 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3173 assert_eq!(route.paths[0][0].short_channel_id, 2);
3174 assert_eq!(route.paths[0][0].fee_msat, 200);
3175 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3176 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3177 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3179 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3180 assert_eq!(route.paths[0][1].short_channel_id, 4);
3181 assert_eq!(route.paths[0][1].fee_msat, 100);
3182 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3183 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3184 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3186 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
3187 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3188 assert_eq!(route.paths[0][2].fee_msat, 0);
3189 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3190 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
3191 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3193 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3194 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3195 assert_eq!(route.paths[0][3].fee_msat, 100);
3196 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3197 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3198 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3202 fn private_multi_hint_last_hops_test() {
3203 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3204 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3206 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3207 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3209 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3210 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3211 let scorer = test_utils::TestScorer::with_penalty(0);
3212 // Test through channels 2, 3, 0xff00, 0xff01.
3213 // Test shows that multiple hop hints are considered.
3215 // Disabling channels 6 & 7 by flags=2
3216 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3217 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3218 short_channel_id: 6,
3220 flags: 2, // to disable
3221 cltv_expiry_delta: 0,
3222 htlc_minimum_msat: 0,
3223 htlc_maximum_msat: OptionalField::Absent,
3225 fee_proportional_millionths: 0,
3226 excess_data: Vec::new()
3228 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3229 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3230 short_channel_id: 7,
3232 flags: 2, // to disable
3233 cltv_expiry_delta: 0,
3234 htlc_minimum_msat: 0,
3235 htlc_maximum_msat: OptionalField::Absent,
3237 fee_proportional_millionths: 0,
3238 excess_data: Vec::new()
3241 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3242 assert_eq!(route.paths[0].len(), 4);
3244 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3245 assert_eq!(route.paths[0][0].short_channel_id, 2);
3246 assert_eq!(route.paths[0][0].fee_msat, 200);
3247 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3248 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3249 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3251 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3252 assert_eq!(route.paths[0][1].short_channel_id, 4);
3253 assert_eq!(route.paths[0][1].fee_msat, 100);
3254 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3255 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3256 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3258 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
3259 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3260 assert_eq!(route.paths[0][2].fee_msat, 0);
3261 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3262 assert_eq!(route.paths[0][2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3263 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3265 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3266 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3267 assert_eq!(route.paths[0][3].fee_msat, 100);
3268 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3269 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3270 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3273 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3274 let zero_fees = RoutingFees {
3276 proportional_millionths: 0,
3278 vec![RouteHint(vec![RouteHintHop {
3279 src_node_id: nodes[4],
3280 short_channel_id: 11,
3282 cltv_expiry_delta: (11 << 4) | 1,
3283 htlc_minimum_msat: None,
3284 htlc_maximum_msat: None,
3286 src_node_id: nodes[3],
3287 short_channel_id: 8,
3289 cltv_expiry_delta: (8 << 4) | 1,
3290 htlc_minimum_msat: None,
3291 htlc_maximum_msat: None,
3292 }]), RouteHint(vec![RouteHintHop {
3293 src_node_id: nodes[4],
3294 short_channel_id: 9,
3297 proportional_millionths: 0,
3299 cltv_expiry_delta: (9 << 4) | 1,
3300 htlc_minimum_msat: None,
3301 htlc_maximum_msat: None,
3302 }]), RouteHint(vec![RouteHintHop {
3303 src_node_id: nodes[5],
3304 short_channel_id: 10,
3306 cltv_expiry_delta: (10 << 4) | 1,
3307 htlc_minimum_msat: None,
3308 htlc_maximum_msat: None,
3313 fn last_hops_with_public_channel_test() {
3314 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3315 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3316 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3317 let scorer = test_utils::TestScorer::with_penalty(0);
3318 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3319 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3320 // This test shows that public routes can be present in the invoice
3321 // which would be handled in the same manner.
3323 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3324 assert_eq!(route.paths[0].len(), 5);
3326 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3327 assert_eq!(route.paths[0][0].short_channel_id, 2);
3328 assert_eq!(route.paths[0][0].fee_msat, 100);
3329 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3330 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3331 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3333 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3334 assert_eq!(route.paths[0][1].short_channel_id, 4);
3335 assert_eq!(route.paths[0][1].fee_msat, 0);
3336 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3337 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3338 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3340 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3341 assert_eq!(route.paths[0][2].short_channel_id, 6);
3342 assert_eq!(route.paths[0][2].fee_msat, 0);
3343 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3344 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3345 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3347 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3348 assert_eq!(route.paths[0][3].short_channel_id, 11);
3349 assert_eq!(route.paths[0][3].fee_msat, 0);
3350 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3351 // If we have a peer in the node map, we'll use their features here since we don't have
3352 // a way of figuring out their features from the invoice:
3353 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3354 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3356 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3357 assert_eq!(route.paths[0][4].short_channel_id, 8);
3358 assert_eq!(route.paths[0][4].fee_msat, 100);
3359 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3360 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3361 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3365 fn our_chans_last_hop_connect_test() {
3366 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3367 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3368 let scorer = test_utils::TestScorer::with_penalty(0);
3369 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3370 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3372 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3373 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3374 let mut last_hops = last_hops(&nodes);
3375 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3376 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();
3377 assert_eq!(route.paths[0].len(), 2);
3379 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3380 assert_eq!(route.paths[0][0].short_channel_id, 42);
3381 assert_eq!(route.paths[0][0].fee_msat, 0);
3382 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3383 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3384 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3386 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3387 assert_eq!(route.paths[0][1].short_channel_id, 8);
3388 assert_eq!(route.paths[0][1].fee_msat, 100);
3389 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3390 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3391 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3393 last_hops[0].0[0].fees.base_msat = 1000;
3395 // Revert to via 6 as the fee on 8 goes up
3396 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3397 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3398 assert_eq!(route.paths[0].len(), 4);
3400 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3401 assert_eq!(route.paths[0][0].short_channel_id, 2);
3402 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3403 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3404 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3405 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3407 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3408 assert_eq!(route.paths[0][1].short_channel_id, 4);
3409 assert_eq!(route.paths[0][1].fee_msat, 100);
3410 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3411 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3412 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3414 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3415 assert_eq!(route.paths[0][2].short_channel_id, 7);
3416 assert_eq!(route.paths[0][2].fee_msat, 0);
3417 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3418 // If we have a peer in the node map, we'll use their features here since we don't have
3419 // a way of figuring out their features from the invoice:
3420 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3421 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3423 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3424 assert_eq!(route.paths[0][3].short_channel_id, 10);
3425 assert_eq!(route.paths[0][3].fee_msat, 100);
3426 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3427 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3428 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3430 // ...but still use 8 for larger payments as 6 has a variable feerate
3431 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3432 assert_eq!(route.paths[0].len(), 5);
3434 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3435 assert_eq!(route.paths[0][0].short_channel_id, 2);
3436 assert_eq!(route.paths[0][0].fee_msat, 3000);
3437 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3438 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3439 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3441 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3442 assert_eq!(route.paths[0][1].short_channel_id, 4);
3443 assert_eq!(route.paths[0][1].fee_msat, 0);
3444 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3445 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3446 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3448 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3449 assert_eq!(route.paths[0][2].short_channel_id, 6);
3450 assert_eq!(route.paths[0][2].fee_msat, 0);
3451 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3452 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3453 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3455 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3456 assert_eq!(route.paths[0][3].short_channel_id, 11);
3457 assert_eq!(route.paths[0][3].fee_msat, 1000);
3458 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3459 // If we have a peer in the node map, we'll use their features here since we don't have
3460 // a way of figuring out their features from the invoice:
3461 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3462 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3464 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3465 assert_eq!(route.paths[0][4].short_channel_id, 8);
3466 assert_eq!(route.paths[0][4].fee_msat, 2000);
3467 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3468 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3469 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3472 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> {
3473 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3474 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3475 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3477 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3478 let last_hops = RouteHint(vec![RouteHintHop {
3479 src_node_id: middle_node_id,
3480 short_channel_id: 8,
3483 proportional_millionths: last_hop_fee_prop,
3485 cltv_expiry_delta: (8 << 4) | 1,
3486 htlc_minimum_msat: None,
3487 htlc_maximum_msat: last_hop_htlc_max,
3489 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3490 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3491 let scorer = test_utils::TestScorer::with_penalty(0);
3492 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3493 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3494 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
3495 let logger = test_utils::TestLogger::new();
3496 let network_graph = NetworkGraph::new(genesis_hash, &logger);
3497 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3498 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &logger, &scorer, &random_seed_bytes);
3503 fn unannounced_path_test() {
3504 // We should be able to send a payment to a destination without any help of a routing graph
3505 // if we have a channel with a common counterparty that appears in the first and last hop
3507 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3509 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3510 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3511 assert_eq!(route.paths[0].len(), 2);
3513 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3514 assert_eq!(route.paths[0][0].short_channel_id, 42);
3515 assert_eq!(route.paths[0][0].fee_msat, 1001);
3516 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3517 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3518 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3520 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3521 assert_eq!(route.paths[0][1].short_channel_id, 8);
3522 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3523 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3524 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3525 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3529 fn overflow_unannounced_path_test_liquidity_underflow() {
3530 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3531 // the last-hop had a fee which overflowed a u64, we'd panic.
3532 // This was due to us adding the first-hop from us unconditionally, causing us to think
3533 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3534 // In this test, we previously hit a subtraction underflow due to having less available
3535 // liquidity at the last hop than 0.
3536 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());
3540 fn overflow_unannounced_path_test_feerate_overflow() {
3541 // This tests for the same case as above, except instead of hitting a subtraction
3542 // underflow, we hit a case where the fee charged at a hop overflowed.
3543 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());
3547 fn available_amount_while_routing_test() {
3548 // Tests whether we choose the correct available channel amount while routing.
3550 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3551 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3552 let scorer = test_utils::TestScorer::with_penalty(0);
3553 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3554 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3555 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3557 // We will use a simple single-path route from
3558 // our node to node2 via node0: channels {1, 3}.
3560 // First disable all other paths.
3561 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3562 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3563 short_channel_id: 2,
3566 cltv_expiry_delta: 0,
3567 htlc_minimum_msat: 0,
3568 htlc_maximum_msat: OptionalField::Present(100_000),
3570 fee_proportional_millionths: 0,
3571 excess_data: Vec::new()
3573 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3574 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3575 short_channel_id: 12,
3578 cltv_expiry_delta: 0,
3579 htlc_minimum_msat: 0,
3580 htlc_maximum_msat: OptionalField::Present(100_000),
3582 fee_proportional_millionths: 0,
3583 excess_data: Vec::new()
3586 // Make the first channel (#1) very permissive,
3587 // and we will be testing all limits on the second channel.
3588 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3589 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3590 short_channel_id: 1,
3593 cltv_expiry_delta: 0,
3594 htlc_minimum_msat: 0,
3595 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3597 fee_proportional_millionths: 0,
3598 excess_data: Vec::new()
3601 // First, let's see if routing works if we have absolutely no idea about the available amount.
3602 // In this case, it should be set to 250_000 sats.
3603 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3604 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3605 short_channel_id: 3,
3608 cltv_expiry_delta: 0,
3609 htlc_minimum_msat: 0,
3610 htlc_maximum_msat: OptionalField::Absent,
3612 fee_proportional_millionths: 0,
3613 excess_data: Vec::new()
3617 // Attempt to route more than available results in a failure.
3618 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3619 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3620 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3621 } else { panic!(); }
3625 // Now, attempt to route an exact amount we have should be fine.
3626 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();
3627 assert_eq!(route.paths.len(), 1);
3628 let path = route.paths.last().unwrap();
3629 assert_eq!(path.len(), 2);
3630 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3631 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3634 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3635 // Disable channel #1 and use another first hop.
3636 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3637 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3638 short_channel_id: 1,
3641 cltv_expiry_delta: 0,
3642 htlc_minimum_msat: 0,
3643 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3645 fee_proportional_millionths: 0,
3646 excess_data: Vec::new()
3649 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3650 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3653 // Attempt to route more than available results in a failure.
3654 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3655 &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) {
3656 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3657 } else { panic!(); }
3661 // Now, attempt to route an exact amount we have should be fine.
3662 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();
3663 assert_eq!(route.paths.len(), 1);
3664 let path = route.paths.last().unwrap();
3665 assert_eq!(path.len(), 2);
3666 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3667 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3670 // Enable channel #1 back.
3671 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3672 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3673 short_channel_id: 1,
3676 cltv_expiry_delta: 0,
3677 htlc_minimum_msat: 0,
3678 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3680 fee_proportional_millionths: 0,
3681 excess_data: Vec::new()
3685 // Now let's see if routing works if we know only htlc_maximum_msat.
3686 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3687 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3688 short_channel_id: 3,
3691 cltv_expiry_delta: 0,
3692 htlc_minimum_msat: 0,
3693 htlc_maximum_msat: OptionalField::Present(15_000),
3695 fee_proportional_millionths: 0,
3696 excess_data: Vec::new()
3700 // Attempt to route more than available results in a failure.
3701 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3702 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3703 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3704 } else { panic!(); }
3708 // Now, attempt to route an exact amount we have should be fine.
3709 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3710 assert_eq!(route.paths.len(), 1);
3711 let path = route.paths.last().unwrap();
3712 assert_eq!(path.len(), 2);
3713 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3714 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3717 // Now let's see if routing works if we know only capacity from the UTXO.
3719 // We can't change UTXO capacity on the fly, so we'll disable
3720 // the existing channel and add another one with the capacity we need.
3721 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3722 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3723 short_channel_id: 3,
3726 cltv_expiry_delta: 0,
3727 htlc_minimum_msat: 0,
3728 htlc_maximum_msat: OptionalField::Absent,
3730 fee_proportional_millionths: 0,
3731 excess_data: Vec::new()
3734 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3735 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3736 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3737 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3738 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3740 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3741 gossip_sync.add_chain_access(Some(chain_monitor));
3743 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3744 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3745 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3746 short_channel_id: 333,
3749 cltv_expiry_delta: (3 << 4) | 1,
3750 htlc_minimum_msat: 0,
3751 htlc_maximum_msat: OptionalField::Absent,
3753 fee_proportional_millionths: 0,
3754 excess_data: Vec::new()
3756 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3757 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3758 short_channel_id: 333,
3761 cltv_expiry_delta: (3 << 4) | 2,
3762 htlc_minimum_msat: 0,
3763 htlc_maximum_msat: OptionalField::Absent,
3765 fee_proportional_millionths: 0,
3766 excess_data: Vec::new()
3770 // Attempt to route more than available results in a failure.
3771 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3772 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3773 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3774 } else { panic!(); }
3778 // Now, attempt to route an exact amount we have should be fine.
3779 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3780 assert_eq!(route.paths.len(), 1);
3781 let path = route.paths.last().unwrap();
3782 assert_eq!(path.len(), 2);
3783 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3784 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3787 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3788 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3789 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3790 short_channel_id: 333,
3793 cltv_expiry_delta: 0,
3794 htlc_minimum_msat: 0,
3795 htlc_maximum_msat: OptionalField::Present(10_000),
3797 fee_proportional_millionths: 0,
3798 excess_data: Vec::new()
3802 // Attempt to route more than available results in a failure.
3803 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3804 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3805 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3806 } else { panic!(); }
3810 // Now, attempt to route an exact amount we have should be fine.
3811 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3812 assert_eq!(route.paths.len(), 1);
3813 let path = route.paths.last().unwrap();
3814 assert_eq!(path.len(), 2);
3815 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3816 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3821 fn available_liquidity_last_hop_test() {
3822 // Check that available liquidity properly limits the path even when only
3823 // one of the latter hops is limited.
3824 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3825 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3826 let scorer = test_utils::TestScorer::with_penalty(0);
3827 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3828 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3829 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3831 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3832 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3833 // Total capacity: 50 sats.
3835 // Disable other potential paths.
3836 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3837 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3838 short_channel_id: 2,
3841 cltv_expiry_delta: 0,
3842 htlc_minimum_msat: 0,
3843 htlc_maximum_msat: OptionalField::Present(100_000),
3845 fee_proportional_millionths: 0,
3846 excess_data: Vec::new()
3848 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3849 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3850 short_channel_id: 7,
3853 cltv_expiry_delta: 0,
3854 htlc_minimum_msat: 0,
3855 htlc_maximum_msat: OptionalField::Present(100_000),
3857 fee_proportional_millionths: 0,
3858 excess_data: Vec::new()
3863 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3864 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3865 short_channel_id: 12,
3868 cltv_expiry_delta: 0,
3869 htlc_minimum_msat: 0,
3870 htlc_maximum_msat: OptionalField::Present(100_000),
3872 fee_proportional_millionths: 0,
3873 excess_data: Vec::new()
3875 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3876 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3877 short_channel_id: 13,
3880 cltv_expiry_delta: 0,
3881 htlc_minimum_msat: 0,
3882 htlc_maximum_msat: OptionalField::Present(100_000),
3884 fee_proportional_millionths: 0,
3885 excess_data: Vec::new()
3888 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3889 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3890 short_channel_id: 6,
3893 cltv_expiry_delta: 0,
3894 htlc_minimum_msat: 0,
3895 htlc_maximum_msat: OptionalField::Present(50_000),
3897 fee_proportional_millionths: 0,
3898 excess_data: Vec::new()
3900 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3901 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3902 short_channel_id: 11,
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 // Attempt to route more than available results in a failure.
3914 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3915 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3916 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3917 } else { panic!(); }
3921 // Now, attempt to route 49 sats (just a bit below the capacity).
3922 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3923 assert_eq!(route.paths.len(), 1);
3924 let mut total_amount_paid_msat = 0;
3925 for path in &route.paths {
3926 assert_eq!(path.len(), 4);
3927 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3928 total_amount_paid_msat += path.last().unwrap().fee_msat;
3930 assert_eq!(total_amount_paid_msat, 49_000);
3934 // Attempt to route an exact amount is also fine
3935 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3936 assert_eq!(route.paths.len(), 1);
3937 let mut total_amount_paid_msat = 0;
3938 for path in &route.paths {
3939 assert_eq!(path.len(), 4);
3940 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3941 total_amount_paid_msat += path.last().unwrap().fee_msat;
3943 assert_eq!(total_amount_paid_msat, 50_000);
3948 fn ignore_fee_first_hop_test() {
3949 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3950 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3951 let scorer = test_utils::TestScorer::with_penalty(0);
3952 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3953 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3954 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3956 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3957 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3958 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3959 short_channel_id: 1,
3962 cltv_expiry_delta: 0,
3963 htlc_minimum_msat: 0,
3964 htlc_maximum_msat: OptionalField::Present(100_000),
3965 fee_base_msat: 1_000_000,
3966 fee_proportional_millionths: 0,
3967 excess_data: Vec::new()
3969 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3970 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3971 short_channel_id: 3,
3974 cltv_expiry_delta: 0,
3975 htlc_minimum_msat: 0,
3976 htlc_maximum_msat: OptionalField::Present(50_000),
3978 fee_proportional_millionths: 0,
3979 excess_data: Vec::new()
3983 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3984 assert_eq!(route.paths.len(), 1);
3985 let mut total_amount_paid_msat = 0;
3986 for path in &route.paths {
3987 assert_eq!(path.len(), 2);
3988 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3989 total_amount_paid_msat += path.last().unwrap().fee_msat;
3991 assert_eq!(total_amount_paid_msat, 50_000);
3996 fn simple_mpp_route_test() {
3997 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3998 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3999 let scorer = test_utils::TestScorer::with_penalty(0);
4000 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4001 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4002 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4004 // We need a route consisting of 3 paths:
4005 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4006 // To achieve this, the amount being transferred should be around
4007 // the total capacity of these 3 paths.
4009 // First, we set limits on these (previously unlimited) channels.
4010 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4012 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4013 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4014 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4015 short_channel_id: 1,
4018 cltv_expiry_delta: 0,
4019 htlc_minimum_msat: 0,
4020 htlc_maximum_msat: OptionalField::Present(100_000),
4022 fee_proportional_millionths: 0,
4023 excess_data: Vec::new()
4025 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4026 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4027 short_channel_id: 3,
4030 cltv_expiry_delta: 0,
4031 htlc_minimum_msat: 0,
4032 htlc_maximum_msat: OptionalField::Present(50_000),
4034 fee_proportional_millionths: 0,
4035 excess_data: Vec::new()
4038 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4039 // (total limit 60).
4040 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4041 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4042 short_channel_id: 12,
4045 cltv_expiry_delta: 0,
4046 htlc_minimum_msat: 0,
4047 htlc_maximum_msat: OptionalField::Present(60_000),
4049 fee_proportional_millionths: 0,
4050 excess_data: Vec::new()
4052 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4053 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4054 short_channel_id: 13,
4057 cltv_expiry_delta: 0,
4058 htlc_minimum_msat: 0,
4059 htlc_maximum_msat: OptionalField::Present(60_000),
4061 fee_proportional_millionths: 0,
4062 excess_data: Vec::new()
4065 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4066 // (total capacity 180 sats).
4067 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4068 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4069 short_channel_id: 2,
4072 cltv_expiry_delta: 0,
4073 htlc_minimum_msat: 0,
4074 htlc_maximum_msat: OptionalField::Present(200_000),
4076 fee_proportional_millionths: 0,
4077 excess_data: Vec::new()
4079 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4080 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4081 short_channel_id: 4,
4084 cltv_expiry_delta: 0,
4085 htlc_minimum_msat: 0,
4086 htlc_maximum_msat: OptionalField::Present(180_000),
4088 fee_proportional_millionths: 0,
4089 excess_data: Vec::new()
4093 // Attempt to route more than available results in a failure.
4094 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4095 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4096 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4097 } else { panic!(); }
4101 // Now, attempt to route 250 sats (just a bit below the capacity).
4102 // Our algorithm should provide us with these 3 paths.
4103 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4104 assert_eq!(route.paths.len(), 3);
4105 let mut total_amount_paid_msat = 0;
4106 for path in &route.paths {
4107 assert_eq!(path.len(), 2);
4108 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4109 total_amount_paid_msat += path.last().unwrap().fee_msat;
4111 assert_eq!(total_amount_paid_msat, 250_000);
4115 // Attempt to route an exact amount is also fine
4116 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4117 assert_eq!(route.paths.len(), 3);
4118 let mut total_amount_paid_msat = 0;
4119 for path in &route.paths {
4120 assert_eq!(path.len(), 2);
4121 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4122 total_amount_paid_msat += path.last().unwrap().fee_msat;
4124 assert_eq!(total_amount_paid_msat, 290_000);
4129 fn long_mpp_route_test() {
4130 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4131 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4132 let scorer = test_utils::TestScorer::with_penalty(0);
4133 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4134 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4135 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4137 // We need a route consisting of 3 paths:
4138 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4139 // Note that these paths overlap (channels 5, 12, 13).
4140 // We will route 300 sats.
4141 // Each path will have 100 sats capacity, those channels which
4142 // are used twice will have 200 sats capacity.
4144 // Disable other potential paths.
4145 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4146 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4147 short_channel_id: 2,
4150 cltv_expiry_delta: 0,
4151 htlc_minimum_msat: 0,
4152 htlc_maximum_msat: OptionalField::Present(100_000),
4154 fee_proportional_millionths: 0,
4155 excess_data: Vec::new()
4157 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4158 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4159 short_channel_id: 7,
4162 cltv_expiry_delta: 0,
4163 htlc_minimum_msat: 0,
4164 htlc_maximum_msat: OptionalField::Present(100_000),
4166 fee_proportional_millionths: 0,
4167 excess_data: Vec::new()
4170 // Path via {node0, node2} is channels {1, 3, 5}.
4171 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4172 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4173 short_channel_id: 1,
4176 cltv_expiry_delta: 0,
4177 htlc_minimum_msat: 0,
4178 htlc_maximum_msat: OptionalField::Present(100_000),
4180 fee_proportional_millionths: 0,
4181 excess_data: Vec::new()
4183 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4184 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4185 short_channel_id: 3,
4188 cltv_expiry_delta: 0,
4189 htlc_minimum_msat: 0,
4190 htlc_maximum_msat: OptionalField::Present(100_000),
4192 fee_proportional_millionths: 0,
4193 excess_data: Vec::new()
4196 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4197 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4198 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4199 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4200 short_channel_id: 5,
4203 cltv_expiry_delta: 0,
4204 htlc_minimum_msat: 0,
4205 htlc_maximum_msat: OptionalField::Present(200_000),
4207 fee_proportional_millionths: 0,
4208 excess_data: Vec::new()
4211 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4212 // Add 100 sats to the capacities of {12, 13}, because these channels
4213 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4214 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4215 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4216 short_channel_id: 12,
4219 cltv_expiry_delta: 0,
4220 htlc_minimum_msat: 0,
4221 htlc_maximum_msat: OptionalField::Present(200_000),
4223 fee_proportional_millionths: 0,
4224 excess_data: Vec::new()
4226 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4227 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4228 short_channel_id: 13,
4231 cltv_expiry_delta: 0,
4232 htlc_minimum_msat: 0,
4233 htlc_maximum_msat: OptionalField::Present(200_000),
4235 fee_proportional_millionths: 0,
4236 excess_data: Vec::new()
4239 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4240 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4241 short_channel_id: 6,
4244 cltv_expiry_delta: 0,
4245 htlc_minimum_msat: 0,
4246 htlc_maximum_msat: OptionalField::Present(100_000),
4248 fee_proportional_millionths: 0,
4249 excess_data: Vec::new()
4251 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4252 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4253 short_channel_id: 11,
4256 cltv_expiry_delta: 0,
4257 htlc_minimum_msat: 0,
4258 htlc_maximum_msat: OptionalField::Present(100_000),
4260 fee_proportional_millionths: 0,
4261 excess_data: Vec::new()
4264 // Path via {node7, node2} is channels {12, 13, 5}.
4265 // We already limited them to 200 sats (they are used twice for 100 sats).
4266 // Nothing to do here.
4269 // Attempt to route more than available results in a failure.
4270 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4271 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4272 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4273 } else { panic!(); }
4277 // Now, attempt to route 300 sats (exact amount we can route).
4278 // Our algorithm should provide us with these 3 paths, 100 sats each.
4279 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4280 assert_eq!(route.paths.len(), 3);
4282 let mut total_amount_paid_msat = 0;
4283 for path in &route.paths {
4284 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4285 total_amount_paid_msat += path.last().unwrap().fee_msat;
4287 assert_eq!(total_amount_paid_msat, 300_000);
4293 fn mpp_cheaper_route_test() {
4294 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4295 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4296 let scorer = test_utils::TestScorer::with_penalty(0);
4297 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4298 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4299 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4301 // This test checks that if we have two cheaper paths and one more expensive path,
4302 // so that liquidity-wise any 2 of 3 combination is sufficient,
4303 // two cheaper paths will be taken.
4304 // These paths have equal available liquidity.
4306 // We need a combination of 3 paths:
4307 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4308 // Note that these paths overlap (channels 5, 12, 13).
4309 // Each path will have 100 sats capacity, those channels which
4310 // are used twice will have 200 sats capacity.
4312 // Disable other potential paths.
4313 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4314 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4315 short_channel_id: 2,
4318 cltv_expiry_delta: 0,
4319 htlc_minimum_msat: 0,
4320 htlc_maximum_msat: OptionalField::Present(100_000),
4322 fee_proportional_millionths: 0,
4323 excess_data: Vec::new()
4325 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4326 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4327 short_channel_id: 7,
4330 cltv_expiry_delta: 0,
4331 htlc_minimum_msat: 0,
4332 htlc_maximum_msat: OptionalField::Present(100_000),
4334 fee_proportional_millionths: 0,
4335 excess_data: Vec::new()
4338 // Path via {node0, node2} is channels {1, 3, 5}.
4339 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4340 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4341 short_channel_id: 1,
4344 cltv_expiry_delta: 0,
4345 htlc_minimum_msat: 0,
4346 htlc_maximum_msat: OptionalField::Present(100_000),
4348 fee_proportional_millionths: 0,
4349 excess_data: Vec::new()
4351 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4352 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4353 short_channel_id: 3,
4356 cltv_expiry_delta: 0,
4357 htlc_minimum_msat: 0,
4358 htlc_maximum_msat: OptionalField::Present(100_000),
4360 fee_proportional_millionths: 0,
4361 excess_data: Vec::new()
4364 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4365 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4366 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4367 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4368 short_channel_id: 5,
4371 cltv_expiry_delta: 0,
4372 htlc_minimum_msat: 0,
4373 htlc_maximum_msat: OptionalField::Present(200_000),
4375 fee_proportional_millionths: 0,
4376 excess_data: Vec::new()
4379 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4380 // Add 100 sats to the capacities of {12, 13}, because these channels
4381 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4382 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4383 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4384 short_channel_id: 12,
4387 cltv_expiry_delta: 0,
4388 htlc_minimum_msat: 0,
4389 htlc_maximum_msat: OptionalField::Present(200_000),
4391 fee_proportional_millionths: 0,
4392 excess_data: Vec::new()
4394 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4395 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4396 short_channel_id: 13,
4399 cltv_expiry_delta: 0,
4400 htlc_minimum_msat: 0,
4401 htlc_maximum_msat: OptionalField::Present(200_000),
4403 fee_proportional_millionths: 0,
4404 excess_data: Vec::new()
4407 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4408 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4409 short_channel_id: 6,
4412 cltv_expiry_delta: 0,
4413 htlc_minimum_msat: 0,
4414 htlc_maximum_msat: OptionalField::Present(100_000),
4415 fee_base_msat: 1_000,
4416 fee_proportional_millionths: 0,
4417 excess_data: Vec::new()
4419 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4420 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4421 short_channel_id: 11,
4424 cltv_expiry_delta: 0,
4425 htlc_minimum_msat: 0,
4426 htlc_maximum_msat: OptionalField::Present(100_000),
4428 fee_proportional_millionths: 0,
4429 excess_data: Vec::new()
4432 // Path via {node7, node2} is channels {12, 13, 5}.
4433 // We already limited them to 200 sats (they are used twice for 100 sats).
4434 // Nothing to do here.
4437 // Now, attempt to route 180 sats.
4438 // Our algorithm should provide us with these 2 paths.
4439 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4440 assert_eq!(route.paths.len(), 2);
4442 let mut total_value_transferred_msat = 0;
4443 let mut total_paid_msat = 0;
4444 for path in &route.paths {
4445 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4446 total_value_transferred_msat += path.last().unwrap().fee_msat;
4448 total_paid_msat += hop.fee_msat;
4451 // If we paid fee, this would be higher.
4452 assert_eq!(total_value_transferred_msat, 180_000);
4453 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4454 assert_eq!(total_fees_paid, 0);
4459 fn fees_on_mpp_route_test() {
4460 // This test makes sure that MPP algorithm properly takes into account
4461 // fees charged on the channels, by making the fees impactful:
4462 // if the fee is not properly accounted for, the behavior is different.
4463 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4464 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4465 let scorer = test_utils::TestScorer::with_penalty(0);
4466 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4467 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4468 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4470 // We need a route consisting of 2 paths:
4471 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4472 // We will route 200 sats, Each path will have 100 sats capacity.
4474 // This test is not particularly stable: e.g.,
4475 // there's a way to route via {node0, node2, node4}.
4476 // It works while pathfinding is deterministic, but can be broken otherwise.
4477 // It's fine to ignore this concern for now.
4479 // Disable other potential paths.
4480 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4481 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4482 short_channel_id: 2,
4485 cltv_expiry_delta: 0,
4486 htlc_minimum_msat: 0,
4487 htlc_maximum_msat: OptionalField::Present(100_000),
4489 fee_proportional_millionths: 0,
4490 excess_data: Vec::new()
4493 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4494 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4495 short_channel_id: 7,
4498 cltv_expiry_delta: 0,
4499 htlc_minimum_msat: 0,
4500 htlc_maximum_msat: OptionalField::Present(100_000),
4502 fee_proportional_millionths: 0,
4503 excess_data: Vec::new()
4506 // Path via {node0, node2} is channels {1, 3, 5}.
4507 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4508 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4509 short_channel_id: 1,
4512 cltv_expiry_delta: 0,
4513 htlc_minimum_msat: 0,
4514 htlc_maximum_msat: OptionalField::Present(100_000),
4516 fee_proportional_millionths: 0,
4517 excess_data: Vec::new()
4519 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4520 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4521 short_channel_id: 3,
4524 cltv_expiry_delta: 0,
4525 htlc_minimum_msat: 0,
4526 htlc_maximum_msat: OptionalField::Present(100_000),
4528 fee_proportional_millionths: 0,
4529 excess_data: Vec::new()
4532 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4533 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4534 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4535 short_channel_id: 5,
4538 cltv_expiry_delta: 0,
4539 htlc_minimum_msat: 0,
4540 htlc_maximum_msat: OptionalField::Present(100_000),
4542 fee_proportional_millionths: 0,
4543 excess_data: Vec::new()
4546 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4547 // All channels should be 100 sats capacity. But for the fee experiment,
4548 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4549 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4550 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4551 // so no matter how large are other channels,
4552 // the whole path will be limited by 100 sats with just these 2 conditions:
4553 // - channel 12 capacity is 250 sats
4554 // - fee for channel 6 is 150 sats
4555 // Let's test this by enforcing these 2 conditions and removing other limits.
4556 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4557 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4558 short_channel_id: 12,
4561 cltv_expiry_delta: 0,
4562 htlc_minimum_msat: 0,
4563 htlc_maximum_msat: OptionalField::Present(250_000),
4565 fee_proportional_millionths: 0,
4566 excess_data: Vec::new()
4568 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4569 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4570 short_channel_id: 13,
4573 cltv_expiry_delta: 0,
4574 htlc_minimum_msat: 0,
4575 htlc_maximum_msat: OptionalField::Absent,
4577 fee_proportional_millionths: 0,
4578 excess_data: Vec::new()
4581 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4582 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4583 short_channel_id: 6,
4586 cltv_expiry_delta: 0,
4587 htlc_minimum_msat: 0,
4588 htlc_maximum_msat: OptionalField::Absent,
4589 fee_base_msat: 150_000,
4590 fee_proportional_millionths: 0,
4591 excess_data: Vec::new()
4593 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4594 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4595 short_channel_id: 11,
4598 cltv_expiry_delta: 0,
4599 htlc_minimum_msat: 0,
4600 htlc_maximum_msat: OptionalField::Absent,
4602 fee_proportional_millionths: 0,
4603 excess_data: Vec::new()
4607 // Attempt to route more than available results in a failure.
4608 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4609 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4610 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4611 } else { panic!(); }
4615 // Now, attempt to route 200 sats (exact amount we can route).
4616 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4617 assert_eq!(route.paths.len(), 2);
4619 let mut total_amount_paid_msat = 0;
4620 for path in &route.paths {
4621 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4622 total_amount_paid_msat += path.last().unwrap().fee_msat;
4624 assert_eq!(total_amount_paid_msat, 200_000);
4625 assert_eq!(route.get_total_fees(), 150_000);
4630 fn mpp_with_last_hops() {
4631 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4632 // via a single last-hop route hint, we'd fail to route if we first collected routes
4633 // totaling close but not quite enough to fund the full payment.
4635 // This was because we considered last-hop hints to have exactly the sought payment amount
4636 // instead of the amount we were trying to collect, needlessly limiting our path searching
4637 // at the very first hop.
4639 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4640 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4641 // to only have the remaining to-collect amount in available liquidity.
4643 // This bug appeared in production in some specific channel configurations.
4644 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4645 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4646 let scorer = test_utils::TestScorer::with_penalty(0);
4647 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4648 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4649 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4650 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4651 src_node_id: nodes[2],
4652 short_channel_id: 42,
4653 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4654 cltv_expiry_delta: 42,
4655 htlc_minimum_msat: None,
4656 htlc_maximum_msat: None,
4659 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4660 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4661 // would first use the no-fee route and then fail to find a path along the second route as
4662 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4663 // under 5% of our payment amount.
4664 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4665 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4666 short_channel_id: 1,
4669 cltv_expiry_delta: (5 << 4) | 5,
4670 htlc_minimum_msat: 0,
4671 htlc_maximum_msat: OptionalField::Present(99_000),
4672 fee_base_msat: u32::max_value(),
4673 fee_proportional_millionths: u32::max_value(),
4674 excess_data: Vec::new()
4676 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4677 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4678 short_channel_id: 2,
4681 cltv_expiry_delta: (5 << 4) | 3,
4682 htlc_minimum_msat: 0,
4683 htlc_maximum_msat: OptionalField::Present(99_000),
4684 fee_base_msat: u32::max_value(),
4685 fee_proportional_millionths: u32::max_value(),
4686 excess_data: Vec::new()
4688 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4689 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4690 short_channel_id: 4,
4693 cltv_expiry_delta: (4 << 4) | 1,
4694 htlc_minimum_msat: 0,
4695 htlc_maximum_msat: OptionalField::Absent,
4697 fee_proportional_millionths: 0,
4698 excess_data: Vec::new()
4700 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4701 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4702 short_channel_id: 13,
4704 flags: 0|2, // Channel disabled
4705 cltv_expiry_delta: (13 << 4) | 1,
4706 htlc_minimum_msat: 0,
4707 htlc_maximum_msat: OptionalField::Absent,
4709 fee_proportional_millionths: 2000000,
4710 excess_data: Vec::new()
4713 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4715 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4716 assert_eq!(route.paths.len(), 2);
4717 // Paths are somewhat randomly ordered, but:
4718 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4719 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4720 assert_eq!(route.paths[0][0].short_channel_id, 2);
4721 assert_eq!(route.paths[0][0].fee_msat, 1);
4722 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4723 assert_eq!(route.paths[1][0].short_channel_id, 1);
4724 assert_eq!(route.paths[1][0].fee_msat, 0);
4725 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4726 assert_eq!(route.get_total_fees(), 1);
4727 assert_eq!(route.get_total_amount(), 100_000);
4731 fn drop_lowest_channel_mpp_route_test() {
4732 // This test checks that low-capacity channel is dropped when after
4733 // path finding we realize that we found more capacity than we need.
4734 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4735 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4736 let scorer = test_utils::TestScorer::with_penalty(0);
4737 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4738 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4739 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4741 // We need a route consisting of 3 paths:
4742 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4744 // The first and the second paths should be sufficient, but the third should be
4745 // cheaper, so that we select it but drop later.
4747 // First, we set limits on these (previously unlimited) channels.
4748 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4750 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4751 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4752 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4753 short_channel_id: 1,
4756 cltv_expiry_delta: 0,
4757 htlc_minimum_msat: 0,
4758 htlc_maximum_msat: OptionalField::Present(100_000),
4760 fee_proportional_millionths: 0,
4761 excess_data: Vec::new()
4763 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4764 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4765 short_channel_id: 3,
4768 cltv_expiry_delta: 0,
4769 htlc_minimum_msat: 0,
4770 htlc_maximum_msat: OptionalField::Present(50_000),
4772 fee_proportional_millionths: 0,
4773 excess_data: Vec::new()
4776 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4777 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4778 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4779 short_channel_id: 12,
4782 cltv_expiry_delta: 0,
4783 htlc_minimum_msat: 0,
4784 htlc_maximum_msat: OptionalField::Present(60_000),
4786 fee_proportional_millionths: 0,
4787 excess_data: Vec::new()
4789 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4790 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4791 short_channel_id: 13,
4794 cltv_expiry_delta: 0,
4795 htlc_minimum_msat: 0,
4796 htlc_maximum_msat: OptionalField::Present(60_000),
4798 fee_proportional_millionths: 0,
4799 excess_data: Vec::new()
4802 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4803 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4804 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4805 short_channel_id: 2,
4808 cltv_expiry_delta: 0,
4809 htlc_minimum_msat: 0,
4810 htlc_maximum_msat: OptionalField::Present(20_000),
4812 fee_proportional_millionths: 0,
4813 excess_data: Vec::new()
4815 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4816 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4817 short_channel_id: 4,
4820 cltv_expiry_delta: 0,
4821 htlc_minimum_msat: 0,
4822 htlc_maximum_msat: OptionalField::Present(20_000),
4824 fee_proportional_millionths: 0,
4825 excess_data: Vec::new()
4829 // Attempt to route more than available results in a failure.
4830 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4831 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4832 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4833 } else { panic!(); }
4837 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4838 // Our algorithm should provide us with these 3 paths.
4839 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4840 assert_eq!(route.paths.len(), 3);
4841 let mut total_amount_paid_msat = 0;
4842 for path in &route.paths {
4843 assert_eq!(path.len(), 2);
4844 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4845 total_amount_paid_msat += path.last().unwrap().fee_msat;
4847 assert_eq!(total_amount_paid_msat, 125_000);
4851 // Attempt to route without the last small cheap channel
4852 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4853 assert_eq!(route.paths.len(), 2);
4854 let mut total_amount_paid_msat = 0;
4855 for path in &route.paths {
4856 assert_eq!(path.len(), 2);
4857 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4858 total_amount_paid_msat += path.last().unwrap().fee_msat;
4860 assert_eq!(total_amount_paid_msat, 90_000);
4865 fn min_criteria_consistency() {
4866 // Test that we don't use an inconsistent metric between updating and walking nodes during
4867 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4868 // was updated with a different criterion from the heap sorting, resulting in loops in
4869 // calculated paths. We test for that specific case here.
4871 // We construct a network that looks like this:
4873 // node2 -1(3)2- node3
4877 // node1 -1(5)2- node4 -1(1)2- node6
4883 // We create a loop on the side of our real path - our destination is node 6, with a
4884 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4885 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4886 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4887 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4888 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4889 // "previous hop" being set to node 3, creating a loop in the path.
4890 let secp_ctx = Secp256k1::new();
4891 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
4892 let logger = Arc::new(test_utils::TestLogger::new());
4893 let network = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
4894 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
4895 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4896 let scorer = test_utils::TestScorer::with_penalty(0);
4897 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4898 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4899 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4901 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4902 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4903 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4904 short_channel_id: 6,
4907 cltv_expiry_delta: (6 << 4) | 0,
4908 htlc_minimum_msat: 0,
4909 htlc_maximum_msat: OptionalField::Absent,
4911 fee_proportional_millionths: 0,
4912 excess_data: Vec::new()
4914 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4916 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4917 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4918 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4919 short_channel_id: 5,
4922 cltv_expiry_delta: (5 << 4) | 0,
4923 htlc_minimum_msat: 0,
4924 htlc_maximum_msat: OptionalField::Absent,
4926 fee_proportional_millionths: 0,
4927 excess_data: Vec::new()
4929 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4931 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4932 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4933 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4934 short_channel_id: 4,
4937 cltv_expiry_delta: (4 << 4) | 0,
4938 htlc_minimum_msat: 0,
4939 htlc_maximum_msat: OptionalField::Absent,
4941 fee_proportional_millionths: 0,
4942 excess_data: Vec::new()
4944 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4946 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4947 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4948 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4949 short_channel_id: 3,
4952 cltv_expiry_delta: (3 << 4) | 0,
4953 htlc_minimum_msat: 0,
4954 htlc_maximum_msat: OptionalField::Absent,
4956 fee_proportional_millionths: 0,
4957 excess_data: Vec::new()
4959 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4961 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4962 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4963 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4964 short_channel_id: 2,
4967 cltv_expiry_delta: (2 << 4) | 0,
4968 htlc_minimum_msat: 0,
4969 htlc_maximum_msat: OptionalField::Absent,
4971 fee_proportional_millionths: 0,
4972 excess_data: Vec::new()
4975 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4976 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4977 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4978 short_channel_id: 1,
4981 cltv_expiry_delta: (1 << 4) | 0,
4982 htlc_minimum_msat: 100,
4983 htlc_maximum_msat: OptionalField::Absent,
4985 fee_proportional_millionths: 0,
4986 excess_data: Vec::new()
4988 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4991 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4992 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4993 assert_eq!(route.paths.len(), 1);
4994 assert_eq!(route.paths[0].len(), 3);
4996 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4997 assert_eq!(route.paths[0][0].short_channel_id, 6);
4998 assert_eq!(route.paths[0][0].fee_msat, 100);
4999 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
5000 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
5001 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
5003 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
5004 assert_eq!(route.paths[0][1].short_channel_id, 5);
5005 assert_eq!(route.paths[0][1].fee_msat, 0);
5006 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
5007 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
5008 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
5010 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
5011 assert_eq!(route.paths[0][2].short_channel_id, 1);
5012 assert_eq!(route.paths[0][2].fee_msat, 10_000);
5013 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
5014 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
5015 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
5021 fn exact_fee_liquidity_limit() {
5022 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5023 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5024 // we calculated fees on a higher value, resulting in us ignoring such paths.
5025 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5026 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5027 let scorer = test_utils::TestScorer::with_penalty(0);
5028 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5029 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5030 let payment_params = PaymentParameters::from_node_id(nodes[2]);
5032 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5034 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5036 short_channel_id: 2,
5039 cltv_expiry_delta: 0,
5040 htlc_minimum_msat: 0,
5041 htlc_maximum_msat: OptionalField::Present(85_000),
5043 fee_proportional_millionths: 0,
5044 excess_data: Vec::new()
5047 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5048 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5049 short_channel_id: 12,
5052 cltv_expiry_delta: (4 << 4) | 1,
5053 htlc_minimum_msat: 0,
5054 htlc_maximum_msat: OptionalField::Present(270_000),
5056 fee_proportional_millionths: 1000000,
5057 excess_data: Vec::new()
5061 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5062 // 200% fee charged channel 13 in the 1-to-2 direction.
5063 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5064 assert_eq!(route.paths.len(), 1);
5065 assert_eq!(route.paths[0].len(), 2);
5067 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5068 assert_eq!(route.paths[0][0].short_channel_id, 12);
5069 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5070 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5071 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5072 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5074 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5075 assert_eq!(route.paths[0][1].short_channel_id, 13);
5076 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5077 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5078 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
5079 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5084 fn htlc_max_reduction_below_min() {
5085 // Test that if, while walking the graph, we reduce the value being sent to meet an
5086 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5087 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5088 // resulting in us thinking there is no possible path, even if other paths exist.
5089 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5090 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5091 let scorer = test_utils::TestScorer::with_penalty(0);
5092 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5093 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5094 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
5096 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5097 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5098 // then try to send 90_000.
5099 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5100 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5101 short_channel_id: 2,
5104 cltv_expiry_delta: 0,
5105 htlc_minimum_msat: 0,
5106 htlc_maximum_msat: OptionalField::Present(80_000),
5108 fee_proportional_millionths: 0,
5109 excess_data: Vec::new()
5111 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5112 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5113 short_channel_id: 4,
5116 cltv_expiry_delta: (4 << 4) | 1,
5117 htlc_minimum_msat: 90_000,
5118 htlc_maximum_msat: OptionalField::Absent,
5120 fee_proportional_millionths: 0,
5121 excess_data: Vec::new()
5125 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5126 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5127 // expensive) channels 12-13 path.
5128 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5129 assert_eq!(route.paths.len(), 1);
5130 assert_eq!(route.paths[0].len(), 2);
5132 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5133 assert_eq!(route.paths[0][0].short_channel_id, 12);
5134 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5135 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5136 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5137 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5139 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5140 assert_eq!(route.paths[0][1].short_channel_id, 13);
5141 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5142 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5143 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
5144 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5149 fn multiple_direct_first_hops() {
5150 // Previously we'd only ever considered one first hop path per counterparty.
5151 // However, as we don't restrict users to one channel per peer, we really need to support
5152 // looking at all first hop paths.
5153 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5154 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5155 // route over multiple channels with the same first hop.
5156 let secp_ctx = Secp256k1::new();
5157 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5158 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
5159 let logger = Arc::new(test_utils::TestLogger::new());
5160 let network_graph = NetworkGraph::new(genesis_hash, Arc::clone(&logger));
5161 let scorer = test_utils::TestScorer::with_penalty(0);
5162 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
5163 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5164 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5167 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5168 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
5169 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
5170 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5171 assert_eq!(route.paths.len(), 1);
5172 assert_eq!(route.paths[0].len(), 1);
5174 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5175 assert_eq!(route.paths[0][0].short_channel_id, 3);
5176 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5179 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5180 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5181 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5182 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5183 assert_eq!(route.paths.len(), 2);
5184 assert_eq!(route.paths[0].len(), 1);
5185 assert_eq!(route.paths[1].len(), 1);
5187 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5188 assert_eq!(route.paths[0][0].short_channel_id, 3);
5189 assert_eq!(route.paths[0][0].fee_msat, 50_000);
5191 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
5192 assert_eq!(route.paths[1][0].short_channel_id, 2);
5193 assert_eq!(route.paths[1][0].fee_msat, 50_000);
5197 // If we have a bunch of outbound channels to the same node, where most are not
5198 // sufficient to pay the full payment, but one is, we should default to just using the
5199 // one single channel that has sufficient balance, avoiding MPP.
5201 // If we have several options above the 3xpayment value threshold, we should pick the
5202 // smallest of them, avoiding further fragmenting our available outbound balance to
5204 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5205 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5206 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5207 &get_channel_details(Some(5), nodes[0], InitFeatures::known(), 50_000),
5208 &get_channel_details(Some(6), nodes[0], InitFeatures::known(), 300_000),
5209 &get_channel_details(Some(7), nodes[0], InitFeatures::known(), 50_000),
5210 &get_channel_details(Some(8), nodes[0], InitFeatures::known(), 50_000),
5211 &get_channel_details(Some(9), nodes[0], InitFeatures::known(), 50_000),
5212 &get_channel_details(Some(4), nodes[0], InitFeatures::known(), 1_000_000),
5213 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5214 assert_eq!(route.paths.len(), 1);
5215 assert_eq!(route.paths[0].len(), 1);
5217 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5218 assert_eq!(route.paths[0][0].short_channel_id, 6);
5219 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5224 fn prefers_shorter_route_with_higher_fees() {
5225 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5226 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5227 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5229 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5230 let scorer = test_utils::TestScorer::with_penalty(0);
5231 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5232 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5233 let route = get_route(
5234 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5235 Arc::clone(&logger), &scorer, &random_seed_bytes
5237 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5239 assert_eq!(route.get_total_fees(), 100);
5240 assert_eq!(route.get_total_amount(), 100);
5241 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5243 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5244 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5245 let scorer = test_utils::TestScorer::with_penalty(100);
5246 let route = get_route(
5247 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5248 Arc::clone(&logger), &scorer, &random_seed_bytes
5250 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5252 assert_eq!(route.get_total_fees(), 300);
5253 assert_eq!(route.get_total_amount(), 100);
5254 assert_eq!(path, vec![2, 4, 7, 10]);
5257 struct BadChannelScorer {
5258 short_channel_id: u64,
5262 impl Writeable for BadChannelScorer {
5263 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5265 impl Score for BadChannelScorer {
5266 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage) -> u64 {
5267 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5270 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5271 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5274 struct BadNodeScorer {
5279 impl Writeable for BadNodeScorer {
5280 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5283 impl Score for BadNodeScorer {
5284 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage) -> u64 {
5285 if *target == self.node_id { u64::max_value() } else { 0 }
5288 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5289 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5293 fn avoids_routing_through_bad_channels_and_nodes() {
5294 let (secp_ctx, network, _, _, logger) = build_graph();
5295 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5296 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5297 let network_graph = network.read_only();
5299 // A path to nodes[6] exists when no penalties are applied to any channel.
5300 let scorer = test_utils::TestScorer::with_penalty(0);
5301 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5302 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5303 let route = get_route(
5304 &our_id, &payment_params, &network_graph, None, 100, 42,
5305 Arc::clone(&logger), &scorer, &random_seed_bytes
5307 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5309 assert_eq!(route.get_total_fees(), 100);
5310 assert_eq!(route.get_total_amount(), 100);
5311 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5313 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5314 let scorer = BadChannelScorer { short_channel_id: 6 };
5315 let route = get_route(
5316 &our_id, &payment_params, &network_graph, None, 100, 42,
5317 Arc::clone(&logger), &scorer, &random_seed_bytes
5319 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5321 assert_eq!(route.get_total_fees(), 300);
5322 assert_eq!(route.get_total_amount(), 100);
5323 assert_eq!(path, vec![2, 4, 7, 10]);
5325 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5326 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5328 &our_id, &payment_params, &network_graph, None, 100, 42,
5329 Arc::clone(&logger), &scorer, &random_seed_bytes
5331 Err(LightningError { err, .. } ) => {
5332 assert_eq!(err, "Failed to find a path to the given destination");
5334 Ok(_) => panic!("Expected error"),
5339 fn total_fees_single_path() {
5343 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5344 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5345 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5348 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5349 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5350 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5353 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5354 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5355 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5358 payment_params: None,
5361 assert_eq!(route.get_total_fees(), 250);
5362 assert_eq!(route.get_total_amount(), 225);
5366 fn total_fees_multi_path() {
5370 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5371 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5372 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5375 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5376 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5377 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5381 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5382 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5383 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5386 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5387 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5388 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5391 payment_params: None,
5394 assert_eq!(route.get_total_fees(), 200);
5395 assert_eq!(route.get_total_amount(), 300);
5399 fn total_empty_route_no_panic() {
5400 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5401 // would both panic if the route was completely empty. We test to ensure they return 0
5402 // here, even though its somewhat nonsensical as a route.
5403 let route = Route { paths: Vec::new(), payment_params: None };
5405 assert_eq!(route.get_total_fees(), 0);
5406 assert_eq!(route.get_total_amount(), 0);
5410 fn limits_total_cltv_delta() {
5411 let (secp_ctx, network, _, _, logger) = build_graph();
5412 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5413 let network_graph = network.read_only();
5415 let scorer = test_utils::TestScorer::with_penalty(0);
5417 // Make sure that generally there is at least one route available
5418 let feasible_max_total_cltv_delta = 1008;
5419 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5420 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5421 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5422 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5423 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5424 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5425 assert_ne!(path.len(), 0);
5427 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5428 let fail_max_total_cltv_delta = 23;
5429 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5430 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5431 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5433 Err(LightningError { err, .. } ) => {
5434 assert_eq!(err, "Failed to find a path to the given destination");
5436 Ok(_) => panic!("Expected error"),
5441 fn limits_path_length() {
5442 let (secp_ctx, network, _, _, logger) = build_line_graph();
5443 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5444 let network_graph = network.read_only();
5446 let scorer = test_utils::TestScorer::with_penalty(0);
5447 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5448 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5450 // First check we can actually create a long route on this graph.
5451 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18]);
5452 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0,
5453 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5454 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5455 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5457 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5458 let fail_payment_params = PaymentParameters::from_node_id(nodes[19]);
5459 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0,
5460 Arc::clone(&logger), &scorer, &random_seed_bytes)
5462 Err(LightningError { err, .. } ) => {
5463 assert_eq!(err, "Failed to find a path to the given destination");
5465 Ok(_) => panic!("Expected error"),
5470 fn adds_and_limits_cltv_offset() {
5471 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5472 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5474 let scorer = test_utils::TestScorer::with_penalty(0);
5476 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5477 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5478 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5479 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5480 assert_eq!(route.paths.len(), 1);
5482 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5484 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5485 let mut route_default = route.clone();
5486 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5487 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5488 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5489 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5490 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5492 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5493 let mut route_limited = route.clone();
5494 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5495 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5496 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5497 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5498 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5502 fn adds_plausible_cltv_offset() {
5503 let (secp_ctx, network, _, _, logger) = build_graph();
5504 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5505 let network_graph = network.read_only();
5506 let network_nodes = network_graph.nodes();
5507 let network_channels = network_graph.channels();
5508 let scorer = test_utils::TestScorer::with_penalty(0);
5509 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5510 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5511 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5513 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5514 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5515 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5517 let mut path_plausibility = vec![];
5519 for p in route.paths {
5520 // 1. Select random observation point
5521 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5522 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5524 prng.process_in_place(&mut random_bytes);
5525 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5526 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5528 // 2. Calculate what CLTV expiry delta we would observe there
5529 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5531 // 3. Starting from the observation point, find candidate paths
5532 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5533 candidates.push_back((observation_point, vec![]));
5535 let mut found_plausible_candidate = false;
5537 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5538 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5539 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5540 found_plausible_candidate = true;
5541 break 'candidate_loop;
5545 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5546 for channel_id in &cur_node.channels {
5547 if let Some(channel_info) = network_channels.get(&channel_id) {
5548 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5549 if let Some(channel_update_info) = dir_info.direction() {
5550 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5551 if cur_path_cltv_deltas.iter().sum::<u32>()
5552 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5553 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5554 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5555 candidates.push_back((*next_id, new_path_cltv_deltas));
5564 path_plausibility.push(found_plausible_candidate);
5566 assert!(path_plausibility.iter().all(|x| *x));
5570 fn builds_correct_path_from_hops() {
5571 let (secp_ctx, network, _, _, logger) = build_graph();
5572 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5573 let network_graph = network.read_only();
5575 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5576 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5578 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5579 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5580 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5581 &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
5582 let route_hop_pubkeys = route.paths[0].iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5583 assert_eq!(hops.len(), route.paths[0].len());
5584 for (idx, hop_pubkey) in hops.iter().enumerate() {
5585 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5589 #[cfg(not(feature = "no-std"))]
5590 pub(super) fn random_init_seed() -> u64 {
5591 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5592 use core::hash::{BuildHasher, Hasher};
5593 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5594 println!("Using seed of {}", seed);
5597 #[cfg(not(feature = "no-std"))]
5598 use util::ser::ReadableArgs;
5601 #[cfg(not(feature = "no-std"))]
5602 fn generate_routes() {
5603 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5605 let mut d = match super::test_utils::get_route_file() {
5612 let logger = test_utils::TestLogger::new();
5613 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5614 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5615 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5617 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5618 let mut seed = random_init_seed() as usize;
5619 let nodes = graph.read_only().nodes().clone();
5620 'load_endpoints: for _ in 0..10 {
5622 seed = seed.overflowing_mul(0xdeadbeef).0;
5623 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5624 seed = seed.overflowing_mul(0xdeadbeef).0;
5625 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5626 let payment_params = PaymentParameters::from_node_id(dst);
5627 let amt = seed as u64 % 200_000_000;
5628 let params = ProbabilisticScoringParameters::default();
5629 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5630 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5631 continue 'load_endpoints;
5638 #[cfg(not(feature = "no-std"))]
5639 fn generate_routes_mpp() {
5640 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5642 let mut d = match super::test_utils::get_route_file() {
5649 let logger = test_utils::TestLogger::new();
5650 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5651 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5652 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5654 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5655 let mut seed = random_init_seed() as usize;
5656 let nodes = graph.read_only().nodes().clone();
5657 'load_endpoints: for _ in 0..10 {
5659 seed = seed.overflowing_mul(0xdeadbeef).0;
5660 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5661 seed = seed.overflowing_mul(0xdeadbeef).0;
5662 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5663 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5664 let amt = seed as u64 % 200_000_000;
5665 let params = ProbabilisticScoringParameters::default();
5666 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5667 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5668 continue 'load_endpoints;
5675 #[cfg(all(test, not(feature = "no-std")))]
5676 pub(crate) mod test_utils {
5678 /// Tries to open a network graph file, or panics with a URL to fetch it.
5679 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5680 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5681 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5682 .or_else(|_| { // Fall back to guessing based on the binary location
5683 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5684 let mut path = std::env::current_exe().unwrap();
5685 path.pop(); // lightning-...
5687 path.pop(); // debug
5688 path.pop(); // target
5689 path.push("lightning");
5690 path.push("net_graph-2021-05-31.bin");
5691 eprintln!("{}", path.to_str().unwrap());
5694 .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");
5695 #[cfg(require_route_graph_test)]
5696 return Ok(res.unwrap());
5697 #[cfg(not(require_route_graph_test))]
5702 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5705 use bitcoin::hashes::Hash;
5706 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5707 use chain::transaction::OutPoint;
5708 use chain::keysinterface::{KeysManager,KeysInterface};
5709 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5710 use ln::features::{InitFeatures, InvoiceFeatures};
5711 use routing::gossip::NetworkGraph;
5712 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters};
5713 use util::logger::{Logger, Record};
5714 use util::ser::ReadableArgs;
5718 struct DummyLogger {}
5719 impl Logger for DummyLogger {
5720 fn log(&self, _record: &Record) {}
5723 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
5724 let mut d = test_utils::get_route_file().unwrap();
5725 NetworkGraph::read(&mut d, logger).unwrap()
5728 fn payer_pubkey() -> PublicKey {
5729 let secp_ctx = Secp256k1::new();
5730 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5734 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5736 channel_id: [0; 32],
5737 counterparty: ChannelCounterparty {
5738 features: InitFeatures::known(),
5740 unspendable_punishment_reserve: 0,
5741 forwarding_info: None,
5742 outbound_htlc_minimum_msat: None,
5743 outbound_htlc_maximum_msat: None,
5745 funding_txo: Some(OutPoint {
5746 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5749 short_channel_id: Some(1),
5750 inbound_scid_alias: None,
5751 outbound_scid_alias: None,
5752 channel_value_satoshis: 10_000_000,
5754 balance_msat: 10_000_000,
5755 outbound_capacity_msat: 10_000_000,
5756 next_outbound_htlc_limit_msat: 10_000_000,
5757 inbound_capacity_msat: 0,
5758 unspendable_punishment_reserve: None,
5759 confirmations_required: None,
5760 force_close_spend_delay: None,
5762 is_channel_ready: true,
5765 inbound_htlc_minimum_msat: None,
5766 inbound_htlc_maximum_msat: None,
5771 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5772 let logger = DummyLogger {};
5773 let network_graph = read_network_graph(&logger);
5774 let scorer = FixedPenaltyScorer::with_penalty(0);
5775 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5779 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5780 let logger = DummyLogger {};
5781 let network_graph = read_network_graph(&logger);
5782 let scorer = FixedPenaltyScorer::with_penalty(0);
5783 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5787 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5788 let logger = DummyLogger {};
5789 let network_graph = read_network_graph(&logger);
5790 let params = ProbabilisticScoringParameters::default();
5791 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5792 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5796 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5797 let logger = DummyLogger {};
5798 let network_graph = read_network_graph(&logger);
5799 let params = ProbabilisticScoringParameters::default();
5800 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5801 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5804 fn generate_routes<S: Score>(
5805 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S,
5806 features: InvoiceFeatures
5808 let nodes = graph.read_only().nodes().clone();
5809 let payer = payer_pubkey();
5810 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5811 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5813 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5814 let mut routes = Vec::new();
5815 let mut route_endpoints = Vec::new();
5816 let mut seed: usize = 0xdeadbeef;
5817 'load_endpoints: for _ in 0..150 {
5820 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5822 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5823 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5824 let first_hop = first_hop(src);
5825 let amt = seed as u64 % 1_000_000;
5826 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5828 route_endpoints.push((first_hop, params, amt));
5829 continue 'load_endpoints;
5834 // ...and seed the scorer with success and failure data...
5835 for route in routes {
5836 let amount = route.get_total_amount();
5837 if amount < 250_000 {
5838 for path in route.paths {
5839 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5841 } else if amount > 750_000 {
5842 for path in route.paths {
5843 let short_channel_id = path[path.len() / 2].short_channel_id;
5844 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5849 // Because we've changed channel scores, its possible we'll take different routes to the
5850 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5851 // requires a too-high CLTV delta.
5852 route_endpoints.retain(|(first_hop, params, amt)| {
5853 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5855 route_endpoints.truncate(100);
5856 assert_eq!(route_endpoints.len(), 100);
5858 // ...then benchmark finding paths between the nodes we learned.
5861 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5862 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());