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;
26 use alloc::collections::BinaryHeap;
31 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
33 /// The node_id of the node at this hop.
34 pub pubkey: PublicKey,
35 /// The node_announcement features of the node at this hop. For the last hop, these may be
36 /// amended to match the features present in the invoice this node generated.
37 pub node_features: NodeFeatures,
38 /// The channel that should be used from the previous hop to reach this node.
39 pub short_channel_id: u64,
40 /// The channel_announcement features of the channel that should be used from the previous hop
41 /// to reach this node.
42 pub channel_features: ChannelFeatures,
43 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
44 /// For the last hop, this should be the full value of the payment (might be more than
45 /// requested if we had to match htlc_minimum_msat).
47 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
48 /// expected at the destination, in excess of the current block height.
49 pub cltv_expiry_delta: u32,
52 impl_writeable_tlv_based!(RouteHop, {
53 (0, pubkey, required),
54 (2, node_features, required),
55 (4, short_channel_id, required),
56 (6, channel_features, required),
57 (8, fee_msat, required),
58 (10, cltv_expiry_delta, required),
61 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
62 /// it can take multiple paths. Each path is composed of one or more hops through the network.
63 #[derive(Clone, Hash, PartialEq, Eq)]
65 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
66 /// last RouteHop in each path must be the same.
67 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
68 /// destination. Thus, this must always be at least length one. While the maximum length of any
69 /// given path is variable, keeping the length of any path to less than 20 should currently
70 /// ensure it is viable.
71 pub paths: Vec<Vec<RouteHop>>,
75 /// Returns the total amount of fees paid on this [`Route`].
77 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
78 /// the amount passed to [`get_route`]'s `final_value_msat`.
79 pub fn get_total_fees(&self) -> u64 {
80 // Do not count last hop of each path since that's the full value of the payment
81 return self.paths.iter()
82 .flat_map(|path| path.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[]))
83 .map(|hop| &hop.fee_msat)
87 /// Returns the total amount paid on this [`Route`], excluding the fees.
88 pub fn get_total_amount(&self) -> u64 {
89 return self.paths.iter()
90 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
95 const SERIALIZATION_VERSION: u8 = 1;
96 const MIN_SERIALIZATION_VERSION: u8 = 1;
98 impl Writeable for Route {
99 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
100 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
101 (self.paths.len() as u64).write(writer)?;
102 for hops in self.paths.iter() {
103 (hops.len() as u8).write(writer)?;
104 for hop in hops.iter() {
108 write_tlv_fields!(writer, {});
113 impl Readable for Route {
114 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
115 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
116 let path_count: u64 = Readable::read(reader)?;
117 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
118 for _ in 0..path_count {
119 let hop_count: u8 = Readable::read(reader)?;
120 let mut hops = Vec::with_capacity(hop_count as usize);
121 for _ in 0..hop_count {
122 hops.push(Readable::read(reader)?);
126 read_tlv_fields!(reader, {});
131 /// A list of hops along a payment path terminating with a channel to the recipient.
132 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
133 pub struct RouteHint(pub Vec<RouteHintHop>);
135 /// A channel descriptor for a hop along a payment path.
136 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
137 pub struct RouteHintHop {
138 /// The node_id of the non-target end of the route
139 pub src_node_id: PublicKey,
140 /// The short_channel_id of this channel
141 pub short_channel_id: u64,
142 /// The fees which must be paid to use this channel
143 pub fees: RoutingFees,
144 /// The difference in CLTV values between this node and the next node.
145 pub cltv_expiry_delta: u16,
146 /// The minimum value, in msat, which must be relayed to the next hop.
147 pub htlc_minimum_msat: Option<u64>,
148 /// The maximum value in msat available for routing with a single HTLC.
149 pub htlc_maximum_msat: Option<u64>,
152 #[derive(Eq, PartialEq)]
153 struct RouteGraphNode {
155 lowest_fee_to_peer_through_node: u64,
156 lowest_fee_to_node: u64,
157 // The maximum value a yet-to-be-constructed payment path might flow through this node.
158 // This value is upper-bounded by us by:
159 // - how much is needed for a path being constructed
160 // - how much value can channels following this node (up to the destination) can contribute,
161 // considering their capacity and fees
162 value_contribution_msat: u64,
163 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
164 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
165 path_htlc_minimum_msat: u64,
168 impl cmp::Ord for RouteGraphNode {
169 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
170 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat);
171 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat);
172 other_score.cmp(&self_score).then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
176 impl cmp::PartialOrd for RouteGraphNode {
177 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
178 Some(self.cmp(other))
182 struct DummyDirectionalChannelInfo {
183 cltv_expiry_delta: u32,
184 htlc_minimum_msat: u64,
185 htlc_maximum_msat: Option<u64>,
189 /// It's useful to keep track of the hops associated with the fees required to use them,
190 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
191 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
192 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
193 #[derive(Clone, Debug)]
194 struct PathBuildingHop<'a> {
195 // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
196 // Note that node_features is calculated separately after our initial graph walk.
198 short_channel_id: u64,
199 channel_features: &'a ChannelFeatures,
201 cltv_expiry_delta: u32,
203 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
204 src_lowest_inbound_fees: RoutingFees,
205 /// Fees of the channel used in this hop.
206 channel_fees: RoutingFees,
207 /// All the fees paid *after* this channel on the way to the destination
208 next_hops_fee_msat: u64,
209 /// Fee paid for the use of the current channel (see channel_fees).
210 /// The value will be actually deducted from the counterparty balance on the previous link.
211 hop_use_fee_msat: u64,
212 /// Used to compare channels when choosing the for routing.
213 /// Includes paying for the use of a hop and the following hops, as well as
214 /// an estimated cost of reaching this hop.
215 /// Might get stale when fees are recomputed. Primarily for internal use.
217 /// This is useful for update_value_and_recompute_fees to make sure
218 /// we don't fall below the minimum. Should not be updated manually and
219 /// generally should not be accessed.
220 htlc_minimum_msat: u64,
221 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
222 /// walk and may be invalid thereafter.
223 path_htlc_minimum_msat: u64,
224 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
225 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
226 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
227 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
228 /// avoid processing them again.
230 #[cfg(any(test, feature = "fuzztarget"))]
231 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
232 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
233 // value_contribution_msat, which requires tracking it here. See comments below where it is
234 // used for more info.
235 value_contribution_msat: u64,
238 // Instantiated with a list of hops with correct data in them collected during path finding,
239 // an instance of this struct should be further modified only via given methods.
241 struct PaymentPath<'a> {
242 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
245 impl<'a> PaymentPath<'a> {
246 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
247 fn get_value_msat(&self) -> u64 {
248 self.hops.last().unwrap().0.fee_msat
251 fn get_total_fee_paid_msat(&self) -> u64 {
252 if self.hops.len() < 1 {
256 // Can't use next_hops_fee_msat because it gets outdated.
257 for (i, (hop, _)) in self.hops.iter().enumerate() {
258 if i != self.hops.len() - 1 {
259 result += hop.fee_msat;
265 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
266 // to change fees may result in an inconsistency.
268 // Sometimes we call this function right after constructing a path which is inconsistent in
269 // that it the value being transferred has decreased while we were doing path finding, leading
270 // to the fees being paid not lining up with the actual limits.
272 // Note that this function is not aware of the available_liquidity limit, and thus does not
273 // support increasing the value being transferred.
274 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
275 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
277 let mut total_fee_paid_msat = 0 as u64;
278 for i in (0..self.hops.len()).rev() {
279 let last_hop = i == self.hops.len() - 1;
281 // For non-last-hop, this value will represent the fees paid on the current hop. It
282 // will consist of the fees for the use of the next hop, and extra fees to match
283 // htlc_minimum_msat of the current channel. Last hop is handled separately.
284 let mut cur_hop_fees_msat = 0;
286 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
289 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
290 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
291 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
292 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
293 // set it too high just to maliciously take more fees by exploiting this
294 // match htlc_minimum_msat logic.
295 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
296 if let Some(extra_fees_msat) = cur_hop.htlc_minimum_msat.checked_sub(cur_hop_transferred_amount_msat) {
297 // Note that there is a risk that *previous hops* (those closer to us, as we go
298 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
300 // This might make us end up with a broken route, although this should be super-rare
301 // in practice, both because of how healthy channels look like, and how we pick
302 // channels in add_entry.
303 // Also, this can't be exploited more heavily than *announce a free path and fail
305 cur_hop_transferred_amount_msat += extra_fees_msat;
306 total_fee_paid_msat += extra_fees_msat;
307 cur_hop_fees_msat += extra_fees_msat;
311 // Final hop is a special case: it usually has just value_msat (by design), but also
312 // it still could overpay for the htlc_minimum_msat.
313 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
315 // Propagate updated fees for the use of the channels to one hop back, where they
316 // will be actually paid (fee_msat). The last hop is handled above separately.
317 cur_hop.fee_msat = cur_hop_fees_msat;
320 // Fee for the use of the current hop which will be deducted on the previous hop.
321 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
322 // this channel is free for us.
324 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.channel_fees) {
325 cur_hop.hop_use_fee_msat = new_fee;
326 total_fee_paid_msat += new_fee;
328 // It should not be possible because this function is called only to reduce the
329 // value. In that case, compute_fee was already called with the same fees for
330 // larger amount and there was no overflow.
338 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
339 let proportional_fee_millions =
340 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
341 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
342 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
346 // This function may be (indirectly) called without any verification,
347 // with channel_fees provided by a caller. We should handle it gracefully.
352 /// Gets a keysend route from us (payer) to the given target node (payee). This is needed because
353 /// keysend payments do not have an invoice from which to pull the payee's supported features, which
354 /// makes it tricky to otherwise supply the `payee_features` parameter of `get_route`.
355 pub fn get_keysend_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee:
356 &PublicKey, first_hops: Option<&[&ChannelDetails]>, last_hops: &[&RouteHint],
357 final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route,
358 LightningError> where L::Target: Logger {
359 let invoice_features = InvoiceFeatures::for_keysend();
360 get_route(our_node_id, network, payee, Some(invoice_features), first_hops, last_hops,
361 final_value_msat, final_cltv, logger)
364 /// Gets a route from us (payer) to the given target node (payee).
366 /// If the payee provided features in their invoice, they should be provided via payee_features.
367 /// Without this, MPP will only be used if the payee's features are available in the network graph.
369 /// Private routing paths between a public node and the target may be included in `last_hops`.
370 /// Currently, only the last hop in each path is considered.
372 /// If some channels aren't announced, it may be useful to fill in a first_hops with the
373 /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
374 /// view of our local channels (from net_graph_msg_handler) will be ignored, and only those
375 /// in first_hops will be used.
377 /// Panics if first_hops contains channels without short_channel_ids
378 /// (ChannelManager::list_usable_channels will never include such channels).
380 /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
381 /// equal), however the enabled/disabled bit on such channels as well as the
382 /// htlc_minimum_msat/htlc_maximum_msat *are* checked as they may change based on the receiving node.
383 pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee: &PublicKey, payee_features: Option<InvoiceFeatures>, first_hops: Option<&[&ChannelDetails]>,
384 last_hops: &[&RouteHint], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
385 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
386 // uptime/success in using a node in the past.
387 if *payee == *our_node_id {
388 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
391 if final_value_msat > MAX_VALUE_MSAT {
392 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
395 if final_value_msat == 0 {
396 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
399 for route in last_hops.iter() {
400 for hop in &route.0 {
401 if hop.src_node_id == *payee {
402 return Err(LightningError{err: "Last hop cannot have a payee as a source.".to_owned(), action: ErrorAction::IgnoreError});
407 // The general routing idea is the following:
408 // 1. Fill first/last hops communicated by the caller.
409 // 2. Attempt to construct a path from payer to payee for transferring
410 // any ~sufficient (described later) value.
411 // If succeed, remember which channels were used and how much liquidity they have available,
412 // so that future paths don't rely on the same liquidity.
413 // 3. Prooceed to the next step if:
414 // - we hit the recommended target value;
415 // - OR if we could not construct a new path. Any next attempt will fail too.
416 // Otherwise, repeat step 2.
417 // 4. See if we managed to collect paths which aggregately are able to transfer target value
418 // (not recommended value). If yes, proceed. If not, fail routing.
419 // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
420 // 6. Of all the found paths, select only those with the lowest total fee.
421 // 7. The last path in every selected route is likely to be more than we need.
422 // Reduce its value-to-transfer and recompute fees.
423 // 8. Choose the best route by the lowest total fee.
425 // As for the actual search algorithm,
426 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
427 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
429 // We are not a faithful Dijkstra's implementation because we can change values which impact
430 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
431 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) then
432 // the value we are currently attempting to send over a path, we simply reduce the value being
433 // sent along the path for any hops after that channel. This may imply that later fees (which
434 // we've already tabulated) are lower because a smaller value is passing through the channels
435 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
436 // channels which were selected earlier (and which may still be used for other paths without a
437 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
440 // One potentially problematic case for this algorithm would be if there are many
441 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
442 // graph walking), we may never find a path which is not liquidity-limited and has lower
443 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
444 // Because we only consider paths with at least 5% of the total value being sent, the damage
445 // from such a case should be limited, however this could be further reduced in the future by
446 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
447 // limits for the purposes of fee calculation.
449 // Alternatively, we could store more detailed path information in the heap (targets, below)
450 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
451 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
452 // and practically (as we would need to store dynamically-allocated path information in heap
453 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
454 // results of such an algorithm would likely be biased towards lower-value paths.
456 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
457 // outside of our current search value, running a path search more times to gather candidate
458 // paths at different values. While this may be acceptable, further path searches may increase
459 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
460 // graph for candidate paths, calculating the maximum value which can realistically be sent at
461 // the same time, remaining generic across different payment values.
463 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
464 // to use as the A* heuristic beyond just the cost to get one node further than the current
467 let network_graph = network.read_only();
468 let network_channels = network_graph.channels();
469 let network_nodes = network_graph.nodes();
470 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
471 cltv_expiry_delta: 0,
472 htlc_minimum_msat: 0,
473 htlc_maximum_msat: None,
476 proportional_millionths: 0,
480 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
481 // it. If the payee supports it they're supposed to include it in the invoice, so that should
483 let allow_mpp = if let Some(features) = &payee_features {
484 features.supports_basic_mpp()
485 } else if let Some(node) = network_nodes.get(&payee) {
486 if let Some(node_info) = node.announcement_info.as_ref() {
487 node_info.features.supports_basic_mpp()
490 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP", our_node_id, payee,
491 if allow_mpp { "with" } else { "without" });
494 // Prepare the data we'll use for payee-to-payer search by
495 // inserting first hops suggested by the caller as targets.
496 // Our search will then attempt to reach them while traversing from the payee node.
497 let mut first_hop_targets: HashMap<_, Vec<(_, ChannelFeatures, _, NodeFeatures)>> =
498 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
499 if let Some(hops) = first_hops {
501 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
502 if chan.counterparty.node_id == *our_node_id {
503 return Err(LightningError{err: "First hop cannot have our_node_id as a destination.".to_owned(), action: ErrorAction::IgnoreError});
505 first_hop_targets.entry(chan.counterparty.node_id).or_insert(Vec::new())
506 .push((short_channel_id, chan.counterparty.features.to_context(), chan.outbound_capacity_msat, chan.counterparty.features.to_context()));
508 if first_hop_targets.is_empty() {
509 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
513 let empty_channel_features = ChannelFeatures::empty();
515 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
516 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
517 // adding duplicate entries when we find a better path to a given node.
518 let mut targets = BinaryHeap::new();
520 // Map from node_id to information about the best current path to that node, including feerate
522 let mut dist = HashMap::with_capacity(network_nodes.len());
524 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
525 // indicating that we may wish to try again with a higher value, potentially paying to meet an
526 // htlc_minimum with extra fees while still finding a cheaper path.
527 let mut hit_minimum_limit;
529 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
530 // We start with a path_value of the exact amount we want, and if that generates a route we may
531 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
532 // amount we want in total across paths, selecting the best subset at the end.
533 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
534 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
535 let mut path_value_msat = final_value_msat;
537 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
538 // This map allows paths to be aware of the channel use by other paths in the same call.
539 // This would help to make a better path finding decisions and not "overbook" channels.
540 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
541 let mut bookkeeped_channels_liquidity_available_msat = HashMap::with_capacity(network_nodes.len());
543 // Keeping track of how much value we already collected across other paths. Helps to decide:
544 // - how much a new path should be transferring (upper bound);
545 // - whether a channel should be disregarded because
546 // it's available liquidity is too small comparing to how much more we need to collect;
547 // - when we want to stop looking for new paths.
548 let mut already_collected_value_msat = 0;
550 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee, our_node_id, final_value_msat);
552 macro_rules! add_entry {
553 // Adds entry which goes from $src_node_id to $dest_node_id
554 // over the channel with id $chan_id with fees described in
555 // $directional_info.
556 // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one,
557 // since that value has to be transferred over this channel.
558 // Returns whether this channel caused an update to `targets`.
559 ( $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,
560 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => { {
561 // We "return" whether we updated the path at the end, via this:
562 let mut did_add_update_path_to_src_node = false;
563 // Channels to self should not be used. This is more of belt-and-suspenders, because in
564 // practice these cases should be caught earlier:
565 // - for regular channels at channel announcement (TODO)
566 // - for first and last hops early in get_route
567 if $src_node_id != $dest_node_id.clone() {
568 let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
569 let mut initial_liquidity_available_msat = None;
570 if let Some(capacity_sats) = $capacity_sats {
571 initial_liquidity_available_msat = Some(capacity_sats * 1000);
574 if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
575 if let Some(available_msat) = initial_liquidity_available_msat {
576 initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
578 initial_liquidity_available_msat = Some(htlc_maximum_msat);
582 match initial_liquidity_available_msat {
583 Some(available_msat) => available_msat,
584 // We assume channels with unknown balance have
585 // a capacity of 0.0025 BTC (or 250_000 sats).
586 None => 250_000 * 1000
590 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
591 // It may be misleading because we might later choose to reduce the value transferred
592 // over these channels, and the channel which was insufficient might become sufficient.
593 // Worst case: we drop a good channel here because it can't cover the high following
594 // fees caused by one expensive channel, but then this channel could have been used
595 // if the amount being transferred over this path is lower.
596 // We do this for now, but this is a subject for removal.
597 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
599 // Routing Fragmentation Mitigation heuristic:
601 // Routing fragmentation across many payment paths increases the overall routing
602 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
603 // Taking too many smaller paths also increases the chance of payment failure.
604 // Thus to avoid this effect, we require from our collected links to provide
605 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
607 // This requirement is currently 5% of the remaining-to-be-collected value.
608 // This means as we successfully advance in our collection,
609 // the absolute liquidity contribution is lowered,
610 // thus increasing the number of potential channels to be selected.
612 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
613 // or 100% if we're not allowed to do multipath payments.
614 let minimal_value_contribution_msat: u64 = if allow_mpp {
615 (recommended_value_msat - already_collected_value_msat + 19) / 20
619 // Verify the liquidity offered by this channel complies to the minimal contribution.
620 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
622 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
623 // Includes paying fees for the use of the following channels.
624 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
625 Some(result) => result,
626 // Can't overflow due to how the values were computed right above.
627 None => unreachable!(),
629 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
630 let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
631 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
633 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
634 // bother considering this channel.
635 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
636 // be only reduced later (not increased), so this channel should just be skipped
637 // as not sufficient.
638 if !over_path_minimum_msat {
639 hit_minimum_limit = true;
640 } else if contributes_sufficient_value {
641 // Note that low contribution here (limited by available_liquidity_msat)
642 // might violate htlc_minimum_msat on the hops which are next along the
643 // payment path (upstream to the payee). To avoid that, we recompute path
644 // path fees knowing the final path contribution after constructing it.
645 let path_htlc_minimum_msat = match compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
646 .map(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) {
647 Some(Some(value_msat)) => cmp::max(value_msat, $directional_info.htlc_minimum_msat),
648 _ => u64::max_value()
650 let hm_entry = dist.entry(&$src_node_id);
651 let old_entry = hm_entry.or_insert_with(|| {
652 // If there was previously no known way to access
653 // the source node (recall it goes payee-to-payer) of $chan_id, first add
654 // a semi-dummy record just to compute the fees to reach the source node.
655 // This will affect our decision on selecting $chan_id
656 // as a way to reach the $dest_node_id.
657 let mut fee_base_msat = u32::max_value();
658 let mut fee_proportional_millionths = u32::max_value();
659 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
660 fee_base_msat = fees.base_msat;
661 fee_proportional_millionths = fees.proportional_millionths;
664 pubkey: $dest_node_id.clone(),
666 channel_features: $chan_features,
668 cltv_expiry_delta: 0,
669 src_lowest_inbound_fees: RoutingFees {
670 base_msat: fee_base_msat,
671 proportional_millionths: fee_proportional_millionths,
673 channel_fees: $directional_info.fees,
674 next_hops_fee_msat: u64::max_value(),
675 hop_use_fee_msat: u64::max_value(),
676 total_fee_msat: u64::max_value(),
677 htlc_minimum_msat: $directional_info.htlc_minimum_msat,
678 path_htlc_minimum_msat,
679 was_processed: false,
680 #[cfg(any(test, feature = "fuzztarget"))]
681 value_contribution_msat,
685 #[allow(unused_mut)] // We only use the mut in cfg(test)
686 let mut should_process = !old_entry.was_processed;
687 #[cfg(any(test, feature = "fuzztarget"))]
689 // In test/fuzzing builds, we do extra checks to make sure the skipping
690 // of already-seen nodes only happens in cases we expect (see below).
691 if !should_process { should_process = true; }
695 let mut hop_use_fee_msat = 0;
696 let mut total_fee_msat = $next_hops_fee_msat;
698 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
699 // will have the same effective-fee
700 if $src_node_id != *our_node_id {
701 match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
702 // max_value means we'll always fail
703 // the old_entry.total_fee_msat > total_fee_msat check
704 None => total_fee_msat = u64::max_value(),
706 hop_use_fee_msat = fee_msat;
707 total_fee_msat += hop_use_fee_msat;
708 // When calculating the lowest inbound fees to a node, we
709 // calculate fees here not based on the actual value we think
710 // will flow over this channel, but on the minimum value that
711 // we'll accept flowing over it. The minimum accepted value
712 // is a constant through each path collection run, ensuring
713 // consistent basis. Otherwise we may later find a
714 // different path to the source node that is more expensive,
715 // but which we consider to be cheaper because we are capacity
716 // constrained and the relative fee becomes lower.
717 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
718 .map(|a| a.checked_add(total_fee_msat)) {
723 total_fee_msat = u64::max_value();
730 let new_graph_node = RouteGraphNode {
731 pubkey: $src_node_id,
732 lowest_fee_to_peer_through_node: total_fee_msat,
733 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
734 value_contribution_msat: value_contribution_msat,
735 path_htlc_minimum_msat,
738 // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
739 // if this way is cheaper than the already known
740 // (considering the cost to "reach" this channel from the route destination,
741 // the cost of using this channel,
742 // and the cost of routing to the source node of this channel).
743 // Also, consider that htlc_minimum_msat_difference, because we might end up
744 // paying it. Consider the following exploit:
745 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
746 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
747 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
748 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
750 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
751 // but it may require additional tracking - we don't want to double-count
752 // the fees included in $next_hops_path_htlc_minimum_msat, but also
753 // can't use something that may decrease on future hops.
754 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat);
755 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat);
757 if !old_entry.was_processed && new_cost < old_cost {
758 targets.push(new_graph_node);
759 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
760 old_entry.hop_use_fee_msat = hop_use_fee_msat;
761 old_entry.total_fee_msat = total_fee_msat;
762 old_entry.pubkey = $dest_node_id.clone();
763 old_entry.short_channel_id = $chan_id.clone();
764 old_entry.channel_features = $chan_features;
765 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
766 old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
767 old_entry.channel_fees = $directional_info.fees;
768 old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
769 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
770 #[cfg(any(test, feature = "fuzztarget"))]
772 old_entry.value_contribution_msat = value_contribution_msat;
774 did_add_update_path_to_src_node = true;
775 } else if old_entry.was_processed && new_cost < old_cost {
776 #[cfg(any(test, feature = "fuzztarget"))]
778 // If we're skipping processing a node which was previously
779 // processed even though we found another path to it with a
780 // cheaper fee, check that it was because the second path we
781 // found (which we are processing now) has a lower value
782 // contribution due to an HTLC minimum limit.
784 // e.g. take a graph with two paths from node 1 to node 2, one
785 // through channel A, and one through channel B. Channel A and
786 // B are both in the to-process heap, with their scores set by
787 // a higher htlc_minimum than fee.
788 // Channel A is processed first, and the channels onwards from
789 // node 1 are added to the to-process heap. Thereafter, we pop
790 // Channel B off of the heap, note that it has a much more
791 // restrictive htlc_maximum_msat, and recalculate the fees for
792 // all of node 1's channels using the new, reduced, amount.
794 // This would be bogus - we'd be selecting a higher-fee path
795 // with a lower htlc_maximum_msat instead of the one we'd
796 // already decided to use.
797 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
798 debug_assert!(value_contribution_msat < old_entry.value_contribution_msat);
805 did_add_update_path_to_src_node
809 let empty_node_features = NodeFeatures::empty();
810 // Find ways (channels with destination) to reach a given node and store them
811 // in the corresponding data structures (routing graph etc).
812 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
813 // meaning how much will be paid in fees after this node (to the best of our knowledge).
814 // This data can later be helpful to optimize routing (pay lower fees).
815 macro_rules! add_entries_to_cheapest_to_target_node {
816 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
817 let skip_node = if let Some(elem) = dist.get_mut($node_id) {
818 let was_processed = elem.was_processed;
819 elem.was_processed = true;
822 // Entries are added to dist in add_entry!() when there is a channel from a node.
823 // Because there are no channels from payee, it will not have a dist entry at this point.
824 // If we're processing any other node, it is always be the result of a channel from it.
825 assert_eq!($node_id, payee);
830 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
831 for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
832 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);
836 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
842 if !features.requires_unknown_bits() {
843 for chan_id in $node.channels.iter() {
844 let chan = network_channels.get(chan_id).unwrap();
845 if !chan.features.requires_unknown_bits() {
846 if chan.node_one == *$node_id {
847 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
848 if first_hops.is_none() || chan.node_two != *our_node_id {
849 if let Some(two_to_one) = chan.two_to_one.as_ref() {
850 if two_to_one.enabled {
851 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);
856 if first_hops.is_none() || chan.node_one != *our_node_id {
857 if let Some(one_to_two) = chan.one_to_two.as_ref() {
858 if one_to_two.enabled {
859 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);
871 let mut payment_paths = Vec::<PaymentPath>::new();
873 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
874 'paths_collection: loop {
875 // For every new path, start from scratch, except
876 // bookkeeped_channels_liquidity_available_msat, which will improve
877 // the further iterations of path finding. Also don't erase first_hop_targets.
880 hit_minimum_limit = false;
882 // If first hop is a private channel and the only way to reach the payee, this is the only
883 // place where it could be added.
884 if let Some(first_channels) = first_hop_targets.get(&payee) {
885 for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
886 let added = add_entry!(first_hop, *our_node_id, payee, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
887 log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, first_hop);
891 // Add the payee as a target, so that the payee-to-payer
892 // search algorithm knows what to start with.
893 match network_nodes.get(payee) {
894 // The payee is not in our network graph, so nothing to add here.
895 // There is still a chance of reaching them via last_hops though,
896 // so don't yet fail the payment here.
897 // If not, targets.pop() will not even let us enter the loop in step 2.
900 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0);
905 // If a caller provided us with last hops, add them to routing targets. Since this happens
906 // earlier than general path finding, they will be somewhat prioritized, although currently
907 // it matters only if the fees are exactly the same.
908 for route in last_hops.iter().filter(|route| !route.0.is_empty()) {
909 let first_hop_in_route = &(route.0)[0];
910 let have_hop_src_in_graph =
911 // Only add the hops in this route to our candidate set if either
912 // we have a direct channel to the first hop or the first hop is
913 // in the regular network graph.
914 first_hop_targets.get(&first_hop_in_route.src_node_id).is_some() ||
915 network_nodes.get(&first_hop_in_route.src_node_id).is_some();
916 if have_hop_src_in_graph {
917 // We start building the path from reverse, i.e., from payee
918 // to the first RouteHintHop in the path.
919 let hop_iter = route.0.iter().rev();
920 let prev_hop_iter = core::iter::once(payee).chain(
921 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
922 let mut hop_used = true;
923 let mut aggregate_next_hops_fee_msat: u64 = 0;
924 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
926 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
927 // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
928 // really sucks, cause we're gonna need that eventually.
929 let hop_htlc_minimum_msat: u64 = hop.htlc_minimum_msat.unwrap_or(0);
931 let directional_info = DummyDirectionalChannelInfo {
932 cltv_expiry_delta: hop.cltv_expiry_delta as u32,
933 htlc_minimum_msat: hop_htlc_minimum_msat,
934 htlc_maximum_msat: hop.htlc_maximum_msat,
938 let reqd_channel_cap = if let Some (val) = final_value_msat.checked_add(match idx {
940 _ => aggregate_next_hops_fee_msat.checked_add(999).unwrap_or(u64::max_value())
941 }) { Some( val / 1000 ) } else { break; }; // converting from msat or breaking if max ~ infinity
944 // We assume that the recipient only included route hints for routes which had
945 // sufficient value to route `final_value_msat`. Note that in the case of "0-value"
946 // invoices where the invoice does not specify value this may not be the case, but
947 // better to include the hints than not.
948 if !add_entry!(hop.short_channel_id, hop.src_node_id, prev_hop_id, directional_info, reqd_channel_cap, &empty_channel_features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat) {
949 // If this hop was not used then there is no use checking the preceding hops
950 // in the RouteHint. We can break by just searching for a direct channel between
951 // last checked hop and first_hop_targets
955 // Searching for a direct channel between last checked hop and first_hop_targets
956 if let Some(first_channels) = first_hop_targets.get(&prev_hop_id) {
957 for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
958 add_entry!(first_hop, *our_node_id , prev_hop_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat);
966 // In the next values of the iterator, the aggregate fees already reflects
967 // the sum of value sent from payer (final_value_msat) and routing fees
968 // for the last node in the RouteHint. We need to just add the fees to
969 // route through the current node so that the preceeding node (next iteration)
971 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
972 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
973 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
975 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
976 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
977 .checked_add(hop_htlc_minimum_msat_inc);
978 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
980 if idx == route.0.len() - 1 {
981 // The last hop in this iterator is the first hop in
982 // overall RouteHint.
983 // If this hop connects to a node with which we have a direct channel,
984 // ignore the network graph and, if the last hop was added, add our
985 // direct channel to the candidate set.
987 // Note that we *must* check if the last hop was added as `add_entry`
988 // always assumes that the third argument is a node to which we have a
990 if let Some(first_channels) = first_hop_targets.get(&hop.src_node_id) {
991 for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
992 add_entry!(first_hop, *our_node_id , hop.src_node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat);
1000 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1002 // At this point, targets are filled with the data from first and
1003 // last hops communicated by the caller, and the payment receiver.
1004 let mut found_new_path = false;
1007 // If this loop terminates due the exhaustion of targets, two situations are possible:
1008 // - not enough outgoing liquidity:
1009 // 0 < already_collected_value_msat < final_value_msat
1010 // - enough outgoing liquidity:
1011 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1012 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1013 // paths_collection will be stopped because found_new_path==false.
1014 // This is not necessarily a routing failure.
1015 'path_construction: while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, .. }) = targets.pop() {
1017 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1018 // traversing the graph and arrange the path out of what we found.
1019 if pubkey == *our_node_id {
1020 let mut new_entry = dist.remove(&our_node_id).unwrap();
1021 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
1024 let mut features_set = false;
1025 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.pubkey) {
1026 for (scid, _, _, ref features) in first_channels {
1027 if *scid == ordered_hops.last().unwrap().0.short_channel_id {
1028 ordered_hops.last_mut().unwrap().1 = features.clone();
1029 features_set = true;
1035 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.pubkey) {
1036 if let Some(node_info) = node.announcement_info.as_ref() {
1037 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1039 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
1042 // We should be able to fill in features for everything except the last
1043 // hop, if the last hop was provided via a BOLT 11 invoice (though we
1044 // should be able to extend it further as BOLT 11 does have feature
1045 // flags for the last hop node itself).
1046 assert!(ordered_hops.last().unwrap().0.pubkey == *payee);
1050 // Means we succesfully traversed from the payer to the payee, now
1051 // save this path for the payment route. Also, update the liquidity
1052 // remaining on the used hops, so that we take them into account
1053 // while looking for more paths.
1054 if ordered_hops.last().unwrap().0.pubkey == *payee {
1058 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.pubkey) {
1059 Some(payment_hop) => payment_hop,
1060 // We can't arrive at None because, if we ever add an entry to targets,
1061 // we also fill in the entry in dist (see add_entry!).
1062 None => unreachable!(),
1064 // We "propagate" the fees one hop backward (topologically) here,
1065 // so that fees paid for a HTLC forwarding on the current channel are
1066 // associated with the previous channel (where they will be subtracted).
1067 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1068 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = new_entry.cltv_expiry_delta;
1069 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
1071 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1072 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1073 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = final_cltv;
1075 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: {:?}",
1076 ordered_hops.len(), value_contribution_msat, ordered_hops);
1078 let mut payment_path = PaymentPath {hops: ordered_hops};
1080 // We could have possibly constructed a slightly inconsistent path: since we reduce
1081 // value being transferred along the way, we could have violated htlc_minimum_msat
1082 // on some channels we already passed (assuming dest->source direction). Here, we
1083 // recompute the fees again, so that if that's the case, we match the currently
1084 // underpaid htlc_minimum_msat with fees.
1085 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1087 // Since a path allows to transfer as much value as
1088 // the smallest channel it has ("bottleneck"), we should recompute
1089 // the fees so sender HTLC don't overpay fees when traversing
1090 // larger channels than the bottleneck. This may happen because
1091 // when we were selecting those channels we were not aware how much value
1092 // this path will transfer, and the relative fee for them
1093 // might have been computed considering a larger value.
1094 // Remember that we used these channels so that we don't rely
1095 // on the same liquidity in future paths.
1096 let mut prevented_redundant_path_selection = false;
1097 for (payment_hop, _) in payment_path.hops.iter() {
1098 let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.short_channel_id).unwrap();
1099 let mut spent_on_hop_msat = value_contribution_msat;
1100 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
1101 spent_on_hop_msat += next_hops_fee_msat;
1102 if spent_on_hop_msat == *channel_liquidity_available_msat {
1103 // If this path used all of this channel's available liquidity, we know
1104 // this path will not be selected again in the next loop iteration.
1105 prevented_redundant_path_selection = true;
1107 *channel_liquidity_available_msat -= spent_on_hop_msat;
1109 if !prevented_redundant_path_selection {
1110 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1111 // we'll probably end up picking the same path again on the next iteration.
1112 // Decrease the available liquidity of a hop in the middle of the path.
1113 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.short_channel_id;
1114 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1115 let victim_liquidity = bookkeeped_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1116 *victim_liquidity = 0;
1119 // Track the total amount all our collected paths allow to send so that we:
1120 // - know when to stop looking for more paths
1121 // - know which of the hops are useless considering how much more sats we need
1122 // (contributes_sufficient_value)
1123 already_collected_value_msat += value_contribution_msat;
1125 payment_paths.push(payment_path);
1126 found_new_path = true;
1127 break 'path_construction;
1130 // If we found a path back to the payee, we shouldn't try to process it again. This is
1131 // the equivalent of the `elem.was_processed` check in
1132 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1133 if pubkey == *payee { continue 'path_construction; }
1135 // Otherwise, since the current target node is not us,
1136 // keep "unrolling" the payment graph from payee to payer by
1137 // finding a way to reach the current target from the payer side.
1138 match network_nodes.get(&pubkey) {
1141 add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat);
1147 // If we don't support MPP, no use trying to gather more value ever.
1148 break 'paths_collection;
1152 // Stop either when the recommended value is reached or if no new path was found in this
1154 // In the latter case, making another path finding attempt won't help,
1155 // because we deterministically terminated the search due to low liquidity.
1156 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1157 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1158 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1159 break 'paths_collection;
1160 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1161 // Further, if this was our first walk of the graph, and we weren't limited by an
1162 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1163 // limited by an htlc_minimum_msat value, find another path with a higher value,
1164 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1165 // still keeping a lower total fee than this path.
1166 if !hit_minimum_limit {
1167 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1168 break 'paths_collection;
1170 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1171 path_value_msat = recommended_value_msat;
1176 if payment_paths.len() == 0 {
1177 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1180 if already_collected_value_msat < final_value_msat {
1181 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1184 // Sort by total fees and take the best paths.
1185 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1186 if payment_paths.len() > 50 {
1187 payment_paths.truncate(50);
1190 // Draw multiple sufficient routes by randomly combining the selected paths.
1191 let mut drawn_routes = Vec::new();
1192 for i in 0..payment_paths.len() {
1193 let mut cur_route = Vec::<PaymentPath>::new();
1194 let mut aggregate_route_value_msat = 0;
1197 // TODO: real random shuffle
1198 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1199 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1202 for payment_path in cur_payment_paths {
1203 cur_route.push(payment_path.clone());
1204 aggregate_route_value_msat += payment_path.get_value_msat();
1205 if aggregate_route_value_msat > final_value_msat {
1206 // Last path likely overpaid. Substract it from the most expensive
1207 // (in terms of proportional fee) path in this route and recompute fees.
1208 // This might be not the most economically efficient way, but fewer paths
1209 // also makes routing more reliable.
1210 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1212 // First, drop some expensive low-value paths entirely if possible.
1213 // Sort by value so that we drop many really-low values first, since
1214 // fewer paths is better: the payment is less likely to fail.
1215 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1216 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1217 cur_route.sort_by_key(|path| path.get_value_msat());
1218 // We should make sure that at least 1 path left.
1219 let mut paths_left = cur_route.len();
1220 cur_route.retain(|path| {
1221 if paths_left == 1 {
1224 let mut keep = true;
1225 let path_value_msat = path.get_value_msat();
1226 if path_value_msat <= overpaid_value_msat {
1228 overpaid_value_msat -= path_value_msat;
1234 if overpaid_value_msat == 0 {
1238 assert!(cur_route.len() > 0);
1241 // Now, substract the overpaid value from the most-expensive path.
1242 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1243 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1244 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.channel_fees.proportional_millionths as u64).sum::<u64>() });
1245 let expensive_payment_path = cur_route.first_mut().unwrap();
1246 // We already dropped all the small channels above, meaning all the
1247 // remaining channels are larger than remaining overpaid_value_msat.
1248 // Thus, this can't be negative.
1249 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1250 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1254 drawn_routes.push(cur_route);
1258 // Select the best route by lowest total fee.
1259 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1260 let mut selected_paths = Vec::<Vec<RouteHop>>::new();
1261 for payment_path in drawn_routes.first().unwrap() {
1262 selected_paths.push(payment_path.hops.iter().map(|(payment_hop, node_features)| {
1264 pubkey: payment_hop.pubkey,
1265 node_features: node_features.clone(),
1266 short_channel_id: payment_hop.short_channel_id,
1267 channel_features: payment_hop.channel_features.clone(),
1268 fee_msat: payment_hop.fee_msat,
1269 cltv_expiry_delta: payment_hop.cltv_expiry_delta,
1274 if let Some(features) = &payee_features {
1275 for path in selected_paths.iter_mut() {
1276 path.last_mut().unwrap().node_features = features.to_context();
1280 let route = Route { paths: selected_paths };
1281 log_info!(logger, "Got route to {}: {}", payee, log_route!(route));
1287 use routing::router::{get_route, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees};
1288 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
1289 use chain::transaction::OutPoint;
1290 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1291 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1292 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1293 use ln::channelmanager;
1294 use util::test_utils;
1295 use util::ser::Writeable;
1297 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1298 use bitcoin::hashes::Hash;
1299 use bitcoin::network::constants::Network;
1300 use bitcoin::blockdata::constants::genesis_block;
1301 use bitcoin::blockdata::script::Builder;
1302 use bitcoin::blockdata::opcodes;
1303 use bitcoin::blockdata::transaction::TxOut;
1307 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1308 use bitcoin::secp256k1::{Secp256k1, All};
1311 use sync::{self, Arc};
1313 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1314 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1315 channelmanager::ChannelDetails {
1316 channel_id: [0; 32],
1317 counterparty: channelmanager::ChannelCounterparty {
1320 unspendable_punishment_reserve: 0,
1321 forwarding_info: None,
1323 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1325 channel_value_satoshis: 0,
1327 outbound_capacity_msat,
1328 inbound_capacity_msat: 42,
1329 unspendable_punishment_reserve: None,
1330 confirmations_required: None,
1331 force_close_spend_delay: None,
1332 is_outbound: true, is_funding_locked: true,
1333 is_usable: true, is_public: true,
1337 // Using the same keys for LN and BTC ids
1339 net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1340 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1342 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1343 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1345 let unsigned_announcement = UnsignedChannelAnnouncement {
1347 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1351 bitcoin_key_1: node_id_1,
1352 bitcoin_key_2: node_id_2,
1353 excess_data: Vec::new(),
1356 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1357 let valid_announcement = ChannelAnnouncement {
1358 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1359 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1360 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1361 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1362 contents: unsigned_announcement.clone(),
1364 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1365 Ok(res) => assert!(res),
1371 net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1372 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1374 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1375 let valid_channel_update = ChannelUpdate {
1376 signature: secp_ctx.sign(&msghash, node_privkey),
1377 contents: update.clone()
1380 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1381 Ok(res) => assert!(res),
1386 fn add_or_update_node(
1387 net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1388 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1390 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1391 let unsigned_announcement = UnsignedNodeAnnouncement {
1397 addresses: Vec::new(),
1398 excess_address_data: Vec::new(),
1399 excess_data: Vec::new(),
1401 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1402 let valid_announcement = NodeAnnouncement {
1403 signature: secp_ctx.sign(&msghash, node_privkey),
1404 contents: unsigned_announcement.clone()
1407 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1413 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1414 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1415 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1418 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1420 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1421 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1423 (our_privkey, our_id, privkeys, pubkeys)
1426 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1427 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1428 // test for it later.
1429 let idx = (id - 1) * 2 + 1;
1431 vec![1 << (idx - 8*3), 0, 0, 0]
1432 } else if idx > 8*2 {
1433 vec![1 << (idx - 8*2), 0, 0]
1434 } else if idx > 8*1 {
1435 vec![1 << (idx - 8*1), 0]
1441 fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>) {
1442 let secp_ctx = Secp256k1::new();
1443 let logger = Arc::new(test_utils::TestLogger::new());
1444 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1445 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
1446 let net_graph_msg_handler = NetGraphMsgHandler::new(network_graph, None, Arc::clone(&logger));
1447 // Build network from our_id to node6:
1449 // -1(1)2- node0 -1(3)2-
1451 // our_id -1(12)2- node7 -1(13)2--- node2
1453 // -1(2)2- node1 -1(4)2-
1456 // chan1 1-to-2: disabled
1457 // chan1 2-to-1: enabled, 0 fee
1459 // chan2 1-to-2: enabled, ignored fee
1460 // chan2 2-to-1: enabled, 0 fee
1462 // chan3 1-to-2: enabled, 0 fee
1463 // chan3 2-to-1: enabled, 100 msat fee
1465 // chan4 1-to-2: enabled, 100% fee
1466 // chan4 2-to-1: enabled, 0 fee
1468 // chan12 1-to-2: enabled, ignored fee
1469 // chan12 2-to-1: enabled, 0 fee
1471 // chan13 1-to-2: enabled, 200% fee
1472 // chan13 2-to-1: enabled, 0 fee
1475 // -1(5)2- node3 -1(8)2--
1479 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1481 // -1(7)2- node5 -1(10)2-
1483 // Channels 5, 8, 9 and 10 are private channels.
1485 // chan5 1-to-2: enabled, 100 msat fee
1486 // chan5 2-to-1: enabled, 0 fee
1488 // chan6 1-to-2: enabled, 0 fee
1489 // chan6 2-to-1: enabled, 0 fee
1491 // chan7 1-to-2: enabled, 100% fee
1492 // chan7 2-to-1: enabled, 0 fee
1494 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1495 // chan8 2-to-1: enabled, 0 fee
1497 // chan9 1-to-2: enabled, 1001 msat fee
1498 // chan9 2-to-1: enabled, 0 fee
1500 // chan10 1-to-2: enabled, 0 fee
1501 // chan10 2-to-1: enabled, 0 fee
1503 // chan11 1-to-2: enabled, 0 fee
1504 // chan11 2-to-1: enabled, 0 fee
1506 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1508 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1509 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1510 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1511 short_channel_id: 1,
1514 cltv_expiry_delta: 0,
1515 htlc_minimum_msat: 0,
1516 htlc_maximum_msat: OptionalField::Absent,
1518 fee_proportional_millionths: 0,
1519 excess_data: Vec::new()
1522 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1524 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1525 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1526 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1527 short_channel_id: 2,
1530 cltv_expiry_delta: u16::max_value(),
1531 htlc_minimum_msat: 0,
1532 htlc_maximum_msat: OptionalField::Absent,
1533 fee_base_msat: u32::max_value(),
1534 fee_proportional_millionths: u32::max_value(),
1535 excess_data: Vec::new()
1537 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1538 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1539 short_channel_id: 2,
1542 cltv_expiry_delta: 0,
1543 htlc_minimum_msat: 0,
1544 htlc_maximum_msat: OptionalField::Absent,
1546 fee_proportional_millionths: 0,
1547 excess_data: Vec::new()
1550 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1552 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1553 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1554 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1555 short_channel_id: 12,
1558 cltv_expiry_delta: u16::max_value(),
1559 htlc_minimum_msat: 0,
1560 htlc_maximum_msat: OptionalField::Absent,
1561 fee_base_msat: u32::max_value(),
1562 fee_proportional_millionths: u32::max_value(),
1563 excess_data: Vec::new()
1565 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1566 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1567 short_channel_id: 12,
1570 cltv_expiry_delta: 0,
1571 htlc_minimum_msat: 0,
1572 htlc_maximum_msat: OptionalField::Absent,
1574 fee_proportional_millionths: 0,
1575 excess_data: Vec::new()
1578 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1580 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1581 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1582 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1583 short_channel_id: 3,
1586 cltv_expiry_delta: (3 << 8) | 1,
1587 htlc_minimum_msat: 0,
1588 htlc_maximum_msat: OptionalField::Absent,
1590 fee_proportional_millionths: 0,
1591 excess_data: Vec::new()
1593 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1594 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1595 short_channel_id: 3,
1598 cltv_expiry_delta: (3 << 8) | 2,
1599 htlc_minimum_msat: 0,
1600 htlc_maximum_msat: OptionalField::Absent,
1602 fee_proportional_millionths: 0,
1603 excess_data: Vec::new()
1606 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1607 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1608 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1609 short_channel_id: 4,
1612 cltv_expiry_delta: (4 << 8) | 1,
1613 htlc_minimum_msat: 0,
1614 htlc_maximum_msat: OptionalField::Absent,
1616 fee_proportional_millionths: 1000000,
1617 excess_data: Vec::new()
1619 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1620 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1621 short_channel_id: 4,
1624 cltv_expiry_delta: (4 << 8) | 2,
1625 htlc_minimum_msat: 0,
1626 htlc_maximum_msat: OptionalField::Absent,
1628 fee_proportional_millionths: 0,
1629 excess_data: Vec::new()
1632 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1633 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1634 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1635 short_channel_id: 13,
1638 cltv_expiry_delta: (13 << 8) | 1,
1639 htlc_minimum_msat: 0,
1640 htlc_maximum_msat: OptionalField::Absent,
1642 fee_proportional_millionths: 2000000,
1643 excess_data: Vec::new()
1645 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1646 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1647 short_channel_id: 13,
1650 cltv_expiry_delta: (13 << 8) | 2,
1651 htlc_minimum_msat: 0,
1652 htlc_maximum_msat: OptionalField::Absent,
1654 fee_proportional_millionths: 0,
1655 excess_data: Vec::new()
1658 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1660 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1661 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1662 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1663 short_channel_id: 6,
1666 cltv_expiry_delta: (6 << 8) | 1,
1667 htlc_minimum_msat: 0,
1668 htlc_maximum_msat: OptionalField::Absent,
1670 fee_proportional_millionths: 0,
1671 excess_data: Vec::new()
1673 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1674 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1675 short_channel_id: 6,
1678 cltv_expiry_delta: (6 << 8) | 2,
1679 htlc_minimum_msat: 0,
1680 htlc_maximum_msat: OptionalField::Absent,
1682 fee_proportional_millionths: 0,
1683 excess_data: Vec::new(),
1686 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1687 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1688 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1689 short_channel_id: 11,
1692 cltv_expiry_delta: (11 << 8) | 1,
1693 htlc_minimum_msat: 0,
1694 htlc_maximum_msat: OptionalField::Absent,
1696 fee_proportional_millionths: 0,
1697 excess_data: Vec::new()
1699 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
1700 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1701 short_channel_id: 11,
1704 cltv_expiry_delta: (11 << 8) | 2,
1705 htlc_minimum_msat: 0,
1706 htlc_maximum_msat: OptionalField::Absent,
1708 fee_proportional_millionths: 0,
1709 excess_data: Vec::new()
1712 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
1714 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
1716 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
1717 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1718 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1719 short_channel_id: 7,
1722 cltv_expiry_delta: (7 << 8) | 1,
1723 htlc_minimum_msat: 0,
1724 htlc_maximum_msat: OptionalField::Absent,
1726 fee_proportional_millionths: 1000000,
1727 excess_data: Vec::new()
1729 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
1730 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1731 short_channel_id: 7,
1734 cltv_expiry_delta: (7 << 8) | 2,
1735 htlc_minimum_msat: 0,
1736 htlc_maximum_msat: OptionalField::Absent,
1738 fee_proportional_millionths: 0,
1739 excess_data: Vec::new()
1742 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
1744 (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
1748 fn simple_route_test() {
1749 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1750 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1752 // Simple route to 2 via 1
1754 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 0, 42, Arc::clone(&logger)) {
1755 assert_eq!(err, "Cannot send a payment of 0 msat");
1756 } else { panic!(); }
1758 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1759 assert_eq!(route.paths[0].len(), 2);
1761 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1762 assert_eq!(route.paths[0][0].short_channel_id, 2);
1763 assert_eq!(route.paths[0][0].fee_msat, 100);
1764 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1765 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1766 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1768 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1769 assert_eq!(route.paths[0][1].short_channel_id, 4);
1770 assert_eq!(route.paths[0][1].fee_msat, 100);
1771 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1772 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1773 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1777 fn invalid_first_hop_test() {
1778 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1779 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1781 // Simple route to 2 via 1
1783 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
1785 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)) {
1786 assert_eq!(err, "First hop cannot have our_node_id as a destination.");
1787 } else { panic!(); }
1789 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1790 assert_eq!(route.paths[0].len(), 2);
1794 fn htlc_minimum_test() {
1795 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1796 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1798 // Simple route to 2 via 1
1800 // Disable other paths
1801 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1802 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1803 short_channel_id: 12,
1805 flags: 2, // to disable
1806 cltv_expiry_delta: 0,
1807 htlc_minimum_msat: 0,
1808 htlc_maximum_msat: OptionalField::Absent,
1810 fee_proportional_millionths: 0,
1811 excess_data: Vec::new()
1813 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1814 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1815 short_channel_id: 3,
1817 flags: 2, // to disable
1818 cltv_expiry_delta: 0,
1819 htlc_minimum_msat: 0,
1820 htlc_maximum_msat: OptionalField::Absent,
1822 fee_proportional_millionths: 0,
1823 excess_data: Vec::new()
1825 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1826 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1827 short_channel_id: 13,
1829 flags: 2, // to disable
1830 cltv_expiry_delta: 0,
1831 htlc_minimum_msat: 0,
1832 htlc_maximum_msat: OptionalField::Absent,
1834 fee_proportional_millionths: 0,
1835 excess_data: Vec::new()
1837 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1838 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1839 short_channel_id: 6,
1841 flags: 2, // to disable
1842 cltv_expiry_delta: 0,
1843 htlc_minimum_msat: 0,
1844 htlc_maximum_msat: OptionalField::Absent,
1846 fee_proportional_millionths: 0,
1847 excess_data: Vec::new()
1849 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1850 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1851 short_channel_id: 7,
1853 flags: 2, // to disable
1854 cltv_expiry_delta: 0,
1855 htlc_minimum_msat: 0,
1856 htlc_maximum_msat: OptionalField::Absent,
1858 fee_proportional_millionths: 0,
1859 excess_data: Vec::new()
1862 // Check against amount_to_transfer_over_msat.
1863 // Set minimal HTLC of 200_000_000 msat.
1864 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1865 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1866 short_channel_id: 2,
1869 cltv_expiry_delta: 0,
1870 htlc_minimum_msat: 200_000_000,
1871 htlc_maximum_msat: OptionalField::Absent,
1873 fee_proportional_millionths: 0,
1874 excess_data: Vec::new()
1877 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
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::Present(199_999_999),
1888 fee_proportional_millionths: 0,
1889 excess_data: Vec::new()
1892 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
1893 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)) {
1894 assert_eq!(err, "Failed to find a path to the given destination");
1895 } else { panic!(); }
1897 // Lift the restriction on the first hop.
1898 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1899 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1900 short_channel_id: 2,
1903 cltv_expiry_delta: 0,
1904 htlc_minimum_msat: 0,
1905 htlc_maximum_msat: OptionalField::Absent,
1907 fee_proportional_millionths: 0,
1908 excess_data: Vec::new()
1911 // A payment above the minimum should pass
1912 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)).unwrap();
1913 assert_eq!(route.paths[0].len(), 2);
1917 fn htlc_minimum_overpay_test() {
1918 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1919 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1921 // A route to node#2 via two paths.
1922 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
1923 // Thus, they can't send 60 without overpaying.
1924 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1925 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1926 short_channel_id: 2,
1929 cltv_expiry_delta: 0,
1930 htlc_minimum_msat: 35_000,
1931 htlc_maximum_msat: OptionalField::Present(40_000),
1933 fee_proportional_millionths: 0,
1934 excess_data: Vec::new()
1936 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1937 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1938 short_channel_id: 12,
1941 cltv_expiry_delta: 0,
1942 htlc_minimum_msat: 35_000,
1943 htlc_maximum_msat: OptionalField::Present(40_000),
1945 fee_proportional_millionths: 0,
1946 excess_data: Vec::new()
1950 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1951 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1952 short_channel_id: 13,
1955 cltv_expiry_delta: 0,
1956 htlc_minimum_msat: 0,
1957 htlc_maximum_msat: OptionalField::Absent,
1959 fee_proportional_millionths: 0,
1960 excess_data: Vec::new()
1962 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1963 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1964 short_channel_id: 4,
1967 cltv_expiry_delta: 0,
1968 htlc_minimum_msat: 0,
1969 htlc_maximum_msat: OptionalField::Absent,
1971 fee_proportional_millionths: 0,
1972 excess_data: Vec::new()
1975 // Disable other paths
1976 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1977 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1978 short_channel_id: 1,
1980 flags: 2, // to disable
1981 cltv_expiry_delta: 0,
1982 htlc_minimum_msat: 0,
1983 htlc_maximum_msat: OptionalField::Absent,
1985 fee_proportional_millionths: 0,
1986 excess_data: Vec::new()
1989 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
1990 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1991 // Overpay fees to hit htlc_minimum_msat.
1992 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
1993 // TODO: this could be better balanced to overpay 10k and not 15k.
1994 assert_eq!(overpaid_fees, 15_000);
1996 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
1997 // while taking even more fee to match htlc_minimum_msat.
1998 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1999 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2000 short_channel_id: 12,
2003 cltv_expiry_delta: 0,
2004 htlc_minimum_msat: 65_000,
2005 htlc_maximum_msat: OptionalField::Present(80_000),
2007 fee_proportional_millionths: 0,
2008 excess_data: Vec::new()
2010 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2011 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2012 short_channel_id: 2,
2015 cltv_expiry_delta: 0,
2016 htlc_minimum_msat: 0,
2017 htlc_maximum_msat: OptionalField::Absent,
2019 fee_proportional_millionths: 0,
2020 excess_data: Vec::new()
2022 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2023 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2024 short_channel_id: 4,
2027 cltv_expiry_delta: 0,
2028 htlc_minimum_msat: 0,
2029 htlc_maximum_msat: OptionalField::Absent,
2031 fee_proportional_millionths: 100_000,
2032 excess_data: Vec::new()
2035 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2036 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
2037 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2038 assert_eq!(route.paths.len(), 1);
2039 assert_eq!(route.paths[0][0].short_channel_id, 12);
2040 let fees = route.paths[0][0].fee_msat;
2041 assert_eq!(fees, 5_000);
2043 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2044 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2045 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2046 // the other channel.
2047 assert_eq!(route.paths.len(), 1);
2048 assert_eq!(route.paths[0][0].short_channel_id, 2);
2049 let fees = route.paths[0][0].fee_msat;
2050 assert_eq!(fees, 5_000);
2054 fn disable_channels_test() {
2055 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2056 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2058 // // Disable channels 4 and 12 by flags=2
2059 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2060 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2061 short_channel_id: 4,
2063 flags: 2, // to disable
2064 cltv_expiry_delta: 0,
2065 htlc_minimum_msat: 0,
2066 htlc_maximum_msat: OptionalField::Absent,
2068 fee_proportional_millionths: 0,
2069 excess_data: Vec::new()
2071 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2072 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2073 short_channel_id: 12,
2075 flags: 2, // to disable
2076 cltv_expiry_delta: 0,
2077 htlc_minimum_msat: 0,
2078 htlc_maximum_msat: OptionalField::Absent,
2080 fee_proportional_millionths: 0,
2081 excess_data: Vec::new()
2084 // If all the channels require some features we don't understand, route should fail
2085 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
2086 assert_eq!(err, "Failed to find a path to the given destination");
2087 } else { panic!(); }
2089 // If we specify a channel to node7, that overrides our local channel view and that gets used
2090 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2091 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2092 assert_eq!(route.paths[0].len(), 2);
2094 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2095 assert_eq!(route.paths[0][0].short_channel_id, 42);
2096 assert_eq!(route.paths[0][0].fee_msat, 200);
2097 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2098 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2099 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2101 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2102 assert_eq!(route.paths[0][1].short_channel_id, 13);
2103 assert_eq!(route.paths[0][1].fee_msat, 100);
2104 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2105 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2106 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2110 fn disable_node_test() {
2111 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2112 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2114 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2115 let unknown_features = NodeFeatures::known().set_unknown_feature_required();
2116 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2117 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2118 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2120 // If all nodes require some features we don't understand, route should fail
2121 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
2122 assert_eq!(err, "Failed to find a path to the given destination");
2123 } else { panic!(); }
2125 // If we specify a channel to node7, that overrides our local channel view and that gets used
2126 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2127 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2128 assert_eq!(route.paths[0].len(), 2);
2130 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2131 assert_eq!(route.paths[0][0].short_channel_id, 42);
2132 assert_eq!(route.paths[0][0].fee_msat, 200);
2133 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2134 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2135 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2137 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2138 assert_eq!(route.paths[0][1].short_channel_id, 13);
2139 assert_eq!(route.paths[0][1].fee_msat, 100);
2140 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2141 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2142 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2144 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2145 // naively) assume that the user checked the feature bits on the invoice, which override
2146 // the node_announcement.
2150 fn our_chans_test() {
2151 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2152 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2154 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2155 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[0], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2156 assert_eq!(route.paths[0].len(), 3);
2158 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2159 assert_eq!(route.paths[0][0].short_channel_id, 2);
2160 assert_eq!(route.paths[0][0].fee_msat, 200);
2161 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2162 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2163 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2165 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2166 assert_eq!(route.paths[0][1].short_channel_id, 4);
2167 assert_eq!(route.paths[0][1].fee_msat, 100);
2168 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
2169 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2170 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2172 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2173 assert_eq!(route.paths[0][2].short_channel_id, 3);
2174 assert_eq!(route.paths[0][2].fee_msat, 100);
2175 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2176 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2177 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2179 // If we specify a channel to node7, that overrides our local channel view and that gets used
2180 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2181 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2182 assert_eq!(route.paths[0].len(), 2);
2184 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2185 assert_eq!(route.paths[0][0].short_channel_id, 42);
2186 assert_eq!(route.paths[0][0].fee_msat, 200);
2187 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2188 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2189 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2191 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2192 assert_eq!(route.paths[0][1].short_channel_id, 13);
2193 assert_eq!(route.paths[0][1].fee_msat, 100);
2194 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2195 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2196 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2199 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2200 let zero_fees = RoutingFees {
2202 proportional_millionths: 0,
2204 vec![RouteHint(vec![RouteHintHop {
2205 src_node_id: nodes[3].clone(),
2206 short_channel_id: 8,
2208 cltv_expiry_delta: (8 << 8) | 1,
2209 htlc_minimum_msat: None,
2210 htlc_maximum_msat: None,
2212 ]), RouteHint(vec![RouteHintHop {
2213 src_node_id: nodes[4].clone(),
2214 short_channel_id: 9,
2217 proportional_millionths: 0,
2219 cltv_expiry_delta: (9 << 8) | 1,
2220 htlc_minimum_msat: None,
2221 htlc_maximum_msat: None,
2222 }]), RouteHint(vec![RouteHintHop {
2223 src_node_id: nodes[5].clone(),
2224 short_channel_id: 10,
2226 cltv_expiry_delta: (10 << 8) | 1,
2227 htlc_minimum_msat: None,
2228 htlc_maximum_msat: None,
2232 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2233 let zero_fees = RoutingFees {
2235 proportional_millionths: 0,
2237 vec![RouteHint(vec![RouteHintHop {
2238 src_node_id: nodes[2].clone(),
2239 short_channel_id: 5,
2242 proportional_millionths: 0,
2244 cltv_expiry_delta: (5 << 8) | 1,
2245 htlc_minimum_msat: None,
2246 htlc_maximum_msat: None,
2248 src_node_id: nodes[3].clone(),
2249 short_channel_id: 8,
2251 cltv_expiry_delta: (8 << 8) | 1,
2252 htlc_minimum_msat: None,
2253 htlc_maximum_msat: None,
2255 ]), RouteHint(vec![RouteHintHop {
2256 src_node_id: nodes[4].clone(),
2257 short_channel_id: 9,
2260 proportional_millionths: 0,
2262 cltv_expiry_delta: (9 << 8) | 1,
2263 htlc_minimum_msat: None,
2264 htlc_maximum_msat: None,
2265 }]), RouteHint(vec![RouteHintHop {
2266 src_node_id: nodes[5].clone(),
2267 short_channel_id: 10,
2269 cltv_expiry_delta: (10 << 8) | 1,
2270 htlc_minimum_msat: None,
2271 htlc_maximum_msat: None,
2276 fn partial_route_hint_test() {
2277 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2278 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2280 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2281 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2282 // RouteHint may be partially used by the algo to build the best path.
2284 // First check that last hop can't have its source as the payee.
2285 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2286 src_node_id: nodes[6],
2287 short_channel_id: 8,
2290 proportional_millionths: 0,
2292 cltv_expiry_delta: (8 << 8) | 1,
2293 htlc_minimum_msat: None,
2294 htlc_maximum_msat: None,
2297 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2298 invalid_last_hops.push(invalid_last_hop);
2300 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &invalid_last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)) {
2301 assert_eq!(err, "Last hop cannot have a payee as a source.");
2302 } else { panic!(); }
2305 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &last_hops_multi_private_channels(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2306 assert_eq!(route.paths[0].len(), 5);
2308 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2309 assert_eq!(route.paths[0][0].short_channel_id, 2);
2310 assert_eq!(route.paths[0][0].fee_msat, 100);
2311 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2312 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2313 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2315 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2316 assert_eq!(route.paths[0][1].short_channel_id, 4);
2317 assert_eq!(route.paths[0][1].fee_msat, 0);
2318 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2319 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2320 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2322 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2323 assert_eq!(route.paths[0][2].short_channel_id, 6);
2324 assert_eq!(route.paths[0][2].fee_msat, 0);
2325 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2326 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2327 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2329 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2330 assert_eq!(route.paths[0][3].short_channel_id, 11);
2331 assert_eq!(route.paths[0][3].fee_msat, 0);
2332 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2333 // If we have a peer in the node map, we'll use their features here since we don't have
2334 // a way of figuring out their features from the invoice:
2335 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2336 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2338 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2339 assert_eq!(route.paths[0][4].short_channel_id, 8);
2340 assert_eq!(route.paths[0][4].fee_msat, 100);
2341 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2342 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2343 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2346 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2347 let zero_fees = RoutingFees {
2349 proportional_millionths: 0,
2351 vec![RouteHint(vec![RouteHintHop {
2352 src_node_id: nodes[3].clone(),
2353 short_channel_id: 8,
2355 cltv_expiry_delta: (8 << 8) | 1,
2356 htlc_minimum_msat: None,
2357 htlc_maximum_msat: None,
2358 }]), RouteHint(vec![
2360 ]), RouteHint(vec![RouteHintHop {
2361 src_node_id: nodes[5].clone(),
2362 short_channel_id: 10,
2364 cltv_expiry_delta: (10 << 8) | 1,
2365 htlc_minimum_msat: None,
2366 htlc_maximum_msat: None,
2371 fn ignores_empty_last_hops_test() {
2372 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2373 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2375 // Test handling of an empty RouteHint passed in Invoice.
2377 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &empty_last_hop(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2378 assert_eq!(route.paths[0].len(), 5);
2380 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2381 assert_eq!(route.paths[0][0].short_channel_id, 2);
2382 assert_eq!(route.paths[0][0].fee_msat, 100);
2383 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2384 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2385 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2387 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2388 assert_eq!(route.paths[0][1].short_channel_id, 4);
2389 assert_eq!(route.paths[0][1].fee_msat, 0);
2390 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2391 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2392 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2394 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2395 assert_eq!(route.paths[0][2].short_channel_id, 6);
2396 assert_eq!(route.paths[0][2].fee_msat, 0);
2397 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2398 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2399 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2401 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2402 assert_eq!(route.paths[0][3].short_channel_id, 11);
2403 assert_eq!(route.paths[0][3].fee_msat, 0);
2404 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2405 // If we have a peer in the node map, we'll use their features here since we don't have
2406 // a way of figuring out their features from the invoice:
2407 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2408 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2410 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2411 assert_eq!(route.paths[0][4].short_channel_id, 8);
2412 assert_eq!(route.paths[0][4].fee_msat, 100);
2413 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2414 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2415 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2418 fn multi_hint_last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2419 let zero_fees = RoutingFees {
2421 proportional_millionths: 0,
2423 vec![RouteHint(vec![RouteHintHop {
2424 src_node_id: nodes[2].clone(),
2425 short_channel_id: 5,
2428 proportional_millionths: 0,
2430 cltv_expiry_delta: (5 << 8) | 1,
2431 htlc_minimum_msat: None,
2432 htlc_maximum_msat: None,
2434 src_node_id: nodes[3].clone(),
2435 short_channel_id: 8,
2437 cltv_expiry_delta: (8 << 8) | 1,
2438 htlc_minimum_msat: None,
2439 htlc_maximum_msat: None,
2440 }]), RouteHint(vec![RouteHintHop {
2441 src_node_id: nodes[5].clone(),
2442 short_channel_id: 10,
2444 cltv_expiry_delta: (10 << 8) | 1,
2445 htlc_minimum_msat: None,
2446 htlc_maximum_msat: None,
2451 fn multi_hint_last_hops_test() {
2452 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2453 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2454 // Test through channels 2, 3, 5, 8.
2455 // Test shows that multiple hop hints are considered.
2457 // Disabling channels 6 & 7 by flags=2
2458 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2459 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2460 short_channel_id: 6,
2462 flags: 2, // to disable
2463 cltv_expiry_delta: 0,
2464 htlc_minimum_msat: 0,
2465 htlc_maximum_msat: OptionalField::Absent,
2467 fee_proportional_millionths: 0,
2468 excess_data: Vec::new()
2470 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2471 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2472 short_channel_id: 7,
2474 flags: 2, // to disable
2475 cltv_expiry_delta: 0,
2476 htlc_minimum_msat: 0,
2477 htlc_maximum_msat: OptionalField::Absent,
2479 fee_proportional_millionths: 0,
2480 excess_data: Vec::new()
2483 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &multi_hint_last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2484 assert_eq!(route.paths[0].len(), 4);
2486 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2487 assert_eq!(route.paths[0][0].short_channel_id, 2);
2488 assert_eq!(route.paths[0][0].fee_msat, 200);
2489 assert_eq!(route.paths[0][0].cltv_expiry_delta, 1025);
2490 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2491 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2493 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2494 assert_eq!(route.paths[0][1].short_channel_id, 4);
2495 assert_eq!(route.paths[0][1].fee_msat, 100);
2496 assert_eq!(route.paths[0][1].cltv_expiry_delta, 1281);
2497 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2498 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2500 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
2501 assert_eq!(route.paths[0][2].short_channel_id, 5);
2502 assert_eq!(route.paths[0][2].fee_msat, 0);
2503 assert_eq!(route.paths[0][2].cltv_expiry_delta, 2049);
2504 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
2505 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new());
2507 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2508 assert_eq!(route.paths[0][3].short_channel_id, 8);
2509 assert_eq!(route.paths[0][3].fee_msat, 100);
2510 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2511 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2512 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2515 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2516 let zero_fees = RoutingFees {
2518 proportional_millionths: 0,
2520 vec![RouteHint(vec![RouteHintHop {
2521 src_node_id: nodes[4].clone(),
2522 short_channel_id: 11,
2524 cltv_expiry_delta: (11 << 8) | 1,
2525 htlc_minimum_msat: None,
2526 htlc_maximum_msat: None,
2528 src_node_id: nodes[3].clone(),
2529 short_channel_id: 8,
2531 cltv_expiry_delta: (8 << 8) | 1,
2532 htlc_minimum_msat: None,
2533 htlc_maximum_msat: None,
2534 }]), RouteHint(vec![RouteHintHop {
2535 src_node_id: nodes[4].clone(),
2536 short_channel_id: 9,
2539 proportional_millionths: 0,
2541 cltv_expiry_delta: (9 << 8) | 1,
2542 htlc_minimum_msat: None,
2543 htlc_maximum_msat: None,
2544 }]), RouteHint(vec![RouteHintHop {
2545 src_node_id: nodes[5].clone(),
2546 short_channel_id: 10,
2548 cltv_expiry_delta: (10 << 8) | 1,
2549 htlc_minimum_msat: None,
2550 htlc_maximum_msat: None,
2555 fn last_hops_with_public_channel_test() {
2556 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2557 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2558 // This test shows that public routes can be present in the invoice
2559 // which would be handled in the same manner.
2561 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &last_hops_with_public_channel(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2562 assert_eq!(route.paths[0].len(), 5);
2564 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2565 assert_eq!(route.paths[0][0].short_channel_id, 2);
2566 assert_eq!(route.paths[0][0].fee_msat, 100);
2567 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2568 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2569 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2571 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2572 assert_eq!(route.paths[0][1].short_channel_id, 4);
2573 assert_eq!(route.paths[0][1].fee_msat, 0);
2574 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2575 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2576 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2578 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2579 assert_eq!(route.paths[0][2].short_channel_id, 6);
2580 assert_eq!(route.paths[0][2].fee_msat, 0);
2581 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2582 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2583 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2585 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2586 assert_eq!(route.paths[0][3].short_channel_id, 11);
2587 assert_eq!(route.paths[0][3].fee_msat, 0);
2588 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2589 // If we have a peer in the node map, we'll use their features here since we don't have
2590 // a way of figuring out their features from the invoice:
2591 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2592 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new());
2594 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2595 assert_eq!(route.paths[0][4].short_channel_id, 8);
2596 assert_eq!(route.paths[0][4].fee_msat, 100);
2597 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2598 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2599 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2603 fn our_chans_last_hop_connect_test() {
2604 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2605 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2607 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2608 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2609 let mut last_hops = last_hops(&nodes);
2610 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2611 assert_eq!(route.paths[0].len(), 2);
2613 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2614 assert_eq!(route.paths[0][0].short_channel_id, 42);
2615 assert_eq!(route.paths[0][0].fee_msat, 0);
2616 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2617 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2618 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2620 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2621 assert_eq!(route.paths[0][1].short_channel_id, 8);
2622 assert_eq!(route.paths[0][1].fee_msat, 100);
2623 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2624 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2625 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2627 last_hops[0].0[0].fees.base_msat = 1000;
2629 // Revert to via 6 as the fee on 8 goes up
2630 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2631 assert_eq!(route.paths[0].len(), 4);
2633 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2634 assert_eq!(route.paths[0][0].short_channel_id, 2);
2635 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2636 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2637 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2638 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2640 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2641 assert_eq!(route.paths[0][1].short_channel_id, 4);
2642 assert_eq!(route.paths[0][1].fee_msat, 100);
2643 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
2644 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2645 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2647 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2648 assert_eq!(route.paths[0][2].short_channel_id, 7);
2649 assert_eq!(route.paths[0][2].fee_msat, 0);
2650 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
2651 // If we have a peer in the node map, we'll use their features here since we don't have
2652 // a way of figuring out their features from the invoice:
2653 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2654 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2656 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2657 assert_eq!(route.paths[0][3].short_channel_id, 10);
2658 assert_eq!(route.paths[0][3].fee_msat, 100);
2659 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2660 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2661 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2663 // ...but still use 8 for larger payments as 6 has a variable feerate
2664 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 2000, 42, Arc::clone(&logger)).unwrap();
2665 assert_eq!(route.paths[0].len(), 5);
2667 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2668 assert_eq!(route.paths[0][0].short_channel_id, 2);
2669 assert_eq!(route.paths[0][0].fee_msat, 3000);
2670 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2671 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2672 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2674 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2675 assert_eq!(route.paths[0][1].short_channel_id, 4);
2676 assert_eq!(route.paths[0][1].fee_msat, 0);
2677 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2678 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2679 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2681 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2682 assert_eq!(route.paths[0][2].short_channel_id, 6);
2683 assert_eq!(route.paths[0][2].fee_msat, 0);
2684 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2685 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2686 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2688 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2689 assert_eq!(route.paths[0][3].short_channel_id, 11);
2690 assert_eq!(route.paths[0][3].fee_msat, 1000);
2691 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2692 // If we have a peer in the node map, we'll use their features here since we don't have
2693 // a way of figuring out their features from the invoice:
2694 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2695 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2697 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2698 assert_eq!(route.paths[0][4].short_channel_id, 8);
2699 assert_eq!(route.paths[0][4].fee_msat, 2000);
2700 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2701 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2702 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2705 fn do_unannounced_path_test(last_hop_htlc_max: Option<u64>, last_hop_fee_prop: u32, outbound_capacity_msat: u64, route_val: u64) -> Result<Route, LightningError> {
2706 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
2707 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2708 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2710 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
2711 let last_hops = RouteHint(vec![RouteHintHop {
2712 src_node_id: middle_node_id,
2713 short_channel_id: 8,
2716 proportional_millionths: last_hop_fee_prop,
2718 cltv_expiry_delta: (8 << 8) | 1,
2719 htlc_minimum_msat: None,
2720 htlc_maximum_msat: last_hop_htlc_max,
2722 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
2723 get_route(&source_node_id, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()), &target_node_id, None, Some(&our_chans.iter().collect::<Vec<_>>()), &vec![&last_hops], route_val, 42, Arc::new(test_utils::TestLogger::new()))
2727 fn unannounced_path_test() {
2728 // We should be able to send a payment to a destination without any help of a routing graph
2729 // if we have a channel with a common counterparty that appears in the first and last hop
2731 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
2733 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2734 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2735 assert_eq!(route.paths[0].len(), 2);
2737 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
2738 assert_eq!(route.paths[0][0].short_channel_id, 42);
2739 assert_eq!(route.paths[0][0].fee_msat, 1001);
2740 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2741 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
2742 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2744 assert_eq!(route.paths[0][1].pubkey, target_node_id);
2745 assert_eq!(route.paths[0][1].short_channel_id, 8);
2746 assert_eq!(route.paths[0][1].fee_msat, 1000000);
2747 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2748 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
2749 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2753 fn overflow_unannounced_path_test_liquidity_underflow() {
2754 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
2755 // the last-hop had a fee which overflowed a u64, we'd panic.
2756 // This was due to us adding the first-hop from us unconditionally, causing us to think
2757 // we'd built a path (as our node is in the "best candidate" set), when we had not.
2758 // In this test, we previously hit a subtraction underflow due to having less available
2759 // liquidity at the last hop than 0.
2760 assert!(do_unannounced_path_test(Some(21_000_000_0000_0000_000), 0, 21_000_000_0000_0000_000, 21_000_000_0000_0000_000).is_err());
2764 fn overflow_unannounced_path_test_feerate_overflow() {
2765 // This tests for the same case as above, except instead of hitting a subtraction
2766 // underflow, we hit a case where the fee charged at a hop overflowed.
2767 assert!(do_unannounced_path_test(Some(21_000_000_0000_0000_000), 50000, 21_000_000_0000_0000_000, 21_000_000_0000_0000_000).is_err());
2771 fn available_amount_while_routing_test() {
2772 // Tests whether we choose the correct available channel amount while routing.
2774 let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
2775 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2777 // We will use a simple single-path route from
2778 // our node to node2 via node0: channels {1, 3}.
2780 // First disable all other paths.
2781 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2782 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2783 short_channel_id: 2,
2786 cltv_expiry_delta: 0,
2787 htlc_minimum_msat: 0,
2788 htlc_maximum_msat: OptionalField::Present(100_000),
2790 fee_proportional_millionths: 0,
2791 excess_data: Vec::new()
2793 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2794 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2795 short_channel_id: 12,
2798 cltv_expiry_delta: 0,
2799 htlc_minimum_msat: 0,
2800 htlc_maximum_msat: OptionalField::Present(100_000),
2802 fee_proportional_millionths: 0,
2803 excess_data: Vec::new()
2806 // Make the first channel (#1) very permissive,
2807 // and we will be testing all limits on the second channel.
2808 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2809 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2810 short_channel_id: 1,
2813 cltv_expiry_delta: 0,
2814 htlc_minimum_msat: 0,
2815 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2817 fee_proportional_millionths: 0,
2818 excess_data: Vec::new()
2821 // First, let's see if routing works if we have absolutely no idea about the available amount.
2822 // In this case, it should be set to 250_000 sats.
2823 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2824 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2825 short_channel_id: 3,
2828 cltv_expiry_delta: 0,
2829 htlc_minimum_msat: 0,
2830 htlc_maximum_msat: OptionalField::Absent,
2832 fee_proportional_millionths: 0,
2833 excess_data: Vec::new()
2837 // Attempt to route more than available results in a failure.
2838 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2839 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
2840 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2841 } else { panic!(); }
2845 // Now, attempt to route an exact amount we have should be fine.
2846 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2847 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
2848 assert_eq!(route.paths.len(), 1);
2849 let path = route.paths.last().unwrap();
2850 assert_eq!(path.len(), 2);
2851 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2852 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
2855 // Check that setting outbound_capacity_msat in first_hops limits the channels.
2856 // Disable channel #1 and use another first hop.
2857 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2858 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2859 short_channel_id: 1,
2862 cltv_expiry_delta: 0,
2863 htlc_minimum_msat: 0,
2864 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2866 fee_proportional_millionths: 0,
2867 excess_data: Vec::new()
2870 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
2871 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
2874 // Attempt to route more than available results in a failure.
2875 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2876 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
2877 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2878 } else { panic!(); }
2882 // Now, attempt to route an exact amount we have should be fine.
2883 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2884 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
2885 assert_eq!(route.paths.len(), 1);
2886 let path = route.paths.last().unwrap();
2887 assert_eq!(path.len(), 2);
2888 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2889 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
2892 // Enable channel #1 back.
2893 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2894 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2895 short_channel_id: 1,
2898 cltv_expiry_delta: 0,
2899 htlc_minimum_msat: 0,
2900 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2902 fee_proportional_millionths: 0,
2903 excess_data: Vec::new()
2907 // Now let's see if routing works if we know only htlc_maximum_msat.
2908 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2909 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2910 short_channel_id: 3,
2913 cltv_expiry_delta: 0,
2914 htlc_minimum_msat: 0,
2915 htlc_maximum_msat: OptionalField::Present(15_000),
2917 fee_proportional_millionths: 0,
2918 excess_data: Vec::new()
2922 // Attempt to route more than available results in a failure.
2923 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2924 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2925 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2926 } else { panic!(); }
2930 // Now, attempt to route an exact amount we have should be fine.
2931 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2932 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2933 assert_eq!(route.paths.len(), 1);
2934 let path = route.paths.last().unwrap();
2935 assert_eq!(path.len(), 2);
2936 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2937 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2940 // Now let's see if routing works if we know only capacity from the UTXO.
2942 // We can't change UTXO capacity on the fly, so we'll disable
2943 // the existing channel and add another one with the capacity we need.
2944 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2945 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2946 short_channel_id: 3,
2949 cltv_expiry_delta: 0,
2950 htlc_minimum_msat: 0,
2951 htlc_maximum_msat: OptionalField::Absent,
2953 fee_proportional_millionths: 0,
2954 excess_data: Vec::new()
2957 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
2958 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
2959 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
2960 .push_opcode(opcodes::all::OP_PUSHNUM_2)
2961 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
2963 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
2964 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
2966 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
2967 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2968 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2969 short_channel_id: 333,
2972 cltv_expiry_delta: (3 << 8) | 1,
2973 htlc_minimum_msat: 0,
2974 htlc_maximum_msat: OptionalField::Absent,
2976 fee_proportional_millionths: 0,
2977 excess_data: Vec::new()
2979 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2980 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2981 short_channel_id: 333,
2984 cltv_expiry_delta: (3 << 8) | 2,
2985 htlc_minimum_msat: 0,
2986 htlc_maximum_msat: OptionalField::Absent,
2988 fee_proportional_millionths: 0,
2989 excess_data: Vec::new()
2993 // Attempt to route more than available results in a failure.
2994 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
2995 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2996 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2997 } else { panic!(); }
3001 // Now, attempt to route an exact amount we have should be fine.
3002 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3003 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
3004 assert_eq!(route.paths.len(), 1);
3005 let path = route.paths.last().unwrap();
3006 assert_eq!(path.len(), 2);
3007 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3008 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3011 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3012 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3013 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3014 short_channel_id: 333,
3017 cltv_expiry_delta: 0,
3018 htlc_minimum_msat: 0,
3019 htlc_maximum_msat: OptionalField::Present(10_000),
3021 fee_proportional_millionths: 0,
3022 excess_data: Vec::new()
3026 // Attempt to route more than available results in a failure.
3027 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3028 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
3029 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3030 } else { panic!(); }
3034 // Now, attempt to route an exact amount we have should be fine.
3035 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3036 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
3037 assert_eq!(route.paths.len(), 1);
3038 let path = route.paths.last().unwrap();
3039 assert_eq!(path.len(), 2);
3040 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3041 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3046 fn available_liquidity_last_hop_test() {
3047 // Check that available liquidity properly limits the path even when only
3048 // one of the latter hops is limited.
3049 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3050 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3052 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3053 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3054 // Total capacity: 50 sats.
3056 // Disable other potential paths.
3057 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3058 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3059 short_channel_id: 2,
3062 cltv_expiry_delta: 0,
3063 htlc_minimum_msat: 0,
3064 htlc_maximum_msat: OptionalField::Present(100_000),
3066 fee_proportional_millionths: 0,
3067 excess_data: Vec::new()
3069 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3070 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3071 short_channel_id: 7,
3074 cltv_expiry_delta: 0,
3075 htlc_minimum_msat: 0,
3076 htlc_maximum_msat: OptionalField::Present(100_000),
3078 fee_proportional_millionths: 0,
3079 excess_data: Vec::new()
3084 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3085 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3086 short_channel_id: 12,
3089 cltv_expiry_delta: 0,
3090 htlc_minimum_msat: 0,
3091 htlc_maximum_msat: OptionalField::Present(100_000),
3093 fee_proportional_millionths: 0,
3094 excess_data: Vec::new()
3096 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3097 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3098 short_channel_id: 13,
3101 cltv_expiry_delta: 0,
3102 htlc_minimum_msat: 0,
3103 htlc_maximum_msat: OptionalField::Present(100_000),
3105 fee_proportional_millionths: 0,
3106 excess_data: Vec::new()
3109 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3110 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3111 short_channel_id: 6,
3114 cltv_expiry_delta: 0,
3115 htlc_minimum_msat: 0,
3116 htlc_maximum_msat: OptionalField::Present(50_000),
3118 fee_proportional_millionths: 0,
3119 excess_data: Vec::new()
3121 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3122 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3123 short_channel_id: 11,
3126 cltv_expiry_delta: 0,
3127 htlc_minimum_msat: 0,
3128 htlc_maximum_msat: OptionalField::Present(100_000),
3130 fee_proportional_millionths: 0,
3131 excess_data: Vec::new()
3134 // Attempt to route more than available results in a failure.
3135 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3136 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
3137 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3138 } else { panic!(); }
3142 // Now, attempt to route 49 sats (just a bit below the capacity).
3143 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3144 Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
3145 assert_eq!(route.paths.len(), 1);
3146 let mut total_amount_paid_msat = 0;
3147 for path in &route.paths {
3148 assert_eq!(path.len(), 4);
3149 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3150 total_amount_paid_msat += path.last().unwrap().fee_msat;
3152 assert_eq!(total_amount_paid_msat, 49_000);
3156 // Attempt to route an exact amount is also fine
3157 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3158 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
3159 assert_eq!(route.paths.len(), 1);
3160 let mut total_amount_paid_msat = 0;
3161 for path in &route.paths {
3162 assert_eq!(path.len(), 4);
3163 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3164 total_amount_paid_msat += path.last().unwrap().fee_msat;
3166 assert_eq!(total_amount_paid_msat, 50_000);
3171 fn ignore_fee_first_hop_test() {
3172 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3173 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3175 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3176 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3177 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3178 short_channel_id: 1,
3181 cltv_expiry_delta: 0,
3182 htlc_minimum_msat: 0,
3183 htlc_maximum_msat: OptionalField::Present(100_000),
3184 fee_base_msat: 1_000_000,
3185 fee_proportional_millionths: 0,
3186 excess_data: Vec::new()
3188 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3189 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3190 short_channel_id: 3,
3193 cltv_expiry_delta: 0,
3194 htlc_minimum_msat: 0,
3195 htlc_maximum_msat: OptionalField::Present(50_000),
3197 fee_proportional_millionths: 0,
3198 excess_data: Vec::new()
3202 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
3203 assert_eq!(route.paths.len(), 1);
3204 let mut total_amount_paid_msat = 0;
3205 for path in &route.paths {
3206 assert_eq!(path.len(), 2);
3207 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3208 total_amount_paid_msat += path.last().unwrap().fee_msat;
3210 assert_eq!(total_amount_paid_msat, 50_000);
3215 fn simple_mpp_route_test() {
3216 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3217 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3219 // We need a route consisting of 3 paths:
3220 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3221 // To achieve this, the amount being transferred should be around
3222 // the total capacity of these 3 paths.
3224 // First, we set limits on these (previously unlimited) channels.
3225 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3227 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3228 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3229 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3230 short_channel_id: 1,
3233 cltv_expiry_delta: 0,
3234 htlc_minimum_msat: 0,
3235 htlc_maximum_msat: OptionalField::Present(100_000),
3237 fee_proportional_millionths: 0,
3238 excess_data: Vec::new()
3240 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3241 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3242 short_channel_id: 3,
3245 cltv_expiry_delta: 0,
3246 htlc_minimum_msat: 0,
3247 htlc_maximum_msat: OptionalField::Present(50_000),
3249 fee_proportional_millionths: 0,
3250 excess_data: Vec::new()
3253 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3254 // (total limit 60).
3255 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3256 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3257 short_channel_id: 12,
3260 cltv_expiry_delta: 0,
3261 htlc_minimum_msat: 0,
3262 htlc_maximum_msat: OptionalField::Present(60_000),
3264 fee_proportional_millionths: 0,
3265 excess_data: Vec::new()
3267 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3268 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3269 short_channel_id: 13,
3272 cltv_expiry_delta: 0,
3273 htlc_minimum_msat: 0,
3274 htlc_maximum_msat: OptionalField::Present(60_000),
3276 fee_proportional_millionths: 0,
3277 excess_data: Vec::new()
3280 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3281 // (total capacity 180 sats).
3282 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3283 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3284 short_channel_id: 2,
3287 cltv_expiry_delta: 0,
3288 htlc_minimum_msat: 0,
3289 htlc_maximum_msat: OptionalField::Present(200_000),
3291 fee_proportional_millionths: 0,
3292 excess_data: Vec::new()
3294 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3295 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3296 short_channel_id: 4,
3299 cltv_expiry_delta: 0,
3300 htlc_minimum_msat: 0,
3301 htlc_maximum_msat: OptionalField::Present(180_000),
3303 fee_proportional_millionths: 0,
3304 excess_data: Vec::new()
3308 // Attempt to route more than available results in a failure.
3309 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph,
3310 &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
3311 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3312 } else { panic!(); }
3316 // Now, attempt to route 250 sats (just a bit below the capacity).
3317 // Our algorithm should provide us with these 3 paths.
3318 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3319 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
3320 assert_eq!(route.paths.len(), 3);
3321 let mut total_amount_paid_msat = 0;
3322 for path in &route.paths {
3323 assert_eq!(path.len(), 2);
3324 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3325 total_amount_paid_msat += path.last().unwrap().fee_msat;
3327 assert_eq!(total_amount_paid_msat, 250_000);
3331 // Attempt to route an exact amount is also fine
3332 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3333 Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
3334 assert_eq!(route.paths.len(), 3);
3335 let mut total_amount_paid_msat = 0;
3336 for path in &route.paths {
3337 assert_eq!(path.len(), 2);
3338 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3339 total_amount_paid_msat += path.last().unwrap().fee_msat;
3341 assert_eq!(total_amount_paid_msat, 290_000);
3346 fn long_mpp_route_test() {
3347 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3348 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3350 // We need a route consisting of 3 paths:
3351 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3352 // Note that these paths overlap (channels 5, 12, 13).
3353 // We will route 300 sats.
3354 // Each path will have 100 sats capacity, those channels which
3355 // are used twice will have 200 sats capacity.
3357 // Disable other potential paths.
3358 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3359 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3360 short_channel_id: 2,
3363 cltv_expiry_delta: 0,
3364 htlc_minimum_msat: 0,
3365 htlc_maximum_msat: OptionalField::Present(100_000),
3367 fee_proportional_millionths: 0,
3368 excess_data: Vec::new()
3370 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3371 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3372 short_channel_id: 7,
3375 cltv_expiry_delta: 0,
3376 htlc_minimum_msat: 0,
3377 htlc_maximum_msat: OptionalField::Present(100_000),
3379 fee_proportional_millionths: 0,
3380 excess_data: Vec::new()
3383 // Path via {node0, node2} is channels {1, 3, 5}.
3384 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3385 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3386 short_channel_id: 1,
3389 cltv_expiry_delta: 0,
3390 htlc_minimum_msat: 0,
3391 htlc_maximum_msat: OptionalField::Present(100_000),
3393 fee_proportional_millionths: 0,
3394 excess_data: Vec::new()
3396 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3397 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3398 short_channel_id: 3,
3401 cltv_expiry_delta: 0,
3402 htlc_minimum_msat: 0,
3403 htlc_maximum_msat: OptionalField::Present(100_000),
3405 fee_proportional_millionths: 0,
3406 excess_data: Vec::new()
3409 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3410 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3411 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3412 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3413 short_channel_id: 5,
3416 cltv_expiry_delta: 0,
3417 htlc_minimum_msat: 0,
3418 htlc_maximum_msat: OptionalField::Present(200_000),
3420 fee_proportional_millionths: 0,
3421 excess_data: Vec::new()
3424 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3425 // Add 100 sats to the capacities of {12, 13}, because these channels
3426 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3427 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3428 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3429 short_channel_id: 12,
3432 cltv_expiry_delta: 0,
3433 htlc_minimum_msat: 0,
3434 htlc_maximum_msat: OptionalField::Present(200_000),
3436 fee_proportional_millionths: 0,
3437 excess_data: Vec::new()
3439 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3440 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3441 short_channel_id: 13,
3444 cltv_expiry_delta: 0,
3445 htlc_minimum_msat: 0,
3446 htlc_maximum_msat: OptionalField::Present(200_000),
3448 fee_proportional_millionths: 0,
3449 excess_data: Vec::new()
3452 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3453 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3454 short_channel_id: 6,
3457 cltv_expiry_delta: 0,
3458 htlc_minimum_msat: 0,
3459 htlc_maximum_msat: OptionalField::Present(100_000),
3461 fee_proportional_millionths: 0,
3462 excess_data: Vec::new()
3464 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3465 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3466 short_channel_id: 11,
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()
3477 // Path via {node7, node2} is channels {12, 13, 5}.
3478 // We already limited them to 200 sats (they are used twice for 100 sats).
3479 // Nothing to do here.
3482 // Attempt to route more than available results in a failure.
3483 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3484 Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
3485 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3486 } else { panic!(); }
3490 // Now, attempt to route 300 sats (exact amount we can route).
3491 // Our algorithm should provide us with these 3 paths, 100 sats each.
3492 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3493 Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
3494 assert_eq!(route.paths.len(), 3);
3496 let mut total_amount_paid_msat = 0;
3497 for path in &route.paths {
3498 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3499 total_amount_paid_msat += path.last().unwrap().fee_msat;
3501 assert_eq!(total_amount_paid_msat, 300_000);
3507 fn mpp_cheaper_route_test() {
3508 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3509 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3511 // This test checks that if we have two cheaper paths and one more expensive path,
3512 // so that liquidity-wise any 2 of 3 combination is sufficient,
3513 // two cheaper paths will be taken.
3514 // These paths have equal available liquidity.
3516 // We need a combination of 3 paths:
3517 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3518 // Note that these paths overlap (channels 5, 12, 13).
3519 // Each path will have 100 sats capacity, those channels which
3520 // are used twice will have 200 sats capacity.
3522 // Disable other potential paths.
3523 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3524 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3525 short_channel_id: 2,
3528 cltv_expiry_delta: 0,
3529 htlc_minimum_msat: 0,
3530 htlc_maximum_msat: OptionalField::Present(100_000),
3532 fee_proportional_millionths: 0,
3533 excess_data: Vec::new()
3535 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3536 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3537 short_channel_id: 7,
3540 cltv_expiry_delta: 0,
3541 htlc_minimum_msat: 0,
3542 htlc_maximum_msat: OptionalField::Present(100_000),
3544 fee_proportional_millionths: 0,
3545 excess_data: Vec::new()
3548 // Path via {node0, node2} is channels {1, 3, 5}.
3549 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3550 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3551 short_channel_id: 1,
3554 cltv_expiry_delta: 0,
3555 htlc_minimum_msat: 0,
3556 htlc_maximum_msat: OptionalField::Present(100_000),
3558 fee_proportional_millionths: 0,
3559 excess_data: Vec::new()
3561 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3562 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3563 short_channel_id: 3,
3566 cltv_expiry_delta: 0,
3567 htlc_minimum_msat: 0,
3568 htlc_maximum_msat: OptionalField::Present(100_000),
3570 fee_proportional_millionths: 0,
3571 excess_data: Vec::new()
3574 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3575 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3576 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3577 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3578 short_channel_id: 5,
3581 cltv_expiry_delta: 0,
3582 htlc_minimum_msat: 0,
3583 htlc_maximum_msat: OptionalField::Present(200_000),
3585 fee_proportional_millionths: 0,
3586 excess_data: Vec::new()
3589 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3590 // Add 100 sats to the capacities of {12, 13}, because these channels
3591 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3592 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3593 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3594 short_channel_id: 12,
3597 cltv_expiry_delta: 0,
3598 htlc_minimum_msat: 0,
3599 htlc_maximum_msat: OptionalField::Present(200_000),
3601 fee_proportional_millionths: 0,
3602 excess_data: Vec::new()
3604 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3605 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3606 short_channel_id: 13,
3609 cltv_expiry_delta: 0,
3610 htlc_minimum_msat: 0,
3611 htlc_maximum_msat: OptionalField::Present(200_000),
3613 fee_proportional_millionths: 0,
3614 excess_data: Vec::new()
3617 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3618 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3619 short_channel_id: 6,
3622 cltv_expiry_delta: 0,
3623 htlc_minimum_msat: 0,
3624 htlc_maximum_msat: OptionalField::Present(100_000),
3625 fee_base_msat: 1_000,
3626 fee_proportional_millionths: 0,
3627 excess_data: Vec::new()
3629 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3630 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3631 short_channel_id: 11,
3634 cltv_expiry_delta: 0,
3635 htlc_minimum_msat: 0,
3636 htlc_maximum_msat: OptionalField::Present(100_000),
3638 fee_proportional_millionths: 0,
3639 excess_data: Vec::new()
3642 // Path via {node7, node2} is channels {12, 13, 5}.
3643 // We already limited them to 200 sats (they are used twice for 100 sats).
3644 // Nothing to do here.
3647 // Now, attempt to route 180 sats.
3648 // Our algorithm should provide us with these 2 paths.
3649 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3650 Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
3651 assert_eq!(route.paths.len(), 2);
3653 let mut total_value_transferred_msat = 0;
3654 let mut total_paid_msat = 0;
3655 for path in &route.paths {
3656 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3657 total_value_transferred_msat += path.last().unwrap().fee_msat;
3659 total_paid_msat += hop.fee_msat;
3662 // If we paid fee, this would be higher.
3663 assert_eq!(total_value_transferred_msat, 180_000);
3664 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3665 assert_eq!(total_fees_paid, 0);
3670 fn fees_on_mpp_route_test() {
3671 // This test makes sure that MPP algorithm properly takes into account
3672 // fees charged on the channels, by making the fees impactful:
3673 // if the fee is not properly accounted for, the behavior is different.
3674 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3675 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3677 // We need a route consisting of 2 paths:
3678 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
3679 // We will route 200 sats, Each path will have 100 sats capacity.
3681 // This test is not particularly stable: e.g.,
3682 // there's a way to route via {node0, node2, node4}.
3683 // It works while pathfinding is deterministic, but can be broken otherwise.
3684 // It's fine to ignore this concern for now.
3686 // Disable other potential paths.
3687 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3688 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3689 short_channel_id: 2,
3692 cltv_expiry_delta: 0,
3693 htlc_minimum_msat: 0,
3694 htlc_maximum_msat: OptionalField::Present(100_000),
3696 fee_proportional_millionths: 0,
3697 excess_data: Vec::new()
3700 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3701 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3702 short_channel_id: 7,
3705 cltv_expiry_delta: 0,
3706 htlc_minimum_msat: 0,
3707 htlc_maximum_msat: OptionalField::Present(100_000),
3709 fee_proportional_millionths: 0,
3710 excess_data: Vec::new()
3713 // Path via {node0, node2} is channels {1, 3, 5}.
3714 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3715 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3716 short_channel_id: 1,
3719 cltv_expiry_delta: 0,
3720 htlc_minimum_msat: 0,
3721 htlc_maximum_msat: OptionalField::Present(100_000),
3723 fee_proportional_millionths: 0,
3724 excess_data: Vec::new()
3726 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3727 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3728 short_channel_id: 3,
3731 cltv_expiry_delta: 0,
3732 htlc_minimum_msat: 0,
3733 htlc_maximum_msat: OptionalField::Present(100_000),
3735 fee_proportional_millionths: 0,
3736 excess_data: Vec::new()
3739 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3740 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3741 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3742 short_channel_id: 5,
3745 cltv_expiry_delta: 0,
3746 htlc_minimum_msat: 0,
3747 htlc_maximum_msat: OptionalField::Present(100_000),
3749 fee_proportional_millionths: 0,
3750 excess_data: Vec::new()
3753 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3754 // All channels should be 100 sats capacity. But for the fee experiment,
3755 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
3756 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
3757 // 100 sats (and pay 150 sats in fees for the use of channel 6),
3758 // so no matter how large are other channels,
3759 // the whole path will be limited by 100 sats with just these 2 conditions:
3760 // - channel 12 capacity is 250 sats
3761 // - fee for channel 6 is 150 sats
3762 // Let's test this by enforcing these 2 conditions and removing other limits.
3763 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3764 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3765 short_channel_id: 12,
3768 cltv_expiry_delta: 0,
3769 htlc_minimum_msat: 0,
3770 htlc_maximum_msat: OptionalField::Present(250_000),
3772 fee_proportional_millionths: 0,
3773 excess_data: Vec::new()
3775 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3776 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3777 short_channel_id: 13,
3780 cltv_expiry_delta: 0,
3781 htlc_minimum_msat: 0,
3782 htlc_maximum_msat: OptionalField::Absent,
3784 fee_proportional_millionths: 0,
3785 excess_data: Vec::new()
3788 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3789 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3790 short_channel_id: 6,
3793 cltv_expiry_delta: 0,
3794 htlc_minimum_msat: 0,
3795 htlc_maximum_msat: OptionalField::Absent,
3796 fee_base_msat: 150_000,
3797 fee_proportional_millionths: 0,
3798 excess_data: Vec::new()
3800 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3801 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3802 short_channel_id: 11,
3805 cltv_expiry_delta: 0,
3806 htlc_minimum_msat: 0,
3807 htlc_maximum_msat: OptionalField::Absent,
3809 fee_proportional_millionths: 0,
3810 excess_data: Vec::new()
3814 // Attempt to route more than available results in a failure.
3815 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3816 Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
3817 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3818 } else { panic!(); }
3822 // Now, attempt to route 200 sats (exact amount we can route).
3823 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[3],
3824 Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
3825 assert_eq!(route.paths.len(), 2);
3827 let mut total_amount_paid_msat = 0;
3828 for path in &route.paths {
3829 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3830 total_amount_paid_msat += path.last().unwrap().fee_msat;
3832 assert_eq!(total_amount_paid_msat, 200_000);
3833 assert_eq!(route.get_total_fees(), 150_000);
3839 fn drop_lowest_channel_mpp_route_test() {
3840 // This test checks that low-capacity channel is dropped when after
3841 // path finding we realize that we found more capacity than we need.
3842 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3843 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3845 // We need a route consisting of 3 paths:
3846 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3848 // The first and the second paths should be sufficient, but the third should be
3849 // cheaper, so that we select it but drop later.
3851 // First, we set limits on these (previously unlimited) channels.
3852 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
3854 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
3855 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3856 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3857 short_channel_id: 1,
3860 cltv_expiry_delta: 0,
3861 htlc_minimum_msat: 0,
3862 htlc_maximum_msat: OptionalField::Present(100_000),
3864 fee_proportional_millionths: 0,
3865 excess_data: Vec::new()
3867 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3868 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3869 short_channel_id: 3,
3872 cltv_expiry_delta: 0,
3873 htlc_minimum_msat: 0,
3874 htlc_maximum_msat: OptionalField::Present(50_000),
3876 fee_proportional_millionths: 0,
3877 excess_data: Vec::new()
3880 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
3881 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3882 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3883 short_channel_id: 12,
3886 cltv_expiry_delta: 0,
3887 htlc_minimum_msat: 0,
3888 htlc_maximum_msat: OptionalField::Present(60_000),
3890 fee_proportional_millionths: 0,
3891 excess_data: Vec::new()
3893 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3894 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3895 short_channel_id: 13,
3898 cltv_expiry_delta: 0,
3899 htlc_minimum_msat: 0,
3900 htlc_maximum_msat: OptionalField::Present(60_000),
3902 fee_proportional_millionths: 0,
3903 excess_data: Vec::new()
3906 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
3907 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3908 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3909 short_channel_id: 2,
3912 cltv_expiry_delta: 0,
3913 htlc_minimum_msat: 0,
3914 htlc_maximum_msat: OptionalField::Present(20_000),
3916 fee_proportional_millionths: 0,
3917 excess_data: Vec::new()
3919 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3920 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3921 short_channel_id: 4,
3924 cltv_expiry_delta: 0,
3925 htlc_minimum_msat: 0,
3926 htlc_maximum_msat: OptionalField::Present(20_000),
3928 fee_proportional_millionths: 0,
3929 excess_data: Vec::new()
3933 // Attempt to route more than available results in a failure.
3934 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3935 Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
3936 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3937 } else { panic!(); }
3941 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
3942 // Our algorithm should provide us with these 3 paths.
3943 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3944 Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
3945 assert_eq!(route.paths.len(), 3);
3946 let mut total_amount_paid_msat = 0;
3947 for path in &route.paths {
3948 assert_eq!(path.len(), 2);
3949 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3950 total_amount_paid_msat += path.last().unwrap().fee_msat;
3952 assert_eq!(total_amount_paid_msat, 125_000);
3956 // Attempt to route without the last small cheap channel
3957 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2],
3958 Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3959 assert_eq!(route.paths.len(), 2);
3960 let mut total_amount_paid_msat = 0;
3961 for path in &route.paths {
3962 assert_eq!(path.len(), 2);
3963 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3964 total_amount_paid_msat += path.last().unwrap().fee_msat;
3966 assert_eq!(total_amount_paid_msat, 90_000);
3971 fn min_criteria_consistency() {
3972 // Test that we don't use an inconsistent metric between updating and walking nodes during
3973 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
3974 // was updated with a different criterion from the heap sorting, resulting in loops in
3975 // calculated paths. We test for that specific case here.
3977 // We construct a network that looks like this:
3979 // node2 -1(3)2- node3
3983 // node1 -1(5)2- node4 -1(1)2- node6
3989 // We create a loop on the side of our real path - our destination is node 6, with a
3990 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
3991 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
3992 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
3993 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
3994 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
3995 // "previous hop" being set to node 3, creating a loop in the path.
3996 let secp_ctx = Secp256k1::new();
3997 let logger = Arc::new(test_utils::TestLogger::new());
3998 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
3999 let net_graph_msg_handler = NetGraphMsgHandler::new(network_graph, None, Arc::clone(&logger));
4000 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4002 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4003 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4004 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4005 short_channel_id: 6,
4008 cltv_expiry_delta: (6 << 8) | 0,
4009 htlc_minimum_msat: 0,
4010 htlc_maximum_msat: OptionalField::Absent,
4012 fee_proportional_millionths: 0,
4013 excess_data: Vec::new()
4015 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4017 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4018 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4019 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4020 short_channel_id: 5,
4023 cltv_expiry_delta: (5 << 8) | 0,
4024 htlc_minimum_msat: 0,
4025 htlc_maximum_msat: OptionalField::Absent,
4027 fee_proportional_millionths: 0,
4028 excess_data: Vec::new()
4030 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4032 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4033 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4034 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4035 short_channel_id: 4,
4038 cltv_expiry_delta: (4 << 8) | 0,
4039 htlc_minimum_msat: 0,
4040 htlc_maximum_msat: OptionalField::Absent,
4042 fee_proportional_millionths: 0,
4043 excess_data: Vec::new()
4045 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4047 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4048 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4049 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4050 short_channel_id: 3,
4053 cltv_expiry_delta: (3 << 8) | 0,
4054 htlc_minimum_msat: 0,
4055 htlc_maximum_msat: OptionalField::Absent,
4057 fee_proportional_millionths: 0,
4058 excess_data: Vec::new()
4060 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4062 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4063 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4064 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4065 short_channel_id: 2,
4068 cltv_expiry_delta: (2 << 8) | 0,
4069 htlc_minimum_msat: 0,
4070 htlc_maximum_msat: OptionalField::Absent,
4072 fee_proportional_millionths: 0,
4073 excess_data: Vec::new()
4076 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4077 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4078 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4079 short_channel_id: 1,
4082 cltv_expiry_delta: (1 << 8) | 0,
4083 htlc_minimum_msat: 100,
4084 htlc_maximum_msat: OptionalField::Absent,
4086 fee_proportional_millionths: 0,
4087 excess_data: Vec::new()
4089 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4092 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4093 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[6], None, None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
4094 assert_eq!(route.paths.len(), 1);
4095 assert_eq!(route.paths[0].len(), 3);
4097 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4098 assert_eq!(route.paths[0][0].short_channel_id, 6);
4099 assert_eq!(route.paths[0][0].fee_msat, 100);
4100 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
4101 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4102 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4104 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4105 assert_eq!(route.paths[0][1].short_channel_id, 5);
4106 assert_eq!(route.paths[0][1].fee_msat, 0);
4107 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
4108 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4109 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4111 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4112 assert_eq!(route.paths[0][2].short_channel_id, 1);
4113 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4114 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4115 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4116 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4122 fn exact_fee_liquidity_limit() {
4123 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4124 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4125 // we calculated fees on a higher value, resulting in us ignoring such paths.
4126 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
4127 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4129 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4131 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4132 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4133 short_channel_id: 2,
4136 cltv_expiry_delta: 0,
4137 htlc_minimum_msat: 0,
4138 htlc_maximum_msat: OptionalField::Present(85_000),
4140 fee_proportional_millionths: 0,
4141 excess_data: Vec::new()
4144 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4145 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4146 short_channel_id: 12,
4149 cltv_expiry_delta: (4 << 8) | 1,
4150 htlc_minimum_msat: 0,
4151 htlc_maximum_msat: OptionalField::Present(270_000),
4153 fee_proportional_millionths: 1000000,
4154 excess_data: Vec::new()
4158 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4159 // 200% fee charged channel 13 in the 1-to-2 direction.
4160 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], None, None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
4161 assert_eq!(route.paths.len(), 1);
4162 assert_eq!(route.paths[0].len(), 2);
4164 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4165 assert_eq!(route.paths[0][0].short_channel_id, 12);
4166 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4167 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
4168 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4169 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4171 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4172 assert_eq!(route.paths[0][1].short_channel_id, 13);
4173 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4174 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4175 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4176 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4181 fn htlc_max_reduction_below_min() {
4182 // Test that if, while walking the graph, we reduce the value being sent to meet an
4183 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4184 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4185 // resulting in us thinking there is no possible path, even if other paths exist.
4186 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
4187 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4189 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4190 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4191 // then try to send 90_000.
4192 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4193 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4194 short_channel_id: 2,
4197 cltv_expiry_delta: 0,
4198 htlc_minimum_msat: 0,
4199 htlc_maximum_msat: OptionalField::Present(80_000),
4201 fee_proportional_millionths: 0,
4202 excess_data: Vec::new()
4204 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4205 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4206 short_channel_id: 4,
4209 cltv_expiry_delta: (4 << 8) | 1,
4210 htlc_minimum_msat: 90_000,
4211 htlc_maximum_msat: OptionalField::Absent,
4213 fee_proportional_millionths: 0,
4214 excess_data: Vec::new()
4218 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
4219 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
4220 // expensive) channels 12-13 path.
4221 let route = get_route(&our_id, &net_graph_msg_handler.network_graph, &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
4222 assert_eq!(route.paths.len(), 1);
4223 assert_eq!(route.paths[0].len(), 2);
4225 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4226 assert_eq!(route.paths[0][0].short_channel_id, 12);
4227 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4228 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
4229 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4230 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4232 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4233 assert_eq!(route.paths[0][1].short_channel_id, 13);
4234 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4235 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4236 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
4237 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4242 fn multiple_direct_first_hops() {
4243 // Previously we'd only ever considered one first hop path per counterparty.
4244 // However, as we don't restrict users to one channel per peer, we really need to support
4245 // looking at all first hop paths.
4246 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
4247 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
4248 // route over multiple channels with the same first hop.
4249 let secp_ctx = Secp256k1::new();
4250 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4251 let logger = Arc::new(test_utils::TestLogger::new());
4252 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
4255 let route = get_route(&our_id, &network_graph, &nodes[0], Some(InvoiceFeatures::known()), Some(&[
4256 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
4257 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
4258 ]), &[], 100_000, 42, Arc::clone(&logger)).unwrap();
4259 assert_eq!(route.paths.len(), 1);
4260 assert_eq!(route.paths[0].len(), 1);
4262 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4263 assert_eq!(route.paths[0][0].short_channel_id, 3);
4264 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4267 let route = get_route(&our_id, &network_graph, &nodes[0], Some(InvoiceFeatures::known()), Some(&[
4268 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4269 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4270 ]), &[], 100_000, 42, Arc::clone(&logger)).unwrap();
4271 assert_eq!(route.paths.len(), 2);
4272 assert_eq!(route.paths[0].len(), 1);
4273 assert_eq!(route.paths[1].len(), 1);
4275 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4276 assert_eq!(route.paths[0][0].short_channel_id, 3);
4277 assert_eq!(route.paths[0][0].fee_msat, 50_000);
4279 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
4280 assert_eq!(route.paths[1][0].short_channel_id, 2);
4281 assert_eq!(route.paths[1][0].fee_msat, 50_000);
4286 fn total_fees_single_path() {
4290 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4291 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4292 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4295 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4296 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4297 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4300 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
4301 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4302 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
4307 assert_eq!(route.get_total_fees(), 250);
4308 assert_eq!(route.get_total_amount(), 225);
4312 fn total_fees_multi_path() {
4316 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4317 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4318 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4321 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4322 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4323 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4327 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4328 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4329 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4332 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4333 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4334 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4339 assert_eq!(route.get_total_fees(), 200);
4340 assert_eq!(route.get_total_amount(), 300);
4344 fn total_empty_route_no_panic() {
4345 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
4346 // would both panic if the route was completely empty. We test to ensure they return 0
4347 // here, even though its somewhat nonsensical as a route.
4348 let route = Route { paths: Vec::new() };
4350 assert_eq!(route.get_total_fees(), 0);
4351 assert_eq!(route.get_total_amount(), 0);
4354 #[cfg(not(feature = "no-std"))]
4355 pub(super) fn random_init_seed() -> u64 {
4356 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
4357 use core::hash::{BuildHasher, Hasher};
4358 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
4359 println!("Using seed of {}", seed);
4362 #[cfg(not(feature = "no-std"))]
4363 use util::ser::Readable;
4366 #[cfg(not(feature = "no-std"))]
4367 fn generate_routes() {
4368 let mut d = match super::test_utils::get_route_file() {
4375 let graph = NetworkGraph::read(&mut d).unwrap();
4377 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4378 let mut seed = random_init_seed() as usize;
4379 let nodes = graph.read_only().nodes().clone();
4380 'load_endpoints: for _ in 0..10 {
4382 seed = seed.overflowing_mul(0xdeadbeef).0;
4383 let src = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4384 seed = seed.overflowing_mul(0xdeadbeef).0;
4385 let dst = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4386 let amt = seed as u64 % 200_000_000;
4387 if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
4388 continue 'load_endpoints;
4395 #[cfg(not(feature = "no-std"))]
4396 fn generate_routes_mpp() {
4397 let mut d = match super::test_utils::get_route_file() {
4404 let graph = NetworkGraph::read(&mut d).unwrap();
4406 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4407 let mut seed = random_init_seed() as usize;
4408 let nodes = graph.read_only().nodes().clone();
4409 'load_endpoints: for _ in 0..10 {
4411 seed = seed.overflowing_mul(0xdeadbeef).0;
4412 let src = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4413 seed = seed.overflowing_mul(0xdeadbeef).0;
4414 let dst = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4415 let amt = seed as u64 % 200_000_000;
4416 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
4417 continue 'load_endpoints;
4424 #[cfg(all(test, not(feature = "no-std")))]
4425 pub(crate) mod test_utils {
4427 /// Tries to open a network graph file, or panics with a URL to fetch it.
4428 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
4429 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
4430 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
4431 .or_else(|_| { // Fall back to guessing based on the binary location
4432 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
4433 let mut path = std::env::current_exe().unwrap();
4434 path.pop(); // lightning-...
4436 path.pop(); // debug
4437 path.pop(); // target
4438 path.push("lightning");
4439 path.push("net_graph-2021-05-31.bin");
4440 eprintln!("{}", path.to_str().unwrap());
4443 .map_err(|_| "Please fetch https://bitcoin.ninja/ldk-net_graph-v0.0.15-2021-05-31.bin and place it at lightning/net_graph-2021-05-31.bin");
4444 #[cfg(require_route_graph_test)]
4445 return Ok(res.unwrap());
4446 #[cfg(not(require_route_graph_test))]
4451 #[cfg(all(test, feature = "unstable", not(feature = "no-std")))]
4454 use util::logger::{Logger, Record};
4458 struct DummyLogger {}
4459 impl Logger for DummyLogger {
4460 fn log(&self, _record: &Record) {}
4464 fn generate_routes(bench: &mut Bencher) {
4465 let mut d = test_utils::get_route_file().unwrap();
4466 let graph = NetworkGraph::read(&mut d).unwrap();
4467 let nodes = graph.read_only().nodes().clone();
4469 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4470 let mut path_endpoints = Vec::new();
4471 let mut seed: usize = 0xdeadbeef;
4472 'load_endpoints: for _ in 0..100 {
4475 let src = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4477 let dst = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4478 let amt = seed as u64 % 1_000_000;
4479 if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
4480 path_endpoints.push((src, dst, amt));
4481 continue 'load_endpoints;
4486 // ...then benchmark finding paths between the nodes we learned.
4489 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
4490 assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
4496 fn generate_mpp_routes(bench: &mut Bencher) {
4497 let mut d = test_utils::get_route_file().unwrap();
4498 let graph = NetworkGraph::read(&mut d).unwrap();
4499 let nodes = graph.read_only().nodes().clone();
4501 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4502 let mut path_endpoints = Vec::new();
4503 let mut seed: usize = 0xdeadbeef;
4504 'load_endpoints: for _ in 0..100 {
4507 let src = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4509 let dst = nodes.keys().skip(seed % nodes.len()).next().unwrap();
4510 let amt = seed as u64 % 1_000_000;
4511 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
4512 path_endpoints.push((src, dst, amt));
4513 continue 'load_endpoints;
4518 // ...then benchmark finding paths between the nodes we learned.
4521 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
4522 assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());