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 chain::transaction::OutPoint;
1169 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1170 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1171 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1172 use ln::channelmanager;
1173 use util::test_utils;
1174 use util::ser::Writeable;
1176 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1177 use bitcoin::hashes::Hash;
1178 use bitcoin::network::constants::Network;
1179 use bitcoin::blockdata::constants::genesis_block;
1180 use bitcoin::blockdata::script::Builder;
1181 use bitcoin::blockdata::opcodes;
1182 use bitcoin::blockdata::transaction::TxOut;
1186 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1187 use bitcoin::secp256k1::{Secp256k1, All};
1191 // Using the same keys for LN and BTC ids
1192 fn add_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey,
1193 node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64) {
1194 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1195 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1197 let unsigned_announcement = UnsignedChannelAnnouncement {
1199 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1203 bitcoin_key_1: node_id_1,
1204 bitcoin_key_2: node_id_2,
1205 excess_data: Vec::new(),
1208 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1209 let valid_announcement = ChannelAnnouncement {
1210 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1211 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1212 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1213 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1214 contents: unsigned_announcement.clone(),
1216 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1217 Ok(res) => assert!(res),
1222 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) {
1223 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1224 let valid_channel_update = ChannelUpdate {
1225 signature: secp_ctx.sign(&msghash, node_privkey),
1226 contents: update.clone()
1229 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1230 Ok(res) => assert!(res),
1235 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,
1236 features: NodeFeatures, timestamp: u32) {
1237 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1238 let unsigned_announcement = UnsignedNodeAnnouncement {
1244 addresses: Vec::new(),
1245 excess_address_data: Vec::new(),
1246 excess_data: Vec::new(),
1248 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1249 let valid_announcement = NodeAnnouncement {
1250 signature: secp_ctx.sign(&msghash, node_privkey),
1251 contents: unsigned_announcement.clone()
1254 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1260 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1261 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1262 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1265 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1267 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1268 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1270 (our_privkey, our_id, privkeys, pubkeys)
1273 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1274 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1275 // test for it later.
1276 let idx = (id - 1) * 2 + 1;
1278 vec![1 << (idx - 8*3), 0, 0, 0]
1279 } else if idx > 8*2 {
1280 vec![1 << (idx - 8*2), 0, 0]
1281 } else if idx > 8*1 {
1282 vec![1 << (idx - 8*1), 0]
1288 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>) {
1289 let secp_ctx = Secp256k1::new();
1290 let logger = Arc::new(test_utils::TestLogger::new());
1291 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1292 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
1293 // Build network from our_id to node7:
1295 // -1(1)2- node0 -1(3)2-
1297 // our_id -1(12)2- node7 -1(13)2--- node2
1299 // -1(2)2- node1 -1(4)2-
1302 // chan1 1-to-2: disabled
1303 // chan1 2-to-1: enabled, 0 fee
1305 // chan2 1-to-2: enabled, ignored fee
1306 // chan2 2-to-1: enabled, 0 fee
1308 // chan3 1-to-2: enabled, 0 fee
1309 // chan3 2-to-1: enabled, 100 msat fee
1311 // chan4 1-to-2: enabled, 100% fee
1312 // chan4 2-to-1: enabled, 0 fee
1314 // chan12 1-to-2: enabled, ignored fee
1315 // chan12 2-to-1: enabled, 0 fee
1317 // chan13 1-to-2: enabled, 200% fee
1318 // chan13 2-to-1: enabled, 0 fee
1321 // -1(5)2- node3 -1(8)2--
1325 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1327 // -1(7)2- node5 -1(10)2-
1329 // chan5 1-to-2: enabled, 100 msat fee
1330 // chan5 2-to-1: enabled, 0 fee
1332 // chan6 1-to-2: enabled, 0 fee
1333 // chan6 2-to-1: enabled, 0 fee
1335 // chan7 1-to-2: enabled, 100% fee
1336 // chan7 2-to-1: enabled, 0 fee
1338 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1339 // chan8 2-to-1: enabled, 0 fee
1341 // chan9 1-to-2: enabled, 1001 msat fee
1342 // chan9 2-to-1: enabled, 0 fee
1344 // chan10 1-to-2: enabled, 0 fee
1345 // chan10 2-to-1: enabled, 0 fee
1347 // chan11 1-to-2: enabled, 0 fee
1348 // chan11 2-to-1: enabled, 0 fee
1350 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1352 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1353 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1354 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1355 short_channel_id: 1,
1358 cltv_expiry_delta: 0,
1359 htlc_minimum_msat: 0,
1360 htlc_maximum_msat: OptionalField::Absent,
1362 fee_proportional_millionths: 0,
1363 excess_data: Vec::new()
1366 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1368 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1369 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1370 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1371 short_channel_id: 2,
1374 cltv_expiry_delta: u16::max_value(),
1375 htlc_minimum_msat: 0,
1376 htlc_maximum_msat: OptionalField::Absent,
1377 fee_base_msat: u32::max_value(),
1378 fee_proportional_millionths: u32::max_value(),
1379 excess_data: Vec::new()
1381 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1382 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1383 short_channel_id: 2,
1386 cltv_expiry_delta: 0,
1387 htlc_minimum_msat: 0,
1388 htlc_maximum_msat: OptionalField::Absent,
1390 fee_proportional_millionths: 0,
1391 excess_data: Vec::new()
1394 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1396 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1397 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1398 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1399 short_channel_id: 12,
1402 cltv_expiry_delta: u16::max_value(),
1403 htlc_minimum_msat: 0,
1404 htlc_maximum_msat: OptionalField::Absent,
1405 fee_base_msat: u32::max_value(),
1406 fee_proportional_millionths: u32::max_value(),
1407 excess_data: Vec::new()
1409 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1410 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1411 short_channel_id: 12,
1414 cltv_expiry_delta: 0,
1415 htlc_minimum_msat: 0,
1416 htlc_maximum_msat: OptionalField::Absent,
1418 fee_proportional_millionths: 0,
1419 excess_data: Vec::new()
1422 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1424 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1425 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1426 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1427 short_channel_id: 3,
1430 cltv_expiry_delta: (3 << 8) | 1,
1431 htlc_minimum_msat: 0,
1432 htlc_maximum_msat: OptionalField::Absent,
1434 fee_proportional_millionths: 0,
1435 excess_data: Vec::new()
1437 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1438 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1439 short_channel_id: 3,
1442 cltv_expiry_delta: (3 << 8) | 2,
1443 htlc_minimum_msat: 0,
1444 htlc_maximum_msat: OptionalField::Absent,
1446 fee_proportional_millionths: 0,
1447 excess_data: Vec::new()
1450 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1451 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1452 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1453 short_channel_id: 4,
1456 cltv_expiry_delta: (4 << 8) | 1,
1457 htlc_minimum_msat: 0,
1458 htlc_maximum_msat: OptionalField::Absent,
1460 fee_proportional_millionths: 1000000,
1461 excess_data: Vec::new()
1463 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1464 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1465 short_channel_id: 4,
1468 cltv_expiry_delta: (4 << 8) | 2,
1469 htlc_minimum_msat: 0,
1470 htlc_maximum_msat: OptionalField::Absent,
1472 fee_proportional_millionths: 0,
1473 excess_data: Vec::new()
1476 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1477 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1478 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1479 short_channel_id: 13,
1482 cltv_expiry_delta: (13 << 8) | 1,
1483 htlc_minimum_msat: 0,
1484 htlc_maximum_msat: OptionalField::Absent,
1486 fee_proportional_millionths: 2000000,
1487 excess_data: Vec::new()
1489 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1490 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1491 short_channel_id: 13,
1494 cltv_expiry_delta: (13 << 8) | 2,
1495 htlc_minimum_msat: 0,
1496 htlc_maximum_msat: OptionalField::Absent,
1498 fee_proportional_millionths: 0,
1499 excess_data: Vec::new()
1502 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1504 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1505 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1506 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1507 short_channel_id: 6,
1510 cltv_expiry_delta: (6 << 8) | 1,
1511 htlc_minimum_msat: 0,
1512 htlc_maximum_msat: OptionalField::Absent,
1514 fee_proportional_millionths: 0,
1515 excess_data: Vec::new()
1517 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1518 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1519 short_channel_id: 6,
1522 cltv_expiry_delta: (6 << 8) | 2,
1523 htlc_minimum_msat: 0,
1524 htlc_maximum_msat: OptionalField::Absent,
1526 fee_proportional_millionths: 0,
1527 excess_data: Vec::new(),
1530 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1531 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1532 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1533 short_channel_id: 11,
1536 cltv_expiry_delta: (11 << 8) | 1,
1537 htlc_minimum_msat: 0,
1538 htlc_maximum_msat: OptionalField::Absent,
1540 fee_proportional_millionths: 0,
1541 excess_data: Vec::new()
1543 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
1544 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1545 short_channel_id: 11,
1548 cltv_expiry_delta: (11 << 8) | 2,
1549 htlc_minimum_msat: 0,
1550 htlc_maximum_msat: OptionalField::Absent,
1552 fee_proportional_millionths: 0,
1553 excess_data: Vec::new()
1556 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
1558 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
1560 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
1561 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1562 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1563 short_channel_id: 7,
1566 cltv_expiry_delta: (7 << 8) | 1,
1567 htlc_minimum_msat: 0,
1568 htlc_maximum_msat: OptionalField::Absent,
1570 fee_proportional_millionths: 1000000,
1571 excess_data: Vec::new()
1573 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
1574 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1575 short_channel_id: 7,
1578 cltv_expiry_delta: (7 << 8) | 2,
1579 htlc_minimum_msat: 0,
1580 htlc_maximum_msat: OptionalField::Absent,
1582 fee_proportional_millionths: 0,
1583 excess_data: Vec::new()
1586 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
1588 (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
1592 fn simple_route_test() {
1593 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1594 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1596 // Simple route to 2 via 1
1598 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)) {
1599 assert_eq!(err, "Cannot send a payment of 0 msat");
1600 } else { panic!(); }
1602 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();
1603 assert_eq!(route.paths[0].len(), 2);
1605 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1606 assert_eq!(route.paths[0][0].short_channel_id, 2);
1607 assert_eq!(route.paths[0][0].fee_msat, 100);
1608 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1609 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1610 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1612 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1613 assert_eq!(route.paths[0][1].short_channel_id, 4);
1614 assert_eq!(route.paths[0][1].fee_msat, 100);
1615 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1616 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1617 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1621 fn invalid_first_hop_test() {
1622 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1623 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1625 // Simple route to 2 via 1
1627 let our_chans = vec![channelmanager::ChannelDetails {
1628 channel_id: [0; 32],
1629 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1630 short_channel_id: Some(2),
1631 remote_network_id: our_id,
1632 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1633 channel_value_satoshis: 100000,
1635 outbound_capacity_msat: 100000,
1636 inbound_capacity_msat: 100000,
1637 is_outbound: true, is_funding_locked: true,
1638 is_usable: true, is_public: true,
1639 counterparty_forwarding_info: None,
1642 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)) {
1643 assert_eq!(err, "First hop cannot have our_node_id as a destination.");
1644 } else { panic!(); }
1646 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();
1647 assert_eq!(route.paths[0].len(), 2);
1651 fn htlc_minimum_test() {
1652 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1653 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1655 // Simple route to 2 via 1
1657 // Disable other paths
1658 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1660 short_channel_id: 12,
1662 flags: 2, // to disable
1663 cltv_expiry_delta: 0,
1664 htlc_minimum_msat: 0,
1665 htlc_maximum_msat: OptionalField::Absent,
1667 fee_proportional_millionths: 0,
1668 excess_data: Vec::new()
1670 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1671 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1672 short_channel_id: 3,
1674 flags: 2, // to disable
1675 cltv_expiry_delta: 0,
1676 htlc_minimum_msat: 0,
1677 htlc_maximum_msat: OptionalField::Absent,
1679 fee_proportional_millionths: 0,
1680 excess_data: Vec::new()
1682 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1683 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1684 short_channel_id: 13,
1686 flags: 2, // to disable
1687 cltv_expiry_delta: 0,
1688 htlc_minimum_msat: 0,
1689 htlc_maximum_msat: OptionalField::Absent,
1691 fee_proportional_millionths: 0,
1692 excess_data: Vec::new()
1694 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1695 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1696 short_channel_id: 6,
1698 flags: 2, // to disable
1699 cltv_expiry_delta: 0,
1700 htlc_minimum_msat: 0,
1701 htlc_maximum_msat: OptionalField::Absent,
1703 fee_proportional_millionths: 0,
1704 excess_data: Vec::new()
1706 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1707 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1708 short_channel_id: 7,
1710 flags: 2, // to disable
1711 cltv_expiry_delta: 0,
1712 htlc_minimum_msat: 0,
1713 htlc_maximum_msat: OptionalField::Absent,
1715 fee_proportional_millionths: 0,
1716 excess_data: Vec::new()
1719 // Check against amount_to_transfer_over_msat.
1720 // Set minimal HTLC of 200_000_000 msat.
1721 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1722 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1723 short_channel_id: 2,
1726 cltv_expiry_delta: 0,
1727 htlc_minimum_msat: 200_000_000,
1728 htlc_maximum_msat: OptionalField::Absent,
1730 fee_proportional_millionths: 0,
1731 excess_data: Vec::new()
1734 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
1736 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1737 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1738 short_channel_id: 4,
1741 cltv_expiry_delta: 0,
1742 htlc_minimum_msat: 0,
1743 htlc_maximum_msat: OptionalField::Present(199_999_999),
1745 fee_proportional_millionths: 0,
1746 excess_data: Vec::new()
1749 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
1750 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)) {
1751 assert_eq!(err, "Failed to find a path to the given destination");
1752 } else { panic!(); }
1754 // Lift the restriction on the first hop.
1755 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1756 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1757 short_channel_id: 2,
1760 cltv_expiry_delta: 0,
1761 htlc_minimum_msat: 0,
1762 htlc_maximum_msat: OptionalField::Absent,
1764 fee_proportional_millionths: 0,
1765 excess_data: Vec::new()
1768 // A payment above the minimum should pass
1769 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();
1770 assert_eq!(route.paths[0].len(), 2);
1774 fn htlc_minimum_overpay_test() {
1775 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1776 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1778 // A route to node#2 via two paths.
1779 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
1780 // Thus, they can't send 60 without overpaying.
1781 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1782 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1783 short_channel_id: 2,
1786 cltv_expiry_delta: 0,
1787 htlc_minimum_msat: 35_000,
1788 htlc_maximum_msat: OptionalField::Present(40_000),
1790 fee_proportional_millionths: 0,
1791 excess_data: Vec::new()
1793 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1794 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1795 short_channel_id: 12,
1798 cltv_expiry_delta: 0,
1799 htlc_minimum_msat: 35_000,
1800 htlc_maximum_msat: OptionalField::Present(40_000),
1802 fee_proportional_millionths: 0,
1803 excess_data: Vec::new()
1807 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1808 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1809 short_channel_id: 13,
1812 cltv_expiry_delta: 0,
1813 htlc_minimum_msat: 0,
1814 htlc_maximum_msat: OptionalField::Absent,
1816 fee_proportional_millionths: 0,
1817 excess_data: Vec::new()
1819 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1820 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1821 short_channel_id: 4,
1824 cltv_expiry_delta: 0,
1825 htlc_minimum_msat: 0,
1826 htlc_maximum_msat: OptionalField::Absent,
1828 fee_proportional_millionths: 0,
1829 excess_data: Vec::new()
1832 // Disable other paths
1833 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1834 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1835 short_channel_id: 1,
1837 flags: 2, // to disable
1838 cltv_expiry_delta: 0,
1839 htlc_minimum_msat: 0,
1840 htlc_maximum_msat: OptionalField::Absent,
1842 fee_proportional_millionths: 0,
1843 excess_data: Vec::new()
1846 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1847 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1848 // Overpay fees to hit htlc_minimum_msat.
1849 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
1850 // TODO: this could be better balanced to overpay 10k and not 15k.
1851 assert_eq!(overpaid_fees, 15_000);
1853 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
1854 // while taking even more fee to match htlc_minimum_msat.
1855 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1856 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1857 short_channel_id: 12,
1860 cltv_expiry_delta: 0,
1861 htlc_minimum_msat: 65_000,
1862 htlc_maximum_msat: OptionalField::Present(80_000),
1864 fee_proportional_millionths: 0,
1865 excess_data: Vec::new()
1867 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1868 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1869 short_channel_id: 2,
1872 cltv_expiry_delta: 0,
1873 htlc_minimum_msat: 0,
1874 htlc_maximum_msat: OptionalField::Absent,
1876 fee_proportional_millionths: 0,
1877 excess_data: Vec::new()
1879 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1880 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1881 short_channel_id: 4,
1884 cltv_expiry_delta: 0,
1885 htlc_minimum_msat: 0,
1886 htlc_maximum_msat: OptionalField::Absent,
1888 fee_proportional_millionths: 100_000,
1889 excess_data: Vec::new()
1892 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1893 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1894 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
1895 assert_eq!(route.paths.len(), 1);
1896 assert_eq!(route.paths[0][0].short_channel_id, 12);
1897 let fees = route.paths[0][0].fee_msat;
1898 assert_eq!(fees, 5_000);
1900 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1901 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
1902 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
1903 // the other channel.
1904 assert_eq!(route.paths.len(), 1);
1905 assert_eq!(route.paths[0][0].short_channel_id, 2);
1906 let fees = route.paths[0][0].fee_msat;
1907 assert_eq!(fees, 5_000);
1911 fn disable_channels_test() {
1912 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1913 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1915 // // Disable channels 4 and 12 by flags=2
1916 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1917 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1918 short_channel_id: 4,
1920 flags: 2, // to disable
1921 cltv_expiry_delta: 0,
1922 htlc_minimum_msat: 0,
1923 htlc_maximum_msat: OptionalField::Absent,
1925 fee_proportional_millionths: 0,
1926 excess_data: Vec::new()
1928 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1929 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1930 short_channel_id: 12,
1932 flags: 2, // to disable
1933 cltv_expiry_delta: 0,
1934 htlc_minimum_msat: 0,
1935 htlc_maximum_msat: OptionalField::Absent,
1937 fee_proportional_millionths: 0,
1938 excess_data: Vec::new()
1941 // If all the channels require some features we don't understand, route should fail
1942 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)) {
1943 assert_eq!(err, "Failed to find a path to the given destination");
1944 } else { panic!(); }
1946 // If we specify a channel to node7, that overrides our local channel view and that gets used
1947 let our_chans = vec![channelmanager::ChannelDetails {
1948 channel_id: [0; 32],
1949 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1950 short_channel_id: Some(42),
1951 remote_network_id: nodes[7].clone(),
1952 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1953 channel_value_satoshis: 0,
1955 outbound_capacity_msat: 250_000_000,
1956 inbound_capacity_msat: 0,
1957 is_outbound: true, is_funding_locked: true,
1958 is_usable: true, is_public: true,
1959 counterparty_forwarding_info: None,
1961 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();
1962 assert_eq!(route.paths[0].len(), 2);
1964 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
1965 assert_eq!(route.paths[0][0].short_channel_id, 42);
1966 assert_eq!(route.paths[0][0].fee_msat, 200);
1967 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
1968 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
1969 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1971 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1972 assert_eq!(route.paths[0][1].short_channel_id, 13);
1973 assert_eq!(route.paths[0][1].fee_msat, 100);
1974 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1975 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1976 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
1980 fn disable_node_test() {
1981 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1982 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1984 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
1985 let mut unknown_features = NodeFeatures::known();
1986 unknown_features.set_required_unknown_bits();
1987 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
1988 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
1989 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
1991 // If all nodes require some features we don't understand, route should fail
1992 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)) {
1993 assert_eq!(err, "Failed to find a path to the given destination");
1994 } else { panic!(); }
1996 // If we specify a channel to node7, that overrides our local channel view and that gets used
1997 let our_chans = vec![channelmanager::ChannelDetails {
1998 channel_id: [0; 32],
1999 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2000 short_channel_id: Some(42),
2001 remote_network_id: nodes[7].clone(),
2002 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2003 channel_value_satoshis: 0,
2005 outbound_capacity_msat: 250_000_000,
2006 inbound_capacity_msat: 0,
2007 is_outbound: true, is_funding_locked: true,
2008 is_usable: true, is_public: true,
2009 counterparty_forwarding_info: None,
2011 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();
2012 assert_eq!(route.paths[0].len(), 2);
2014 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2015 assert_eq!(route.paths[0][0].short_channel_id, 42);
2016 assert_eq!(route.paths[0][0].fee_msat, 200);
2017 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2018 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2019 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2021 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2022 assert_eq!(route.paths[0][1].short_channel_id, 13);
2023 assert_eq!(route.paths[0][1].fee_msat, 100);
2024 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2025 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2026 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2028 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2029 // naively) assume that the user checked the feature bits on the invoice, which override
2030 // the node_announcement.
2034 fn our_chans_test() {
2035 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2036 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2038 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2039 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();
2040 assert_eq!(route.paths[0].len(), 3);
2042 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2043 assert_eq!(route.paths[0][0].short_channel_id, 2);
2044 assert_eq!(route.paths[0][0].fee_msat, 200);
2045 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2046 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2047 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2049 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2050 assert_eq!(route.paths[0][1].short_channel_id, 4);
2051 assert_eq!(route.paths[0][1].fee_msat, 100);
2052 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
2053 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2054 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2056 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2057 assert_eq!(route.paths[0][2].short_channel_id, 3);
2058 assert_eq!(route.paths[0][2].fee_msat, 100);
2059 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2060 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2061 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2063 // If we specify a channel to node7, that overrides our local channel view and that gets used
2064 let our_chans = vec![channelmanager::ChannelDetails {
2065 channel_id: [0; 32],
2066 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2067 short_channel_id: Some(42),
2068 remote_network_id: nodes[7].clone(),
2069 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2070 channel_value_satoshis: 0,
2072 outbound_capacity_msat: 250_000_000,
2073 inbound_capacity_msat: 0,
2074 is_outbound: true, is_funding_locked: true,
2075 is_usable: true, is_public: true,
2076 counterparty_forwarding_info: None,
2078 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();
2079 assert_eq!(route.paths[0].len(), 2);
2081 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2082 assert_eq!(route.paths[0][0].short_channel_id, 42);
2083 assert_eq!(route.paths[0][0].fee_msat, 200);
2084 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2085 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2086 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2088 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2089 assert_eq!(route.paths[0][1].short_channel_id, 13);
2090 assert_eq!(route.paths[0][1].fee_msat, 100);
2091 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2092 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2093 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2096 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHintHop> {
2097 let zero_fees = RoutingFees {
2099 proportional_millionths: 0,
2102 src_node_id: nodes[3].clone(),
2103 short_channel_id: 8,
2105 cltv_expiry_delta: (8 << 8) | 1,
2106 htlc_minimum_msat: None,
2107 htlc_maximum_msat: None,
2109 src_node_id: nodes[4].clone(),
2110 short_channel_id: 9,
2113 proportional_millionths: 0,
2115 cltv_expiry_delta: (9 << 8) | 1,
2116 htlc_minimum_msat: None,
2117 htlc_maximum_msat: None,
2119 src_node_id: nodes[5].clone(),
2120 short_channel_id: 10,
2122 cltv_expiry_delta: (10 << 8) | 1,
2123 htlc_minimum_msat: None,
2124 htlc_maximum_msat: None,
2129 fn last_hops_test() {
2130 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2131 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2133 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2135 // First check that lst hop can't have its source as the payee.
2136 let invalid_last_hop = RouteHintHop {
2137 src_node_id: nodes[6],
2138 short_channel_id: 8,
2141 proportional_millionths: 0,
2143 cltv_expiry_delta: (8 << 8) | 1,
2144 htlc_minimum_msat: None,
2145 htlc_maximum_msat: None,
2148 let mut invalid_last_hops = last_hops(&nodes);
2149 invalid_last_hops.push(invalid_last_hop);
2151 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)) {
2152 assert_eq!(err, "Last hop cannot have a payee as a source.");
2153 } else { panic!(); }
2156 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();
2157 assert_eq!(route.paths[0].len(), 5);
2159 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2160 assert_eq!(route.paths[0][0].short_channel_id, 2);
2161 assert_eq!(route.paths[0][0].fee_msat, 100);
2162 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2163 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2164 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2166 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2167 assert_eq!(route.paths[0][1].short_channel_id, 4);
2168 assert_eq!(route.paths[0][1].fee_msat, 0);
2169 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2170 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2171 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2173 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2174 assert_eq!(route.paths[0][2].short_channel_id, 6);
2175 assert_eq!(route.paths[0][2].fee_msat, 0);
2176 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2177 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2178 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2180 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2181 assert_eq!(route.paths[0][3].short_channel_id, 11);
2182 assert_eq!(route.paths[0][3].fee_msat, 0);
2183 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2184 // If we have a peer in the node map, we'll use their features here since we don't have
2185 // a way of figuring out their features from the invoice:
2186 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2187 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2189 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2190 assert_eq!(route.paths[0][4].short_channel_id, 8);
2191 assert_eq!(route.paths[0][4].fee_msat, 100);
2192 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2193 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2194 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2198 fn our_chans_last_hop_connect_test() {
2199 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2200 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2202 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2203 let our_chans = vec![channelmanager::ChannelDetails {
2204 channel_id: [0; 32],
2205 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2206 short_channel_id: Some(42),
2207 remote_network_id: nodes[3].clone(),
2208 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2209 channel_value_satoshis: 0,
2211 outbound_capacity_msat: 250_000_000,
2212 inbound_capacity_msat: 0,
2213 is_outbound: true, is_funding_locked: true,
2214 is_usable: true, is_public: true,
2215 counterparty_forwarding_info: None,
2217 let mut last_hops = last_hops(&nodes);
2218 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();
2219 assert_eq!(route.paths[0].len(), 2);
2221 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2222 assert_eq!(route.paths[0][0].short_channel_id, 42);
2223 assert_eq!(route.paths[0][0].fee_msat, 0);
2224 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2225 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2226 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2228 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2229 assert_eq!(route.paths[0][1].short_channel_id, 8);
2230 assert_eq!(route.paths[0][1].fee_msat, 100);
2231 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2232 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2233 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2235 last_hops[0].fees.base_msat = 1000;
2237 // Revert to via 6 as the fee on 8 goes up
2238 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();
2239 assert_eq!(route.paths[0].len(), 4);
2241 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2242 assert_eq!(route.paths[0][0].short_channel_id, 2);
2243 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2244 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2245 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2246 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2248 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2249 assert_eq!(route.paths[0][1].short_channel_id, 4);
2250 assert_eq!(route.paths[0][1].fee_msat, 100);
2251 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
2252 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2253 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2255 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2256 assert_eq!(route.paths[0][2].short_channel_id, 7);
2257 assert_eq!(route.paths[0][2].fee_msat, 0);
2258 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
2259 // If we have a peer in the node map, we'll use their features here since we don't have
2260 // a way of figuring out their features from the invoice:
2261 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2262 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2264 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2265 assert_eq!(route.paths[0][3].short_channel_id, 10);
2266 assert_eq!(route.paths[0][3].fee_msat, 100);
2267 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2268 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2269 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2271 // ...but still use 8 for larger payments as 6 has a variable feerate
2272 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();
2273 assert_eq!(route.paths[0].len(), 5);
2275 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2276 assert_eq!(route.paths[0][0].short_channel_id, 2);
2277 assert_eq!(route.paths[0][0].fee_msat, 3000);
2278 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2279 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2280 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2282 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2283 assert_eq!(route.paths[0][1].short_channel_id, 4);
2284 assert_eq!(route.paths[0][1].fee_msat, 0);
2285 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2286 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2287 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2289 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2290 assert_eq!(route.paths[0][2].short_channel_id, 6);
2291 assert_eq!(route.paths[0][2].fee_msat, 0);
2292 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2293 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2294 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2296 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2297 assert_eq!(route.paths[0][3].short_channel_id, 11);
2298 assert_eq!(route.paths[0][3].fee_msat, 1000);
2299 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2300 // If we have a peer in the node map, we'll use their features here since we don't have
2301 // a way of figuring out their features from the invoice:
2302 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2303 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2305 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2306 assert_eq!(route.paths[0][4].short_channel_id, 8);
2307 assert_eq!(route.paths[0][4].fee_msat, 2000);
2308 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2309 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2310 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2314 fn unannounced_path_test() {
2315 // We should be able to send a payment to a destination without any help of a routing graph
2316 // if we have a channel with a common counterparty that appears in the first and last hop
2318 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
2319 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2320 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2322 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
2323 let last_hops = vec![RouteHintHop {
2324 src_node_id: middle_node_id,
2325 short_channel_id: 8,
2328 proportional_millionths: 0,
2330 cltv_expiry_delta: (8 << 8) | 1,
2331 htlc_minimum_msat: None,
2332 htlc_maximum_msat: None,
2334 let our_chans = vec![channelmanager::ChannelDetails {
2335 channel_id: [0; 32],
2336 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2337 short_channel_id: Some(42),
2338 remote_network_id: middle_node_id,
2339 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2340 channel_value_satoshis: 100000,
2342 outbound_capacity_msat: 100000,
2343 inbound_capacity_msat: 100000,
2344 is_outbound: true, is_funding_locked: true,
2345 is_usable: true, is_public: true,
2346 counterparty_forwarding_info: None,
2348 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();
2350 assert_eq!(route.paths[0].len(), 2);
2352 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
2353 assert_eq!(route.paths[0][0].short_channel_id, 42);
2354 assert_eq!(route.paths[0][0].fee_msat, 1000);
2355 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2356 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
2357 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2359 assert_eq!(route.paths[0][1].pubkey, target_node_id);
2360 assert_eq!(route.paths[0][1].short_channel_id, 8);
2361 assert_eq!(route.paths[0][1].fee_msat, 100);
2362 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2363 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
2364 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2368 fn available_amount_while_routing_test() {
2369 // Tests whether we choose the correct available channel amount while routing.
2371 let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
2372 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2374 // We will use a simple single-path route from
2375 // our node to node2 via node0: channels {1, 3}.
2377 // First disable all other paths.
2378 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2379 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2380 short_channel_id: 2,
2383 cltv_expiry_delta: 0,
2384 htlc_minimum_msat: 0,
2385 htlc_maximum_msat: OptionalField::Present(100_000),
2387 fee_proportional_millionths: 0,
2388 excess_data: Vec::new()
2390 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2391 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2392 short_channel_id: 12,
2395 cltv_expiry_delta: 0,
2396 htlc_minimum_msat: 0,
2397 htlc_maximum_msat: OptionalField::Present(100_000),
2399 fee_proportional_millionths: 0,
2400 excess_data: Vec::new()
2403 // Make the first channel (#1) very permissive,
2404 // and we will be testing all limits on the second channel.
2405 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2406 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2407 short_channel_id: 1,
2410 cltv_expiry_delta: 0,
2411 htlc_minimum_msat: 0,
2412 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2414 fee_proportional_millionths: 0,
2415 excess_data: Vec::new()
2418 // First, let's see if routing works if we have absolutely no idea about the available amount.
2419 // In this case, it should be set to 250_000 sats.
2420 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2421 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2422 short_channel_id: 3,
2425 cltv_expiry_delta: 0,
2426 htlc_minimum_msat: 0,
2427 htlc_maximum_msat: OptionalField::Absent,
2429 fee_proportional_millionths: 0,
2430 excess_data: Vec::new()
2434 // Attempt to route more than available results in a failure.
2435 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2436 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
2437 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2438 } else { panic!(); }
2442 // Now, attempt to route an exact amount we have should be fine.
2443 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2444 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
2445 assert_eq!(route.paths.len(), 1);
2446 let path = route.paths.last().unwrap();
2447 assert_eq!(path.len(), 2);
2448 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2449 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
2452 // Check that setting outbound_capacity_msat in first_hops limits the channels.
2453 // Disable channel #1 and use another first hop.
2454 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2455 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2456 short_channel_id: 1,
2459 cltv_expiry_delta: 0,
2460 htlc_minimum_msat: 0,
2461 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2463 fee_proportional_millionths: 0,
2464 excess_data: Vec::new()
2467 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
2468 let our_chans = vec![channelmanager::ChannelDetails {
2469 channel_id: [0; 32],
2470 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2471 short_channel_id: Some(42),
2472 remote_network_id: nodes[0].clone(),
2473 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2474 channel_value_satoshis: 0,
2476 outbound_capacity_msat: 200_000_000,
2477 inbound_capacity_msat: 0,
2478 is_outbound: true, is_funding_locked: true,
2479 is_usable: true, is_public: true,
2480 counterparty_forwarding_info: None,
2484 // Attempt to route more than available results in a failure.
2485 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2486 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
2487 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2488 } else { panic!(); }
2492 // Now, attempt to route an exact amount we have should be fine.
2493 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2494 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
2495 assert_eq!(route.paths.len(), 1);
2496 let path = route.paths.last().unwrap();
2497 assert_eq!(path.len(), 2);
2498 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2499 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
2502 // Enable channel #1 back.
2503 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2504 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2505 short_channel_id: 1,
2508 cltv_expiry_delta: 0,
2509 htlc_minimum_msat: 0,
2510 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2512 fee_proportional_millionths: 0,
2513 excess_data: Vec::new()
2517 // Now let's see if routing works if we know only htlc_maximum_msat.
2518 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2519 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2520 short_channel_id: 3,
2523 cltv_expiry_delta: 0,
2524 htlc_minimum_msat: 0,
2525 htlc_maximum_msat: OptionalField::Present(15_000),
2527 fee_proportional_millionths: 0,
2528 excess_data: Vec::new()
2532 // Attempt to route more than available results in a failure.
2533 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2534 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2535 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2536 } else { panic!(); }
2540 // Now, attempt to route an exact amount we have should be fine.
2541 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2542 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2543 assert_eq!(route.paths.len(), 1);
2544 let path = route.paths.last().unwrap();
2545 assert_eq!(path.len(), 2);
2546 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2547 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2550 // Now let's see if routing works if we know only capacity from the UTXO.
2552 // We can't change UTXO capacity on the fly, so we'll disable
2553 // the existing channel and add another one with the capacity we need.
2554 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2555 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2556 short_channel_id: 3,
2559 cltv_expiry_delta: 0,
2560 htlc_minimum_msat: 0,
2561 htlc_maximum_msat: OptionalField::Absent,
2563 fee_proportional_millionths: 0,
2564 excess_data: Vec::new()
2567 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
2568 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
2569 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
2570 .push_opcode(opcodes::all::OP_PUSHNUM_2)
2571 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
2573 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
2574 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
2576 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
2577 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2578 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2579 short_channel_id: 333,
2582 cltv_expiry_delta: (3 << 8) | 1,
2583 htlc_minimum_msat: 0,
2584 htlc_maximum_msat: OptionalField::Absent,
2586 fee_proportional_millionths: 0,
2587 excess_data: Vec::new()
2589 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2590 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2591 short_channel_id: 333,
2594 cltv_expiry_delta: (3 << 8) | 2,
2595 htlc_minimum_msat: 0,
2596 htlc_maximum_msat: OptionalField::Absent,
2598 fee_proportional_millionths: 0,
2599 excess_data: Vec::new()
2603 // Attempt to route more than available results in a failure.
2604 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2605 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2606 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2607 } else { panic!(); }
2611 // Now, attempt to route an exact amount we have should be fine.
2612 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2613 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2614 assert_eq!(route.paths.len(), 1);
2615 let path = route.paths.last().unwrap();
2616 assert_eq!(path.len(), 2);
2617 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2618 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2621 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
2622 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2623 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2624 short_channel_id: 333,
2627 cltv_expiry_delta: 0,
2628 htlc_minimum_msat: 0,
2629 htlc_maximum_msat: OptionalField::Present(10_000),
2631 fee_proportional_millionths: 0,
2632 excess_data: Vec::new()
2636 // Attempt to route more than available results in a failure.
2637 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2638 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
2639 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2640 } else { panic!(); }
2644 // Now, attempt to route an exact amount we have should be fine.
2645 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2646 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
2647 assert_eq!(route.paths.len(), 1);
2648 let path = route.paths.last().unwrap();
2649 assert_eq!(path.len(), 2);
2650 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2651 assert_eq!(path.last().unwrap().fee_msat, 10_000);
2656 fn available_liquidity_last_hop_test() {
2657 // Check that available liquidity properly limits the path even when only
2658 // one of the latter hops is limited.
2659 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2660 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2662 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
2663 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
2664 // Total capacity: 50 sats.
2666 // Disable other potential paths.
2667 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2668 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2669 short_channel_id: 2,
2672 cltv_expiry_delta: 0,
2673 htlc_minimum_msat: 0,
2674 htlc_maximum_msat: OptionalField::Present(100_000),
2676 fee_proportional_millionths: 0,
2677 excess_data: Vec::new()
2679 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2680 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2681 short_channel_id: 7,
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()
2694 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2695 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2696 short_channel_id: 12,
2699 cltv_expiry_delta: 0,
2700 htlc_minimum_msat: 0,
2701 htlc_maximum_msat: OptionalField::Present(100_000),
2703 fee_proportional_millionths: 0,
2704 excess_data: Vec::new()
2706 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2707 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2708 short_channel_id: 13,
2711 cltv_expiry_delta: 0,
2712 htlc_minimum_msat: 0,
2713 htlc_maximum_msat: OptionalField::Present(100_000),
2715 fee_proportional_millionths: 0,
2716 excess_data: Vec::new()
2719 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2720 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2721 short_channel_id: 6,
2724 cltv_expiry_delta: 0,
2725 htlc_minimum_msat: 0,
2726 htlc_maximum_msat: OptionalField::Present(50_000),
2728 fee_proportional_millionths: 0,
2729 excess_data: Vec::new()
2731 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2732 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2733 short_channel_id: 11,
2736 cltv_expiry_delta: 0,
2737 htlc_minimum_msat: 0,
2738 htlc_maximum_msat: OptionalField::Present(100_000),
2740 fee_proportional_millionths: 0,
2741 excess_data: Vec::new()
2744 // Attempt to route more than available results in a failure.
2745 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2746 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
2747 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2748 } else { panic!(); }
2752 // Now, attempt to route 49 sats (just a bit below the capacity).
2753 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2754 Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
2755 assert_eq!(route.paths.len(), 1);
2756 let mut total_amount_paid_msat = 0;
2757 for path in &route.paths {
2758 assert_eq!(path.len(), 4);
2759 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2760 total_amount_paid_msat += path.last().unwrap().fee_msat;
2762 assert_eq!(total_amount_paid_msat, 49_000);
2766 // Attempt to route an exact amount is also fine
2767 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2768 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2769 assert_eq!(route.paths.len(), 1);
2770 let mut total_amount_paid_msat = 0;
2771 for path in &route.paths {
2772 assert_eq!(path.len(), 4);
2773 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2774 total_amount_paid_msat += path.last().unwrap().fee_msat;
2776 assert_eq!(total_amount_paid_msat, 50_000);
2781 fn ignore_fee_first_hop_test() {
2782 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2783 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2785 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2786 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2787 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2788 short_channel_id: 1,
2791 cltv_expiry_delta: 0,
2792 htlc_minimum_msat: 0,
2793 htlc_maximum_msat: OptionalField::Present(100_000),
2794 fee_base_msat: 1_000_000,
2795 fee_proportional_millionths: 0,
2796 excess_data: Vec::new()
2798 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2799 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2800 short_channel_id: 3,
2803 cltv_expiry_delta: 0,
2804 htlc_minimum_msat: 0,
2805 htlc_maximum_msat: OptionalField::Present(50_000),
2807 fee_proportional_millionths: 0,
2808 excess_data: Vec::new()
2812 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();
2813 assert_eq!(route.paths.len(), 1);
2814 let mut total_amount_paid_msat = 0;
2815 for path in &route.paths {
2816 assert_eq!(path.len(), 2);
2817 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2818 total_amount_paid_msat += path.last().unwrap().fee_msat;
2820 assert_eq!(total_amount_paid_msat, 50_000);
2825 fn simple_mpp_route_test() {
2826 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2827 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2829 // We need a route consisting of 3 paths:
2830 // From our node to node2 via node0, node7, node1 (three paths one hop each).
2831 // To achieve this, the amount being transferred should be around
2832 // the total capacity of these 3 paths.
2834 // First, we set limits on these (previously unlimited) channels.
2835 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
2837 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2838 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2839 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2840 short_channel_id: 1,
2843 cltv_expiry_delta: 0,
2844 htlc_minimum_msat: 0,
2845 htlc_maximum_msat: OptionalField::Present(100_000),
2847 fee_proportional_millionths: 0,
2848 excess_data: Vec::new()
2850 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2852 short_channel_id: 3,
2855 cltv_expiry_delta: 0,
2856 htlc_minimum_msat: 0,
2857 htlc_maximum_msat: OptionalField::Present(50_000),
2859 fee_proportional_millionths: 0,
2860 excess_data: Vec::new()
2863 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
2864 // (total limit 60).
2865 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2866 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2867 short_channel_id: 12,
2870 cltv_expiry_delta: 0,
2871 htlc_minimum_msat: 0,
2872 htlc_maximum_msat: OptionalField::Present(60_000),
2874 fee_proportional_millionths: 0,
2875 excess_data: Vec::new()
2877 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2878 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2879 short_channel_id: 13,
2882 cltv_expiry_delta: 0,
2883 htlc_minimum_msat: 0,
2884 htlc_maximum_msat: OptionalField::Present(60_000),
2886 fee_proportional_millionths: 0,
2887 excess_data: Vec::new()
2890 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
2891 // (total capacity 180 sats).
2892 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2893 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2894 short_channel_id: 2,
2897 cltv_expiry_delta: 0,
2898 htlc_minimum_msat: 0,
2899 htlc_maximum_msat: OptionalField::Present(200_000),
2901 fee_proportional_millionths: 0,
2902 excess_data: Vec::new()
2904 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2905 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2906 short_channel_id: 4,
2909 cltv_expiry_delta: 0,
2910 htlc_minimum_msat: 0,
2911 htlc_maximum_msat: OptionalField::Present(180_000),
2913 fee_proportional_millionths: 0,
2914 excess_data: Vec::new()
2918 // Attempt to route more than available results in a failure.
2919 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(),
2920 &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
2921 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2922 } else { panic!(); }
2926 // Now, attempt to route 250 sats (just a bit below the capacity).
2927 // Our algorithm should provide us with these 3 paths.
2928 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2929 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
2930 assert_eq!(route.paths.len(), 3);
2931 let mut total_amount_paid_msat = 0;
2932 for path in &route.paths {
2933 assert_eq!(path.len(), 2);
2934 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2935 total_amount_paid_msat += path.last().unwrap().fee_msat;
2937 assert_eq!(total_amount_paid_msat, 250_000);
2941 // Attempt to route an exact amount is also fine
2942 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2943 Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
2944 assert_eq!(route.paths.len(), 3);
2945 let mut total_amount_paid_msat = 0;
2946 for path in &route.paths {
2947 assert_eq!(path.len(), 2);
2948 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2949 total_amount_paid_msat += path.last().unwrap().fee_msat;
2951 assert_eq!(total_amount_paid_msat, 290_000);
2956 fn long_mpp_route_test() {
2957 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2958 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2960 // We need a route consisting of 3 paths:
2961 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
2962 // Note that these paths overlap (channels 5, 12, 13).
2963 // We will route 300 sats.
2964 // Each path will have 100 sats capacity, those channels which
2965 // are used twice will have 200 sats capacity.
2967 // Disable other potential paths.
2968 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2969 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2970 short_channel_id: 2,
2973 cltv_expiry_delta: 0,
2974 htlc_minimum_msat: 0,
2975 htlc_maximum_msat: OptionalField::Present(100_000),
2977 fee_proportional_millionths: 0,
2978 excess_data: Vec::new()
2980 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2981 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2982 short_channel_id: 7,
2985 cltv_expiry_delta: 0,
2986 htlc_minimum_msat: 0,
2987 htlc_maximum_msat: OptionalField::Present(100_000),
2989 fee_proportional_millionths: 0,
2990 excess_data: Vec::new()
2993 // Path via {node0, node2} is channels {1, 3, 5}.
2994 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2996 short_channel_id: 1,
2999 cltv_expiry_delta: 0,
3000 htlc_minimum_msat: 0,
3001 htlc_maximum_msat: OptionalField::Present(100_000),
3003 fee_proportional_millionths: 0,
3004 excess_data: Vec::new()
3006 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3008 short_channel_id: 3,
3011 cltv_expiry_delta: 0,
3012 htlc_minimum_msat: 0,
3013 htlc_maximum_msat: OptionalField::Present(100_000),
3015 fee_proportional_millionths: 0,
3016 excess_data: Vec::new()
3019 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3020 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3021 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3022 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3023 short_channel_id: 5,
3026 cltv_expiry_delta: 0,
3027 htlc_minimum_msat: 0,
3028 htlc_maximum_msat: OptionalField::Present(200_000),
3030 fee_proportional_millionths: 0,
3031 excess_data: Vec::new()
3034 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3035 // Add 100 sats to the capacities of {12, 13}, because these channels
3036 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3037 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3038 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3039 short_channel_id: 12,
3042 cltv_expiry_delta: 0,
3043 htlc_minimum_msat: 0,
3044 htlc_maximum_msat: OptionalField::Present(200_000),
3046 fee_proportional_millionths: 0,
3047 excess_data: Vec::new()
3049 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3050 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3051 short_channel_id: 13,
3054 cltv_expiry_delta: 0,
3055 htlc_minimum_msat: 0,
3056 htlc_maximum_msat: OptionalField::Present(200_000),
3058 fee_proportional_millionths: 0,
3059 excess_data: Vec::new()
3062 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3063 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3064 short_channel_id: 6,
3067 cltv_expiry_delta: 0,
3068 htlc_minimum_msat: 0,
3069 htlc_maximum_msat: OptionalField::Present(100_000),
3071 fee_proportional_millionths: 0,
3072 excess_data: Vec::new()
3074 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3075 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3076 short_channel_id: 11,
3079 cltv_expiry_delta: 0,
3080 htlc_minimum_msat: 0,
3081 htlc_maximum_msat: OptionalField::Present(100_000),
3083 fee_proportional_millionths: 0,
3084 excess_data: Vec::new()
3087 // Path via {node7, node2} is channels {12, 13, 5}.
3088 // We already limited them to 200 sats (they are used twice for 100 sats).
3089 // Nothing to do here.
3092 // Attempt to route more than available results in a failure.
3093 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3094 Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
3095 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3096 } else { panic!(); }
3100 // Now, attempt to route 300 sats (exact amount we can route).
3101 // Our algorithm should provide us with these 3 paths, 100 sats each.
3102 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3103 Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
3104 assert_eq!(route.paths.len(), 3);
3106 let mut total_amount_paid_msat = 0;
3107 for path in &route.paths {
3108 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3109 total_amount_paid_msat += path.last().unwrap().fee_msat;
3111 assert_eq!(total_amount_paid_msat, 300_000);
3117 fn mpp_cheaper_route_test() {
3118 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3119 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3121 // This test checks that if we have two cheaper paths and one more expensive path,
3122 // so that liquidity-wise any 2 of 3 combination is sufficient,
3123 // two cheaper paths will be taken.
3124 // These paths have equal available liquidity.
3126 // We need a combination of 3 paths:
3127 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3128 // Note that these paths overlap (channels 5, 12, 13).
3129 // Each path will have 100 sats capacity, those channels which
3130 // are used twice will have 200 sats capacity.
3132 // Disable other potential paths.
3133 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3134 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3135 short_channel_id: 2,
3138 cltv_expiry_delta: 0,
3139 htlc_minimum_msat: 0,
3140 htlc_maximum_msat: OptionalField::Present(100_000),
3142 fee_proportional_millionths: 0,
3143 excess_data: Vec::new()
3145 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3146 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3147 short_channel_id: 7,
3150 cltv_expiry_delta: 0,
3151 htlc_minimum_msat: 0,
3152 htlc_maximum_msat: OptionalField::Present(100_000),
3154 fee_proportional_millionths: 0,
3155 excess_data: Vec::new()
3158 // Path via {node0, node2} is channels {1, 3, 5}.
3159 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3160 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3161 short_channel_id: 1,
3164 cltv_expiry_delta: 0,
3165 htlc_minimum_msat: 0,
3166 htlc_maximum_msat: OptionalField::Present(100_000),
3168 fee_proportional_millionths: 0,
3169 excess_data: Vec::new()
3171 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3172 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3173 short_channel_id: 3,
3176 cltv_expiry_delta: 0,
3177 htlc_minimum_msat: 0,
3178 htlc_maximum_msat: OptionalField::Present(100_000),
3180 fee_proportional_millionths: 0,
3181 excess_data: Vec::new()
3184 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3185 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3186 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3187 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3188 short_channel_id: 5,
3191 cltv_expiry_delta: 0,
3192 htlc_minimum_msat: 0,
3193 htlc_maximum_msat: OptionalField::Present(200_000),
3195 fee_proportional_millionths: 0,
3196 excess_data: Vec::new()
3199 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3200 // Add 100 sats to the capacities of {12, 13}, because these channels
3201 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3202 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3203 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3204 short_channel_id: 12,
3207 cltv_expiry_delta: 0,
3208 htlc_minimum_msat: 0,
3209 htlc_maximum_msat: OptionalField::Present(200_000),
3211 fee_proportional_millionths: 0,
3212 excess_data: Vec::new()
3214 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3215 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3216 short_channel_id: 13,
3219 cltv_expiry_delta: 0,
3220 htlc_minimum_msat: 0,
3221 htlc_maximum_msat: OptionalField::Present(200_000),
3223 fee_proportional_millionths: 0,
3224 excess_data: Vec::new()
3227 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3228 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3229 short_channel_id: 6,
3232 cltv_expiry_delta: 0,
3233 htlc_minimum_msat: 0,
3234 htlc_maximum_msat: OptionalField::Present(100_000),
3235 fee_base_msat: 1_000,
3236 fee_proportional_millionths: 0,
3237 excess_data: Vec::new()
3239 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3240 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3241 short_channel_id: 11,
3244 cltv_expiry_delta: 0,
3245 htlc_minimum_msat: 0,
3246 htlc_maximum_msat: OptionalField::Present(100_000),
3248 fee_proportional_millionths: 0,
3249 excess_data: Vec::new()
3252 // Path via {node7, node2} is channels {12, 13, 5}.
3253 // We already limited them to 200 sats (they are used twice for 100 sats).
3254 // Nothing to do here.
3257 // Now, attempt to route 180 sats.
3258 // Our algorithm should provide us with these 2 paths.
3259 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3260 Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
3261 assert_eq!(route.paths.len(), 2);
3263 let mut total_value_transferred_msat = 0;
3264 let mut total_paid_msat = 0;
3265 for path in &route.paths {
3266 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3267 total_value_transferred_msat += path.last().unwrap().fee_msat;
3269 total_paid_msat += hop.fee_msat;
3272 // If we paid fee, this would be higher.
3273 assert_eq!(total_value_transferred_msat, 180_000);
3274 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3275 assert_eq!(total_fees_paid, 0);
3280 fn fees_on_mpp_route_test() {
3281 // This test makes sure that MPP algorithm properly takes into account
3282 // fees charged on the channels, by making the fees impactful:
3283 // if the fee is not properly accounted for, the behavior is different.
3284 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3285 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3287 // We need a route consisting of 2 paths:
3288 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
3289 // We will route 200 sats, Each path will have 100 sats capacity.
3291 // This test is not particularly stable: e.g.,
3292 // there's a way to route via {node0, node2, node4}.
3293 // It works while pathfinding is deterministic, but can be broken otherwise.
3294 // It's fine to ignore this concern for now.
3296 // Disable other potential paths.
3297 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3298 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3299 short_channel_id: 2,
3302 cltv_expiry_delta: 0,
3303 htlc_minimum_msat: 0,
3304 htlc_maximum_msat: OptionalField::Present(100_000),
3306 fee_proportional_millionths: 0,
3307 excess_data: Vec::new()
3310 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3311 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3312 short_channel_id: 7,
3315 cltv_expiry_delta: 0,
3316 htlc_minimum_msat: 0,
3317 htlc_maximum_msat: OptionalField::Present(100_000),
3319 fee_proportional_millionths: 0,
3320 excess_data: Vec::new()
3323 // Path via {node0, node2} is channels {1, 3, 5}.
3324 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3325 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3326 short_channel_id: 1,
3329 cltv_expiry_delta: 0,
3330 htlc_minimum_msat: 0,
3331 htlc_maximum_msat: OptionalField::Present(100_000),
3333 fee_proportional_millionths: 0,
3334 excess_data: Vec::new()
3336 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3337 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3338 short_channel_id: 3,
3341 cltv_expiry_delta: 0,
3342 htlc_minimum_msat: 0,
3343 htlc_maximum_msat: OptionalField::Present(100_000),
3345 fee_proportional_millionths: 0,
3346 excess_data: Vec::new()
3349 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3350 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3351 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3352 short_channel_id: 5,
3355 cltv_expiry_delta: 0,
3356 htlc_minimum_msat: 0,
3357 htlc_maximum_msat: OptionalField::Present(100_000),
3359 fee_proportional_millionths: 0,
3360 excess_data: Vec::new()
3363 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3364 // All channels should be 100 sats capacity. But for the fee experiment,
3365 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
3366 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
3367 // 100 sats (and pay 150 sats in fees for the use of channel 6),
3368 // so no matter how large are other channels,
3369 // the whole path will be limited by 100 sats with just these 2 conditions:
3370 // - channel 12 capacity is 250 sats
3371 // - fee for channel 6 is 150 sats
3372 // Let's test this by enforcing these 2 conditions and removing other limits.
3373 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3374 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3375 short_channel_id: 12,
3378 cltv_expiry_delta: 0,
3379 htlc_minimum_msat: 0,
3380 htlc_maximum_msat: OptionalField::Present(250_000),
3382 fee_proportional_millionths: 0,
3383 excess_data: Vec::new()
3385 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3386 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3387 short_channel_id: 13,
3390 cltv_expiry_delta: 0,
3391 htlc_minimum_msat: 0,
3392 htlc_maximum_msat: OptionalField::Absent,
3394 fee_proportional_millionths: 0,
3395 excess_data: Vec::new()
3398 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3399 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3400 short_channel_id: 6,
3403 cltv_expiry_delta: 0,
3404 htlc_minimum_msat: 0,
3405 htlc_maximum_msat: OptionalField::Absent,
3406 fee_base_msat: 150_000,
3407 fee_proportional_millionths: 0,
3408 excess_data: Vec::new()
3410 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3411 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3412 short_channel_id: 11,
3415 cltv_expiry_delta: 0,
3416 htlc_minimum_msat: 0,
3417 htlc_maximum_msat: OptionalField::Absent,
3419 fee_proportional_millionths: 0,
3420 excess_data: Vec::new()
3424 // Attempt to route more than available results in a failure.
3425 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3426 Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
3427 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3428 } else { panic!(); }
3432 // Now, attempt to route 200 sats (exact amount we can route).
3433 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3434 Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
3435 assert_eq!(route.paths.len(), 2);
3437 let mut total_amount_paid_msat = 0;
3438 for path in &route.paths {
3439 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3440 total_amount_paid_msat += path.last().unwrap().fee_msat;
3442 assert_eq!(total_amount_paid_msat, 200_000);
3448 fn drop_lowest_channel_mpp_route_test() {
3449 // This test checks that low-capacity channel is dropped when after
3450 // path finding we realize that we found more capacity than we need.
3451 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3452 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3454 // We need a route consisting of 3 paths:
3455 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3457 // The first and the second paths should be sufficient, but the third should be
3458 // cheaper, so that we select it but drop later.
3460 // First, we set limits on these (previously unlimited) channels.
3461 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
3463 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
3464 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3465 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3466 short_channel_id: 1,
3469 cltv_expiry_delta: 0,
3470 htlc_minimum_msat: 0,
3471 htlc_maximum_msat: OptionalField::Present(100_000),
3473 fee_proportional_millionths: 0,
3474 excess_data: Vec::new()
3476 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3477 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3478 short_channel_id: 3,
3481 cltv_expiry_delta: 0,
3482 htlc_minimum_msat: 0,
3483 htlc_maximum_msat: OptionalField::Present(50_000),
3485 fee_proportional_millionths: 0,
3486 excess_data: Vec::new()
3489 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
3490 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3491 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3492 short_channel_id: 12,
3495 cltv_expiry_delta: 0,
3496 htlc_minimum_msat: 0,
3497 htlc_maximum_msat: OptionalField::Present(60_000),
3499 fee_proportional_millionths: 0,
3500 excess_data: Vec::new()
3502 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3503 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3504 short_channel_id: 13,
3507 cltv_expiry_delta: 0,
3508 htlc_minimum_msat: 0,
3509 htlc_maximum_msat: OptionalField::Present(60_000),
3511 fee_proportional_millionths: 0,
3512 excess_data: Vec::new()
3515 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
3516 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3517 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3518 short_channel_id: 2,
3521 cltv_expiry_delta: 0,
3522 htlc_minimum_msat: 0,
3523 htlc_maximum_msat: OptionalField::Present(20_000),
3525 fee_proportional_millionths: 0,
3526 excess_data: Vec::new()
3528 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3529 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3530 short_channel_id: 4,
3533 cltv_expiry_delta: 0,
3534 htlc_minimum_msat: 0,
3535 htlc_maximum_msat: OptionalField::Present(20_000),
3537 fee_proportional_millionths: 0,
3538 excess_data: Vec::new()
3542 // Attempt to route more than available results in a failure.
3543 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3544 Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
3545 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3546 } else { panic!(); }
3550 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
3551 // Our algorithm should provide us with these 3 paths.
3552 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3553 Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
3554 assert_eq!(route.paths.len(), 3);
3555 let mut total_amount_paid_msat = 0;
3556 for path in &route.paths {
3557 assert_eq!(path.len(), 2);
3558 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3559 total_amount_paid_msat += path.last().unwrap().fee_msat;
3561 assert_eq!(total_amount_paid_msat, 125_000);
3565 // Attempt to route without the last small cheap channel
3566 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3567 Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3568 assert_eq!(route.paths.len(), 2);
3569 let mut total_amount_paid_msat = 0;
3570 for path in &route.paths {
3571 assert_eq!(path.len(), 2);
3572 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3573 total_amount_paid_msat += path.last().unwrap().fee_msat;
3575 assert_eq!(total_amount_paid_msat, 90_000);
3580 fn min_criteria_consistency() {
3581 // Test that we don't use an inconsistent metric between updating and walking nodes during
3582 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
3583 // was updated with a different criterion from the heap sorting, resulting in loops in
3584 // calculated paths. We test for that specific case here.
3586 // We construct a network that looks like this:
3588 // node2 -1(3)2- node3
3592 // node1 -1(5)2- node4 -1(1)2- node6
3598 // We create a loop on the side of our real path - our destination is node 6, with a
3599 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
3600 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
3601 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
3602 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
3603 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
3604 // "previous hop" being set to node 3, creating a loop in the path.
3605 let secp_ctx = Secp256k1::new();
3606 let logger = Arc::new(test_utils::TestLogger::new());
3607 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
3608 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3610 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
3611 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3612 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3613 short_channel_id: 6,
3616 cltv_expiry_delta: (6 << 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[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
3625 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3626 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3627 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3628 short_channel_id: 5,
3631 cltv_expiry_delta: (5 << 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[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
3640 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
3641 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3642 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3643 short_channel_id: 4,
3646 cltv_expiry_delta: (4 << 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[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
3655 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
3656 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
3657 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3658 short_channel_id: 3,
3661 cltv_expiry_delta: (3 << 8) | 0,
3662 htlc_minimum_msat: 0,
3663 htlc_maximum_msat: OptionalField::Absent,
3665 fee_proportional_millionths: 0,
3666 excess_data: Vec::new()
3668 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
3670 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
3671 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3672 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3673 short_channel_id: 2,
3676 cltv_expiry_delta: (2 << 8) | 0,
3677 htlc_minimum_msat: 0,
3678 htlc_maximum_msat: OptionalField::Absent,
3680 fee_proportional_millionths: 0,
3681 excess_data: Vec::new()
3684 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
3685 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3686 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3687 short_channel_id: 1,
3690 cltv_expiry_delta: (1 << 8) | 0,
3691 htlc_minimum_msat: 100,
3692 htlc_maximum_msat: OptionalField::Absent,
3694 fee_proportional_millionths: 0,
3695 excess_data: Vec::new()
3697 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
3700 // Now ensure the route flows simply over nodes 1 and 4 to 6.
3701 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();
3702 assert_eq!(route.paths.len(), 1);
3703 assert_eq!(route.paths[0].len(), 3);
3705 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3706 assert_eq!(route.paths[0][0].short_channel_id, 6);
3707 assert_eq!(route.paths[0][0].fee_msat, 100);
3708 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
3709 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
3710 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
3712 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
3713 assert_eq!(route.paths[0][1].short_channel_id, 5);
3714 assert_eq!(route.paths[0][1].fee_msat, 0);
3715 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
3716 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
3717 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
3719 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
3720 assert_eq!(route.paths[0][2].short_channel_id, 1);
3721 assert_eq!(route.paths[0][2].fee_msat, 10_000);
3722 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
3723 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3724 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
3730 fn exact_fee_liquidity_limit() {
3731 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
3732 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
3733 // we calculated fees on a higher value, resulting in us ignoring such paths.
3734 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3735 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
3737 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
3739 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3740 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3741 short_channel_id: 2,
3744 cltv_expiry_delta: 0,
3745 htlc_minimum_msat: 0,
3746 htlc_maximum_msat: OptionalField::Present(85_000),
3748 fee_proportional_millionths: 0,
3749 excess_data: Vec::new()
3752 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3753 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3754 short_channel_id: 12,
3757 cltv_expiry_delta: (4 << 8) | 1,
3758 htlc_minimum_msat: 0,
3759 htlc_maximum_msat: OptionalField::Present(270_000),
3761 fee_proportional_millionths: 1000000,
3762 excess_data: Vec::new()
3766 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
3767 // 200% fee charged channel 13 in the 1-to-2 direction.
3768 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();
3769 assert_eq!(route.paths.len(), 1);
3770 assert_eq!(route.paths[0].len(), 2);
3772 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3773 assert_eq!(route.paths[0][0].short_channel_id, 12);
3774 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3775 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3776 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3777 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3779 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3780 assert_eq!(route.paths[0][1].short_channel_id, 13);
3781 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3782 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3783 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3784 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3789 fn htlc_max_reduction_below_min() {
3790 // Test that if, while walking the graph, we reduce the value being sent to meet an
3791 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
3792 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
3793 // resulting in us thinking there is no possible path, even if other paths exist.
3794 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3795 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3797 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
3798 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
3799 // then try to send 90_000.
3800 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3801 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3802 short_channel_id: 2,
3805 cltv_expiry_delta: 0,
3806 htlc_minimum_msat: 0,
3807 htlc_maximum_msat: OptionalField::Present(80_000),
3809 fee_proportional_millionths: 0,
3810 excess_data: Vec::new()
3812 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3813 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3814 short_channel_id: 4,
3817 cltv_expiry_delta: (4 << 8) | 1,
3818 htlc_minimum_msat: 90_000,
3819 htlc_maximum_msat: OptionalField::Absent,
3821 fee_proportional_millionths: 0,
3822 excess_data: Vec::new()
3826 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
3827 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
3828 // expensive) channels 12-13 path.
3829 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();
3830 assert_eq!(route.paths.len(), 1);
3831 assert_eq!(route.paths[0].len(), 2);
3833 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3834 assert_eq!(route.paths[0][0].short_channel_id, 12);
3835 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3836 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3837 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3838 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3840 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3841 assert_eq!(route.paths[0][1].short_channel_id, 13);
3842 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3843 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3844 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
3845 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3850 use util::ser::Readable;
3851 /// Tries to open a network graph file, or panics with a URL to fetch it.
3852 pub(super) fn get_route_file() -> Result<std::fs::File, std::io::Error> {
3853 let res = File::open("net_graph-2021-02-12.bin") // By default we're run in RL/lightning
3854 .or_else(|_| File::open("lightning/net_graph-2021-02-12.bin")) // We may be run manually in RL/
3855 .or_else(|_| { // Fall back to guessing based on the binary location
3856 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
3857 let mut path = std::env::current_exe().unwrap();
3858 path.pop(); // lightning-...
3860 path.pop(); // debug
3861 path.pop(); // target
3862 path.push("lightning");
3863 path.push("net_graph-2021-02-12.bin");
3864 eprintln!("{}", path.to_str().unwrap());
3867 #[cfg(require_route_graph_test)]
3868 return Ok(res.expect("Didn't have route graph and was configured to require it"));
3869 #[cfg(not(require_route_graph_test))]
3873 pub(super) fn random_init_seed() -> u64 {
3874 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
3875 use core::hash::{BuildHasher, Hasher};
3876 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
3877 println!("Using seed of {}", seed);
3882 fn generate_routes() {
3883 let mut d = match get_route_file() {
3886 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");
3890 let graph = NetworkGraph::read(&mut d).unwrap();
3892 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3893 let mut seed = random_init_seed() as usize;
3894 'load_endpoints: for _ in 0..10 {
3896 seed = seed.overflowing_mul(0xdeadbeef).0;
3897 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3898 seed = seed.overflowing_mul(0xdeadbeef).0;
3899 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3900 let amt = seed as u64 % 200_000_000;
3901 if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3902 continue 'load_endpoints;
3909 fn generate_routes_mpp() {
3910 let mut d = match get_route_file() {
3913 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");
3917 let graph = NetworkGraph::read(&mut d).unwrap();
3919 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3920 let mut seed = random_init_seed() as usize;
3921 'load_endpoints: for _ in 0..10 {
3923 seed = seed.overflowing_mul(0xdeadbeef).0;
3924 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3925 seed = seed.overflowing_mul(0xdeadbeef).0;
3926 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3927 let amt = seed as u64 % 200_000_000;
3928 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3929 continue 'load_endpoints;
3936 #[cfg(all(test, feature = "unstable"))]
3939 use util::logger::{Logger, Record};
3943 struct DummyLogger {}
3944 impl Logger for DummyLogger {
3945 fn log(&self, _record: &Record) {}
3949 fn generate_routes(bench: &mut Bencher) {
3950 let mut d = tests::get_route_file()
3951 .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");
3952 let graph = NetworkGraph::read(&mut d).unwrap();
3954 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3955 let mut path_endpoints = Vec::new();
3956 let mut seed: usize = 0xdeadbeef;
3957 'load_endpoints: for _ in 0..100 {
3960 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3962 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3963 let amt = seed as u64 % 1_000_000;
3964 if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
3965 path_endpoints.push((src, dst, amt));
3966 continue 'load_endpoints;
3971 // ...then benchmark finding paths between the nodes we learned.
3974 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
3975 assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
3981 fn generate_mpp_routes(bench: &mut Bencher) {
3982 let mut d = tests::get_route_file()
3983 .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");
3984 let graph = NetworkGraph::read(&mut d).unwrap();
3986 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3987 let mut path_endpoints = Vec::new();
3988 let mut seed: usize = 0xdeadbeef;
3989 'load_endpoints: for _ in 0..100 {
3992 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3994 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3995 let amt = seed as u64 % 1_000_000;
3996 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
3997 path_endpoints.push((src, dst, amt));
3998 continue 'load_endpoints;
4003 // ...then benchmark finding paths between the nodes we learned.
4006 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
4007 assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());