1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The top-level routing/network map tracking logic lives here.
12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::network_graph::{NetworkGraph, RoutingFees};
21 use util::ser::{Writeable, Readable};
22 use util::logger::Logger;
25 use std::collections::{HashMap, BinaryHeap};
29 #[derive(Clone, PartialEq)]
31 /// The node_id of the node at this hop.
32 pub pubkey: PublicKey,
33 /// The node_announcement features of the node at this hop. For the last hop, these may be
34 /// amended to match the features present in the invoice this node generated.
35 pub node_features: NodeFeatures,
36 /// The channel that should be used from the previous hop to reach this node.
37 pub short_channel_id: u64,
38 /// The channel_announcement features of the channel that should be used from the previous hop
39 /// to reach this node.
40 pub channel_features: ChannelFeatures,
41 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
42 /// For the last hop, this should be the full value of the payment (might be more than
43 /// requested if we had to match htlc_minimum_msat).
45 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
46 /// expected at the destination, in excess of the current block height.
47 pub cltv_expiry_delta: u32,
51 impl Writeable for Vec<RouteHop> {
52 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
53 (self.len() as u8).write(writer)?;
54 for hop in self.iter() {
55 hop.pubkey.write(writer)?;
56 hop.node_features.write(writer)?;
57 hop.short_channel_id.write(writer)?;
58 hop.channel_features.write(writer)?;
59 hop.fee_msat.write(writer)?;
60 hop.cltv_expiry_delta.write(writer)?;
67 impl Readable for Vec<RouteHop> {
68 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Vec<RouteHop>, DecodeError> {
69 let hops_count: u8 = Readable::read(reader)?;
70 let mut hops = Vec::with_capacity(hops_count as usize);
71 for _ in 0..hops_count {
73 pubkey: Readable::read(reader)?,
74 node_features: Readable::read(reader)?,
75 short_channel_id: Readable::read(reader)?,
76 channel_features: Readable::read(reader)?,
77 fee_msat: Readable::read(reader)?,
78 cltv_expiry_delta: Readable::read(reader)?,
85 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
86 /// it can take multiple paths. Each path is composed of one or more hops through the network.
87 #[derive(Clone, PartialEq)]
89 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
90 /// last RouteHop in each path must be the same.
91 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
92 /// destination. Thus, this must always be at least length one. While the maximum length of any
93 /// given path is variable, keeping the length of any path to less than 20 should currently
94 /// ensure it is viable.
95 pub paths: Vec<Vec<RouteHop>>,
98 impl Writeable for Route {
99 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
100 (self.paths.len() as u64).write(writer)?;
101 for hops in self.paths.iter() {
108 impl Readable for Route {
109 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
110 let path_count: u64 = Readable::read(reader)?;
111 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
112 for _ in 0..path_count {
113 paths.push(Readable::read(reader)?);
119 /// A channel descriptor which provides a last-hop route to get_route
120 #[derive(Eq, PartialEq, Debug, Clone)]
121 pub struct RouteHintHop {
122 /// The node_id of the non-target end of the route
123 pub src_node_id: PublicKey,
124 /// The short_channel_id of this channel
125 pub short_channel_id: u64,
126 /// The fees which must be paid to use this channel
127 pub fees: RoutingFees,
128 /// The difference in CLTV values between this node and the next node.
129 pub cltv_expiry_delta: u16,
130 /// The minimum value, in msat, which must be relayed to the next hop.
131 pub htlc_minimum_msat: Option<u64>,
132 /// The maximum value in msat available for routing with a single HTLC.
133 pub htlc_maximum_msat: Option<u64>,
136 #[derive(Eq, PartialEq)]
137 struct RouteGraphNode {
139 lowest_fee_to_peer_through_node: u64,
140 lowest_fee_to_node: u64,
141 // The maximum value a yet-to-be-constructed payment path might flow through this node.
142 // This value is upper-bounded by us by:
143 // - how much is needed for a path being constructed
144 // - how much value can channels following this node (up to the destination) can contribute,
145 // considering their capacity and fees
146 value_contribution_msat: u64,
147 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
148 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
149 path_htlc_minimum_msat: u64,
152 impl cmp::Ord for RouteGraphNode {
153 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
154 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat);
155 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat);
156 other_score.cmp(&self_score).then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
160 impl cmp::PartialOrd for RouteGraphNode {
161 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
162 Some(self.cmp(other))
166 struct DummyDirectionalChannelInfo {
167 cltv_expiry_delta: u32,
168 htlc_minimum_msat: u64,
169 htlc_maximum_msat: Option<u64>,
173 /// It's useful to keep track of the hops associated with the fees required to use them,
174 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
175 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
176 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
178 struct PathBuildingHop<'a> {
179 // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
180 // Note that node_features is calculated separately after our initial graph walk.
182 short_channel_id: u64,
183 channel_features: &'a ChannelFeatures,
185 cltv_expiry_delta: u32,
187 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
188 src_lowest_inbound_fees: RoutingFees,
189 /// Fees of the channel used in this hop.
190 channel_fees: RoutingFees,
191 /// All the fees paid *after* this channel on the way to the destination
192 next_hops_fee_msat: u64,
193 /// Fee paid for the use of the current channel (see channel_fees).
194 /// The value will be actually deducted from the counterparty balance on the previous link.
195 hop_use_fee_msat: u64,
196 /// Used to compare channels when choosing the for routing.
197 /// Includes paying for the use of a hop and the following hops, as well as
198 /// an estimated cost of reaching this hop.
199 /// Might get stale when fees are recomputed. Primarily for internal use.
201 /// This is useful for update_value_and_recompute_fees to make sure
202 /// we don't fall below the minimum. Should not be updated manually and
203 /// generally should not be accessed.
204 htlc_minimum_msat: u64,
205 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
206 /// walk and may be invalid thereafter.
207 path_htlc_minimum_msat: u64,
208 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
209 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
210 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
211 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
212 /// avoid processing them again.
214 #[cfg(any(test, feature = "fuzztarget"))]
215 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
216 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
217 // value_contribution_msat, which requires tracking it here. See comments below where it is
218 // used for more info.
219 value_contribution_msat: u64,
222 // Instantiated with a list of hops with correct data in them collected during path finding,
223 // an instance of this struct should be further modified only via given methods.
225 struct PaymentPath<'a> {
226 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
229 impl<'a> PaymentPath<'a> {
230 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
231 fn get_value_msat(&self) -> u64 {
232 self.hops.last().unwrap().0.fee_msat
235 fn get_total_fee_paid_msat(&self) -> u64 {
236 if self.hops.len() < 1 {
240 // Can't use next_hops_fee_msat because it gets outdated.
241 for (i, (hop, _)) in self.hops.iter().enumerate() {
242 if i != self.hops.len() - 1 {
243 result += hop.fee_msat;
249 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
250 // to change fees may result in an inconsistency.
252 // Sometimes we call this function right after constructing a path which is inconsistent in
253 // that it the value being transferred has decreased while we were doing path finding, leading
254 // to the fees being paid not lining up with the actual limits.
256 // Note that this function is not aware of the available_liquidity limit, and thus does not
257 // support increasing the value being transferred.
258 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
259 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
261 let mut total_fee_paid_msat = 0 as u64;
262 for i in (0..self.hops.len()).rev() {
263 let last_hop = i == self.hops.len() - 1;
265 // For non-last-hop, this value will represent the fees paid on the current hop. It
266 // will consist of the fees for the use of the next hop, and extra fees to match
267 // htlc_minimum_msat of the current channel. Last hop is handled separately.
268 let mut cur_hop_fees_msat = 0;
270 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
273 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
274 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
275 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
276 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
277 // set it too high just to maliciously take more fees by exploiting this
278 // match htlc_minimum_msat logic.
279 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
280 if let Some(extra_fees_msat) = cur_hop.htlc_minimum_msat.checked_sub(cur_hop_transferred_amount_msat) {
281 // Note that there is a risk that *previous hops* (those closer to us, as we go
282 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
284 // This might make us end up with a broken route, although this should be super-rare
285 // in practice, both because of how healthy channels look like, and how we pick
286 // channels in add_entry.
287 // Also, this can't be exploited more heavily than *announce a free path and fail
289 cur_hop_transferred_amount_msat += extra_fees_msat;
290 total_fee_paid_msat += extra_fees_msat;
291 cur_hop_fees_msat += extra_fees_msat;
295 // Final hop is a special case: it usually has just value_msat (by design), but also
296 // it still could overpay for the htlc_minimum_msat.
297 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
299 // Propagate updated fees for the use of the channels to one hop back, where they
300 // will be actually paid (fee_msat). The last hop is handled above separately.
301 cur_hop.fee_msat = cur_hop_fees_msat;
304 // Fee for the use of the current hop which will be deducted on the previous hop.
305 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
306 // this channel is free for us.
308 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.channel_fees) {
309 cur_hop.hop_use_fee_msat = new_fee;
310 total_fee_paid_msat += new_fee;
312 // It should not be possible because this function is called only to reduce the
313 // value. In that case, compute_fee was already called with the same fees for
314 // larger amount and there was no overflow.
322 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
323 let proportional_fee_millions =
324 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
325 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
326 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
330 // This function may be (indirectly) called without any verification,
331 // with channel_fees provided by a caller. We should handle it gracefully.
336 /// Gets a route from us (payer) to the given target node (payee).
338 /// If the payee provided features in their invoice, they should be provided via payee_features.
339 /// Without this, MPP will only be used if the payee's features are available in the network graph.
341 /// Extra routing hops between known nodes and the target will be used if they are included in
344 /// If some channels aren't announced, it may be useful to fill in a first_hops with the
345 /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
346 /// view of our local channels (from net_graph_msg_handler) will be ignored, and only those
347 /// in first_hops will be used.
349 /// Panics if first_hops contains channels without short_channel_ids
350 /// (ChannelManager::list_usable_channels will never include such channels).
352 /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
353 /// equal), however the enabled/disabled bit on such channels as well as the
354 /// htlc_minimum_msat/htlc_maximum_msat *are* checked as they may change based on the receiving node.
355 pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee: &PublicKey, payee_features: Option<InvoiceFeatures>, first_hops: Option<&[&ChannelDetails]>,
356 last_hops: &[&RouteHintHop], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
357 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
358 // uptime/success in using a node in the past.
359 if *payee == *our_node_id {
360 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
363 if final_value_msat > MAX_VALUE_MSAT {
364 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
367 if final_value_msat == 0 {
368 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
371 for last_hop in last_hops {
372 if last_hop.src_node_id == *payee {
373 return Err(LightningError{err: "Last hop cannot have a payee as a source.".to_owned(), action: ErrorAction::IgnoreError});
377 // The general routing idea is the following:
378 // 1. Fill first/last hops communicated by the caller.
379 // 2. Attempt to construct a path from payer to payee for transferring
380 // any ~sufficient (described later) value.
381 // If succeed, remember which channels were used and how much liquidity they have available,
382 // so that future paths don't rely on the same liquidity.
383 // 3. Prooceed to the next step if:
384 // - we hit the recommended target value;
385 // - OR if we could not construct a new path. Any next attempt will fail too.
386 // Otherwise, repeat step 2.
387 // 4. See if we managed to collect paths which aggregately are able to transfer target value
388 // (not recommended value). If yes, proceed. If not, fail routing.
389 // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
390 // 6. Of all the found paths, select only those with the lowest total fee.
391 // 7. The last path in every selected route is likely to be more than we need.
392 // Reduce its value-to-transfer and recompute fees.
393 // 8. Choose the best route by the lowest total fee.
395 // As for the actual search algorithm,
396 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
397 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
399 // We are not a faithful Dijkstra's implementation because we can change values which impact
400 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
401 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) then
402 // the value we are currently attempting to send over a path, we simply reduce the value being
403 // sent along the path for any hops after that channel. This may imply that later fees (which
404 // we've already tabulated) are lower because a smaller value is passing through the channels
405 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
406 // channels which were selected earlier (and which may still be used for other paths without a
407 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
410 // One potentially problematic case for this algorithm would be if there are many
411 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
412 // graph walking), we may never find a path which is not liquidity-limited and has lower
413 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
414 // Because we only consider paths with at least 5% of the total value being sent, the damage
415 // from such a case should be limited, however this could be further reduced in the future by
416 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
417 // limits for the purposes of fee calculation.
419 // Alternatively, we could store more detailed path information in the heap (targets, below)
420 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
421 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
422 // and practically (as we would need to store dynamically-allocated path information in heap
423 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
424 // results of such an algorithm would likely be biased towards lower-value paths.
426 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
427 // outside of our current search value, running a path search more times to gather candidate
428 // paths at different values. While this may be acceptable, further path searches may increase
429 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
430 // graph for candidate paths, calculating the maximum value which can realistically be sent at
431 // the same time, remaining generic across different payment values.
433 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
434 // to use as the A* heuristic beyond just the cost to get one node further than the current
437 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
438 cltv_expiry_delta: 0,
439 htlc_minimum_msat: 0,
440 htlc_maximum_msat: None,
443 proportional_millionths: 0,
447 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
448 // it. If the payee supports it they're supposed to include it in the invoice, so that should
450 let allow_mpp = if let Some(features) = &payee_features {
451 features.supports_basic_mpp()
452 } else if let Some(node) = network.get_nodes().get(&payee) {
453 if let Some(node_info) = node.announcement_info.as_ref() {
454 node_info.features.supports_basic_mpp()
459 // Prepare the data we'll use for payee-to-payer search by
460 // inserting first hops suggested by the caller as targets.
461 // Our search will then attempt to reach them while traversing from the payee node.
462 let mut first_hop_targets: HashMap<_, (_, ChannelFeatures, _, NodeFeatures)> =
463 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
464 if let Some(hops) = first_hops {
466 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
467 if chan.remote_network_id == *our_node_id {
468 return Err(LightningError{err: "First hop cannot have our_node_id as a destination.".to_owned(), action: ErrorAction::IgnoreError});
470 first_hop_targets.insert(chan.remote_network_id, (short_channel_id, chan.counterparty_features.to_context(), chan.outbound_capacity_msat, chan.counterparty_features.to_context()));
472 if first_hop_targets.is_empty() {
473 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
477 let empty_channel_features = ChannelFeatures::empty();
479 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
480 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
481 // adding duplicate entries when we find a better path to a given node.
482 let mut targets = BinaryHeap::new();
484 // Map from node_id to information about the best current path to that node, including feerate
486 let mut dist = HashMap::with_capacity(network.get_nodes().len());
488 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
489 // indicating that we may wish to try again with a higher value, potentially paying to meet an
490 // htlc_minimum with extra fees while still finding a cheaper path.
491 let mut hit_minimum_limit;
493 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
494 // We start with a path_value of the exact amount we want, and if that generates a route we may
495 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
496 // amount we want in total across paths, selecting the best subset at the end.
497 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
498 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
499 let mut path_value_msat = final_value_msat;
501 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
502 // This map allows paths to be aware of the channel use by other paths in the same call.
503 // This would help to make a better path finding decisions and not "overbook" channels.
504 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
505 let mut bookkeeped_channels_liquidity_available_msat = HashMap::with_capacity(network.get_nodes().len());
507 // Keeping track of how much value we already collected across other paths. Helps to decide:
508 // - how much a new path should be transferring (upper bound);
509 // - whether a channel should be disregarded because
510 // it's available liquidity is too small comparing to how much more we need to collect;
511 // - when we want to stop looking for new paths.
512 let mut already_collected_value_msat = 0;
514 macro_rules! add_entry {
515 // Adds entry which goes from $src_node_id to $dest_node_id
516 // over the channel with id $chan_id with fees described in
517 // $directional_info.
518 // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one,
519 // since that value has to be transferred over this channel.
520 ( $chan_id: expr, $src_node_id: expr, $dest_node_id: expr, $directional_info: expr, $capacity_sats: expr, $chan_features: expr, $next_hops_fee_msat: expr,
521 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
522 // Channels to self should not be used. This is more of belt-and-suspenders, because in
523 // practice these cases should be caught earlier:
524 // - for regular channels at channel announcement (TODO)
525 // - for first and last hops early in get_route
526 if $src_node_id != $dest_node_id.clone() {
527 let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
528 let mut initial_liquidity_available_msat = None;
529 if let Some(capacity_sats) = $capacity_sats {
530 initial_liquidity_available_msat = Some(capacity_sats * 1000);
533 if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
534 if let Some(available_msat) = initial_liquidity_available_msat {
535 initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
537 initial_liquidity_available_msat = Some(htlc_maximum_msat);
541 match initial_liquidity_available_msat {
542 Some(available_msat) => available_msat,
543 // We assume channels with unknown balance have
544 // a capacity of 0.0025 BTC (or 250_000 sats).
545 None => 250_000 * 1000
549 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
550 // It may be misleading because we might later choose to reduce the value transferred
551 // over these channels, and the channel which was insufficient might become sufficient.
552 // Worst case: we drop a good channel here because it can't cover the high following
553 // fees caused by one expensive channel, but then this channel could have been used
554 // if the amount being transferred over this path is lower.
555 // We do this for now, but this is a subject for removal.
556 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
558 // Routing Fragmentation Mitigation heuristic:
560 // Routing fragmentation across many payment paths increases the overall routing
561 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
562 // Taking too many smaller paths also increases the chance of payment failure.
563 // Thus to avoid this effect, we require from our collected links to provide
564 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
566 // This requirement is currently 5% of the remaining-to-be-collected value.
567 // This means as we successfully advance in our collection,
568 // the absolute liquidity contribution is lowered,
569 // thus increasing the number of potential channels to be selected.
571 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
572 // or 100% if we're not allowed to do multipath payments.
573 let minimal_value_contribution_msat: u64 = if allow_mpp {
574 (recommended_value_msat - already_collected_value_msat + 19) / 20
578 // Verify the liquidity offered by this channel complies to the minimal contribution.
579 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
581 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
582 // Includes paying fees for the use of the following channels.
583 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
584 Some(result) => result,
585 // Can't overflow due to how the values were computed right above.
586 None => unreachable!(),
588 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
589 let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
590 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
592 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
593 // bother considering this channel.
594 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
595 // be only reduced later (not increased), so this channel should just be skipped
596 // as not sufficient.
597 if !over_path_minimum_msat {
598 hit_minimum_limit = true;
599 } else if contributes_sufficient_value {
600 // Note that low contribution here (limited by available_liquidity_msat)
601 // might violate htlc_minimum_msat on the hops which are next along the
602 // payment path (upstream to the payee). To avoid that, we recompute path
603 // path fees knowing the final path contribution after constructing it.
604 let path_htlc_minimum_msat = match compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
605 .map(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) {
606 Some(Some(value_msat)) => cmp::max(value_msat, $directional_info.htlc_minimum_msat),
607 _ => u64::max_value()
609 let hm_entry = dist.entry(&$src_node_id);
610 let old_entry = hm_entry.or_insert_with(|| {
611 // If there was previously no known way to access
612 // the source node (recall it goes payee-to-payer) of $chan_id, first add
613 // a semi-dummy record just to compute the fees to reach the source node.
614 // This will affect our decision on selecting $chan_id
615 // as a way to reach the $dest_node_id.
616 let mut fee_base_msat = u32::max_value();
617 let mut fee_proportional_millionths = u32::max_value();
618 if let Some(Some(fees)) = network.get_nodes().get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
619 fee_base_msat = fees.base_msat;
620 fee_proportional_millionths = fees.proportional_millionths;
623 pubkey: $dest_node_id.clone(),
625 channel_features: $chan_features,
627 cltv_expiry_delta: 0,
628 src_lowest_inbound_fees: RoutingFees {
629 base_msat: fee_base_msat,
630 proportional_millionths: fee_proportional_millionths,
632 channel_fees: $directional_info.fees,
633 next_hops_fee_msat: u64::max_value(),
634 hop_use_fee_msat: u64::max_value(),
635 total_fee_msat: u64::max_value(),
636 htlc_minimum_msat: $directional_info.htlc_minimum_msat,
637 path_htlc_minimum_msat,
638 was_processed: false,
639 #[cfg(any(test, feature = "fuzztarget"))]
640 value_contribution_msat,
644 #[allow(unused_mut)] // We only use the mut in cfg(test)
645 let mut should_process = !old_entry.was_processed;
646 #[cfg(any(test, feature = "fuzztarget"))]
648 // In test/fuzzing builds, we do extra checks to make sure the skipping
649 // of already-seen nodes only happens in cases we expect (see below).
650 if !should_process { should_process = true; }
654 let mut hop_use_fee_msat = 0;
655 let mut total_fee_msat = $next_hops_fee_msat;
657 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
658 // will have the same effective-fee
659 if $src_node_id != *our_node_id {
660 match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
661 // max_value means we'll always fail
662 // the old_entry.total_fee_msat > total_fee_msat check
663 None => total_fee_msat = u64::max_value(),
665 hop_use_fee_msat = fee_msat;
666 total_fee_msat += hop_use_fee_msat;
667 // When calculating the lowest inbound fees to a node, we
668 // calculate fees here not based on the actual value we think
669 // will flow over this channel, but on the minimum value that
670 // we'll accept flowing over it. The minimum accepted value
671 // is a constant through each path collection run, ensuring
672 // consistent basis. Otherwise we may later find a
673 // different path to the source node that is more expensive,
674 // but which we consider to be cheaper because we are capacity
675 // constrained and the relative fee becomes lower.
676 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
677 .map(|a| a.checked_add(total_fee_msat)) {
682 total_fee_msat = u64::max_value();
689 let new_graph_node = RouteGraphNode {
690 pubkey: $src_node_id,
691 lowest_fee_to_peer_through_node: total_fee_msat,
692 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
693 value_contribution_msat: value_contribution_msat,
694 path_htlc_minimum_msat,
697 // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
698 // if this way is cheaper than the already known
699 // (considering the cost to "reach" this channel from the route destination,
700 // the cost of using this channel,
701 // and the cost of routing to the source node of this channel).
702 // Also, consider that htlc_minimum_msat_difference, because we might end up
703 // paying it. Consider the following exploit:
704 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
705 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
706 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
707 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
709 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
710 // but it may require additional tracking - we don't want to double-count
711 // the fees included in $next_hops_path_htlc_minimum_msat, but also
712 // can't use something that may decrease on future hops.
713 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat);
714 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat);
716 if !old_entry.was_processed && new_cost < old_cost {
717 targets.push(new_graph_node);
718 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
719 old_entry.hop_use_fee_msat = hop_use_fee_msat;
720 old_entry.total_fee_msat = total_fee_msat;
721 old_entry.pubkey = $dest_node_id.clone();
722 old_entry.short_channel_id = $chan_id.clone();
723 old_entry.channel_features = $chan_features;
724 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
725 old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
726 old_entry.channel_fees = $directional_info.fees;
727 old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
728 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
729 #[cfg(any(test, feature = "fuzztarget"))]
731 old_entry.value_contribution_msat = value_contribution_msat;
733 } else if old_entry.was_processed && new_cost < old_cost {
734 #[cfg(any(test, feature = "fuzztarget"))]
736 // If we're skipping processing a node which was previously
737 // processed even though we found another path to it with a
738 // cheaper fee, check that it was because the second path we
739 // found (which we are processing now) has a lower value
740 // contribution due to an HTLC minimum limit.
742 // e.g. take a graph with two paths from node 1 to node 2, one
743 // through channel A, and one through channel B. Channel A and
744 // B are both in the to-process heap, with their scores set by
745 // a higher htlc_minimum than fee.
746 // Channel A is processed first, and the channels onwards from
747 // node 1 are added to the to-process heap. Thereafter, we pop
748 // Channel B off of the heap, note that it has a much more
749 // restrictive htlc_maximum_msat, and recalculate the fees for
750 // all of node 1's channels using the new, reduced, amount.
752 // This would be bogus - we'd be selecting a higher-fee path
753 // with a lower htlc_maximum_msat instead of the one we'd
754 // already decided to use.
755 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
756 debug_assert!(value_contribution_msat < old_entry.value_contribution_msat);
766 let empty_node_features = NodeFeatures::empty();
767 // Find ways (channels with destination) to reach a given node and store them
768 // in the corresponding data structures (routing graph etc).
769 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
770 // meaning how much will be paid in fees after this node (to the best of our knowledge).
771 // This data can later be helpful to optimize routing (pay lower fees).
772 macro_rules! add_entries_to_cheapest_to_target_node {
773 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
774 let skip_node = if let Some(elem) = dist.get_mut($node_id) {
775 let was_processed = elem.was_processed;
776 elem.was_processed = true;
779 // Entries are added to dist in add_entry!() when there is a channel from a node.
780 // Because there are no channels from payee, it will not have a dist entry at this point.
781 // If we're processing any other node, it is always be the result of a channel from it.
782 assert_eq!($node_id, payee);
787 if first_hops.is_some() {
788 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&$node_id) {
789 add_entry!(first_hop, *our_node_id, $node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat);
793 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
799 if !features.requires_unknown_bits() {
800 for chan_id in $node.channels.iter() {
801 let chan = network.get_channels().get(chan_id).unwrap();
802 if !chan.features.requires_unknown_bits() {
803 if chan.node_one == *$node_id {
804 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
805 if first_hops.is_none() || chan.node_two != *our_node_id {
806 if let Some(two_to_one) = chan.two_to_one.as_ref() {
807 if two_to_one.enabled {
808 add_entry!(chan_id, chan.node_two, chan.node_one, two_to_one, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat);
813 if first_hops.is_none() || chan.node_one != *our_node_id {
814 if let Some(one_to_two) = chan.one_to_two.as_ref() {
815 if one_to_two.enabled {
816 add_entry!(chan_id, chan.node_one, chan.node_two, one_to_two, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat);
828 let mut payment_paths = Vec::<PaymentPath>::new();
830 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
831 'paths_collection: loop {
832 // For every new path, start from scratch, except
833 // bookkeeped_channels_liquidity_available_msat, which will improve
834 // the further iterations of path finding. Also don't erase first_hop_targets.
837 hit_minimum_limit = false;
839 // If first hop is a private channel and the only way to reach the payee, this is the only
840 // place where it could be added.
841 if first_hops.is_some() {
842 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&payee) {
843 add_entry!(first_hop, *our_node_id, payee, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
847 // Add the payee as a target, so that the payee-to-payer
848 // search algorithm knows what to start with.
849 match network.get_nodes().get(payee) {
850 // The payee is not in our network graph, so nothing to add here.
851 // There is still a chance of reaching them via last_hops though,
852 // so don't yet fail the payment here.
853 // If not, targets.pop() will not even let us enter the loop in step 2.
856 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0);
861 // If a caller provided us with last hops, add them to routing targets. Since this happens
862 // earlier than general path finding, they will be somewhat prioritized, although currently
863 // it matters only if the fees are exactly the same.
864 for hop in last_hops.iter() {
865 let have_hop_src_in_graph =
866 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&hop.src_node_id) {
867 // If this hop connects to a node with which we have a direct channel, ignore
868 // the network graph and add both the hop and our direct channel to
869 // the candidate set.
871 // Currently there are no channel-context features defined, so we are a
872 // bit lazy here. In the future, we should pull them out via our
873 // ChannelManager, but there's no reason to waste the space until we
875 add_entry!(first_hop, *our_node_id , hop.src_node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
878 // In any other case, only add the hop if the source is in the regular network
880 network.get_nodes().get(&hop.src_node_id).is_some()
882 if have_hop_src_in_graph {
883 // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
884 // really sucks, cause we're gonna need that eventually.
885 let last_hop_htlc_minimum_msat: u64 = match hop.htlc_minimum_msat {
886 Some(htlc_minimum_msat) => htlc_minimum_msat,
889 let directional_info = DummyDirectionalChannelInfo {
890 cltv_expiry_delta: hop.cltv_expiry_delta as u32,
891 htlc_minimum_msat: last_hop_htlc_minimum_msat,
892 htlc_maximum_msat: hop.htlc_maximum_msat,
895 add_entry!(hop.short_channel_id, hop.src_node_id, payee, directional_info, None::<u64>, &empty_channel_features, 0, path_value_msat, 0);
899 // At this point, targets are filled with the data from first and
900 // last hops communicated by the caller, and the payment receiver.
901 let mut found_new_path = false;
904 // If this loop terminates due the exhaustion of targets, two situations are possible:
905 // - not enough outgoing liquidity:
906 // 0 < already_collected_value_msat < final_value_msat
907 // - enough outgoing liquidity:
908 // final_value_msat <= already_collected_value_msat < recommended_value_msat
909 // Both these cases (and other cases except reaching recommended_value_msat) mean that
910 // paths_collection will be stopped because found_new_path==false.
911 // This is not necessarily a routing failure.
912 'path_construction: while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, .. }) = targets.pop() {
914 // Since we're going payee-to-payer, hitting our node as a target means we should stop
915 // traversing the graph and arrange the path out of what we found.
916 if pubkey == *our_node_id {
917 let mut new_entry = dist.remove(&our_node_id).unwrap();
918 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
921 if let Some(&(_, _, _, ref features)) = first_hop_targets.get(&ordered_hops.last().unwrap().0.pubkey) {
922 ordered_hops.last_mut().unwrap().1 = features.clone();
923 } else if let Some(node) = network.get_nodes().get(&ordered_hops.last().unwrap().0.pubkey) {
924 if let Some(node_info) = node.announcement_info.as_ref() {
925 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
927 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
930 // We should be able to fill in features for everything except the last
931 // hop, if the last hop was provided via a BOLT 11 invoice (though we
932 // should be able to extend it further as BOLT 11 does have feature
933 // flags for the last hop node itself).
934 assert!(ordered_hops.last().unwrap().0.pubkey == *payee);
937 // Means we succesfully traversed from the payer to the payee, now
938 // save this path for the payment route. Also, update the liquidity
939 // remaining on the used hops, so that we take them into account
940 // while looking for more paths.
941 if ordered_hops.last().unwrap().0.pubkey == *payee {
945 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.pubkey) {
946 Some(payment_hop) => payment_hop,
947 // We can't arrive at None because, if we ever add an entry to targets,
948 // we also fill in the entry in dist (see add_entry!).
949 None => unreachable!(),
951 // We "propagate" the fees one hop backward (topologically) here,
952 // so that fees paid for a HTLC forwarding on the current channel are
953 // associated with the previous channel (where they will be subtracted).
954 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
955 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = new_entry.cltv_expiry_delta;
956 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
958 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
959 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
960 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = final_cltv;
962 let mut payment_path = PaymentPath {hops: ordered_hops};
964 // We could have possibly constructed a slightly inconsistent path: since we reduce
965 // value being transferred along the way, we could have violated htlc_minimum_msat
966 // on some channels we already passed (assuming dest->source direction). Here, we
967 // recompute the fees again, so that if that's the case, we match the currently
968 // underpaid htlc_minimum_msat with fees.
969 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
971 // Since a path allows to transfer as much value as
972 // the smallest channel it has ("bottleneck"), we should recompute
973 // the fees so sender HTLC don't overpay fees when traversing
974 // larger channels than the bottleneck. This may happen because
975 // when we were selecting those channels we were not aware how much value
976 // this path will transfer, and the relative fee for them
977 // might have been computed considering a larger value.
978 // Remember that we used these channels so that we don't rely
979 // on the same liquidity in future paths.
980 let mut prevented_redundant_path_selection = false;
981 for (payment_hop, _) in payment_path.hops.iter() {
982 let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.short_channel_id).unwrap();
983 let mut spent_on_hop_msat = value_contribution_msat;
984 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
985 spent_on_hop_msat += next_hops_fee_msat;
986 if spent_on_hop_msat == *channel_liquidity_available_msat {
987 // If this path used all of this channel's available liquidity, we know
988 // this path will not be selected again in the next loop iteration.
989 prevented_redundant_path_selection = true;
991 *channel_liquidity_available_msat -= spent_on_hop_msat;
993 if !prevented_redundant_path_selection {
994 // If we weren't capped by hitting a liquidity limit on a channel in the path,
995 // we'll probably end up picking the same path again on the next iteration.
996 // Decrease the available liquidity of a hop in the middle of the path.
997 let victim_liquidity = bookkeeped_channels_liquidity_available_msat.get_mut(
998 &payment_path.hops[(payment_path.hops.len() - 1) / 2].0.short_channel_id).unwrap();
999 *victim_liquidity = 0;
1002 // Track the total amount all our collected paths allow to send so that we:
1003 // - know when to stop looking for more paths
1004 // - know which of the hops are useless considering how much more sats we need
1005 // (contributes_sufficient_value)
1006 already_collected_value_msat += value_contribution_msat;
1008 payment_paths.push(payment_path);
1009 found_new_path = true;
1010 break 'path_construction;
1013 // If we found a path back to the payee, we shouldn't try to process it again. This is
1014 // the equivalent of the `elem.was_processed` check in
1015 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1016 if pubkey == *payee { continue 'path_construction; }
1018 // Otherwise, since the current target node is not us,
1019 // keep "unrolling" the payment graph from payee to payer by
1020 // finding a way to reach the current target from the payer side.
1021 match network.get_nodes().get(&pubkey) {
1024 add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat);
1030 // If we don't support MPP, no use trying to gather more value ever.
1031 break 'paths_collection;
1035 // Stop either when the recommended value is reached or if no new path was found in this
1037 // In the latter case, making another path finding attempt won't help,
1038 // because we deterministically terminated the search due to low liquidity.
1039 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1040 break 'paths_collection;
1041 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1042 // Further, if this was our first walk of the graph, and we weren't limited by an
1043 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1044 // limited by an htlc_minimum_msat value, find another path with a higher value,
1045 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1046 // still keeping a lower total fee than this path.
1047 if !hit_minimum_limit {
1048 break 'paths_collection;
1050 path_value_msat = recommended_value_msat;
1055 if payment_paths.len() == 0 {
1056 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1059 if already_collected_value_msat < final_value_msat {
1060 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1063 // Sort by total fees and take the best paths.
1064 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1065 if payment_paths.len() > 50 {
1066 payment_paths.truncate(50);
1069 // Draw multiple sufficient routes by randomly combining the selected paths.
1070 let mut drawn_routes = Vec::new();
1071 for i in 0..payment_paths.len() {
1072 let mut cur_route = Vec::<PaymentPath>::new();
1073 let mut aggregate_route_value_msat = 0;
1076 // TODO: real random shuffle
1077 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1078 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1081 for payment_path in cur_payment_paths {
1082 cur_route.push(payment_path.clone());
1083 aggregate_route_value_msat += payment_path.get_value_msat();
1084 if aggregate_route_value_msat > final_value_msat {
1085 // Last path likely overpaid. Substract it from the most expensive
1086 // (in terms of proportional fee) path in this route and recompute fees.
1087 // This might be not the most economically efficient way, but fewer paths
1088 // also makes routing more reliable.
1089 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1091 // First, drop some expensive low-value paths entirely if possible.
1092 // Sort by value so that we drop many really-low values first, since
1093 // fewer paths is better: the payment is less likely to fail.
1094 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1095 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1096 cur_route.sort_by_key(|path| path.get_value_msat());
1097 // We should make sure that at least 1 path left.
1098 let mut paths_left = cur_route.len();
1099 cur_route.retain(|path| {
1100 if paths_left == 1 {
1103 let mut keep = true;
1104 let path_value_msat = path.get_value_msat();
1105 if path_value_msat <= overpaid_value_msat {
1107 overpaid_value_msat -= path_value_msat;
1113 if overpaid_value_msat == 0 {
1117 assert!(cur_route.len() > 0);
1120 // Now, substract the overpaid value from the most-expensive path.
1121 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1122 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1123 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.channel_fees.proportional_millionths as u64).sum::<u64>() });
1124 let expensive_payment_path = cur_route.first_mut().unwrap();
1125 // We already dropped all the small channels above, meaning all the
1126 // remaining channels are larger than remaining overpaid_value_msat.
1127 // Thus, this can't be negative.
1128 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1129 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1133 drawn_routes.push(cur_route);
1137 // Select the best route by lowest total fee.
1138 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1139 let mut selected_paths = Vec::<Vec<RouteHop>>::new();
1140 for payment_path in drawn_routes.first().unwrap() {
1141 selected_paths.push(payment_path.hops.iter().map(|(payment_hop, node_features)| {
1143 pubkey: payment_hop.pubkey,
1144 node_features: node_features.clone(),
1145 short_channel_id: payment_hop.short_channel_id,
1146 channel_features: payment_hop.channel_features.clone(),
1147 fee_msat: payment_hop.fee_msat,
1148 cltv_expiry_delta: payment_hop.cltv_expiry_delta,
1153 if let Some(features) = &payee_features {
1154 for path in selected_paths.iter_mut() {
1155 path.last_mut().unwrap().node_features = features.to_context();
1159 let route = Route { paths: selected_paths };
1160 log_trace!(logger, "Got route: {}", log_route!(route));
1166 use routing::router::{get_route, RouteHintHop, RoutingFees};
1167 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
1168 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1169 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1170 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1171 use ln::channelmanager;
1172 use util::test_utils;
1173 use util::ser::Writeable;
1175 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1176 use bitcoin::hashes::Hash;
1177 use bitcoin::network::constants::Network;
1178 use bitcoin::blockdata::constants::genesis_block;
1179 use bitcoin::blockdata::script::Builder;
1180 use bitcoin::blockdata::opcodes;
1181 use bitcoin::blockdata::transaction::TxOut;
1185 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1186 use bitcoin::secp256k1::{Secp256k1, All};
1190 // Using the same keys for LN and BTC ids
1191 fn add_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey,
1192 node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64) {
1193 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1194 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1196 let unsigned_announcement = UnsignedChannelAnnouncement {
1198 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1202 bitcoin_key_1: node_id_1,
1203 bitcoin_key_2: node_id_2,
1204 excess_data: Vec::new(),
1207 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1208 let valid_announcement = ChannelAnnouncement {
1209 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1210 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1211 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1212 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1213 contents: unsigned_announcement.clone(),
1215 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1216 Ok(res) => assert!(res),
1221 fn update_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate) {
1222 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1223 let valid_channel_update = ChannelUpdate {
1224 signature: secp_ctx.sign(&msghash, node_privkey),
1225 contents: update.clone()
1228 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1229 Ok(res) => assert!(res),
1234 fn add_or_update_node(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey,
1235 features: NodeFeatures, timestamp: u32) {
1236 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1237 let unsigned_announcement = UnsignedNodeAnnouncement {
1243 addresses: Vec::new(),
1244 excess_address_data: Vec::new(),
1245 excess_data: Vec::new(),
1247 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1248 let valid_announcement = NodeAnnouncement {
1249 signature: secp_ctx.sign(&msghash, node_privkey),
1250 contents: unsigned_announcement.clone()
1253 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1259 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1260 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1261 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1264 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1266 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1267 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1269 (our_privkey, our_id, privkeys, pubkeys)
1272 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1273 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1274 // test for it later.
1275 let idx = (id - 1) * 2 + 1;
1277 vec![1 << (idx - 8*3), 0, 0, 0]
1278 } else if idx > 8*2 {
1279 vec![1 << (idx - 8*2), 0, 0]
1280 } else if idx > 8*1 {
1281 vec![1 << (idx - 8*1), 0]
1287 fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<crate::util::test_utils::TestLogger>>, std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<test_utils::TestLogger>) {
1288 let secp_ctx = Secp256k1::new();
1289 let logger = Arc::new(test_utils::TestLogger::new());
1290 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1291 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
1292 // Build network from our_id to node7:
1294 // -1(1)2- node0 -1(3)2-
1296 // our_id -1(12)2- node7 -1(13)2--- node2
1298 // -1(2)2- node1 -1(4)2-
1301 // chan1 1-to-2: disabled
1302 // chan1 2-to-1: enabled, 0 fee
1304 // chan2 1-to-2: enabled, ignored fee
1305 // chan2 2-to-1: enabled, 0 fee
1307 // chan3 1-to-2: enabled, 0 fee
1308 // chan3 2-to-1: enabled, 100 msat fee
1310 // chan4 1-to-2: enabled, 100% fee
1311 // chan4 2-to-1: enabled, 0 fee
1313 // chan12 1-to-2: enabled, ignored fee
1314 // chan12 2-to-1: enabled, 0 fee
1316 // chan13 1-to-2: enabled, 200% fee
1317 // chan13 2-to-1: enabled, 0 fee
1320 // -1(5)2- node3 -1(8)2--
1324 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1326 // -1(7)2- node5 -1(10)2-
1328 // chan5 1-to-2: enabled, 100 msat fee
1329 // chan5 2-to-1: enabled, 0 fee
1331 // chan6 1-to-2: enabled, 0 fee
1332 // chan6 2-to-1: enabled, 0 fee
1334 // chan7 1-to-2: enabled, 100% fee
1335 // chan7 2-to-1: enabled, 0 fee
1337 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1338 // chan8 2-to-1: enabled, 0 fee
1340 // chan9 1-to-2: enabled, 1001 msat fee
1341 // chan9 2-to-1: enabled, 0 fee
1343 // chan10 1-to-2: enabled, 0 fee
1344 // chan10 2-to-1: enabled, 0 fee
1346 // chan11 1-to-2: enabled, 0 fee
1347 // chan11 2-to-1: enabled, 0 fee
1349 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1351 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1352 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1353 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1354 short_channel_id: 1,
1357 cltv_expiry_delta: 0,
1358 htlc_minimum_msat: 0,
1359 htlc_maximum_msat: OptionalField::Absent,
1361 fee_proportional_millionths: 0,
1362 excess_data: Vec::new()
1365 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1367 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1368 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1369 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1370 short_channel_id: 2,
1373 cltv_expiry_delta: u16::max_value(),
1374 htlc_minimum_msat: 0,
1375 htlc_maximum_msat: OptionalField::Absent,
1376 fee_base_msat: u32::max_value(),
1377 fee_proportional_millionths: u32::max_value(),
1378 excess_data: Vec::new()
1380 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1381 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1382 short_channel_id: 2,
1385 cltv_expiry_delta: 0,
1386 htlc_minimum_msat: 0,
1387 htlc_maximum_msat: OptionalField::Absent,
1389 fee_proportional_millionths: 0,
1390 excess_data: Vec::new()
1393 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1395 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1396 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1397 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1398 short_channel_id: 12,
1401 cltv_expiry_delta: u16::max_value(),
1402 htlc_minimum_msat: 0,
1403 htlc_maximum_msat: OptionalField::Absent,
1404 fee_base_msat: u32::max_value(),
1405 fee_proportional_millionths: u32::max_value(),
1406 excess_data: Vec::new()
1408 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1409 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1410 short_channel_id: 12,
1413 cltv_expiry_delta: 0,
1414 htlc_minimum_msat: 0,
1415 htlc_maximum_msat: OptionalField::Absent,
1417 fee_proportional_millionths: 0,
1418 excess_data: Vec::new()
1421 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1423 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1424 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1425 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1426 short_channel_id: 3,
1429 cltv_expiry_delta: (3 << 8) | 1,
1430 htlc_minimum_msat: 0,
1431 htlc_maximum_msat: OptionalField::Absent,
1433 fee_proportional_millionths: 0,
1434 excess_data: Vec::new()
1436 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1437 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1438 short_channel_id: 3,
1441 cltv_expiry_delta: (3 << 8) | 2,
1442 htlc_minimum_msat: 0,
1443 htlc_maximum_msat: OptionalField::Absent,
1445 fee_proportional_millionths: 0,
1446 excess_data: Vec::new()
1449 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1450 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1451 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1452 short_channel_id: 4,
1455 cltv_expiry_delta: (4 << 8) | 1,
1456 htlc_minimum_msat: 0,
1457 htlc_maximum_msat: OptionalField::Absent,
1459 fee_proportional_millionths: 1000000,
1460 excess_data: Vec::new()
1462 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1464 short_channel_id: 4,
1467 cltv_expiry_delta: (4 << 8) | 2,
1468 htlc_minimum_msat: 0,
1469 htlc_maximum_msat: OptionalField::Absent,
1471 fee_proportional_millionths: 0,
1472 excess_data: Vec::new()
1475 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1476 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1477 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1478 short_channel_id: 13,
1481 cltv_expiry_delta: (13 << 8) | 1,
1482 htlc_minimum_msat: 0,
1483 htlc_maximum_msat: OptionalField::Absent,
1485 fee_proportional_millionths: 2000000,
1486 excess_data: Vec::new()
1488 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1489 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1490 short_channel_id: 13,
1493 cltv_expiry_delta: (13 << 8) | 2,
1494 htlc_minimum_msat: 0,
1495 htlc_maximum_msat: OptionalField::Absent,
1497 fee_proportional_millionths: 0,
1498 excess_data: Vec::new()
1501 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1503 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1504 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1505 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1506 short_channel_id: 6,
1509 cltv_expiry_delta: (6 << 8) | 1,
1510 htlc_minimum_msat: 0,
1511 htlc_maximum_msat: OptionalField::Absent,
1513 fee_proportional_millionths: 0,
1514 excess_data: Vec::new()
1516 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1517 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1518 short_channel_id: 6,
1521 cltv_expiry_delta: (6 << 8) | 2,
1522 htlc_minimum_msat: 0,
1523 htlc_maximum_msat: OptionalField::Absent,
1525 fee_proportional_millionths: 0,
1526 excess_data: Vec::new(),
1529 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1530 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1531 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1532 short_channel_id: 11,
1535 cltv_expiry_delta: (11 << 8) | 1,
1536 htlc_minimum_msat: 0,
1537 htlc_maximum_msat: OptionalField::Absent,
1539 fee_proportional_millionths: 0,
1540 excess_data: Vec::new()
1542 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
1543 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1544 short_channel_id: 11,
1547 cltv_expiry_delta: (11 << 8) | 2,
1548 htlc_minimum_msat: 0,
1549 htlc_maximum_msat: OptionalField::Absent,
1551 fee_proportional_millionths: 0,
1552 excess_data: Vec::new()
1555 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
1557 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
1559 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
1560 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1561 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1562 short_channel_id: 7,
1565 cltv_expiry_delta: (7 << 8) | 1,
1566 htlc_minimum_msat: 0,
1567 htlc_maximum_msat: OptionalField::Absent,
1569 fee_proportional_millionths: 1000000,
1570 excess_data: Vec::new()
1572 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
1573 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1574 short_channel_id: 7,
1577 cltv_expiry_delta: (7 << 8) | 2,
1578 htlc_minimum_msat: 0,
1579 htlc_maximum_msat: OptionalField::Absent,
1581 fee_proportional_millionths: 0,
1582 excess_data: Vec::new()
1585 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
1587 (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
1591 fn simple_route_test() {
1592 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1593 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1595 // Simple route to 2 via 1
1597 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 0, 42, Arc::clone(&logger)) {
1598 assert_eq!(err, "Cannot send a payment of 0 msat");
1599 } else { panic!(); }
1601 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1602 assert_eq!(route.paths[0].len(), 2);
1604 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1605 assert_eq!(route.paths[0][0].short_channel_id, 2);
1606 assert_eq!(route.paths[0][0].fee_msat, 100);
1607 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1608 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1609 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1611 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1612 assert_eq!(route.paths[0][1].short_channel_id, 4);
1613 assert_eq!(route.paths[0][1].fee_msat, 100);
1614 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1615 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1616 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1620 fn invalid_first_hop_test() {
1621 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1622 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1624 // Simple route to 2 via 1
1626 let our_chans = vec![channelmanager::ChannelDetails {
1627 channel_id: [0; 32],
1628 short_channel_id: Some(2),
1629 remote_network_id: our_id,
1630 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1631 channel_value_satoshis: 100000,
1633 outbound_capacity_msat: 100000,
1634 inbound_capacity_msat: 100000,
1636 counterparty_forwarding_info: None,
1639 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)) {
1640 assert_eq!(err, "First hop cannot have our_node_id as a destination.");
1641 } else { panic!(); }
1643 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1644 assert_eq!(route.paths[0].len(), 2);
1648 fn htlc_minimum_test() {
1649 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1650 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1652 // Simple route to 2 via 1
1654 // Disable other paths
1655 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1656 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1657 short_channel_id: 12,
1659 flags: 2, // to disable
1660 cltv_expiry_delta: 0,
1661 htlc_minimum_msat: 0,
1662 htlc_maximum_msat: OptionalField::Absent,
1664 fee_proportional_millionths: 0,
1665 excess_data: Vec::new()
1667 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1668 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1669 short_channel_id: 3,
1671 flags: 2, // to disable
1672 cltv_expiry_delta: 0,
1673 htlc_minimum_msat: 0,
1674 htlc_maximum_msat: OptionalField::Absent,
1676 fee_proportional_millionths: 0,
1677 excess_data: Vec::new()
1679 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1680 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1681 short_channel_id: 13,
1683 flags: 2, // to disable
1684 cltv_expiry_delta: 0,
1685 htlc_minimum_msat: 0,
1686 htlc_maximum_msat: OptionalField::Absent,
1688 fee_proportional_millionths: 0,
1689 excess_data: Vec::new()
1691 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1692 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1693 short_channel_id: 6,
1695 flags: 2, // to disable
1696 cltv_expiry_delta: 0,
1697 htlc_minimum_msat: 0,
1698 htlc_maximum_msat: OptionalField::Absent,
1700 fee_proportional_millionths: 0,
1701 excess_data: Vec::new()
1703 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1704 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1705 short_channel_id: 7,
1707 flags: 2, // to disable
1708 cltv_expiry_delta: 0,
1709 htlc_minimum_msat: 0,
1710 htlc_maximum_msat: OptionalField::Absent,
1712 fee_proportional_millionths: 0,
1713 excess_data: Vec::new()
1716 // Check against amount_to_transfer_over_msat.
1717 // Set minimal HTLC of 200_000_000 msat.
1718 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1719 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1720 short_channel_id: 2,
1723 cltv_expiry_delta: 0,
1724 htlc_minimum_msat: 200_000_000,
1725 htlc_maximum_msat: OptionalField::Absent,
1727 fee_proportional_millionths: 0,
1728 excess_data: Vec::new()
1731 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
1733 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1734 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1735 short_channel_id: 4,
1738 cltv_expiry_delta: 0,
1739 htlc_minimum_msat: 0,
1740 htlc_maximum_msat: OptionalField::Present(199_999_999),
1742 fee_proportional_millionths: 0,
1743 excess_data: Vec::new()
1746 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
1747 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)) {
1748 assert_eq!(err, "Failed to find a path to the given destination");
1749 } else { panic!(); }
1751 // Lift the restriction on the first hop.
1752 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1753 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1754 short_channel_id: 2,
1757 cltv_expiry_delta: 0,
1758 htlc_minimum_msat: 0,
1759 htlc_maximum_msat: OptionalField::Absent,
1761 fee_proportional_millionths: 0,
1762 excess_data: Vec::new()
1765 // A payment above the minimum should pass
1766 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)).unwrap();
1767 assert_eq!(route.paths[0].len(), 2);
1771 fn htlc_minimum_overpay_test() {
1772 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1773 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1775 // A route to node#2 via two paths.
1776 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
1777 // Thus, they can't send 60 without overpaying.
1778 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1779 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1780 short_channel_id: 2,
1783 cltv_expiry_delta: 0,
1784 htlc_minimum_msat: 35_000,
1785 htlc_maximum_msat: OptionalField::Present(40_000),
1787 fee_proportional_millionths: 0,
1788 excess_data: Vec::new()
1790 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1791 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1792 short_channel_id: 12,
1795 cltv_expiry_delta: 0,
1796 htlc_minimum_msat: 35_000,
1797 htlc_maximum_msat: OptionalField::Present(40_000),
1799 fee_proportional_millionths: 0,
1800 excess_data: Vec::new()
1804 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1805 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1806 short_channel_id: 13,
1809 cltv_expiry_delta: 0,
1810 htlc_minimum_msat: 0,
1811 htlc_maximum_msat: OptionalField::Absent,
1813 fee_proportional_millionths: 0,
1814 excess_data: Vec::new()
1816 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1817 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1818 short_channel_id: 4,
1821 cltv_expiry_delta: 0,
1822 htlc_minimum_msat: 0,
1823 htlc_maximum_msat: OptionalField::Absent,
1825 fee_proportional_millionths: 0,
1826 excess_data: Vec::new()
1829 // Disable other paths
1830 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1831 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1832 short_channel_id: 1,
1834 flags: 2, // to disable
1835 cltv_expiry_delta: 0,
1836 htlc_minimum_msat: 0,
1837 htlc_maximum_msat: OptionalField::Absent,
1839 fee_proportional_millionths: 0,
1840 excess_data: Vec::new()
1843 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1844 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1845 // Overpay fees to hit htlc_minimum_msat.
1846 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
1847 // TODO: this could be better balanced to overpay 10k and not 15k.
1848 assert_eq!(overpaid_fees, 15_000);
1850 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
1851 // while taking even more fee to match htlc_minimum_msat.
1852 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1853 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1854 short_channel_id: 12,
1857 cltv_expiry_delta: 0,
1858 htlc_minimum_msat: 65_000,
1859 htlc_maximum_msat: OptionalField::Present(80_000),
1861 fee_proportional_millionths: 0,
1862 excess_data: Vec::new()
1864 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1865 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1866 short_channel_id: 2,
1869 cltv_expiry_delta: 0,
1870 htlc_minimum_msat: 0,
1871 htlc_maximum_msat: OptionalField::Absent,
1873 fee_proportional_millionths: 0,
1874 excess_data: Vec::new()
1876 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1877 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1878 short_channel_id: 4,
1881 cltv_expiry_delta: 0,
1882 htlc_minimum_msat: 0,
1883 htlc_maximum_msat: OptionalField::Absent,
1885 fee_proportional_millionths: 100_000,
1886 excess_data: Vec::new()
1889 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1890 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1891 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
1892 assert_eq!(route.paths.len(), 1);
1893 assert_eq!(route.paths[0][0].short_channel_id, 12);
1894 let fees = route.paths[0][0].fee_msat;
1895 assert_eq!(fees, 5_000);
1897 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1898 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
1899 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
1900 // the other channel.
1901 assert_eq!(route.paths.len(), 1);
1902 assert_eq!(route.paths[0][0].short_channel_id, 2);
1903 let fees = route.paths[0][0].fee_msat;
1904 assert_eq!(fees, 5_000);
1908 fn disable_channels_test() {
1909 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1910 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1912 // // Disable channels 4 and 12 by flags=2
1913 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1914 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1915 short_channel_id: 4,
1917 flags: 2, // to disable
1918 cltv_expiry_delta: 0,
1919 htlc_minimum_msat: 0,
1920 htlc_maximum_msat: OptionalField::Absent,
1922 fee_proportional_millionths: 0,
1923 excess_data: Vec::new()
1925 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1926 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1927 short_channel_id: 12,
1929 flags: 2, // to disable
1930 cltv_expiry_delta: 0,
1931 htlc_minimum_msat: 0,
1932 htlc_maximum_msat: OptionalField::Absent,
1934 fee_proportional_millionths: 0,
1935 excess_data: Vec::new()
1938 // If all the channels require some features we don't understand, route should fail
1939 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
1940 assert_eq!(err, "Failed to find a path to the given destination");
1941 } else { panic!(); }
1943 // If we specify a channel to node7, that overrides our local channel view and that gets used
1944 let our_chans = vec![channelmanager::ChannelDetails {
1945 channel_id: [0; 32],
1946 short_channel_id: Some(42),
1947 remote_network_id: nodes[7].clone(),
1948 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1949 channel_value_satoshis: 0,
1951 outbound_capacity_msat: 250_000_000,
1952 inbound_capacity_msat: 0,
1954 counterparty_forwarding_info: None,
1956 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1957 assert_eq!(route.paths[0].len(), 2);
1959 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
1960 assert_eq!(route.paths[0][0].short_channel_id, 42);
1961 assert_eq!(route.paths[0][0].fee_msat, 200);
1962 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
1963 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
1964 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1966 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1967 assert_eq!(route.paths[0][1].short_channel_id, 13);
1968 assert_eq!(route.paths[0][1].fee_msat, 100);
1969 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1970 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1971 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
1975 fn disable_node_test() {
1976 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1977 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1979 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
1980 let mut unknown_features = NodeFeatures::known();
1981 unknown_features.set_required_unknown_bits();
1982 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
1983 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
1984 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
1986 // If all nodes require some features we don't understand, route should fail
1987 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
1988 assert_eq!(err, "Failed to find a path to the given destination");
1989 } else { panic!(); }
1991 // If we specify a channel to node7, that overrides our local channel view and that gets used
1992 let our_chans = vec![channelmanager::ChannelDetails {
1993 channel_id: [0; 32],
1994 short_channel_id: Some(42),
1995 remote_network_id: nodes[7].clone(),
1996 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1997 channel_value_satoshis: 0,
1999 outbound_capacity_msat: 250_000_000,
2000 inbound_capacity_msat: 0,
2002 counterparty_forwarding_info: None,
2004 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2005 assert_eq!(route.paths[0].len(), 2);
2007 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2008 assert_eq!(route.paths[0][0].short_channel_id, 42);
2009 assert_eq!(route.paths[0][0].fee_msat, 200);
2010 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2011 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2012 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2014 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2015 assert_eq!(route.paths[0][1].short_channel_id, 13);
2016 assert_eq!(route.paths[0][1].fee_msat, 100);
2017 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2018 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2019 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2021 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2022 // naively) assume that the user checked the feature bits on the invoice, which override
2023 // the node_announcement.
2027 fn our_chans_test() {
2028 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2029 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2031 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2032 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[0], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2033 assert_eq!(route.paths[0].len(), 3);
2035 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2036 assert_eq!(route.paths[0][0].short_channel_id, 2);
2037 assert_eq!(route.paths[0][0].fee_msat, 200);
2038 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2039 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2040 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2042 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2043 assert_eq!(route.paths[0][1].short_channel_id, 4);
2044 assert_eq!(route.paths[0][1].fee_msat, 100);
2045 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
2046 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2047 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2049 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2050 assert_eq!(route.paths[0][2].short_channel_id, 3);
2051 assert_eq!(route.paths[0][2].fee_msat, 100);
2052 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2053 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2054 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2056 // If we specify a channel to node7, that overrides our local channel view and that gets used
2057 let our_chans = vec![channelmanager::ChannelDetails {
2058 channel_id: [0; 32],
2059 short_channel_id: Some(42),
2060 remote_network_id: nodes[7].clone(),
2061 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2062 channel_value_satoshis: 0,
2064 outbound_capacity_msat: 250_000_000,
2065 inbound_capacity_msat: 0,
2067 counterparty_forwarding_info: None,
2069 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2070 assert_eq!(route.paths[0].len(), 2);
2072 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2073 assert_eq!(route.paths[0][0].short_channel_id, 42);
2074 assert_eq!(route.paths[0][0].fee_msat, 200);
2075 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2076 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2077 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2079 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2080 assert_eq!(route.paths[0][1].short_channel_id, 13);
2081 assert_eq!(route.paths[0][1].fee_msat, 100);
2082 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2083 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2084 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2087 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHintHop> {
2088 let zero_fees = RoutingFees {
2090 proportional_millionths: 0,
2093 src_node_id: nodes[3].clone(),
2094 short_channel_id: 8,
2096 cltv_expiry_delta: (8 << 8) | 1,
2097 htlc_minimum_msat: None,
2098 htlc_maximum_msat: None,
2100 src_node_id: nodes[4].clone(),
2101 short_channel_id: 9,
2104 proportional_millionths: 0,
2106 cltv_expiry_delta: (9 << 8) | 1,
2107 htlc_minimum_msat: None,
2108 htlc_maximum_msat: None,
2110 src_node_id: nodes[5].clone(),
2111 short_channel_id: 10,
2113 cltv_expiry_delta: (10 << 8) | 1,
2114 htlc_minimum_msat: None,
2115 htlc_maximum_msat: None,
2120 fn last_hops_test() {
2121 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2122 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2124 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2126 // First check that lst hop can't have its source as the payee.
2127 let invalid_last_hop = RouteHintHop {
2128 src_node_id: nodes[6],
2129 short_channel_id: 8,
2132 proportional_millionths: 0,
2134 cltv_expiry_delta: (8 << 8) | 1,
2135 htlc_minimum_msat: None,
2136 htlc_maximum_msat: None,
2139 let mut invalid_last_hops = last_hops(&nodes);
2140 invalid_last_hops.push(invalid_last_hop);
2142 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &invalid_last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)) {
2143 assert_eq!(err, "Last hop cannot have a payee as a source.");
2144 } else { panic!(); }
2147 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2148 assert_eq!(route.paths[0].len(), 5);
2150 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2151 assert_eq!(route.paths[0][0].short_channel_id, 2);
2152 assert_eq!(route.paths[0][0].fee_msat, 100);
2153 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2154 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2155 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2157 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2158 assert_eq!(route.paths[0][1].short_channel_id, 4);
2159 assert_eq!(route.paths[0][1].fee_msat, 0);
2160 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2161 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2162 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2164 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2165 assert_eq!(route.paths[0][2].short_channel_id, 6);
2166 assert_eq!(route.paths[0][2].fee_msat, 0);
2167 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2168 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2169 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2171 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2172 assert_eq!(route.paths[0][3].short_channel_id, 11);
2173 assert_eq!(route.paths[0][3].fee_msat, 0);
2174 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2175 // If we have a peer in the node map, we'll use their features here since we don't have
2176 // a way of figuring out their features from the invoice:
2177 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2178 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2180 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2181 assert_eq!(route.paths[0][4].short_channel_id, 8);
2182 assert_eq!(route.paths[0][4].fee_msat, 100);
2183 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2184 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2185 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2189 fn our_chans_last_hop_connect_test() {
2190 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2191 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2193 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2194 let our_chans = vec![channelmanager::ChannelDetails {
2195 channel_id: [0; 32],
2196 short_channel_id: Some(42),
2197 remote_network_id: nodes[3].clone(),
2198 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2199 channel_value_satoshis: 0,
2201 outbound_capacity_msat: 250_000_000,
2202 inbound_capacity_msat: 0,
2204 counterparty_forwarding_info: None,
2206 let mut last_hops = last_hops(&nodes);
2207 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2208 assert_eq!(route.paths[0].len(), 2);
2210 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2211 assert_eq!(route.paths[0][0].short_channel_id, 42);
2212 assert_eq!(route.paths[0][0].fee_msat, 0);
2213 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2214 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2215 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2217 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2218 assert_eq!(route.paths[0][1].short_channel_id, 8);
2219 assert_eq!(route.paths[0][1].fee_msat, 100);
2220 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2221 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2222 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2224 last_hops[0].fees.base_msat = 1000;
2226 // Revert to via 6 as the fee on 8 goes up
2227 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2228 assert_eq!(route.paths[0].len(), 4);
2230 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2231 assert_eq!(route.paths[0][0].short_channel_id, 2);
2232 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2233 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2234 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2235 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2237 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2238 assert_eq!(route.paths[0][1].short_channel_id, 4);
2239 assert_eq!(route.paths[0][1].fee_msat, 100);
2240 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
2241 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2242 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2244 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2245 assert_eq!(route.paths[0][2].short_channel_id, 7);
2246 assert_eq!(route.paths[0][2].fee_msat, 0);
2247 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
2248 // If we have a peer in the node map, we'll use their features here since we don't have
2249 // a way of figuring out their features from the invoice:
2250 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2251 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2253 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2254 assert_eq!(route.paths[0][3].short_channel_id, 10);
2255 assert_eq!(route.paths[0][3].fee_msat, 100);
2256 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2257 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2258 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2260 // ...but still use 8 for larger payments as 6 has a variable feerate
2261 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 2000, 42, Arc::clone(&logger)).unwrap();
2262 assert_eq!(route.paths[0].len(), 5);
2264 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2265 assert_eq!(route.paths[0][0].short_channel_id, 2);
2266 assert_eq!(route.paths[0][0].fee_msat, 3000);
2267 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2268 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2269 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2271 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2272 assert_eq!(route.paths[0][1].short_channel_id, 4);
2273 assert_eq!(route.paths[0][1].fee_msat, 0);
2274 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2275 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2276 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2278 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2279 assert_eq!(route.paths[0][2].short_channel_id, 6);
2280 assert_eq!(route.paths[0][2].fee_msat, 0);
2281 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2282 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2283 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2285 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2286 assert_eq!(route.paths[0][3].short_channel_id, 11);
2287 assert_eq!(route.paths[0][3].fee_msat, 1000);
2288 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2289 // If we have a peer in the node map, we'll use their features here since we don't have
2290 // a way of figuring out their features from the invoice:
2291 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2292 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2294 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2295 assert_eq!(route.paths[0][4].short_channel_id, 8);
2296 assert_eq!(route.paths[0][4].fee_msat, 2000);
2297 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2298 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2299 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2303 fn unannounced_path_test() {
2304 // We should be able to send a payment to a destination without any help of a routing graph
2305 // if we have a channel with a common counterparty that appears in the first and last hop
2307 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
2308 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2309 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2311 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
2312 let last_hops = vec![RouteHintHop {
2313 src_node_id: middle_node_id,
2314 short_channel_id: 8,
2317 proportional_millionths: 0,
2319 cltv_expiry_delta: (8 << 8) | 1,
2320 htlc_minimum_msat: None,
2321 htlc_maximum_msat: None,
2323 let our_chans = vec![channelmanager::ChannelDetails {
2324 channel_id: [0; 32],
2325 short_channel_id: Some(42),
2326 remote_network_id: middle_node_id,
2327 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2328 channel_value_satoshis: 100000,
2330 outbound_capacity_msat: 100000,
2331 inbound_capacity_msat: 100000,
2333 counterparty_forwarding_info: None,
2335 let route = get_route(&source_node_id, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()), &target_node_id, None, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::new(test_utils::TestLogger::new())).unwrap();
2337 assert_eq!(route.paths[0].len(), 2);
2339 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
2340 assert_eq!(route.paths[0][0].short_channel_id, 42);
2341 assert_eq!(route.paths[0][0].fee_msat, 1000);
2342 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2343 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
2344 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2346 assert_eq!(route.paths[0][1].pubkey, target_node_id);
2347 assert_eq!(route.paths[0][1].short_channel_id, 8);
2348 assert_eq!(route.paths[0][1].fee_msat, 100);
2349 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2350 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
2351 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2355 fn available_amount_while_routing_test() {
2356 // Tests whether we choose the correct available channel amount while routing.
2358 let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
2359 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2361 // We will use a simple single-path route from
2362 // our node to node2 via node0: channels {1, 3}.
2364 // First disable all other paths.
2365 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2366 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2367 short_channel_id: 2,
2370 cltv_expiry_delta: 0,
2371 htlc_minimum_msat: 0,
2372 htlc_maximum_msat: OptionalField::Present(100_000),
2374 fee_proportional_millionths: 0,
2375 excess_data: Vec::new()
2377 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2378 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2379 short_channel_id: 12,
2382 cltv_expiry_delta: 0,
2383 htlc_minimum_msat: 0,
2384 htlc_maximum_msat: OptionalField::Present(100_000),
2386 fee_proportional_millionths: 0,
2387 excess_data: Vec::new()
2390 // Make the first channel (#1) very permissive,
2391 // and we will be testing all limits on the second channel.
2392 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2393 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2394 short_channel_id: 1,
2397 cltv_expiry_delta: 0,
2398 htlc_minimum_msat: 0,
2399 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2401 fee_proportional_millionths: 0,
2402 excess_data: Vec::new()
2405 // First, let's see if routing works if we have absolutely no idea about the available amount.
2406 // In this case, it should be set to 250_000 sats.
2407 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2408 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2409 short_channel_id: 3,
2412 cltv_expiry_delta: 0,
2413 htlc_minimum_msat: 0,
2414 htlc_maximum_msat: OptionalField::Absent,
2416 fee_proportional_millionths: 0,
2417 excess_data: Vec::new()
2421 // Attempt to route more than available results in a failure.
2422 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2423 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
2424 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2425 } else { panic!(); }
2429 // Now, attempt to route an exact amount we have should be fine.
2430 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2431 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
2432 assert_eq!(route.paths.len(), 1);
2433 let path = route.paths.last().unwrap();
2434 assert_eq!(path.len(), 2);
2435 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2436 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
2439 // Check that setting outbound_capacity_msat in first_hops limits the channels.
2440 // Disable channel #1 and use another first hop.
2441 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2442 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2443 short_channel_id: 1,
2446 cltv_expiry_delta: 0,
2447 htlc_minimum_msat: 0,
2448 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2450 fee_proportional_millionths: 0,
2451 excess_data: Vec::new()
2454 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
2455 let our_chans = vec![channelmanager::ChannelDetails {
2456 channel_id: [0; 32],
2457 short_channel_id: Some(42),
2458 remote_network_id: nodes[0].clone(),
2459 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2460 channel_value_satoshis: 0,
2462 outbound_capacity_msat: 200_000_000,
2463 inbound_capacity_msat: 0,
2465 counterparty_forwarding_info: None,
2469 // Attempt to route more than available results in a failure.
2470 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2471 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
2472 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2473 } else { panic!(); }
2477 // Now, attempt to route an exact amount we have should be fine.
2478 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2479 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
2480 assert_eq!(route.paths.len(), 1);
2481 let path = route.paths.last().unwrap();
2482 assert_eq!(path.len(), 2);
2483 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2484 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
2487 // Enable channel #1 back.
2488 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2489 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2490 short_channel_id: 1,
2493 cltv_expiry_delta: 0,
2494 htlc_minimum_msat: 0,
2495 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2497 fee_proportional_millionths: 0,
2498 excess_data: Vec::new()
2502 // Now let's see if routing works if we know only htlc_maximum_msat.
2503 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2504 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2505 short_channel_id: 3,
2508 cltv_expiry_delta: 0,
2509 htlc_minimum_msat: 0,
2510 htlc_maximum_msat: OptionalField::Present(15_000),
2512 fee_proportional_millionths: 0,
2513 excess_data: Vec::new()
2517 // Attempt to route more than available results in a failure.
2518 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2519 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2520 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2521 } else { panic!(); }
2525 // Now, attempt to route an exact amount we have should be fine.
2526 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2527 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2528 assert_eq!(route.paths.len(), 1);
2529 let path = route.paths.last().unwrap();
2530 assert_eq!(path.len(), 2);
2531 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2532 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2535 // Now let's see if routing works if we know only capacity from the UTXO.
2537 // We can't change UTXO capacity on the fly, so we'll disable
2538 // the existing channel and add another one with the capacity we need.
2539 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2540 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2541 short_channel_id: 3,
2544 cltv_expiry_delta: 0,
2545 htlc_minimum_msat: 0,
2546 htlc_maximum_msat: OptionalField::Absent,
2548 fee_proportional_millionths: 0,
2549 excess_data: Vec::new()
2552 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
2553 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
2554 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
2555 .push_opcode(opcodes::all::OP_PUSHNUM_2)
2556 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
2558 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
2559 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
2561 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
2562 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2563 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2564 short_channel_id: 333,
2567 cltv_expiry_delta: (3 << 8) | 1,
2568 htlc_minimum_msat: 0,
2569 htlc_maximum_msat: OptionalField::Absent,
2571 fee_proportional_millionths: 0,
2572 excess_data: Vec::new()
2574 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2575 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2576 short_channel_id: 333,
2579 cltv_expiry_delta: (3 << 8) | 2,
2580 htlc_minimum_msat: 0,
2581 htlc_maximum_msat: OptionalField::Absent,
2583 fee_proportional_millionths: 0,
2584 excess_data: Vec::new()
2588 // Attempt to route more than available results in a failure.
2589 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2590 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2591 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2592 } else { panic!(); }
2596 // Now, attempt to route an exact amount we have should be fine.
2597 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2598 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2599 assert_eq!(route.paths.len(), 1);
2600 let path = route.paths.last().unwrap();
2601 assert_eq!(path.len(), 2);
2602 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2603 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2606 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
2607 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2608 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2609 short_channel_id: 333,
2612 cltv_expiry_delta: 0,
2613 htlc_minimum_msat: 0,
2614 htlc_maximum_msat: OptionalField::Present(10_000),
2616 fee_proportional_millionths: 0,
2617 excess_data: Vec::new()
2621 // Attempt to route more than available results in a failure.
2622 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2623 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
2624 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2625 } else { panic!(); }
2629 // Now, attempt to route an exact amount we have should be fine.
2630 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2631 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
2632 assert_eq!(route.paths.len(), 1);
2633 let path = route.paths.last().unwrap();
2634 assert_eq!(path.len(), 2);
2635 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2636 assert_eq!(path.last().unwrap().fee_msat, 10_000);
2641 fn available_liquidity_last_hop_test() {
2642 // Check that available liquidity properly limits the path even when only
2643 // one of the latter hops is limited.
2644 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2645 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2647 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
2648 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
2649 // Total capacity: 50 sats.
2651 // Disable other potential paths.
2652 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2653 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2654 short_channel_id: 2,
2657 cltv_expiry_delta: 0,
2658 htlc_minimum_msat: 0,
2659 htlc_maximum_msat: OptionalField::Present(100_000),
2661 fee_proportional_millionths: 0,
2662 excess_data: Vec::new()
2664 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2665 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2666 short_channel_id: 7,
2669 cltv_expiry_delta: 0,
2670 htlc_minimum_msat: 0,
2671 htlc_maximum_msat: OptionalField::Present(100_000),
2673 fee_proportional_millionths: 0,
2674 excess_data: Vec::new()
2679 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2680 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2681 short_channel_id: 12,
2684 cltv_expiry_delta: 0,
2685 htlc_minimum_msat: 0,
2686 htlc_maximum_msat: OptionalField::Present(100_000),
2688 fee_proportional_millionths: 0,
2689 excess_data: Vec::new()
2691 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2692 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2693 short_channel_id: 13,
2696 cltv_expiry_delta: 0,
2697 htlc_minimum_msat: 0,
2698 htlc_maximum_msat: OptionalField::Present(100_000),
2700 fee_proportional_millionths: 0,
2701 excess_data: Vec::new()
2704 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2705 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2706 short_channel_id: 6,
2709 cltv_expiry_delta: 0,
2710 htlc_minimum_msat: 0,
2711 htlc_maximum_msat: OptionalField::Present(50_000),
2713 fee_proportional_millionths: 0,
2714 excess_data: Vec::new()
2716 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2717 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2718 short_channel_id: 11,
2721 cltv_expiry_delta: 0,
2722 htlc_minimum_msat: 0,
2723 htlc_maximum_msat: OptionalField::Present(100_000),
2725 fee_proportional_millionths: 0,
2726 excess_data: Vec::new()
2729 // Attempt to route more than available results in a failure.
2730 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2731 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
2732 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2733 } else { panic!(); }
2737 // Now, attempt to route 49 sats (just a bit below the capacity).
2738 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2739 Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
2740 assert_eq!(route.paths.len(), 1);
2741 let mut total_amount_paid_msat = 0;
2742 for path in &route.paths {
2743 assert_eq!(path.len(), 4);
2744 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2745 total_amount_paid_msat += path.last().unwrap().fee_msat;
2747 assert_eq!(total_amount_paid_msat, 49_000);
2751 // Attempt to route an exact amount is also fine
2752 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2753 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2754 assert_eq!(route.paths.len(), 1);
2755 let mut total_amount_paid_msat = 0;
2756 for path in &route.paths {
2757 assert_eq!(path.len(), 4);
2758 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2759 total_amount_paid_msat += path.last().unwrap().fee_msat;
2761 assert_eq!(total_amount_paid_msat, 50_000);
2766 fn ignore_fee_first_hop_test() {
2767 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2768 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2770 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2771 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2772 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2773 short_channel_id: 1,
2776 cltv_expiry_delta: 0,
2777 htlc_minimum_msat: 0,
2778 htlc_maximum_msat: OptionalField::Present(100_000),
2779 fee_base_msat: 1_000_000,
2780 fee_proportional_millionths: 0,
2781 excess_data: Vec::new()
2783 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2784 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2785 short_channel_id: 3,
2788 cltv_expiry_delta: 0,
2789 htlc_minimum_msat: 0,
2790 htlc_maximum_msat: OptionalField::Present(50_000),
2792 fee_proportional_millionths: 0,
2793 excess_data: Vec::new()
2797 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2798 assert_eq!(route.paths.len(), 1);
2799 let mut total_amount_paid_msat = 0;
2800 for path in &route.paths {
2801 assert_eq!(path.len(), 2);
2802 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2803 total_amount_paid_msat += path.last().unwrap().fee_msat;
2805 assert_eq!(total_amount_paid_msat, 50_000);
2810 fn simple_mpp_route_test() {
2811 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2812 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2814 // We need a route consisting of 3 paths:
2815 // From our node to node2 via node0, node7, node1 (three paths one hop each).
2816 // To achieve this, the amount being transferred should be around
2817 // the total capacity of these 3 paths.
2819 // First, we set limits on these (previously unlimited) channels.
2820 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
2822 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2823 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2824 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2825 short_channel_id: 1,
2828 cltv_expiry_delta: 0,
2829 htlc_minimum_msat: 0,
2830 htlc_maximum_msat: OptionalField::Present(100_000),
2832 fee_proportional_millionths: 0,
2833 excess_data: Vec::new()
2835 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2836 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2837 short_channel_id: 3,
2840 cltv_expiry_delta: 0,
2841 htlc_minimum_msat: 0,
2842 htlc_maximum_msat: OptionalField::Present(50_000),
2844 fee_proportional_millionths: 0,
2845 excess_data: Vec::new()
2848 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
2849 // (total limit 60).
2850 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2852 short_channel_id: 12,
2855 cltv_expiry_delta: 0,
2856 htlc_minimum_msat: 0,
2857 htlc_maximum_msat: OptionalField::Present(60_000),
2859 fee_proportional_millionths: 0,
2860 excess_data: Vec::new()
2862 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2863 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2864 short_channel_id: 13,
2867 cltv_expiry_delta: 0,
2868 htlc_minimum_msat: 0,
2869 htlc_maximum_msat: OptionalField::Present(60_000),
2871 fee_proportional_millionths: 0,
2872 excess_data: Vec::new()
2875 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
2876 // (total capacity 180 sats).
2877 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2878 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2879 short_channel_id: 2,
2882 cltv_expiry_delta: 0,
2883 htlc_minimum_msat: 0,
2884 htlc_maximum_msat: OptionalField::Present(200_000),
2886 fee_proportional_millionths: 0,
2887 excess_data: Vec::new()
2889 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2890 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2891 short_channel_id: 4,
2894 cltv_expiry_delta: 0,
2895 htlc_minimum_msat: 0,
2896 htlc_maximum_msat: OptionalField::Present(180_000),
2898 fee_proportional_millionths: 0,
2899 excess_data: Vec::new()
2903 // Attempt to route more than available results in a failure.
2904 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(),
2905 &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
2906 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2907 } else { panic!(); }
2911 // Now, attempt to route 250 sats (just a bit below the capacity).
2912 // Our algorithm should provide us with these 3 paths.
2913 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2914 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
2915 assert_eq!(route.paths.len(), 3);
2916 let mut total_amount_paid_msat = 0;
2917 for path in &route.paths {
2918 assert_eq!(path.len(), 2);
2919 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2920 total_amount_paid_msat += path.last().unwrap().fee_msat;
2922 assert_eq!(total_amount_paid_msat, 250_000);
2926 // Attempt to route an exact amount is also fine
2927 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2928 Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
2929 assert_eq!(route.paths.len(), 3);
2930 let mut total_amount_paid_msat = 0;
2931 for path in &route.paths {
2932 assert_eq!(path.len(), 2);
2933 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2934 total_amount_paid_msat += path.last().unwrap().fee_msat;
2936 assert_eq!(total_amount_paid_msat, 290_000);
2941 fn long_mpp_route_test() {
2942 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2943 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2945 // We need a route consisting of 3 paths:
2946 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
2947 // Note that these paths overlap (channels 5, 12, 13).
2948 // We will route 300 sats.
2949 // Each path will have 100 sats capacity, those channels which
2950 // are used twice will have 200 sats capacity.
2952 // Disable other potential paths.
2953 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2954 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2955 short_channel_id: 2,
2958 cltv_expiry_delta: 0,
2959 htlc_minimum_msat: 0,
2960 htlc_maximum_msat: OptionalField::Present(100_000),
2962 fee_proportional_millionths: 0,
2963 excess_data: Vec::new()
2965 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2966 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2967 short_channel_id: 7,
2970 cltv_expiry_delta: 0,
2971 htlc_minimum_msat: 0,
2972 htlc_maximum_msat: OptionalField::Present(100_000),
2974 fee_proportional_millionths: 0,
2975 excess_data: Vec::new()
2978 // Path via {node0, node2} is channels {1, 3, 5}.
2979 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2980 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2981 short_channel_id: 1,
2984 cltv_expiry_delta: 0,
2985 htlc_minimum_msat: 0,
2986 htlc_maximum_msat: OptionalField::Present(100_000),
2988 fee_proportional_millionths: 0,
2989 excess_data: Vec::new()
2991 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2992 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2993 short_channel_id: 3,
2996 cltv_expiry_delta: 0,
2997 htlc_minimum_msat: 0,
2998 htlc_maximum_msat: OptionalField::Present(100_000),
3000 fee_proportional_millionths: 0,
3001 excess_data: Vec::new()
3004 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3005 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3006 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3008 short_channel_id: 5,
3011 cltv_expiry_delta: 0,
3012 htlc_minimum_msat: 0,
3013 htlc_maximum_msat: OptionalField::Present(200_000),
3015 fee_proportional_millionths: 0,
3016 excess_data: Vec::new()
3019 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3020 // Add 100 sats to the capacities of {12, 13}, because these channels
3021 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3022 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3023 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3024 short_channel_id: 12,
3027 cltv_expiry_delta: 0,
3028 htlc_minimum_msat: 0,
3029 htlc_maximum_msat: OptionalField::Present(200_000),
3031 fee_proportional_millionths: 0,
3032 excess_data: Vec::new()
3034 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3036 short_channel_id: 13,
3039 cltv_expiry_delta: 0,
3040 htlc_minimum_msat: 0,
3041 htlc_maximum_msat: OptionalField::Present(200_000),
3043 fee_proportional_millionths: 0,
3044 excess_data: Vec::new()
3047 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3048 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3049 short_channel_id: 6,
3052 cltv_expiry_delta: 0,
3053 htlc_minimum_msat: 0,
3054 htlc_maximum_msat: OptionalField::Present(100_000),
3056 fee_proportional_millionths: 0,
3057 excess_data: Vec::new()
3059 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3060 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3061 short_channel_id: 11,
3064 cltv_expiry_delta: 0,
3065 htlc_minimum_msat: 0,
3066 htlc_maximum_msat: OptionalField::Present(100_000),
3068 fee_proportional_millionths: 0,
3069 excess_data: Vec::new()
3072 // Path via {node7, node2} is channels {12, 13, 5}.
3073 // We already limited them to 200 sats (they are used twice for 100 sats).
3074 // Nothing to do here.
3077 // Attempt to route more than available results in a failure.
3078 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3079 Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
3080 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3081 } else { panic!(); }
3085 // Now, attempt to route 300 sats (exact amount we can route).
3086 // Our algorithm should provide us with these 3 paths, 100 sats each.
3087 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3088 Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
3089 assert_eq!(route.paths.len(), 3);
3091 let mut total_amount_paid_msat = 0;
3092 for path in &route.paths {
3093 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3094 total_amount_paid_msat += path.last().unwrap().fee_msat;
3096 assert_eq!(total_amount_paid_msat, 300_000);
3102 fn mpp_cheaper_route_test() {
3103 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3104 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3106 // This test checks that if we have two cheaper paths and one more expensive path,
3107 // so that liquidity-wise any 2 of 3 combination is sufficient,
3108 // two cheaper paths will be taken.
3109 // These paths have equal available liquidity.
3111 // We need a combination of 3 paths:
3112 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3113 // Note that these paths overlap (channels 5, 12, 13).
3114 // Each path will have 100 sats capacity, those channels which
3115 // are used twice will have 200 sats capacity.
3117 // Disable other potential paths.
3118 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3119 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3120 short_channel_id: 2,
3123 cltv_expiry_delta: 0,
3124 htlc_minimum_msat: 0,
3125 htlc_maximum_msat: OptionalField::Present(100_000),
3127 fee_proportional_millionths: 0,
3128 excess_data: Vec::new()
3130 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3131 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3132 short_channel_id: 7,
3135 cltv_expiry_delta: 0,
3136 htlc_minimum_msat: 0,
3137 htlc_maximum_msat: OptionalField::Present(100_000),
3139 fee_proportional_millionths: 0,
3140 excess_data: Vec::new()
3143 // Path via {node0, node2} is channels {1, 3, 5}.
3144 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3145 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3146 short_channel_id: 1,
3149 cltv_expiry_delta: 0,
3150 htlc_minimum_msat: 0,
3151 htlc_maximum_msat: OptionalField::Present(100_000),
3153 fee_proportional_millionths: 0,
3154 excess_data: Vec::new()
3156 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3157 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3158 short_channel_id: 3,
3161 cltv_expiry_delta: 0,
3162 htlc_minimum_msat: 0,
3163 htlc_maximum_msat: OptionalField::Present(100_000),
3165 fee_proportional_millionths: 0,
3166 excess_data: Vec::new()
3169 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3170 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3171 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3172 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3173 short_channel_id: 5,
3176 cltv_expiry_delta: 0,
3177 htlc_minimum_msat: 0,
3178 htlc_maximum_msat: OptionalField::Present(200_000),
3180 fee_proportional_millionths: 0,
3181 excess_data: Vec::new()
3184 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3185 // Add 100 sats to the capacities of {12, 13}, because these channels
3186 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3187 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3188 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3189 short_channel_id: 12,
3192 cltv_expiry_delta: 0,
3193 htlc_minimum_msat: 0,
3194 htlc_maximum_msat: OptionalField::Present(200_000),
3196 fee_proportional_millionths: 0,
3197 excess_data: Vec::new()
3199 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3200 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3201 short_channel_id: 13,
3204 cltv_expiry_delta: 0,
3205 htlc_minimum_msat: 0,
3206 htlc_maximum_msat: OptionalField::Present(200_000),
3208 fee_proportional_millionths: 0,
3209 excess_data: Vec::new()
3212 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3213 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3214 short_channel_id: 6,
3217 cltv_expiry_delta: 0,
3218 htlc_minimum_msat: 0,
3219 htlc_maximum_msat: OptionalField::Present(100_000),
3220 fee_base_msat: 1_000,
3221 fee_proportional_millionths: 0,
3222 excess_data: Vec::new()
3224 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3225 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3226 short_channel_id: 11,
3229 cltv_expiry_delta: 0,
3230 htlc_minimum_msat: 0,
3231 htlc_maximum_msat: OptionalField::Present(100_000),
3233 fee_proportional_millionths: 0,
3234 excess_data: Vec::new()
3237 // Path via {node7, node2} is channels {12, 13, 5}.
3238 // We already limited them to 200 sats (they are used twice for 100 sats).
3239 // Nothing to do here.
3242 // Now, attempt to route 180 sats.
3243 // Our algorithm should provide us with these 2 paths.
3244 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3245 Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
3246 assert_eq!(route.paths.len(), 2);
3248 let mut total_value_transferred_msat = 0;
3249 let mut total_paid_msat = 0;
3250 for path in &route.paths {
3251 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3252 total_value_transferred_msat += path.last().unwrap().fee_msat;
3254 total_paid_msat += hop.fee_msat;
3257 // If we paid fee, this would be higher.
3258 assert_eq!(total_value_transferred_msat, 180_000);
3259 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3260 assert_eq!(total_fees_paid, 0);
3265 fn fees_on_mpp_route_test() {
3266 // This test makes sure that MPP algorithm properly takes into account
3267 // fees charged on the channels, by making the fees impactful:
3268 // if the fee is not properly accounted for, the behavior is different.
3269 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3270 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3272 // We need a route consisting of 2 paths:
3273 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
3274 // We will route 200 sats, Each path will have 100 sats capacity.
3276 // This test is not particularly stable: e.g.,
3277 // there's a way to route via {node0, node2, node4}.
3278 // It works while pathfinding is deterministic, but can be broken otherwise.
3279 // It's fine to ignore this concern for now.
3281 // Disable other potential paths.
3282 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3283 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3284 short_channel_id: 2,
3287 cltv_expiry_delta: 0,
3288 htlc_minimum_msat: 0,
3289 htlc_maximum_msat: OptionalField::Present(100_000),
3291 fee_proportional_millionths: 0,
3292 excess_data: Vec::new()
3295 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3296 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3297 short_channel_id: 7,
3300 cltv_expiry_delta: 0,
3301 htlc_minimum_msat: 0,
3302 htlc_maximum_msat: OptionalField::Present(100_000),
3304 fee_proportional_millionths: 0,
3305 excess_data: Vec::new()
3308 // Path via {node0, node2} is channels {1, 3, 5}.
3309 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3310 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3311 short_channel_id: 1,
3314 cltv_expiry_delta: 0,
3315 htlc_minimum_msat: 0,
3316 htlc_maximum_msat: OptionalField::Present(100_000),
3318 fee_proportional_millionths: 0,
3319 excess_data: Vec::new()
3321 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3323 short_channel_id: 3,
3326 cltv_expiry_delta: 0,
3327 htlc_minimum_msat: 0,
3328 htlc_maximum_msat: OptionalField::Present(100_000),
3330 fee_proportional_millionths: 0,
3331 excess_data: Vec::new()
3334 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3335 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3336 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3337 short_channel_id: 5,
3340 cltv_expiry_delta: 0,
3341 htlc_minimum_msat: 0,
3342 htlc_maximum_msat: OptionalField::Present(100_000),
3344 fee_proportional_millionths: 0,
3345 excess_data: Vec::new()
3348 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3349 // All channels should be 100 sats capacity. But for the fee experiment,
3350 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
3351 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
3352 // 100 sats (and pay 150 sats in fees for the use of channel 6),
3353 // so no matter how large are other channels,
3354 // the whole path will be limited by 100 sats with just these 2 conditions:
3355 // - channel 12 capacity is 250 sats
3356 // - fee for channel 6 is 150 sats
3357 // Let's test this by enforcing these 2 conditions and removing other limits.
3358 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3359 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3360 short_channel_id: 12,
3363 cltv_expiry_delta: 0,
3364 htlc_minimum_msat: 0,
3365 htlc_maximum_msat: OptionalField::Present(250_000),
3367 fee_proportional_millionths: 0,
3368 excess_data: Vec::new()
3370 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3371 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3372 short_channel_id: 13,
3375 cltv_expiry_delta: 0,
3376 htlc_minimum_msat: 0,
3377 htlc_maximum_msat: OptionalField::Absent,
3379 fee_proportional_millionths: 0,
3380 excess_data: Vec::new()
3383 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3384 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3385 short_channel_id: 6,
3388 cltv_expiry_delta: 0,
3389 htlc_minimum_msat: 0,
3390 htlc_maximum_msat: OptionalField::Absent,
3391 fee_base_msat: 150_000,
3392 fee_proportional_millionths: 0,
3393 excess_data: Vec::new()
3395 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3396 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3397 short_channel_id: 11,
3400 cltv_expiry_delta: 0,
3401 htlc_minimum_msat: 0,
3402 htlc_maximum_msat: OptionalField::Absent,
3404 fee_proportional_millionths: 0,
3405 excess_data: Vec::new()
3409 // Attempt to route more than available results in a failure.
3410 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3411 Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
3412 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3413 } else { panic!(); }
3417 // Now, attempt to route 200 sats (exact amount we can route).
3418 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3419 Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
3420 assert_eq!(route.paths.len(), 2);
3422 let mut total_amount_paid_msat = 0;
3423 for path in &route.paths {
3424 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3425 total_amount_paid_msat += path.last().unwrap().fee_msat;
3427 assert_eq!(total_amount_paid_msat, 200_000);
3433 fn drop_lowest_channel_mpp_route_test() {
3434 // This test checks that low-capacity channel is dropped when after
3435 // path finding we realize that we found more capacity than we need.
3436 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3437 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3439 // We need a route consisting of 3 paths:
3440 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3442 // The first and the second paths should be sufficient, but the third should be
3443 // cheaper, so that we select it but drop later.
3445 // First, we set limits on these (previously unlimited) channels.
3446 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
3448 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
3449 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3451 short_channel_id: 1,
3454 cltv_expiry_delta: 0,
3455 htlc_minimum_msat: 0,
3456 htlc_maximum_msat: OptionalField::Present(100_000),
3458 fee_proportional_millionths: 0,
3459 excess_data: Vec::new()
3461 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3462 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3463 short_channel_id: 3,
3466 cltv_expiry_delta: 0,
3467 htlc_minimum_msat: 0,
3468 htlc_maximum_msat: OptionalField::Present(50_000),
3470 fee_proportional_millionths: 0,
3471 excess_data: Vec::new()
3474 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
3475 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3477 short_channel_id: 12,
3480 cltv_expiry_delta: 0,
3481 htlc_minimum_msat: 0,
3482 htlc_maximum_msat: OptionalField::Present(60_000),
3484 fee_proportional_millionths: 0,
3485 excess_data: Vec::new()
3487 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3488 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3489 short_channel_id: 13,
3492 cltv_expiry_delta: 0,
3493 htlc_minimum_msat: 0,
3494 htlc_maximum_msat: OptionalField::Present(60_000),
3496 fee_proportional_millionths: 0,
3497 excess_data: Vec::new()
3500 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
3501 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3502 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3503 short_channel_id: 2,
3506 cltv_expiry_delta: 0,
3507 htlc_minimum_msat: 0,
3508 htlc_maximum_msat: OptionalField::Present(20_000),
3510 fee_proportional_millionths: 0,
3511 excess_data: Vec::new()
3513 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3514 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3515 short_channel_id: 4,
3518 cltv_expiry_delta: 0,
3519 htlc_minimum_msat: 0,
3520 htlc_maximum_msat: OptionalField::Present(20_000),
3522 fee_proportional_millionths: 0,
3523 excess_data: Vec::new()
3527 // Attempt to route more than available results in a failure.
3528 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3529 Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
3530 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3531 } else { panic!(); }
3535 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
3536 // Our algorithm should provide us with these 3 paths.
3537 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3538 Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
3539 assert_eq!(route.paths.len(), 3);
3540 let mut total_amount_paid_msat = 0;
3541 for path in &route.paths {
3542 assert_eq!(path.len(), 2);
3543 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3544 total_amount_paid_msat += path.last().unwrap().fee_msat;
3546 assert_eq!(total_amount_paid_msat, 125_000);
3550 // Attempt to route without the last small cheap channel
3551 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3552 Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3553 assert_eq!(route.paths.len(), 2);
3554 let mut total_amount_paid_msat = 0;
3555 for path in &route.paths {
3556 assert_eq!(path.len(), 2);
3557 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3558 total_amount_paid_msat += path.last().unwrap().fee_msat;
3560 assert_eq!(total_amount_paid_msat, 90_000);
3565 fn min_criteria_consistency() {
3566 // Test that we don't use an inconsistent metric between updating and walking nodes during
3567 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
3568 // was updated with a different criterion from the heap sorting, resulting in loops in
3569 // calculated paths. We test for that specific case here.
3571 // We construct a network that looks like this:
3573 // node2 -1(3)2- node3
3577 // node1 -1(5)2- node4 -1(1)2- node6
3583 // We create a loop on the side of our real path - our destination is node 6, with a
3584 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
3585 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
3586 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
3587 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
3588 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
3589 // "previous hop" being set to node 3, creating a loop in the path.
3590 let secp_ctx = Secp256k1::new();
3591 let logger = Arc::new(test_utils::TestLogger::new());
3592 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
3593 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3595 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
3596 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3597 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3598 short_channel_id: 6,
3601 cltv_expiry_delta: (6 << 8) | 0,
3602 htlc_minimum_msat: 0,
3603 htlc_maximum_msat: OptionalField::Absent,
3605 fee_proportional_millionths: 0,
3606 excess_data: Vec::new()
3608 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
3610 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3611 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3612 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3613 short_channel_id: 5,
3616 cltv_expiry_delta: (5 << 8) | 0,
3617 htlc_minimum_msat: 0,
3618 htlc_maximum_msat: OptionalField::Absent,
3620 fee_proportional_millionths: 0,
3621 excess_data: Vec::new()
3623 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
3625 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
3626 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3627 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3628 short_channel_id: 4,
3631 cltv_expiry_delta: (4 << 8) | 0,
3632 htlc_minimum_msat: 0,
3633 htlc_maximum_msat: OptionalField::Absent,
3635 fee_proportional_millionths: 0,
3636 excess_data: Vec::new()
3638 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
3640 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
3641 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
3642 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3643 short_channel_id: 3,
3646 cltv_expiry_delta: (3 << 8) | 0,
3647 htlc_minimum_msat: 0,
3648 htlc_maximum_msat: OptionalField::Absent,
3650 fee_proportional_millionths: 0,
3651 excess_data: Vec::new()
3653 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
3655 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
3656 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3657 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3658 short_channel_id: 2,
3661 cltv_expiry_delta: (2 << 8) | 0,
3662 htlc_minimum_msat: 0,
3663 htlc_maximum_msat: OptionalField::Absent,
3665 fee_proportional_millionths: 0,
3666 excess_data: Vec::new()
3669 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
3670 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3671 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3672 short_channel_id: 1,
3675 cltv_expiry_delta: (1 << 8) | 0,
3676 htlc_minimum_msat: 100,
3677 htlc_maximum_msat: OptionalField::Absent,
3679 fee_proportional_millionths: 0,
3680 excess_data: Vec::new()
3682 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
3685 // Now ensure the route flows simply over nodes 1 and 4 to 6.
3686 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
3687 assert_eq!(route.paths.len(), 1);
3688 assert_eq!(route.paths[0].len(), 3);
3690 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3691 assert_eq!(route.paths[0][0].short_channel_id, 6);
3692 assert_eq!(route.paths[0][0].fee_msat, 100);
3693 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
3694 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
3695 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
3697 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
3698 assert_eq!(route.paths[0][1].short_channel_id, 5);
3699 assert_eq!(route.paths[0][1].fee_msat, 0);
3700 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
3701 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
3702 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
3704 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
3705 assert_eq!(route.paths[0][2].short_channel_id, 1);
3706 assert_eq!(route.paths[0][2].fee_msat, 10_000);
3707 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
3708 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3709 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
3715 fn exact_fee_liquidity_limit() {
3716 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
3717 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
3718 // we calculated fees on a higher value, resulting in us ignoring such paths.
3719 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3720 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
3722 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
3724 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3725 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3726 short_channel_id: 2,
3729 cltv_expiry_delta: 0,
3730 htlc_minimum_msat: 0,
3731 htlc_maximum_msat: OptionalField::Present(85_000),
3733 fee_proportional_millionths: 0,
3734 excess_data: Vec::new()
3737 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3739 short_channel_id: 12,
3742 cltv_expiry_delta: (4 << 8) | 1,
3743 htlc_minimum_msat: 0,
3744 htlc_maximum_msat: OptionalField::Present(270_000),
3746 fee_proportional_millionths: 1000000,
3747 excess_data: Vec::new()
3751 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
3752 // 200% fee charged channel 13 in the 1-to-2 direction.
3753 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3754 assert_eq!(route.paths.len(), 1);
3755 assert_eq!(route.paths[0].len(), 2);
3757 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3758 assert_eq!(route.paths[0][0].short_channel_id, 12);
3759 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3760 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3761 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3762 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3764 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3765 assert_eq!(route.paths[0][1].short_channel_id, 13);
3766 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3767 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3768 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3769 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3774 fn htlc_max_reduction_below_min() {
3775 // Test that if, while walking the graph, we reduce the value being sent to meet an
3776 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
3777 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
3778 // resulting in us thinking there is no possible path, even if other paths exist.
3779 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3780 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3782 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
3783 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
3784 // then try to send 90_000.
3785 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3786 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3787 short_channel_id: 2,
3790 cltv_expiry_delta: 0,
3791 htlc_minimum_msat: 0,
3792 htlc_maximum_msat: OptionalField::Present(80_000),
3794 fee_proportional_millionths: 0,
3795 excess_data: Vec::new()
3797 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3798 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3799 short_channel_id: 4,
3802 cltv_expiry_delta: (4 << 8) | 1,
3803 htlc_minimum_msat: 90_000,
3804 htlc_maximum_msat: OptionalField::Absent,
3806 fee_proportional_millionths: 0,
3807 excess_data: Vec::new()
3811 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
3812 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
3813 // expensive) channels 12-13 path.
3814 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3815 assert_eq!(route.paths.len(), 1);
3816 assert_eq!(route.paths[0].len(), 2);
3818 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3819 assert_eq!(route.paths[0][0].short_channel_id, 12);
3820 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3821 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3822 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3823 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3825 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3826 assert_eq!(route.paths[0][1].short_channel_id, 13);
3827 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3828 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3829 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
3830 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3835 use util::ser::Readable;
3836 /// Tries to open a network graph file, or panics with a URL to fetch it.
3837 pub(super) fn get_route_file() -> Result<std::fs::File, std::io::Error> {
3838 let res = File::open("net_graph-2021-02-12.bin") // By default we're run in RL/lightning
3839 .or_else(|_| File::open("lightning/net_graph-2021-02-12.bin")) // We may be run manually in RL/
3840 .or_else(|_| { // Fall back to guessing based on the binary location
3841 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
3842 let mut path = std::env::current_exe().unwrap();
3843 path.pop(); // lightning-...
3845 path.pop(); // debug
3846 path.pop(); // target
3847 path.push("lightning");
3848 path.push("net_graph-2021-02-12.bin");
3849 eprintln!("{}", path.to_str().unwrap());
3852 #[cfg(require_route_graph_test)]
3853 return Ok(res.expect("Didn't have route graph and was configured to require it"));
3854 #[cfg(not(require_route_graph_test))]
3858 pub(super) fn random_init_seed() -> u64 {
3859 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
3860 use std::hash::{BuildHasher, Hasher};
3861 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
3862 println!("Using seed of {}", seed);
3867 fn generate_routes() {
3868 let mut d = match get_route_file() {
3871 eprintln!("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
3875 let graph = NetworkGraph::read(&mut d).unwrap();
3877 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3878 let mut seed = random_init_seed() as usize;
3879 'load_endpoints: for _ in 0..10 {
3881 seed = seed.overflowing_mul(0xdeadbeef).0;
3882 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3883 seed = seed.overflowing_mul(0xdeadbeef).0;
3884 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3885 let amt = seed as u64 % 200_000_000;
3886 if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3887 continue 'load_endpoints;
3894 fn generate_routes_mpp() {
3895 let mut d = match get_route_file() {
3898 eprintln!("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
3902 let graph = NetworkGraph::read(&mut d).unwrap();
3904 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3905 let mut seed = random_init_seed() as usize;
3906 'load_endpoints: for _ in 0..10 {
3908 seed = seed.overflowing_mul(0xdeadbeef).0;
3909 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3910 seed = seed.overflowing_mul(0xdeadbeef).0;
3911 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3912 let amt = seed as u64 % 200_000_000;
3913 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3914 continue 'load_endpoints;
3921 #[cfg(all(test, feature = "unstable"))]
3924 use util::logger::{Logger, Record};
3928 struct DummyLogger {}
3929 impl Logger for DummyLogger {
3930 fn log(&self, _record: &Record) {}
3934 fn generate_routes(bench: &mut Bencher) {
3935 let mut d = tests::get_route_file()
3936 .expect("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
3937 let graph = NetworkGraph::read(&mut d).unwrap();
3939 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3940 let mut path_endpoints = Vec::new();
3941 let mut seed: usize = 0xdeadbeef;
3942 'load_endpoints: for _ in 0..100 {
3945 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3947 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3948 let amt = seed as u64 % 1_000_000;
3949 if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
3950 path_endpoints.push((src, dst, amt));
3951 continue 'load_endpoints;
3956 // ...then benchmark finding paths between the nodes we learned.
3959 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
3960 assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
3966 fn generate_mpp_routes(bench: &mut Bencher) {
3967 let mut d = tests::get_route_file()
3968 .expect("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
3969 let graph = NetworkGraph::read(&mut d).unwrap();
3971 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3972 let mut path_endpoints = Vec::new();
3973 let mut seed: usize = 0xdeadbeef;
3974 'load_endpoints: for _ in 0..100 {
3977 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3979 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3980 let amt = seed as u64 % 1_000_000;
3981 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
3982 path_endpoints.push((src, dst, amt));
3983 continue 'load_endpoints;
3988 // ...then benchmark finding paths between the nodes we learned.
3991 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
3992 assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());