1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The top-level routing/network map tracking logic lives here.
12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::network_graph::{NetworkGraph, RoutingFees};
21 use util::ser::{Writeable, Readable};
22 use util::logger::Logger;
25 use alloc::collections::BinaryHeap;
30 #[derive(Clone, PartialEq)]
32 /// The node_id of the node at this hop.
33 pub pubkey: PublicKey,
34 /// The node_announcement features of the node at this hop. For the last hop, these may be
35 /// amended to match the features present in the invoice this node generated.
36 pub node_features: NodeFeatures,
37 /// The channel that should be used from the previous hop to reach this node.
38 pub short_channel_id: u64,
39 /// The channel_announcement features of the channel that should be used from the previous hop
40 /// to reach this node.
41 pub channel_features: ChannelFeatures,
42 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
43 /// For the last hop, this should be the full value of the payment (might be more than
44 /// requested if we had to match htlc_minimum_msat).
46 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
47 /// expected at the destination, in excess of the current block height.
48 pub cltv_expiry_delta: u32,
51 impl_writeable_tlv_based!(RouteHop, {
52 (0, pubkey, required),
53 (2, node_features, required),
54 (4, short_channel_id, required),
55 (6, channel_features, required),
56 (8, fee_msat, required),
57 (10, cltv_expiry_delta, required),
60 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
61 /// it can take multiple paths. Each path is composed of one or more hops through the network.
62 #[derive(Clone, PartialEq)]
64 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
65 /// last RouteHop in each path must be the same.
66 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
67 /// destination. Thus, this must always be at least length one. While the maximum length of any
68 /// given path is variable, keeping the length of any path to less than 20 should currently
69 /// ensure it is viable.
70 pub paths: Vec<Vec<RouteHop>>,
73 const SERIALIZATION_VERSION: u8 = 1;
74 const MIN_SERIALIZATION_VERSION: u8 = 1;
76 impl Writeable for Route {
77 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
78 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
79 (self.paths.len() as u64).write(writer)?;
80 for hops in self.paths.iter() {
81 (hops.len() as u8).write(writer)?;
82 for hop in hops.iter() {
86 write_tlv_fields!(writer, {});
91 impl Readable for Route {
92 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
93 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
94 let path_count: u64 = Readable::read(reader)?;
95 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
96 for _ in 0..path_count {
97 let hop_count: u8 = Readable::read(reader)?;
98 let mut hops = Vec::with_capacity(hop_count as usize);
99 for _ in 0..hop_count {
100 hops.push(Readable::read(reader)?);
104 read_tlv_fields!(reader, {});
109 /// A list of hops along a payment path terminating with a channel to the recipient.
110 #[derive(Eq, PartialEq, Debug, Clone)]
111 pub struct RouteHint(pub Vec<RouteHintHop>);
113 /// A channel descriptor for a hop along a payment path.
114 #[derive(Eq, PartialEq, Debug, Clone)]
115 pub struct RouteHintHop {
116 /// The node_id of the non-target end of the route
117 pub src_node_id: PublicKey,
118 /// The short_channel_id of this channel
119 pub short_channel_id: u64,
120 /// The fees which must be paid to use this channel
121 pub fees: RoutingFees,
122 /// The difference in CLTV values between this node and the next node.
123 pub cltv_expiry_delta: u16,
124 /// The minimum value, in msat, which must be relayed to the next hop.
125 pub htlc_minimum_msat: Option<u64>,
126 /// The maximum value in msat available for routing with a single HTLC.
127 pub htlc_maximum_msat: Option<u64>,
130 #[derive(Eq, PartialEq)]
131 struct RouteGraphNode {
133 lowest_fee_to_peer_through_node: u64,
134 lowest_fee_to_node: u64,
135 // The maximum value a yet-to-be-constructed payment path might flow through this node.
136 // This value is upper-bounded by us by:
137 // - how much is needed for a path being constructed
138 // - how much value can channels following this node (up to the destination) can contribute,
139 // considering their capacity and fees
140 value_contribution_msat: u64,
141 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
142 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
143 path_htlc_minimum_msat: u64,
146 impl cmp::Ord for RouteGraphNode {
147 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
148 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat);
149 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat);
150 other_score.cmp(&self_score).then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
154 impl cmp::PartialOrd for RouteGraphNode {
155 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
156 Some(self.cmp(other))
160 struct DummyDirectionalChannelInfo {
161 cltv_expiry_delta: u32,
162 htlc_minimum_msat: u64,
163 htlc_maximum_msat: Option<u64>,
167 /// It's useful to keep track of the hops associated with the fees required to use them,
168 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
169 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
170 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
171 #[derive(Clone, Debug)]
172 struct PathBuildingHop<'a> {
173 // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
174 // Note that node_features is calculated separately after our initial graph walk.
176 short_channel_id: u64,
177 channel_features: &'a ChannelFeatures,
179 cltv_expiry_delta: u32,
181 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
182 src_lowest_inbound_fees: RoutingFees,
183 /// Fees of the channel used in this hop.
184 channel_fees: RoutingFees,
185 /// All the fees paid *after* this channel on the way to the destination
186 next_hops_fee_msat: u64,
187 /// Fee paid for the use of the current channel (see channel_fees).
188 /// The value will be actually deducted from the counterparty balance on the previous link.
189 hop_use_fee_msat: u64,
190 /// Used to compare channels when choosing the for routing.
191 /// Includes paying for the use of a hop and the following hops, as well as
192 /// an estimated cost of reaching this hop.
193 /// Might get stale when fees are recomputed. Primarily for internal use.
195 /// This is useful for update_value_and_recompute_fees to make sure
196 /// we don't fall below the minimum. Should not be updated manually and
197 /// generally should not be accessed.
198 htlc_minimum_msat: u64,
199 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
200 /// walk and may be invalid thereafter.
201 path_htlc_minimum_msat: u64,
202 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
203 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
204 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
205 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
206 /// avoid processing them again.
208 #[cfg(any(test, feature = "fuzztarget"))]
209 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
210 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
211 // value_contribution_msat, which requires tracking it here. See comments below where it is
212 // used for more info.
213 value_contribution_msat: u64,
216 // Instantiated with a list of hops with correct data in them collected during path finding,
217 // an instance of this struct should be further modified only via given methods.
219 struct PaymentPath<'a> {
220 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
223 impl<'a> PaymentPath<'a> {
224 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
225 fn get_value_msat(&self) -> u64 {
226 self.hops.last().unwrap().0.fee_msat
229 fn get_total_fee_paid_msat(&self) -> u64 {
230 if self.hops.len() < 1 {
234 // Can't use next_hops_fee_msat because it gets outdated.
235 for (i, (hop, _)) in self.hops.iter().enumerate() {
236 if i != self.hops.len() - 1 {
237 result += hop.fee_msat;
243 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
244 // to change fees may result in an inconsistency.
246 // Sometimes we call this function right after constructing a path which is inconsistent in
247 // that it the value being transferred has decreased while we were doing path finding, leading
248 // to the fees being paid not lining up with the actual limits.
250 // Note that this function is not aware of the available_liquidity limit, and thus does not
251 // support increasing the value being transferred.
252 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
253 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
255 let mut total_fee_paid_msat = 0 as u64;
256 for i in (0..self.hops.len()).rev() {
257 let last_hop = i == self.hops.len() - 1;
259 // For non-last-hop, this value will represent the fees paid on the current hop. It
260 // will consist of the fees for the use of the next hop, and extra fees to match
261 // htlc_minimum_msat of the current channel. Last hop is handled separately.
262 let mut cur_hop_fees_msat = 0;
264 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
267 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
268 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
269 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
270 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
271 // set it too high just to maliciously take more fees by exploiting this
272 // match htlc_minimum_msat logic.
273 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
274 if let Some(extra_fees_msat) = cur_hop.htlc_minimum_msat.checked_sub(cur_hop_transferred_amount_msat) {
275 // Note that there is a risk that *previous hops* (those closer to us, as we go
276 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
278 // This might make us end up with a broken route, although this should be super-rare
279 // in practice, both because of how healthy channels look like, and how we pick
280 // channels in add_entry.
281 // Also, this can't be exploited more heavily than *announce a free path and fail
283 cur_hop_transferred_amount_msat += extra_fees_msat;
284 total_fee_paid_msat += extra_fees_msat;
285 cur_hop_fees_msat += extra_fees_msat;
289 // Final hop is a special case: it usually has just value_msat (by design), but also
290 // it still could overpay for the htlc_minimum_msat.
291 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
293 // Propagate updated fees for the use of the channels to one hop back, where they
294 // will be actually paid (fee_msat). The last hop is handled above separately.
295 cur_hop.fee_msat = cur_hop_fees_msat;
298 // Fee for the use of the current hop which will be deducted on the previous hop.
299 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
300 // this channel is free for us.
302 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.channel_fees) {
303 cur_hop.hop_use_fee_msat = new_fee;
304 total_fee_paid_msat += new_fee;
306 // It should not be possible because this function is called only to reduce the
307 // value. In that case, compute_fee was already called with the same fees for
308 // larger amount and there was no overflow.
316 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
317 let proportional_fee_millions =
318 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
319 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
320 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
324 // This function may be (indirectly) called without any verification,
325 // with channel_fees provided by a caller. We should handle it gracefully.
330 /// Gets a route from us (payer) to the given target node (payee).
332 /// If the payee provided features in their invoice, they should be provided via payee_features.
333 /// Without this, MPP will only be used if the payee's features are available in the network graph.
335 /// Private routing paths between a public node and the target may be included in `last_hops`.
336 /// Currently, only the last hop in each path is considered.
338 /// If some channels aren't announced, it may be useful to fill in a first_hops with the
339 /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
340 /// view of our local channels (from net_graph_msg_handler) will be ignored, and only those
341 /// in first_hops will be used.
343 /// Panics if first_hops contains channels without short_channel_ids
344 /// (ChannelManager::list_usable_channels will never include such channels).
346 /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
347 /// equal), however the enabled/disabled bit on such channels as well as the
348 /// htlc_minimum_msat/htlc_maximum_msat *are* checked as they may change based on the receiving node.
349 pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee: &PublicKey, payee_features: Option<InvoiceFeatures>, first_hops: Option<&[&ChannelDetails]>,
350 last_hops: &[&RouteHint], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
351 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
352 // uptime/success in using a node in the past.
353 if *payee == *our_node_id {
354 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
357 if final_value_msat > MAX_VALUE_MSAT {
358 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
361 if final_value_msat == 0 {
362 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
365 let last_hops = last_hops.iter().filter_map(|hops| hops.0.last()).collect::<Vec<_>>();
366 for last_hop in last_hops.iter() {
367 if last_hop.src_node_id == *payee {
368 return Err(LightningError{err: "Last hop cannot have a payee as a source.".to_owned(), action: ErrorAction::IgnoreError});
372 // The general routing idea is the following:
373 // 1. Fill first/last hops communicated by the caller.
374 // 2. Attempt to construct a path from payer to payee for transferring
375 // any ~sufficient (described later) value.
376 // If succeed, remember which channels were used and how much liquidity they have available,
377 // so that future paths don't rely on the same liquidity.
378 // 3. Prooceed to the next step if:
379 // - we hit the recommended target value;
380 // - OR if we could not construct a new path. Any next attempt will fail too.
381 // Otherwise, repeat step 2.
382 // 4. See if we managed to collect paths which aggregately are able to transfer target value
383 // (not recommended value). If yes, proceed. If not, fail routing.
384 // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
385 // 6. Of all the found paths, select only those with the lowest total fee.
386 // 7. The last path in every selected route is likely to be more than we need.
387 // Reduce its value-to-transfer and recompute fees.
388 // 8. Choose the best route by the lowest total fee.
390 // As for the actual search algorithm,
391 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
392 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
394 // We are not a faithful Dijkstra's implementation because we can change values which impact
395 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
396 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) then
397 // the value we are currently attempting to send over a path, we simply reduce the value being
398 // sent along the path for any hops after that channel. This may imply that later fees (which
399 // we've already tabulated) are lower because a smaller value is passing through the channels
400 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
401 // channels which were selected earlier (and which may still be used for other paths without a
402 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
405 // One potentially problematic case for this algorithm would be if there are many
406 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
407 // graph walking), we may never find a path which is not liquidity-limited and has lower
408 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
409 // Because we only consider paths with at least 5% of the total value being sent, the damage
410 // from such a case should be limited, however this could be further reduced in the future by
411 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
412 // limits for the purposes of fee calculation.
414 // Alternatively, we could store more detailed path information in the heap (targets, below)
415 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
416 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
417 // and practically (as we would need to store dynamically-allocated path information in heap
418 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
419 // results of such an algorithm would likely be biased towards lower-value paths.
421 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
422 // outside of our current search value, running a path search more times to gather candidate
423 // paths at different values. While this may be acceptable, further path searches may increase
424 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
425 // graph for candidate paths, calculating the maximum value which can realistically be sent at
426 // the same time, remaining generic across different payment values.
428 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
429 // to use as the A* heuristic beyond just the cost to get one node further than the current
432 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
433 cltv_expiry_delta: 0,
434 htlc_minimum_msat: 0,
435 htlc_maximum_msat: None,
438 proportional_millionths: 0,
442 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
443 // it. If the payee supports it they're supposed to include it in the invoice, so that should
445 let allow_mpp = if let Some(features) = &payee_features {
446 features.supports_basic_mpp()
447 } else if let Some(node) = network.get_nodes().get(&payee) {
448 if let Some(node_info) = node.announcement_info.as_ref() {
449 node_info.features.supports_basic_mpp()
454 // Prepare the data we'll use for payee-to-payer search by
455 // inserting first hops suggested by the caller as targets.
456 // Our search will then attempt to reach them while traversing from the payee node.
457 let mut first_hop_targets: HashMap<_, (_, ChannelFeatures, _, NodeFeatures)> =
458 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
459 if let Some(hops) = first_hops {
461 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
462 if chan.remote_network_id == *our_node_id {
463 return Err(LightningError{err: "First hop cannot have our_node_id as a destination.".to_owned(), action: ErrorAction::IgnoreError});
465 first_hop_targets.insert(chan.remote_network_id, (short_channel_id, chan.counterparty_features.to_context(), chan.outbound_capacity_msat, chan.counterparty_features.to_context()));
467 if first_hop_targets.is_empty() {
468 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
472 let empty_channel_features = ChannelFeatures::empty();
474 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
475 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
476 // adding duplicate entries when we find a better path to a given node.
477 let mut targets = BinaryHeap::new();
479 // Map from node_id to information about the best current path to that node, including feerate
481 let mut dist = HashMap::with_capacity(network.get_nodes().len());
483 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
484 // indicating that we may wish to try again with a higher value, potentially paying to meet an
485 // htlc_minimum with extra fees while still finding a cheaper path.
486 let mut hit_minimum_limit;
488 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
489 // We start with a path_value of the exact amount we want, and if that generates a route we may
490 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
491 // amount we want in total across paths, selecting the best subset at the end.
492 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
493 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
494 let mut path_value_msat = final_value_msat;
496 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
497 // This map allows paths to be aware of the channel use by other paths in the same call.
498 // This would help to make a better path finding decisions and not "overbook" channels.
499 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
500 let mut bookkeeped_channels_liquidity_available_msat = HashMap::with_capacity(network.get_nodes().len());
502 // Keeping track of how much value we already collected across other paths. Helps to decide:
503 // - how much a new path should be transferring (upper bound);
504 // - whether a channel should be disregarded because
505 // it's available liquidity is too small comparing to how much more we need to collect;
506 // - when we want to stop looking for new paths.
507 let mut already_collected_value_msat = 0;
509 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee, our_node_id, final_value_msat);
511 macro_rules! add_entry {
512 // Adds entry which goes from $src_node_id to $dest_node_id
513 // over the channel with id $chan_id with fees described in
514 // $directional_info.
515 // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one,
516 // since that value has to be transferred over this channel.
517 // Returns whether this channel caused an update to `targets`.
518 ( $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,
519 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => { {
520 // We "return" whether we updated the path at the end, via this:
521 let mut did_add_update_path_to_src_node = false;
522 // Channels to self should not be used. This is more of belt-and-suspenders, because in
523 // practice these cases should be caught earlier:
524 // - for regular channels at channel announcement (TODO)
525 // - for first and last hops early in get_route
526 if $src_node_id != $dest_node_id.clone() {
527 let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
528 let mut initial_liquidity_available_msat = None;
529 if let Some(capacity_sats) = $capacity_sats {
530 initial_liquidity_available_msat = Some(capacity_sats * 1000);
533 if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
534 if let Some(available_msat) = initial_liquidity_available_msat {
535 initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
537 initial_liquidity_available_msat = Some(htlc_maximum_msat);
541 match initial_liquidity_available_msat {
542 Some(available_msat) => available_msat,
543 // We assume channels with unknown balance have
544 // a capacity of 0.0025 BTC (or 250_000 sats).
545 None => 250_000 * 1000
549 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
550 // It may be misleading because we might later choose to reduce the value transferred
551 // over these channels, and the channel which was insufficient might become sufficient.
552 // Worst case: we drop a good channel here because it can't cover the high following
553 // fees caused by one expensive channel, but then this channel could have been used
554 // if the amount being transferred over this path is lower.
555 // We do this for now, but this is a subject for removal.
556 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
558 // Routing Fragmentation Mitigation heuristic:
560 // Routing fragmentation across many payment paths increases the overall routing
561 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
562 // Taking too many smaller paths also increases the chance of payment failure.
563 // Thus to avoid this effect, we require from our collected links to provide
564 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
566 // This requirement is currently 5% of the remaining-to-be-collected value.
567 // This means as we successfully advance in our collection,
568 // the absolute liquidity contribution is lowered,
569 // thus increasing the number of potential channels to be selected.
571 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
572 // or 100% if we're not allowed to do multipath payments.
573 let minimal_value_contribution_msat: u64 = if allow_mpp {
574 (recommended_value_msat - already_collected_value_msat + 19) / 20
578 // Verify the liquidity offered by this channel complies to the minimal contribution.
579 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
581 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
582 // Includes paying fees for the use of the following channels.
583 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
584 Some(result) => result,
585 // Can't overflow due to how the values were computed right above.
586 None => unreachable!(),
588 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
589 let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
590 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
592 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
593 // bother considering this channel.
594 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
595 // be only reduced later (not increased), so this channel should just be skipped
596 // as not sufficient.
597 if !over_path_minimum_msat {
598 hit_minimum_limit = true;
599 } else if contributes_sufficient_value {
600 // Note that low contribution here (limited by available_liquidity_msat)
601 // might violate htlc_minimum_msat on the hops which are next along the
602 // payment path (upstream to the payee). To avoid that, we recompute path
603 // path fees knowing the final path contribution after constructing it.
604 let path_htlc_minimum_msat = match compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
605 .map(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) {
606 Some(Some(value_msat)) => cmp::max(value_msat, $directional_info.htlc_minimum_msat),
607 _ => u64::max_value()
609 let hm_entry = dist.entry(&$src_node_id);
610 let old_entry = hm_entry.or_insert_with(|| {
611 // If there was previously no known way to access
612 // the source node (recall it goes payee-to-payer) of $chan_id, first add
613 // a semi-dummy record just to compute the fees to reach the source node.
614 // This will affect our decision on selecting $chan_id
615 // as a way to reach the $dest_node_id.
616 let mut fee_base_msat = u32::max_value();
617 let mut fee_proportional_millionths = u32::max_value();
618 if let Some(Some(fees)) = network.get_nodes().get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
619 fee_base_msat = fees.base_msat;
620 fee_proportional_millionths = fees.proportional_millionths;
623 pubkey: $dest_node_id.clone(),
625 channel_features: $chan_features,
627 cltv_expiry_delta: 0,
628 src_lowest_inbound_fees: RoutingFees {
629 base_msat: fee_base_msat,
630 proportional_millionths: fee_proportional_millionths,
632 channel_fees: $directional_info.fees,
633 next_hops_fee_msat: u64::max_value(),
634 hop_use_fee_msat: u64::max_value(),
635 total_fee_msat: u64::max_value(),
636 htlc_minimum_msat: $directional_info.htlc_minimum_msat,
637 path_htlc_minimum_msat,
638 was_processed: false,
639 #[cfg(any(test, feature = "fuzztarget"))]
640 value_contribution_msat,
644 #[allow(unused_mut)] // We only use the mut in cfg(test)
645 let mut should_process = !old_entry.was_processed;
646 #[cfg(any(test, feature = "fuzztarget"))]
648 // In test/fuzzing builds, we do extra checks to make sure the skipping
649 // of already-seen nodes only happens in cases we expect (see below).
650 if !should_process { should_process = true; }
654 let mut hop_use_fee_msat = 0;
655 let mut total_fee_msat = $next_hops_fee_msat;
657 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
658 // will have the same effective-fee
659 if $src_node_id != *our_node_id {
660 match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
661 // max_value means we'll always fail
662 // the old_entry.total_fee_msat > total_fee_msat check
663 None => total_fee_msat = u64::max_value(),
665 hop_use_fee_msat = fee_msat;
666 total_fee_msat += hop_use_fee_msat;
667 // When calculating the lowest inbound fees to a node, we
668 // calculate fees here not based on the actual value we think
669 // will flow over this channel, but on the minimum value that
670 // we'll accept flowing over it. The minimum accepted value
671 // is a constant through each path collection run, ensuring
672 // consistent basis. Otherwise we may later find a
673 // different path to the source node that is more expensive,
674 // but which we consider to be cheaper because we are capacity
675 // constrained and the relative fee becomes lower.
676 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
677 .map(|a| a.checked_add(total_fee_msat)) {
682 total_fee_msat = u64::max_value();
689 let new_graph_node = RouteGraphNode {
690 pubkey: $src_node_id,
691 lowest_fee_to_peer_through_node: total_fee_msat,
692 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
693 value_contribution_msat: value_contribution_msat,
694 path_htlc_minimum_msat,
697 // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
698 // if this way is cheaper than the already known
699 // (considering the cost to "reach" this channel from the route destination,
700 // the cost of using this channel,
701 // and the cost of routing to the source node of this channel).
702 // Also, consider that htlc_minimum_msat_difference, because we might end up
703 // paying it. Consider the following exploit:
704 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
705 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
706 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
707 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
709 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
710 // but it may require additional tracking - we don't want to double-count
711 // the fees included in $next_hops_path_htlc_minimum_msat, but also
712 // can't use something that may decrease on future hops.
713 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat);
714 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat);
716 if !old_entry.was_processed && new_cost < old_cost {
717 targets.push(new_graph_node);
718 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
719 old_entry.hop_use_fee_msat = hop_use_fee_msat;
720 old_entry.total_fee_msat = total_fee_msat;
721 old_entry.pubkey = $dest_node_id.clone();
722 old_entry.short_channel_id = $chan_id.clone();
723 old_entry.channel_features = $chan_features;
724 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
725 old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
726 old_entry.channel_fees = $directional_info.fees;
727 old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
728 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
729 #[cfg(any(test, feature = "fuzztarget"))]
731 old_entry.value_contribution_msat = value_contribution_msat;
733 did_add_update_path_to_src_node = true;
734 } else if old_entry.was_processed && new_cost < old_cost {
735 #[cfg(any(test, feature = "fuzztarget"))]
737 // If we're skipping processing a node which was previously
738 // processed even though we found another path to it with a
739 // cheaper fee, check that it was because the second path we
740 // found (which we are processing now) has a lower value
741 // contribution due to an HTLC minimum limit.
743 // e.g. take a graph with two paths from node 1 to node 2, one
744 // through channel A, and one through channel B. Channel A and
745 // B are both in the to-process heap, with their scores set by
746 // a higher htlc_minimum than fee.
747 // Channel A is processed first, and the channels onwards from
748 // node 1 are added to the to-process heap. Thereafter, we pop
749 // Channel B off of the heap, note that it has a much more
750 // restrictive htlc_maximum_msat, and recalculate the fees for
751 // all of node 1's channels using the new, reduced, amount.
753 // This would be bogus - we'd be selecting a higher-fee path
754 // with a lower htlc_maximum_msat instead of the one we'd
755 // already decided to use.
756 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
757 debug_assert!(value_contribution_msat < old_entry.value_contribution_msat);
764 did_add_update_path_to_src_node
768 let empty_node_features = NodeFeatures::empty();
769 // Find ways (channels with destination) to reach a given node and store them
770 // in the corresponding data structures (routing graph etc).
771 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
772 // meaning how much will be paid in fees after this node (to the best of our knowledge).
773 // This data can later be helpful to optimize routing (pay lower fees).
774 macro_rules! add_entries_to_cheapest_to_target_node {
775 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
776 let skip_node = if let Some(elem) = dist.get_mut($node_id) {
777 let was_processed = elem.was_processed;
778 elem.was_processed = true;
781 // Entries are added to dist in add_entry!() when there is a channel from a node.
782 // Because there are no channels from payee, it will not have a dist entry at this point.
783 // If we're processing any other node, it is always be the result of a channel from it.
784 assert_eq!($node_id, payee);
789 if first_hops.is_some() {
790 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&$node_id) {
791 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);
795 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
801 if !features.requires_unknown_bits() {
802 for chan_id in $node.channels.iter() {
803 let chan = network.get_channels().get(chan_id).unwrap();
804 if !chan.features.requires_unknown_bits() {
805 if chan.node_one == *$node_id {
806 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
807 if first_hops.is_none() || chan.node_two != *our_node_id {
808 if let Some(two_to_one) = chan.two_to_one.as_ref() {
809 if two_to_one.enabled {
810 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);
815 if first_hops.is_none() || chan.node_one != *our_node_id {
816 if let Some(one_to_two) = chan.one_to_two.as_ref() {
817 if one_to_two.enabled {
818 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);
830 let mut payment_paths = Vec::<PaymentPath>::new();
832 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
833 'paths_collection: loop {
834 // For every new path, start from scratch, except
835 // bookkeeped_channels_liquidity_available_msat, which will improve
836 // the further iterations of path finding. Also don't erase first_hop_targets.
839 hit_minimum_limit = false;
841 // If first hop is a private channel and the only way to reach the payee, this is the only
842 // place where it could be added.
843 if first_hops.is_some() {
844 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&payee) {
845 add_entry!(first_hop, *our_node_id, payee, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
849 // Add the payee as a target, so that the payee-to-payer
850 // search algorithm knows what to start with.
851 match network.get_nodes().get(payee) {
852 // The payee is not in our network graph, so nothing to add here.
853 // There is still a chance of reaching them via last_hops though,
854 // so don't yet fail the payment here.
855 // If not, targets.pop() will not even let us enter the loop in step 2.
858 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0);
863 // If a caller provided us with last hops, add them to routing targets. Since this happens
864 // earlier than general path finding, they will be somewhat prioritized, although currently
865 // it matters only if the fees are exactly the same.
866 for hop in last_hops.iter() {
867 let have_hop_src_in_graph =
868 // Only add the last hop to our candidate set if either we have a direct channel or
869 // they are in the regular network graph.
870 first_hop_targets.get(&hop.src_node_id).is_some() ||
871 network.get_nodes().get(&hop.src_node_id).is_some();
872 if have_hop_src_in_graph {
873 // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
874 // really sucks, cause we're gonna need that eventually.
875 let last_hop_htlc_minimum_msat: u64 = match hop.htlc_minimum_msat {
876 Some(htlc_minimum_msat) => htlc_minimum_msat,
879 let directional_info = DummyDirectionalChannelInfo {
880 cltv_expiry_delta: hop.cltv_expiry_delta as u32,
881 htlc_minimum_msat: last_hop_htlc_minimum_msat,
882 htlc_maximum_msat: hop.htlc_maximum_msat,
885 if add_entry!(hop.short_channel_id, hop.src_node_id, payee, directional_info, None::<u64>, &empty_channel_features, 0, path_value_msat, 0) {
886 // If this hop connects to a node with which we have a direct channel,
887 // ignore the network graph and, if the last hop was added, add our
888 // direct channel to the candidate set.
890 // Note that we *must* check if the last hop was added as `add_entry`
891 // always assumes that the third argument is a node to which we have a
893 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&hop.src_node_id) {
894 add_entry!(first_hop, *our_node_id , hop.src_node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
900 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
902 // At this point, targets are filled with the data from first and
903 // last hops communicated by the caller, and the payment receiver.
904 let mut found_new_path = false;
907 // If this loop terminates due the exhaustion of targets, two situations are possible:
908 // - not enough outgoing liquidity:
909 // 0 < already_collected_value_msat < final_value_msat
910 // - enough outgoing liquidity:
911 // final_value_msat <= already_collected_value_msat < recommended_value_msat
912 // Both these cases (and other cases except reaching recommended_value_msat) mean that
913 // paths_collection will be stopped because found_new_path==false.
914 // This is not necessarily a routing failure.
915 'path_construction: while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, .. }) = targets.pop() {
917 // Since we're going payee-to-payer, hitting our node as a target means we should stop
918 // traversing the graph and arrange the path out of what we found.
919 if pubkey == *our_node_id {
920 let mut new_entry = dist.remove(&our_node_id).unwrap();
921 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
924 if let Some(&(_, _, _, ref features)) = first_hop_targets.get(&ordered_hops.last().unwrap().0.pubkey) {
925 ordered_hops.last_mut().unwrap().1 = features.clone();
926 } else if let Some(node) = network.get_nodes().get(&ordered_hops.last().unwrap().0.pubkey) {
927 if let Some(node_info) = node.announcement_info.as_ref() {
928 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
930 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
933 // We should be able to fill in features for everything except the last
934 // hop, if the last hop was provided via a BOLT 11 invoice (though we
935 // should be able to extend it further as BOLT 11 does have feature
936 // flags for the last hop node itself).
937 assert!(ordered_hops.last().unwrap().0.pubkey == *payee);
940 // Means we succesfully traversed from the payer to the payee, now
941 // save this path for the payment route. Also, update the liquidity
942 // remaining on the used hops, so that we take them into account
943 // while looking for more paths.
944 if ordered_hops.last().unwrap().0.pubkey == *payee {
948 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.pubkey) {
949 Some(payment_hop) => payment_hop,
950 // We can't arrive at None because, if we ever add an entry to targets,
951 // we also fill in the entry in dist (see add_entry!).
952 None => unreachable!(),
954 // We "propagate" the fees one hop backward (topologically) here,
955 // so that fees paid for a HTLC forwarding on the current channel are
956 // associated with the previous channel (where they will be subtracted).
957 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
958 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = new_entry.cltv_expiry_delta;
959 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
961 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
962 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
963 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = final_cltv;
965 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: {:?}",
966 ordered_hops.len(), value_contribution_msat, ordered_hops);
968 let mut payment_path = PaymentPath {hops: ordered_hops};
970 // We could have possibly constructed a slightly inconsistent path: since we reduce
971 // value being transferred along the way, we could have violated htlc_minimum_msat
972 // on some channels we already passed (assuming dest->source direction). Here, we
973 // recompute the fees again, so that if that's the case, we match the currently
974 // underpaid htlc_minimum_msat with fees.
975 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
977 // Since a path allows to transfer as much value as
978 // the smallest channel it has ("bottleneck"), we should recompute
979 // the fees so sender HTLC don't overpay fees when traversing
980 // larger channels than the bottleneck. This may happen because
981 // when we were selecting those channels we were not aware how much value
982 // this path will transfer, and the relative fee for them
983 // might have been computed considering a larger value.
984 // Remember that we used these channels so that we don't rely
985 // on the same liquidity in future paths.
986 let mut prevented_redundant_path_selection = false;
987 for (payment_hop, _) in payment_path.hops.iter() {
988 let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.short_channel_id).unwrap();
989 let mut spent_on_hop_msat = value_contribution_msat;
990 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
991 spent_on_hop_msat += next_hops_fee_msat;
992 if spent_on_hop_msat == *channel_liquidity_available_msat {
993 // If this path used all of this channel's available liquidity, we know
994 // this path will not be selected again in the next loop iteration.
995 prevented_redundant_path_selection = true;
997 *channel_liquidity_available_msat -= spent_on_hop_msat;
999 if !prevented_redundant_path_selection {
1000 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1001 // we'll probably end up picking the same path again on the next iteration.
1002 // Decrease the available liquidity of a hop in the middle of the path.
1003 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.short_channel_id;
1004 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1005 let victim_liquidity = bookkeeped_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1006 *victim_liquidity = 0;
1009 // Track the total amount all our collected paths allow to send so that we:
1010 // - know when to stop looking for more paths
1011 // - know which of the hops are useless considering how much more sats we need
1012 // (contributes_sufficient_value)
1013 already_collected_value_msat += value_contribution_msat;
1015 payment_paths.push(payment_path);
1016 found_new_path = true;
1017 break 'path_construction;
1020 // If we found a path back to the payee, we shouldn't try to process it again. This is
1021 // the equivalent of the `elem.was_processed` check in
1022 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1023 if pubkey == *payee { continue 'path_construction; }
1025 // Otherwise, since the current target node is not us,
1026 // keep "unrolling" the payment graph from payee to payer by
1027 // finding a way to reach the current target from the payer side.
1028 match network.get_nodes().get(&pubkey) {
1031 add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat);
1037 // If we don't support MPP, no use trying to gather more value ever.
1038 break 'paths_collection;
1042 // Stop either when the recommended value is reached or if no new path was found in this
1044 // In the latter case, making another path finding attempt won't help,
1045 // because we deterministically terminated the search due to low liquidity.
1046 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1047 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1048 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1049 break 'paths_collection;
1050 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1051 // Further, if this was our first walk of the graph, and we weren't limited by an
1052 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1053 // limited by an htlc_minimum_msat value, find another path with a higher value,
1054 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1055 // still keeping a lower total fee than this path.
1056 if !hit_minimum_limit {
1057 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1058 break 'paths_collection;
1060 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1061 path_value_msat = recommended_value_msat;
1066 if payment_paths.len() == 0 {
1067 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1070 if already_collected_value_msat < final_value_msat {
1071 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1074 // Sort by total fees and take the best paths.
1075 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1076 if payment_paths.len() > 50 {
1077 payment_paths.truncate(50);
1080 // Draw multiple sufficient routes by randomly combining the selected paths.
1081 let mut drawn_routes = Vec::new();
1082 for i in 0..payment_paths.len() {
1083 let mut cur_route = Vec::<PaymentPath>::new();
1084 let mut aggregate_route_value_msat = 0;
1087 // TODO: real random shuffle
1088 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1089 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1092 for payment_path in cur_payment_paths {
1093 cur_route.push(payment_path.clone());
1094 aggregate_route_value_msat += payment_path.get_value_msat();
1095 if aggregate_route_value_msat > final_value_msat {
1096 // Last path likely overpaid. Substract it from the most expensive
1097 // (in terms of proportional fee) path in this route and recompute fees.
1098 // This might be not the most economically efficient way, but fewer paths
1099 // also makes routing more reliable.
1100 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1102 // First, drop some expensive low-value paths entirely if possible.
1103 // Sort by value so that we drop many really-low values first, since
1104 // fewer paths is better: the payment is less likely to fail.
1105 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1106 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1107 cur_route.sort_by_key(|path| path.get_value_msat());
1108 // We should make sure that at least 1 path left.
1109 let mut paths_left = cur_route.len();
1110 cur_route.retain(|path| {
1111 if paths_left == 1 {
1114 let mut keep = true;
1115 let path_value_msat = path.get_value_msat();
1116 if path_value_msat <= overpaid_value_msat {
1118 overpaid_value_msat -= path_value_msat;
1124 if overpaid_value_msat == 0 {
1128 assert!(cur_route.len() > 0);
1131 // Now, substract the overpaid value from the most-expensive path.
1132 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1133 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1134 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.channel_fees.proportional_millionths as u64).sum::<u64>() });
1135 let expensive_payment_path = cur_route.first_mut().unwrap();
1136 // We already dropped all the small channels above, meaning all the
1137 // remaining channels are larger than remaining overpaid_value_msat.
1138 // Thus, this can't be negative.
1139 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1140 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1144 drawn_routes.push(cur_route);
1148 // Select the best route by lowest total fee.
1149 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1150 let mut selected_paths = Vec::<Vec<RouteHop>>::new();
1151 for payment_path in drawn_routes.first().unwrap() {
1152 selected_paths.push(payment_path.hops.iter().map(|(payment_hop, node_features)| {
1154 pubkey: payment_hop.pubkey,
1155 node_features: node_features.clone(),
1156 short_channel_id: payment_hop.short_channel_id,
1157 channel_features: payment_hop.channel_features.clone(),
1158 fee_msat: payment_hop.fee_msat,
1159 cltv_expiry_delta: payment_hop.cltv_expiry_delta,
1164 if let Some(features) = &payee_features {
1165 for path in selected_paths.iter_mut() {
1166 path.last_mut().unwrap().node_features = features.to_context();
1170 let route = Route { paths: selected_paths };
1171 log_info!(logger, "Got route to {}: {}", payee, log_route!(route));
1177 use routing::router::{get_route, Route, RouteHint, RouteHintHop, RoutingFees};
1178 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
1179 use chain::transaction::OutPoint;
1180 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1181 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1182 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1183 use ln::channelmanager;
1184 use util::test_utils;
1185 use util::ser::Writeable;
1187 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1188 use bitcoin::hashes::Hash;
1189 use bitcoin::network::constants::Network;
1190 use bitcoin::blockdata::constants::genesis_block;
1191 use bitcoin::blockdata::script::Builder;
1192 use bitcoin::blockdata::opcodes;
1193 use bitcoin::blockdata::transaction::TxOut;
1197 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1198 use bitcoin::secp256k1::{Secp256k1, All};
1203 // Using the same keys for LN and BTC ids
1204 fn add_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey,
1205 node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64) {
1206 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1207 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1209 let unsigned_announcement = UnsignedChannelAnnouncement {
1211 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1215 bitcoin_key_1: node_id_1,
1216 bitcoin_key_2: node_id_2,
1217 excess_data: Vec::new(),
1220 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1221 let valid_announcement = ChannelAnnouncement {
1222 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1223 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1224 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1225 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1226 contents: unsigned_announcement.clone(),
1228 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1229 Ok(res) => assert!(res),
1234 fn update_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate) {
1235 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1236 let valid_channel_update = ChannelUpdate {
1237 signature: secp_ctx.sign(&msghash, node_privkey),
1238 contents: update.clone()
1241 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1242 Ok(res) => assert!(res),
1247 fn add_or_update_node(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey,
1248 features: NodeFeatures, timestamp: u32) {
1249 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1250 let unsigned_announcement = UnsignedNodeAnnouncement {
1256 addresses: Vec::new(),
1257 excess_address_data: Vec::new(),
1258 excess_data: Vec::new(),
1260 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1261 let valid_announcement = NodeAnnouncement {
1262 signature: secp_ctx.sign(&msghash, node_privkey),
1263 contents: unsigned_announcement.clone()
1266 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1272 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1273 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1274 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1277 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1279 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1280 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1282 (our_privkey, our_id, privkeys, pubkeys)
1285 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1286 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1287 // test for it later.
1288 let idx = (id - 1) * 2 + 1;
1290 vec![1 << (idx - 8*3), 0, 0, 0]
1291 } else if idx > 8*2 {
1292 vec![1 << (idx - 8*2), 0, 0]
1293 } else if idx > 8*1 {
1294 vec![1 << (idx - 8*1), 0]
1300 fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<crate::util::test_utils::TestLogger>>, std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<test_utils::TestLogger>) {
1301 let secp_ctx = Secp256k1::new();
1302 let logger = Arc::new(test_utils::TestLogger::new());
1303 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1304 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
1305 // Build network from our_id to node7:
1307 // -1(1)2- node0 -1(3)2-
1309 // our_id -1(12)2- node7 -1(13)2--- node2
1311 // -1(2)2- node1 -1(4)2-
1314 // chan1 1-to-2: disabled
1315 // chan1 2-to-1: enabled, 0 fee
1317 // chan2 1-to-2: enabled, ignored fee
1318 // chan2 2-to-1: enabled, 0 fee
1320 // chan3 1-to-2: enabled, 0 fee
1321 // chan3 2-to-1: enabled, 100 msat fee
1323 // chan4 1-to-2: enabled, 100% fee
1324 // chan4 2-to-1: enabled, 0 fee
1326 // chan12 1-to-2: enabled, ignored fee
1327 // chan12 2-to-1: enabled, 0 fee
1329 // chan13 1-to-2: enabled, 200% fee
1330 // chan13 2-to-1: enabled, 0 fee
1333 // -1(5)2- node3 -1(8)2--
1337 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1339 // -1(7)2- node5 -1(10)2-
1341 // chan5 1-to-2: enabled, 100 msat fee
1342 // chan5 2-to-1: enabled, 0 fee
1344 // chan6 1-to-2: enabled, 0 fee
1345 // chan6 2-to-1: enabled, 0 fee
1347 // chan7 1-to-2: enabled, 100% fee
1348 // chan7 2-to-1: enabled, 0 fee
1350 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1351 // chan8 2-to-1: enabled, 0 fee
1353 // chan9 1-to-2: enabled, 1001 msat fee
1354 // chan9 2-to-1: enabled, 0 fee
1356 // chan10 1-to-2: enabled, 0 fee
1357 // chan10 2-to-1: enabled, 0 fee
1359 // chan11 1-to-2: enabled, 0 fee
1360 // chan11 2-to-1: enabled, 0 fee
1362 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1364 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1365 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1366 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1367 short_channel_id: 1,
1370 cltv_expiry_delta: 0,
1371 htlc_minimum_msat: 0,
1372 htlc_maximum_msat: OptionalField::Absent,
1374 fee_proportional_millionths: 0,
1375 excess_data: Vec::new()
1378 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1380 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1381 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1382 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1383 short_channel_id: 2,
1386 cltv_expiry_delta: u16::max_value(),
1387 htlc_minimum_msat: 0,
1388 htlc_maximum_msat: OptionalField::Absent,
1389 fee_base_msat: u32::max_value(),
1390 fee_proportional_millionths: u32::max_value(),
1391 excess_data: Vec::new()
1393 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1394 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1395 short_channel_id: 2,
1398 cltv_expiry_delta: 0,
1399 htlc_minimum_msat: 0,
1400 htlc_maximum_msat: OptionalField::Absent,
1402 fee_proportional_millionths: 0,
1403 excess_data: Vec::new()
1406 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1408 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1409 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1410 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1411 short_channel_id: 12,
1414 cltv_expiry_delta: u16::max_value(),
1415 htlc_minimum_msat: 0,
1416 htlc_maximum_msat: OptionalField::Absent,
1417 fee_base_msat: u32::max_value(),
1418 fee_proportional_millionths: u32::max_value(),
1419 excess_data: Vec::new()
1421 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1422 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1423 short_channel_id: 12,
1426 cltv_expiry_delta: 0,
1427 htlc_minimum_msat: 0,
1428 htlc_maximum_msat: OptionalField::Absent,
1430 fee_proportional_millionths: 0,
1431 excess_data: Vec::new()
1434 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1436 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1437 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1438 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1439 short_channel_id: 3,
1442 cltv_expiry_delta: (3 << 8) | 1,
1443 htlc_minimum_msat: 0,
1444 htlc_maximum_msat: OptionalField::Absent,
1446 fee_proportional_millionths: 0,
1447 excess_data: Vec::new()
1449 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1451 short_channel_id: 3,
1454 cltv_expiry_delta: (3 << 8) | 2,
1455 htlc_minimum_msat: 0,
1456 htlc_maximum_msat: OptionalField::Absent,
1458 fee_proportional_millionths: 0,
1459 excess_data: Vec::new()
1462 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1463 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1464 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1465 short_channel_id: 4,
1468 cltv_expiry_delta: (4 << 8) | 1,
1469 htlc_minimum_msat: 0,
1470 htlc_maximum_msat: OptionalField::Absent,
1472 fee_proportional_millionths: 1000000,
1473 excess_data: Vec::new()
1475 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1477 short_channel_id: 4,
1480 cltv_expiry_delta: (4 << 8) | 2,
1481 htlc_minimum_msat: 0,
1482 htlc_maximum_msat: OptionalField::Absent,
1484 fee_proportional_millionths: 0,
1485 excess_data: Vec::new()
1488 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1489 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1490 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1491 short_channel_id: 13,
1494 cltv_expiry_delta: (13 << 8) | 1,
1495 htlc_minimum_msat: 0,
1496 htlc_maximum_msat: OptionalField::Absent,
1498 fee_proportional_millionths: 2000000,
1499 excess_data: Vec::new()
1501 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1502 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1503 short_channel_id: 13,
1506 cltv_expiry_delta: (13 << 8) | 2,
1507 htlc_minimum_msat: 0,
1508 htlc_maximum_msat: OptionalField::Absent,
1510 fee_proportional_millionths: 0,
1511 excess_data: Vec::new()
1514 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1516 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1517 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1518 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1519 short_channel_id: 6,
1522 cltv_expiry_delta: (6 << 8) | 1,
1523 htlc_minimum_msat: 0,
1524 htlc_maximum_msat: OptionalField::Absent,
1526 fee_proportional_millionths: 0,
1527 excess_data: Vec::new()
1529 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1530 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1531 short_channel_id: 6,
1534 cltv_expiry_delta: (6 << 8) | 2,
1535 htlc_minimum_msat: 0,
1536 htlc_maximum_msat: OptionalField::Absent,
1538 fee_proportional_millionths: 0,
1539 excess_data: Vec::new(),
1542 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1543 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1544 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1545 short_channel_id: 11,
1548 cltv_expiry_delta: (11 << 8) | 1,
1549 htlc_minimum_msat: 0,
1550 htlc_maximum_msat: OptionalField::Absent,
1552 fee_proportional_millionths: 0,
1553 excess_data: Vec::new()
1555 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
1556 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1557 short_channel_id: 11,
1560 cltv_expiry_delta: (11 << 8) | 2,
1561 htlc_minimum_msat: 0,
1562 htlc_maximum_msat: OptionalField::Absent,
1564 fee_proportional_millionths: 0,
1565 excess_data: Vec::new()
1568 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
1570 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
1572 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
1573 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1574 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1575 short_channel_id: 7,
1578 cltv_expiry_delta: (7 << 8) | 1,
1579 htlc_minimum_msat: 0,
1580 htlc_maximum_msat: OptionalField::Absent,
1582 fee_proportional_millionths: 1000000,
1583 excess_data: Vec::new()
1585 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
1586 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1587 short_channel_id: 7,
1590 cltv_expiry_delta: (7 << 8) | 2,
1591 htlc_minimum_msat: 0,
1592 htlc_maximum_msat: OptionalField::Absent,
1594 fee_proportional_millionths: 0,
1595 excess_data: Vec::new()
1598 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
1600 (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
1604 fn simple_route_test() {
1605 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1606 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1608 // Simple route to 2 via 1
1610 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 0, 42, Arc::clone(&logger)) {
1611 assert_eq!(err, "Cannot send a payment of 0 msat");
1612 } else { panic!(); }
1614 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1615 assert_eq!(route.paths[0].len(), 2);
1617 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1618 assert_eq!(route.paths[0][0].short_channel_id, 2);
1619 assert_eq!(route.paths[0][0].fee_msat, 100);
1620 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1621 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1622 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1624 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1625 assert_eq!(route.paths[0][1].short_channel_id, 4);
1626 assert_eq!(route.paths[0][1].fee_msat, 100);
1627 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1628 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1629 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1633 fn invalid_first_hop_test() {
1634 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1635 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1637 // Simple route to 2 via 1
1639 let our_chans = vec![channelmanager::ChannelDetails {
1640 channel_id: [0; 32],
1641 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1642 short_channel_id: Some(2),
1643 remote_network_id: our_id,
1644 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1645 channel_value_satoshis: 100000,
1647 outbound_capacity_msat: 100000,
1648 inbound_capacity_msat: 100000,
1649 to_self_reserve_satoshis: None,
1650 to_remote_reserve_satoshis: 0,
1651 confirmations_required: None,
1652 spend_csv_on_our_commitment_funds: None,
1653 is_outbound: true, is_funding_locked: true,
1654 is_usable: true, is_public: true,
1655 counterparty_forwarding_info: None,
1658 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)) {
1659 assert_eq!(err, "First hop cannot have our_node_id as a destination.");
1660 } else { panic!(); }
1662 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1663 assert_eq!(route.paths[0].len(), 2);
1667 fn htlc_minimum_test() {
1668 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1669 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1671 // Simple route to 2 via 1
1673 // Disable other paths
1674 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1675 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1676 short_channel_id: 12,
1678 flags: 2, // to disable
1679 cltv_expiry_delta: 0,
1680 htlc_minimum_msat: 0,
1681 htlc_maximum_msat: OptionalField::Absent,
1683 fee_proportional_millionths: 0,
1684 excess_data: Vec::new()
1686 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1687 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1688 short_channel_id: 3,
1690 flags: 2, // to disable
1691 cltv_expiry_delta: 0,
1692 htlc_minimum_msat: 0,
1693 htlc_maximum_msat: OptionalField::Absent,
1695 fee_proportional_millionths: 0,
1696 excess_data: Vec::new()
1698 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1699 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1700 short_channel_id: 13,
1702 flags: 2, // to disable
1703 cltv_expiry_delta: 0,
1704 htlc_minimum_msat: 0,
1705 htlc_maximum_msat: OptionalField::Absent,
1707 fee_proportional_millionths: 0,
1708 excess_data: Vec::new()
1710 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1711 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1712 short_channel_id: 6,
1714 flags: 2, // to disable
1715 cltv_expiry_delta: 0,
1716 htlc_minimum_msat: 0,
1717 htlc_maximum_msat: OptionalField::Absent,
1719 fee_proportional_millionths: 0,
1720 excess_data: Vec::new()
1722 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1723 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1724 short_channel_id: 7,
1726 flags: 2, // to disable
1727 cltv_expiry_delta: 0,
1728 htlc_minimum_msat: 0,
1729 htlc_maximum_msat: OptionalField::Absent,
1731 fee_proportional_millionths: 0,
1732 excess_data: Vec::new()
1735 // Check against amount_to_transfer_over_msat.
1736 // Set minimal HTLC of 200_000_000 msat.
1737 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1739 short_channel_id: 2,
1742 cltv_expiry_delta: 0,
1743 htlc_minimum_msat: 200_000_000,
1744 htlc_maximum_msat: OptionalField::Absent,
1746 fee_proportional_millionths: 0,
1747 excess_data: Vec::new()
1750 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
1752 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1753 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1754 short_channel_id: 4,
1757 cltv_expiry_delta: 0,
1758 htlc_minimum_msat: 0,
1759 htlc_maximum_msat: OptionalField::Present(199_999_999),
1761 fee_proportional_millionths: 0,
1762 excess_data: Vec::new()
1765 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
1766 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)) {
1767 assert_eq!(err, "Failed to find a path to the given destination");
1768 } else { panic!(); }
1770 // Lift the restriction on the first hop.
1771 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1772 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1773 short_channel_id: 2,
1776 cltv_expiry_delta: 0,
1777 htlc_minimum_msat: 0,
1778 htlc_maximum_msat: OptionalField::Absent,
1780 fee_proportional_millionths: 0,
1781 excess_data: Vec::new()
1784 // A payment above the minimum should pass
1785 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)).unwrap();
1786 assert_eq!(route.paths[0].len(), 2);
1790 fn htlc_minimum_overpay_test() {
1791 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1792 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1794 // A route to node#2 via two paths.
1795 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
1796 // Thus, they can't send 60 without overpaying.
1797 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1798 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1799 short_channel_id: 2,
1802 cltv_expiry_delta: 0,
1803 htlc_minimum_msat: 35_000,
1804 htlc_maximum_msat: OptionalField::Present(40_000),
1806 fee_proportional_millionths: 0,
1807 excess_data: Vec::new()
1809 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1810 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1811 short_channel_id: 12,
1814 cltv_expiry_delta: 0,
1815 htlc_minimum_msat: 35_000,
1816 htlc_maximum_msat: OptionalField::Present(40_000),
1818 fee_proportional_millionths: 0,
1819 excess_data: Vec::new()
1823 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1824 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1825 short_channel_id: 13,
1828 cltv_expiry_delta: 0,
1829 htlc_minimum_msat: 0,
1830 htlc_maximum_msat: OptionalField::Absent,
1832 fee_proportional_millionths: 0,
1833 excess_data: Vec::new()
1835 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1836 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1837 short_channel_id: 4,
1840 cltv_expiry_delta: 0,
1841 htlc_minimum_msat: 0,
1842 htlc_maximum_msat: OptionalField::Absent,
1844 fee_proportional_millionths: 0,
1845 excess_data: Vec::new()
1848 // Disable other paths
1849 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1850 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1851 short_channel_id: 1,
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 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1863 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1864 // Overpay fees to hit htlc_minimum_msat.
1865 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
1866 // TODO: this could be better balanced to overpay 10k and not 15k.
1867 assert_eq!(overpaid_fees, 15_000);
1869 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
1870 // while taking even more fee to match htlc_minimum_msat.
1871 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1872 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1873 short_channel_id: 12,
1876 cltv_expiry_delta: 0,
1877 htlc_minimum_msat: 65_000,
1878 htlc_maximum_msat: OptionalField::Present(80_000),
1880 fee_proportional_millionths: 0,
1881 excess_data: Vec::new()
1883 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1884 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1885 short_channel_id: 2,
1888 cltv_expiry_delta: 0,
1889 htlc_minimum_msat: 0,
1890 htlc_maximum_msat: OptionalField::Absent,
1892 fee_proportional_millionths: 0,
1893 excess_data: Vec::new()
1895 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1896 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1897 short_channel_id: 4,
1900 cltv_expiry_delta: 0,
1901 htlc_minimum_msat: 0,
1902 htlc_maximum_msat: OptionalField::Absent,
1904 fee_proportional_millionths: 100_000,
1905 excess_data: Vec::new()
1908 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1909 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1910 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
1911 assert_eq!(route.paths.len(), 1);
1912 assert_eq!(route.paths[0][0].short_channel_id, 12);
1913 let fees = route.paths[0][0].fee_msat;
1914 assert_eq!(fees, 5_000);
1916 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1917 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
1918 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
1919 // the other channel.
1920 assert_eq!(route.paths.len(), 1);
1921 assert_eq!(route.paths[0][0].short_channel_id, 2);
1922 let fees = route.paths[0][0].fee_msat;
1923 assert_eq!(fees, 5_000);
1927 fn disable_channels_test() {
1928 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1929 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1931 // // Disable channels 4 and 12 by flags=2
1932 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1933 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1934 short_channel_id: 4,
1936 flags: 2, // to disable
1937 cltv_expiry_delta: 0,
1938 htlc_minimum_msat: 0,
1939 htlc_maximum_msat: OptionalField::Absent,
1941 fee_proportional_millionths: 0,
1942 excess_data: Vec::new()
1944 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1945 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1946 short_channel_id: 12,
1948 flags: 2, // to disable
1949 cltv_expiry_delta: 0,
1950 htlc_minimum_msat: 0,
1951 htlc_maximum_msat: OptionalField::Absent,
1953 fee_proportional_millionths: 0,
1954 excess_data: Vec::new()
1957 // If all the channels require some features we don't understand, route should fail
1958 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
1959 assert_eq!(err, "Failed to find a path to the given destination");
1960 } else { panic!(); }
1962 // If we specify a channel to node7, that overrides our local channel view and that gets used
1963 let our_chans = vec![channelmanager::ChannelDetails {
1964 channel_id: [0; 32],
1965 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1966 short_channel_id: Some(42),
1967 remote_network_id: nodes[7].clone(),
1968 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1969 channel_value_satoshis: 0,
1971 outbound_capacity_msat: 250_000_000,
1972 inbound_capacity_msat: 0,
1973 to_self_reserve_satoshis: None,
1974 to_remote_reserve_satoshis: 0,
1975 confirmations_required: None,
1976 spend_csv_on_our_commitment_funds: None,
1977 is_outbound: true, is_funding_locked: true,
1978 is_usable: true, is_public: true,
1979 counterparty_forwarding_info: None,
1981 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
1982 assert_eq!(route.paths[0].len(), 2);
1984 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
1985 assert_eq!(route.paths[0][0].short_channel_id, 42);
1986 assert_eq!(route.paths[0][0].fee_msat, 200);
1987 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
1988 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
1989 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1991 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1992 assert_eq!(route.paths[0][1].short_channel_id, 13);
1993 assert_eq!(route.paths[0][1].fee_msat, 100);
1994 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1995 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1996 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2000 fn disable_node_test() {
2001 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2002 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2004 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2005 let mut unknown_features = NodeFeatures::known();
2006 unknown_features.set_required_unknown_bits();
2007 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2008 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2009 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2011 // If all nodes require some features we don't understand, route should fail
2012 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
2013 assert_eq!(err, "Failed to find a path to the given destination");
2014 } else { panic!(); }
2016 // If we specify a channel to node7, that overrides our local channel view and that gets used
2017 let our_chans = vec![channelmanager::ChannelDetails {
2018 channel_id: [0; 32],
2019 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2020 short_channel_id: Some(42),
2021 remote_network_id: nodes[7].clone(),
2022 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2023 channel_value_satoshis: 0,
2025 outbound_capacity_msat: 250_000_000,
2026 inbound_capacity_msat: 0,
2027 to_self_reserve_satoshis: None,
2028 to_remote_reserve_satoshis: 0,
2029 confirmations_required: None,
2030 spend_csv_on_our_commitment_funds: None,
2031 is_outbound: true, is_funding_locked: true,
2032 is_usable: true, is_public: true,
2033 counterparty_forwarding_info: None,
2035 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2036 assert_eq!(route.paths[0].len(), 2);
2038 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2039 assert_eq!(route.paths[0][0].short_channel_id, 42);
2040 assert_eq!(route.paths[0][0].fee_msat, 200);
2041 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2042 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2043 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2045 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2046 assert_eq!(route.paths[0][1].short_channel_id, 13);
2047 assert_eq!(route.paths[0][1].fee_msat, 100);
2048 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2049 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2050 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2052 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2053 // naively) assume that the user checked the feature bits on the invoice, which override
2054 // the node_announcement.
2058 fn our_chans_test() {
2059 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2060 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2062 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2063 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[0], None, None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2064 assert_eq!(route.paths[0].len(), 3);
2066 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2067 assert_eq!(route.paths[0][0].short_channel_id, 2);
2068 assert_eq!(route.paths[0][0].fee_msat, 200);
2069 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2070 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2071 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2073 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2074 assert_eq!(route.paths[0][1].short_channel_id, 4);
2075 assert_eq!(route.paths[0][1].fee_msat, 100);
2076 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
2077 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2078 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2080 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2081 assert_eq!(route.paths[0][2].short_channel_id, 3);
2082 assert_eq!(route.paths[0][2].fee_msat, 100);
2083 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2084 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2085 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2087 // If we specify a channel to node7, that overrides our local channel view and that gets used
2088 let our_chans = vec![channelmanager::ChannelDetails {
2089 channel_id: [0; 32],
2090 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2091 short_channel_id: Some(42),
2092 remote_network_id: nodes[7].clone(),
2093 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2094 channel_value_satoshis: 0,
2096 outbound_capacity_msat: 250_000_000,
2097 inbound_capacity_msat: 0,
2098 to_self_reserve_satoshis: None,
2099 to_remote_reserve_satoshis: 0,
2100 confirmations_required: None,
2101 spend_csv_on_our_commitment_funds: None,
2102 is_outbound: true, is_funding_locked: true,
2103 is_usable: true, is_public: true,
2104 counterparty_forwarding_info: None,
2106 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2107 assert_eq!(route.paths[0].len(), 2);
2109 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2110 assert_eq!(route.paths[0][0].short_channel_id, 42);
2111 assert_eq!(route.paths[0][0].fee_msat, 200);
2112 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2113 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2114 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2116 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2117 assert_eq!(route.paths[0][1].short_channel_id, 13);
2118 assert_eq!(route.paths[0][1].fee_msat, 100);
2119 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2120 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2121 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2124 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2125 let zero_fees = RoutingFees {
2127 proportional_millionths: 0,
2129 vec![RouteHint(vec![RouteHintHop {
2130 src_node_id: nodes[3].clone(),
2131 short_channel_id: 8,
2133 cltv_expiry_delta: (8 << 8) | 1,
2134 htlc_minimum_msat: None,
2135 htlc_maximum_msat: None,
2136 }]), RouteHint(vec![RouteHintHop {
2137 src_node_id: nodes[4].clone(),
2138 short_channel_id: 9,
2141 proportional_millionths: 0,
2143 cltv_expiry_delta: (9 << 8) | 1,
2144 htlc_minimum_msat: None,
2145 htlc_maximum_msat: None,
2146 }]), RouteHint(vec![RouteHintHop {
2147 src_node_id: nodes[5].clone(),
2148 short_channel_id: 10,
2150 cltv_expiry_delta: (10 << 8) | 1,
2151 htlc_minimum_msat: None,
2152 htlc_maximum_msat: None,
2157 fn last_hops_test() {
2158 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2159 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2161 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2163 // First check that last hop can't have its source as the payee.
2164 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2165 src_node_id: nodes[6],
2166 short_channel_id: 8,
2169 proportional_millionths: 0,
2171 cltv_expiry_delta: (8 << 8) | 1,
2172 htlc_minimum_msat: None,
2173 htlc_maximum_msat: None,
2176 let mut invalid_last_hops = last_hops(&nodes);
2177 invalid_last_hops.push(invalid_last_hop);
2179 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &invalid_last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)) {
2180 assert_eq!(err, "Last hop cannot have a payee as a source.");
2181 } else { panic!(); }
2184 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2185 assert_eq!(route.paths[0].len(), 5);
2187 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2188 assert_eq!(route.paths[0][0].short_channel_id, 2);
2189 assert_eq!(route.paths[0][0].fee_msat, 100);
2190 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2191 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2192 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2194 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2195 assert_eq!(route.paths[0][1].short_channel_id, 4);
2196 assert_eq!(route.paths[0][1].fee_msat, 0);
2197 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2198 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2199 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2201 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2202 assert_eq!(route.paths[0][2].short_channel_id, 6);
2203 assert_eq!(route.paths[0][2].fee_msat, 0);
2204 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2205 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2206 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2208 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2209 assert_eq!(route.paths[0][3].short_channel_id, 11);
2210 assert_eq!(route.paths[0][3].fee_msat, 0);
2211 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2212 // If we have a peer in the node map, we'll use their features here since we don't have
2213 // a way of figuring out their features from the invoice:
2214 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2215 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2217 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2218 assert_eq!(route.paths[0][4].short_channel_id, 8);
2219 assert_eq!(route.paths[0][4].fee_msat, 100);
2220 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2221 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2222 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2226 fn our_chans_last_hop_connect_test() {
2227 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2228 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2230 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2231 let our_chans = vec![channelmanager::ChannelDetails {
2232 channel_id: [0; 32],
2233 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2234 short_channel_id: Some(42),
2235 remote_network_id: nodes[3].clone(),
2236 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2237 channel_value_satoshis: 0,
2239 outbound_capacity_msat: 250_000_000,
2240 inbound_capacity_msat: 0,
2241 to_self_reserve_satoshis: None,
2242 to_remote_reserve_satoshis: 0,
2243 confirmations_required: None,
2244 spend_csv_on_our_commitment_funds: None,
2245 is_outbound: true, is_funding_locked: true,
2246 is_usable: true, is_public: true,
2247 counterparty_forwarding_info: None,
2249 let mut last_hops = last_hops(&nodes);
2250 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2251 assert_eq!(route.paths[0].len(), 2);
2253 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2254 assert_eq!(route.paths[0][0].short_channel_id, 42);
2255 assert_eq!(route.paths[0][0].fee_msat, 0);
2256 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2257 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2258 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2260 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2261 assert_eq!(route.paths[0][1].short_channel_id, 8);
2262 assert_eq!(route.paths[0][1].fee_msat, 100);
2263 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2264 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2265 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2267 last_hops[0].0[0].fees.base_msat = 1000;
2269 // Revert to via 6 as the fee on 8 goes up
2270 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2271 assert_eq!(route.paths[0].len(), 4);
2273 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2274 assert_eq!(route.paths[0][0].short_channel_id, 2);
2275 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2276 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2277 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2278 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2280 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2281 assert_eq!(route.paths[0][1].short_channel_id, 4);
2282 assert_eq!(route.paths[0][1].fee_msat, 100);
2283 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
2284 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2285 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2287 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2288 assert_eq!(route.paths[0][2].short_channel_id, 7);
2289 assert_eq!(route.paths[0][2].fee_msat, 0);
2290 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
2291 // If we have a peer in the node map, we'll use their features here since we don't have
2292 // a way of figuring out their features from the invoice:
2293 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2294 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2296 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2297 assert_eq!(route.paths[0][3].short_channel_id, 10);
2298 assert_eq!(route.paths[0][3].fee_msat, 100);
2299 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2300 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2301 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2303 // ...but still use 8 for larger payments as 6 has a variable feerate
2304 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops.iter().collect::<Vec<_>>(), 2000, 42, Arc::clone(&logger)).unwrap();
2305 assert_eq!(route.paths[0].len(), 5);
2307 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2308 assert_eq!(route.paths[0][0].short_channel_id, 2);
2309 assert_eq!(route.paths[0][0].fee_msat, 3000);
2310 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2311 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2312 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2314 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2315 assert_eq!(route.paths[0][1].short_channel_id, 4);
2316 assert_eq!(route.paths[0][1].fee_msat, 0);
2317 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2318 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2319 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2321 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2322 assert_eq!(route.paths[0][2].short_channel_id, 6);
2323 assert_eq!(route.paths[0][2].fee_msat, 0);
2324 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2325 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2326 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2328 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2329 assert_eq!(route.paths[0][3].short_channel_id, 11);
2330 assert_eq!(route.paths[0][3].fee_msat, 1000);
2331 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2332 // If we have a peer in the node map, we'll use their features here since we don't have
2333 // a way of figuring out their features from the invoice:
2334 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2335 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2337 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2338 assert_eq!(route.paths[0][4].short_channel_id, 8);
2339 assert_eq!(route.paths[0][4].fee_msat, 2000);
2340 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2341 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2342 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2345 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> {
2346 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
2347 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2348 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2350 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
2351 let last_hops = RouteHint(vec![RouteHintHop {
2352 src_node_id: middle_node_id,
2353 short_channel_id: 8,
2356 proportional_millionths: last_hop_fee_prop,
2358 cltv_expiry_delta: (8 << 8) | 1,
2359 htlc_minimum_msat: None,
2360 htlc_maximum_msat: last_hop_htlc_max,
2362 let our_chans = vec![channelmanager::ChannelDetails {
2363 channel_id: [0; 32],
2364 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2365 short_channel_id: Some(42),
2366 remote_network_id: middle_node_id,
2367 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2368 channel_value_satoshis: 100000,
2370 outbound_capacity_msat: outbound_capacity_msat,
2371 inbound_capacity_msat: 100000,
2372 to_self_reserve_satoshis: None,
2373 to_remote_reserve_satoshis: 0,
2374 confirmations_required: None,
2375 spend_csv_on_our_commitment_funds: None,
2376 is_outbound: true, is_funding_locked: true,
2377 is_usable: true, is_public: true,
2378 counterparty_forwarding_info: None,
2380 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()))
2384 fn unannounced_path_test() {
2385 // We should be able to send a payment to a destination without any help of a routing graph
2386 // if we have a channel with a common counterparty that appears in the first and last hop
2388 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
2390 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2391 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2392 assert_eq!(route.paths[0].len(), 2);
2394 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
2395 assert_eq!(route.paths[0][0].short_channel_id, 42);
2396 assert_eq!(route.paths[0][0].fee_msat, 1001);
2397 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2398 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
2399 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2401 assert_eq!(route.paths[0][1].pubkey, target_node_id);
2402 assert_eq!(route.paths[0][1].short_channel_id, 8);
2403 assert_eq!(route.paths[0][1].fee_msat, 1000000);
2404 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2405 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
2406 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2410 fn overflow_unannounced_path_test_liquidity_underflow() {
2411 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
2412 // the last-hop had a fee which overflowed a u64, we'd panic.
2413 // This was due to us adding the first-hop from us unconditionally, causing us to think
2414 // we'd built a path (as our node is in the "best candidate" set), when we had not.
2415 // In this test, we previously hit a subtraction underflow due to having less available
2416 // liquidity at the last hop than 0.
2417 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());
2421 fn overflow_unannounced_path_test_feerate_overflow() {
2422 // This tests for the same case as above, except instead of hitting a subtraction
2423 // underflow, we hit a case where the fee charged at a hop overflowed.
2424 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());
2428 fn available_amount_while_routing_test() {
2429 // Tests whether we choose the correct available channel amount while routing.
2431 let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
2432 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2434 // We will use a simple single-path route from
2435 // our node to node2 via node0: channels {1, 3}.
2437 // First disable all other paths.
2438 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2439 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2440 short_channel_id: 2,
2443 cltv_expiry_delta: 0,
2444 htlc_minimum_msat: 0,
2445 htlc_maximum_msat: OptionalField::Present(100_000),
2447 fee_proportional_millionths: 0,
2448 excess_data: Vec::new()
2450 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2451 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2452 short_channel_id: 12,
2455 cltv_expiry_delta: 0,
2456 htlc_minimum_msat: 0,
2457 htlc_maximum_msat: OptionalField::Present(100_000),
2459 fee_proportional_millionths: 0,
2460 excess_data: Vec::new()
2463 // Make the first channel (#1) very permissive,
2464 // and we will be testing all limits on the second channel.
2465 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2466 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2467 short_channel_id: 1,
2470 cltv_expiry_delta: 0,
2471 htlc_minimum_msat: 0,
2472 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2474 fee_proportional_millionths: 0,
2475 excess_data: Vec::new()
2478 // First, let's see if routing works if we have absolutely no idea about the available amount.
2479 // In this case, it should be set to 250_000 sats.
2480 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2481 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2482 short_channel_id: 3,
2485 cltv_expiry_delta: 0,
2486 htlc_minimum_msat: 0,
2487 htlc_maximum_msat: OptionalField::Absent,
2489 fee_proportional_millionths: 0,
2490 excess_data: Vec::new()
2494 // Attempt to route more than available results in a failure.
2495 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2496 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
2497 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2498 } else { panic!(); }
2502 // Now, attempt to route an exact amount we have should be fine.
2503 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2504 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
2505 assert_eq!(route.paths.len(), 1);
2506 let path = route.paths.last().unwrap();
2507 assert_eq!(path.len(), 2);
2508 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2509 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
2512 // Check that setting outbound_capacity_msat in first_hops limits the channels.
2513 // Disable channel #1 and use another first hop.
2514 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2515 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2516 short_channel_id: 1,
2519 cltv_expiry_delta: 0,
2520 htlc_minimum_msat: 0,
2521 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2523 fee_proportional_millionths: 0,
2524 excess_data: Vec::new()
2527 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
2528 let our_chans = vec![channelmanager::ChannelDetails {
2529 channel_id: [0; 32],
2530 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2531 short_channel_id: Some(42),
2532 remote_network_id: nodes[0].clone(),
2533 counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
2534 channel_value_satoshis: 0,
2536 outbound_capacity_msat: 200_000_000,
2537 inbound_capacity_msat: 0,
2538 to_self_reserve_satoshis: None,
2539 to_remote_reserve_satoshis: 0,
2540 confirmations_required: None,
2541 spend_csv_on_our_commitment_funds: None,
2542 is_outbound: true, is_funding_locked: true,
2543 is_usable: true, is_public: true,
2544 counterparty_forwarding_info: None,
2548 // Attempt to route more than available results in a failure.
2549 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2550 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
2551 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2552 } else { panic!(); }
2556 // Now, attempt to route an exact amount we have should be fine.
2557 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2558 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
2559 assert_eq!(route.paths.len(), 1);
2560 let path = route.paths.last().unwrap();
2561 assert_eq!(path.len(), 2);
2562 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2563 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
2566 // Enable channel #1 back.
2567 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2568 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2569 short_channel_id: 1,
2572 cltv_expiry_delta: 0,
2573 htlc_minimum_msat: 0,
2574 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2576 fee_proportional_millionths: 0,
2577 excess_data: Vec::new()
2581 // Now let's see if routing works if we know only htlc_maximum_msat.
2582 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2583 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2584 short_channel_id: 3,
2587 cltv_expiry_delta: 0,
2588 htlc_minimum_msat: 0,
2589 htlc_maximum_msat: OptionalField::Present(15_000),
2591 fee_proportional_millionths: 0,
2592 excess_data: Vec::new()
2596 // Attempt to route more than available results in a failure.
2597 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2598 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2599 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2600 } else { panic!(); }
2604 // Now, attempt to route an exact amount we have should be fine.
2605 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2606 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2607 assert_eq!(route.paths.len(), 1);
2608 let path = route.paths.last().unwrap();
2609 assert_eq!(path.len(), 2);
2610 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2611 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2614 // Now let's see if routing works if we know only capacity from the UTXO.
2616 // We can't change UTXO capacity on the fly, so we'll disable
2617 // the existing channel and add another one with the capacity we need.
2618 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2619 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2620 short_channel_id: 3,
2623 cltv_expiry_delta: 0,
2624 htlc_minimum_msat: 0,
2625 htlc_maximum_msat: OptionalField::Absent,
2627 fee_proportional_millionths: 0,
2628 excess_data: Vec::new()
2631 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
2632 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
2633 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
2634 .push_opcode(opcodes::all::OP_PUSHNUM_2)
2635 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
2637 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
2638 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
2640 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
2641 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2642 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2643 short_channel_id: 333,
2646 cltv_expiry_delta: (3 << 8) | 1,
2647 htlc_minimum_msat: 0,
2648 htlc_maximum_msat: OptionalField::Absent,
2650 fee_proportional_millionths: 0,
2651 excess_data: Vec::new()
2653 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2654 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2655 short_channel_id: 333,
2658 cltv_expiry_delta: (3 << 8) | 2,
2659 htlc_minimum_msat: 0,
2660 htlc_maximum_msat: OptionalField::Absent,
2662 fee_proportional_millionths: 0,
2663 excess_data: Vec::new()
2667 // Attempt to route more than available results in a failure.
2668 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2669 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2670 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2671 } else { panic!(); }
2675 // Now, attempt to route an exact amount we have should be fine.
2676 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2677 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2678 assert_eq!(route.paths.len(), 1);
2679 let path = route.paths.last().unwrap();
2680 assert_eq!(path.len(), 2);
2681 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2682 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2685 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
2686 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2687 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2688 short_channel_id: 333,
2691 cltv_expiry_delta: 0,
2692 htlc_minimum_msat: 0,
2693 htlc_maximum_msat: OptionalField::Present(10_000),
2695 fee_proportional_millionths: 0,
2696 excess_data: Vec::new()
2700 // Attempt to route more than available results in a failure.
2701 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2702 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
2703 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2704 } else { panic!(); }
2708 // Now, attempt to route an exact amount we have should be fine.
2709 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2710 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
2711 assert_eq!(route.paths.len(), 1);
2712 let path = route.paths.last().unwrap();
2713 assert_eq!(path.len(), 2);
2714 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2715 assert_eq!(path.last().unwrap().fee_msat, 10_000);
2720 fn available_liquidity_last_hop_test() {
2721 // Check that available liquidity properly limits the path even when only
2722 // one of the latter hops is limited.
2723 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2724 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2726 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
2727 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
2728 // Total capacity: 50 sats.
2730 // Disable other potential paths.
2731 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2732 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2733 short_channel_id: 2,
2736 cltv_expiry_delta: 0,
2737 htlc_minimum_msat: 0,
2738 htlc_maximum_msat: OptionalField::Present(100_000),
2740 fee_proportional_millionths: 0,
2741 excess_data: Vec::new()
2743 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2744 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2745 short_channel_id: 7,
2748 cltv_expiry_delta: 0,
2749 htlc_minimum_msat: 0,
2750 htlc_maximum_msat: OptionalField::Present(100_000),
2752 fee_proportional_millionths: 0,
2753 excess_data: Vec::new()
2758 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2759 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2760 short_channel_id: 12,
2763 cltv_expiry_delta: 0,
2764 htlc_minimum_msat: 0,
2765 htlc_maximum_msat: OptionalField::Present(100_000),
2767 fee_proportional_millionths: 0,
2768 excess_data: Vec::new()
2770 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2771 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2772 short_channel_id: 13,
2775 cltv_expiry_delta: 0,
2776 htlc_minimum_msat: 0,
2777 htlc_maximum_msat: OptionalField::Present(100_000),
2779 fee_proportional_millionths: 0,
2780 excess_data: Vec::new()
2783 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2784 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2785 short_channel_id: 6,
2788 cltv_expiry_delta: 0,
2789 htlc_minimum_msat: 0,
2790 htlc_maximum_msat: OptionalField::Present(50_000),
2792 fee_proportional_millionths: 0,
2793 excess_data: Vec::new()
2795 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2796 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2797 short_channel_id: 11,
2800 cltv_expiry_delta: 0,
2801 htlc_minimum_msat: 0,
2802 htlc_maximum_msat: OptionalField::Present(100_000),
2804 fee_proportional_millionths: 0,
2805 excess_data: Vec::new()
2808 // Attempt to route more than available results in a failure.
2809 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2810 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
2811 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2812 } else { panic!(); }
2816 // Now, attempt to route 49 sats (just a bit below the capacity).
2817 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2818 Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
2819 assert_eq!(route.paths.len(), 1);
2820 let mut total_amount_paid_msat = 0;
2821 for path in &route.paths {
2822 assert_eq!(path.len(), 4);
2823 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2824 total_amount_paid_msat += path.last().unwrap().fee_msat;
2826 assert_eq!(total_amount_paid_msat, 49_000);
2830 // Attempt to route an exact amount is also fine
2831 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2832 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2833 assert_eq!(route.paths.len(), 1);
2834 let mut total_amount_paid_msat = 0;
2835 for path in &route.paths {
2836 assert_eq!(path.len(), 4);
2837 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2838 total_amount_paid_msat += path.last().unwrap().fee_msat;
2840 assert_eq!(total_amount_paid_msat, 50_000);
2845 fn ignore_fee_first_hop_test() {
2846 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2847 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2849 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2850 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2852 short_channel_id: 1,
2855 cltv_expiry_delta: 0,
2856 htlc_minimum_msat: 0,
2857 htlc_maximum_msat: OptionalField::Present(100_000),
2858 fee_base_msat: 1_000_000,
2859 fee_proportional_millionths: 0,
2860 excess_data: Vec::new()
2862 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2863 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2864 short_channel_id: 3,
2867 cltv_expiry_delta: 0,
2868 htlc_minimum_msat: 0,
2869 htlc_maximum_msat: OptionalField::Present(50_000),
2871 fee_proportional_millionths: 0,
2872 excess_data: Vec::new()
2876 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2877 assert_eq!(route.paths.len(), 1);
2878 let mut total_amount_paid_msat = 0;
2879 for path in &route.paths {
2880 assert_eq!(path.len(), 2);
2881 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2882 total_amount_paid_msat += path.last().unwrap().fee_msat;
2884 assert_eq!(total_amount_paid_msat, 50_000);
2889 fn simple_mpp_route_test() {
2890 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2891 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2893 // We need a route consisting of 3 paths:
2894 // From our node to node2 via node0, node7, node1 (three paths one hop each).
2895 // To achieve this, the amount being transferred should be around
2896 // the total capacity of these 3 paths.
2898 // First, we set limits on these (previously unlimited) channels.
2899 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
2901 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2902 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2903 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2904 short_channel_id: 1,
2907 cltv_expiry_delta: 0,
2908 htlc_minimum_msat: 0,
2909 htlc_maximum_msat: OptionalField::Present(100_000),
2911 fee_proportional_millionths: 0,
2912 excess_data: Vec::new()
2914 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2915 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2916 short_channel_id: 3,
2919 cltv_expiry_delta: 0,
2920 htlc_minimum_msat: 0,
2921 htlc_maximum_msat: OptionalField::Present(50_000),
2923 fee_proportional_millionths: 0,
2924 excess_data: Vec::new()
2927 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
2928 // (total limit 60).
2929 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2930 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2931 short_channel_id: 12,
2934 cltv_expiry_delta: 0,
2935 htlc_minimum_msat: 0,
2936 htlc_maximum_msat: OptionalField::Present(60_000),
2938 fee_proportional_millionths: 0,
2939 excess_data: Vec::new()
2941 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2942 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2943 short_channel_id: 13,
2946 cltv_expiry_delta: 0,
2947 htlc_minimum_msat: 0,
2948 htlc_maximum_msat: OptionalField::Present(60_000),
2950 fee_proportional_millionths: 0,
2951 excess_data: Vec::new()
2954 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
2955 // (total capacity 180 sats).
2956 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2957 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2958 short_channel_id: 2,
2961 cltv_expiry_delta: 0,
2962 htlc_minimum_msat: 0,
2963 htlc_maximum_msat: OptionalField::Present(200_000),
2965 fee_proportional_millionths: 0,
2966 excess_data: Vec::new()
2968 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2969 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2970 short_channel_id: 4,
2973 cltv_expiry_delta: 0,
2974 htlc_minimum_msat: 0,
2975 htlc_maximum_msat: OptionalField::Present(180_000),
2977 fee_proportional_millionths: 0,
2978 excess_data: Vec::new()
2982 // Attempt to route more than available results in a failure.
2983 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(),
2984 &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
2985 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2986 } else { panic!(); }
2990 // Now, attempt to route 250 sats (just a bit below the capacity).
2991 // Our algorithm should provide us with these 3 paths.
2992 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2993 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
2994 assert_eq!(route.paths.len(), 3);
2995 let mut total_amount_paid_msat = 0;
2996 for path in &route.paths {
2997 assert_eq!(path.len(), 2);
2998 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2999 total_amount_paid_msat += path.last().unwrap().fee_msat;
3001 assert_eq!(total_amount_paid_msat, 250_000);
3005 // Attempt to route an exact amount is also fine
3006 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3007 Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
3008 assert_eq!(route.paths.len(), 3);
3009 let mut total_amount_paid_msat = 0;
3010 for path in &route.paths {
3011 assert_eq!(path.len(), 2);
3012 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3013 total_amount_paid_msat += path.last().unwrap().fee_msat;
3015 assert_eq!(total_amount_paid_msat, 290_000);
3020 fn long_mpp_route_test() {
3021 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3022 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3024 // We need a route consisting of 3 paths:
3025 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3026 // Note that these paths overlap (channels 5, 12, 13).
3027 // We will route 300 sats.
3028 // Each path will have 100 sats capacity, those channels which
3029 // are used twice will have 200 sats capacity.
3031 // Disable other potential paths.
3032 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3033 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3034 short_channel_id: 2,
3037 cltv_expiry_delta: 0,
3038 htlc_minimum_msat: 0,
3039 htlc_maximum_msat: OptionalField::Present(100_000),
3041 fee_proportional_millionths: 0,
3042 excess_data: Vec::new()
3044 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3045 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3046 short_channel_id: 7,
3049 cltv_expiry_delta: 0,
3050 htlc_minimum_msat: 0,
3051 htlc_maximum_msat: OptionalField::Present(100_000),
3053 fee_proportional_millionths: 0,
3054 excess_data: Vec::new()
3057 // Path via {node0, node2} is channels {1, 3, 5}.
3058 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3059 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3060 short_channel_id: 1,
3063 cltv_expiry_delta: 0,
3064 htlc_minimum_msat: 0,
3065 htlc_maximum_msat: OptionalField::Present(100_000),
3067 fee_proportional_millionths: 0,
3068 excess_data: Vec::new()
3070 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3071 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3072 short_channel_id: 3,
3075 cltv_expiry_delta: 0,
3076 htlc_minimum_msat: 0,
3077 htlc_maximum_msat: OptionalField::Present(100_000),
3079 fee_proportional_millionths: 0,
3080 excess_data: Vec::new()
3083 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3084 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3085 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3086 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3087 short_channel_id: 5,
3090 cltv_expiry_delta: 0,
3091 htlc_minimum_msat: 0,
3092 htlc_maximum_msat: OptionalField::Present(200_000),
3094 fee_proportional_millionths: 0,
3095 excess_data: Vec::new()
3098 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3099 // Add 100 sats to the capacities of {12, 13}, because these channels
3100 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3101 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3102 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3103 short_channel_id: 12,
3106 cltv_expiry_delta: 0,
3107 htlc_minimum_msat: 0,
3108 htlc_maximum_msat: OptionalField::Present(200_000),
3110 fee_proportional_millionths: 0,
3111 excess_data: Vec::new()
3113 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3114 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3115 short_channel_id: 13,
3118 cltv_expiry_delta: 0,
3119 htlc_minimum_msat: 0,
3120 htlc_maximum_msat: OptionalField::Present(200_000),
3122 fee_proportional_millionths: 0,
3123 excess_data: Vec::new()
3126 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3127 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3128 short_channel_id: 6,
3131 cltv_expiry_delta: 0,
3132 htlc_minimum_msat: 0,
3133 htlc_maximum_msat: OptionalField::Present(100_000),
3135 fee_proportional_millionths: 0,
3136 excess_data: Vec::new()
3138 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3139 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3140 short_channel_id: 11,
3143 cltv_expiry_delta: 0,
3144 htlc_minimum_msat: 0,
3145 htlc_maximum_msat: OptionalField::Present(100_000),
3147 fee_proportional_millionths: 0,
3148 excess_data: Vec::new()
3151 // Path via {node7, node2} is channels {12, 13, 5}.
3152 // We already limited them to 200 sats (they are used twice for 100 sats).
3153 // Nothing to do here.
3156 // Attempt to route more than available results in a failure.
3157 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3158 Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
3159 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3160 } else { panic!(); }
3164 // Now, attempt to route 300 sats (exact amount we can route).
3165 // Our algorithm should provide us with these 3 paths, 100 sats each.
3166 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3167 Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
3168 assert_eq!(route.paths.len(), 3);
3170 let mut total_amount_paid_msat = 0;
3171 for path in &route.paths {
3172 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3173 total_amount_paid_msat += path.last().unwrap().fee_msat;
3175 assert_eq!(total_amount_paid_msat, 300_000);
3181 fn mpp_cheaper_route_test() {
3182 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3183 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3185 // This test checks that if we have two cheaper paths and one more expensive path,
3186 // so that liquidity-wise any 2 of 3 combination is sufficient,
3187 // two cheaper paths will be taken.
3188 // These paths have equal available liquidity.
3190 // We need a combination of 3 paths:
3191 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3192 // Note that these paths overlap (channels 5, 12, 13).
3193 // Each path will have 100 sats capacity, those channels which
3194 // are used twice will have 200 sats capacity.
3196 // Disable other potential paths.
3197 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3198 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3199 short_channel_id: 2,
3202 cltv_expiry_delta: 0,
3203 htlc_minimum_msat: 0,
3204 htlc_maximum_msat: OptionalField::Present(100_000),
3206 fee_proportional_millionths: 0,
3207 excess_data: Vec::new()
3209 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3210 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3211 short_channel_id: 7,
3214 cltv_expiry_delta: 0,
3215 htlc_minimum_msat: 0,
3216 htlc_maximum_msat: OptionalField::Present(100_000),
3218 fee_proportional_millionths: 0,
3219 excess_data: Vec::new()
3222 // Path via {node0, node2} is channels {1, 3, 5}.
3223 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3224 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3225 short_channel_id: 1,
3228 cltv_expiry_delta: 0,
3229 htlc_minimum_msat: 0,
3230 htlc_maximum_msat: OptionalField::Present(100_000),
3232 fee_proportional_millionths: 0,
3233 excess_data: Vec::new()
3235 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3236 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3237 short_channel_id: 3,
3240 cltv_expiry_delta: 0,
3241 htlc_minimum_msat: 0,
3242 htlc_maximum_msat: OptionalField::Present(100_000),
3244 fee_proportional_millionths: 0,
3245 excess_data: Vec::new()
3248 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3249 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3250 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3251 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3252 short_channel_id: 5,
3255 cltv_expiry_delta: 0,
3256 htlc_minimum_msat: 0,
3257 htlc_maximum_msat: OptionalField::Present(200_000),
3259 fee_proportional_millionths: 0,
3260 excess_data: Vec::new()
3263 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3264 // Add 100 sats to the capacities of {12, 13}, because these channels
3265 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3266 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3267 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3268 short_channel_id: 12,
3271 cltv_expiry_delta: 0,
3272 htlc_minimum_msat: 0,
3273 htlc_maximum_msat: OptionalField::Present(200_000),
3275 fee_proportional_millionths: 0,
3276 excess_data: Vec::new()
3278 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3279 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3280 short_channel_id: 13,
3283 cltv_expiry_delta: 0,
3284 htlc_minimum_msat: 0,
3285 htlc_maximum_msat: OptionalField::Present(200_000),
3287 fee_proportional_millionths: 0,
3288 excess_data: Vec::new()
3291 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3292 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3293 short_channel_id: 6,
3296 cltv_expiry_delta: 0,
3297 htlc_minimum_msat: 0,
3298 htlc_maximum_msat: OptionalField::Present(100_000),
3299 fee_base_msat: 1_000,
3300 fee_proportional_millionths: 0,
3301 excess_data: Vec::new()
3303 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3304 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3305 short_channel_id: 11,
3308 cltv_expiry_delta: 0,
3309 htlc_minimum_msat: 0,
3310 htlc_maximum_msat: OptionalField::Present(100_000),
3312 fee_proportional_millionths: 0,
3313 excess_data: Vec::new()
3316 // Path via {node7, node2} is channels {12, 13, 5}.
3317 // We already limited them to 200 sats (they are used twice for 100 sats).
3318 // Nothing to do here.
3321 // Now, attempt to route 180 sats.
3322 // Our algorithm should provide us with these 2 paths.
3323 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3324 Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
3325 assert_eq!(route.paths.len(), 2);
3327 let mut total_value_transferred_msat = 0;
3328 let mut total_paid_msat = 0;
3329 for path in &route.paths {
3330 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3331 total_value_transferred_msat += path.last().unwrap().fee_msat;
3333 total_paid_msat += hop.fee_msat;
3336 // If we paid fee, this would be higher.
3337 assert_eq!(total_value_transferred_msat, 180_000);
3338 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3339 assert_eq!(total_fees_paid, 0);
3344 fn fees_on_mpp_route_test() {
3345 // This test makes sure that MPP algorithm properly takes into account
3346 // fees charged on the channels, by making the fees impactful:
3347 // if the fee is not properly accounted for, the behavior is different.
3348 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3349 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3351 // We need a route consisting of 2 paths:
3352 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
3353 // We will route 200 sats, Each path will have 100 sats capacity.
3355 // This test is not particularly stable: e.g.,
3356 // there's a way to route via {node0, node2, node4}.
3357 // It works while pathfinding is deterministic, but can be broken otherwise.
3358 // It's fine to ignore this concern for now.
3360 // Disable other potential paths.
3361 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3362 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3363 short_channel_id: 2,
3366 cltv_expiry_delta: 0,
3367 htlc_minimum_msat: 0,
3368 htlc_maximum_msat: OptionalField::Present(100_000),
3370 fee_proportional_millionths: 0,
3371 excess_data: Vec::new()
3374 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3375 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3376 short_channel_id: 7,
3379 cltv_expiry_delta: 0,
3380 htlc_minimum_msat: 0,
3381 htlc_maximum_msat: OptionalField::Present(100_000),
3383 fee_proportional_millionths: 0,
3384 excess_data: Vec::new()
3387 // Path via {node0, node2} is channels {1, 3, 5}.
3388 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3390 short_channel_id: 1,
3393 cltv_expiry_delta: 0,
3394 htlc_minimum_msat: 0,
3395 htlc_maximum_msat: OptionalField::Present(100_000),
3397 fee_proportional_millionths: 0,
3398 excess_data: Vec::new()
3400 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3401 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3402 short_channel_id: 3,
3405 cltv_expiry_delta: 0,
3406 htlc_minimum_msat: 0,
3407 htlc_maximum_msat: OptionalField::Present(100_000),
3409 fee_proportional_millionths: 0,
3410 excess_data: Vec::new()
3413 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3414 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3415 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3416 short_channel_id: 5,
3419 cltv_expiry_delta: 0,
3420 htlc_minimum_msat: 0,
3421 htlc_maximum_msat: OptionalField::Present(100_000),
3423 fee_proportional_millionths: 0,
3424 excess_data: Vec::new()
3427 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3428 // All channels should be 100 sats capacity. But for the fee experiment,
3429 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
3430 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
3431 // 100 sats (and pay 150 sats in fees for the use of channel 6),
3432 // so no matter how large are other channels,
3433 // the whole path will be limited by 100 sats with just these 2 conditions:
3434 // - channel 12 capacity is 250 sats
3435 // - fee for channel 6 is 150 sats
3436 // Let's test this by enforcing these 2 conditions and removing other limits.
3437 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3438 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3439 short_channel_id: 12,
3442 cltv_expiry_delta: 0,
3443 htlc_minimum_msat: 0,
3444 htlc_maximum_msat: OptionalField::Present(250_000),
3446 fee_proportional_millionths: 0,
3447 excess_data: Vec::new()
3449 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3451 short_channel_id: 13,
3454 cltv_expiry_delta: 0,
3455 htlc_minimum_msat: 0,
3456 htlc_maximum_msat: OptionalField::Absent,
3458 fee_proportional_millionths: 0,
3459 excess_data: Vec::new()
3462 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3464 short_channel_id: 6,
3467 cltv_expiry_delta: 0,
3468 htlc_minimum_msat: 0,
3469 htlc_maximum_msat: OptionalField::Absent,
3470 fee_base_msat: 150_000,
3471 fee_proportional_millionths: 0,
3472 excess_data: Vec::new()
3474 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3475 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3476 short_channel_id: 11,
3479 cltv_expiry_delta: 0,
3480 htlc_minimum_msat: 0,
3481 htlc_maximum_msat: OptionalField::Absent,
3483 fee_proportional_millionths: 0,
3484 excess_data: Vec::new()
3488 // Attempt to route more than available results in a failure.
3489 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3490 Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
3491 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3492 } else { panic!(); }
3496 // Now, attempt to route 200 sats (exact amount we can route).
3497 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3498 Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
3499 assert_eq!(route.paths.len(), 2);
3501 let mut total_amount_paid_msat = 0;
3502 for path in &route.paths {
3503 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3504 total_amount_paid_msat += path.last().unwrap().fee_msat;
3506 assert_eq!(total_amount_paid_msat, 200_000);
3512 fn drop_lowest_channel_mpp_route_test() {
3513 // This test checks that low-capacity channel is dropped when after
3514 // path finding we realize that we found more capacity than we need.
3515 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3516 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3518 // We need a route consisting of 3 paths:
3519 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3521 // The first and the second paths should be sufficient, but the third should be
3522 // cheaper, so that we select it but drop later.
3524 // First, we set limits on these (previously unlimited) channels.
3525 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
3527 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
3528 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3529 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3530 short_channel_id: 1,
3533 cltv_expiry_delta: 0,
3534 htlc_minimum_msat: 0,
3535 htlc_maximum_msat: OptionalField::Present(100_000),
3537 fee_proportional_millionths: 0,
3538 excess_data: Vec::new()
3540 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3541 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3542 short_channel_id: 3,
3545 cltv_expiry_delta: 0,
3546 htlc_minimum_msat: 0,
3547 htlc_maximum_msat: OptionalField::Present(50_000),
3549 fee_proportional_millionths: 0,
3550 excess_data: Vec::new()
3553 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
3554 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3555 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3556 short_channel_id: 12,
3559 cltv_expiry_delta: 0,
3560 htlc_minimum_msat: 0,
3561 htlc_maximum_msat: OptionalField::Present(60_000),
3563 fee_proportional_millionths: 0,
3564 excess_data: Vec::new()
3566 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3567 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3568 short_channel_id: 13,
3571 cltv_expiry_delta: 0,
3572 htlc_minimum_msat: 0,
3573 htlc_maximum_msat: OptionalField::Present(60_000),
3575 fee_proportional_millionths: 0,
3576 excess_data: Vec::new()
3579 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
3580 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3581 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3582 short_channel_id: 2,
3585 cltv_expiry_delta: 0,
3586 htlc_minimum_msat: 0,
3587 htlc_maximum_msat: OptionalField::Present(20_000),
3589 fee_proportional_millionths: 0,
3590 excess_data: Vec::new()
3592 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3593 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3594 short_channel_id: 4,
3597 cltv_expiry_delta: 0,
3598 htlc_minimum_msat: 0,
3599 htlc_maximum_msat: OptionalField::Present(20_000),
3601 fee_proportional_millionths: 0,
3602 excess_data: Vec::new()
3606 // Attempt to route more than available results in a failure.
3607 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3608 Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
3609 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3610 } else { panic!(); }
3614 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
3615 // Our algorithm should provide us with these 3 paths.
3616 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3617 Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
3618 assert_eq!(route.paths.len(), 3);
3619 let mut total_amount_paid_msat = 0;
3620 for path in &route.paths {
3621 assert_eq!(path.len(), 2);
3622 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3623 total_amount_paid_msat += path.last().unwrap().fee_msat;
3625 assert_eq!(total_amount_paid_msat, 125_000);
3629 // Attempt to route without the last small cheap channel
3630 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3631 Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3632 assert_eq!(route.paths.len(), 2);
3633 let mut total_amount_paid_msat = 0;
3634 for path in &route.paths {
3635 assert_eq!(path.len(), 2);
3636 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3637 total_amount_paid_msat += path.last().unwrap().fee_msat;
3639 assert_eq!(total_amount_paid_msat, 90_000);
3644 fn min_criteria_consistency() {
3645 // Test that we don't use an inconsistent metric between updating and walking nodes during
3646 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
3647 // was updated with a different criterion from the heap sorting, resulting in loops in
3648 // calculated paths. We test for that specific case here.
3650 // We construct a network that looks like this:
3652 // node2 -1(3)2- node3
3656 // node1 -1(5)2- node4 -1(1)2- node6
3662 // We create a loop on the side of our real path - our destination is node 6, with a
3663 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
3664 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
3665 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
3666 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
3667 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
3668 // "previous hop" being set to node 3, creating a loop in the path.
3669 let secp_ctx = Secp256k1::new();
3670 let logger = Arc::new(test_utils::TestLogger::new());
3671 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
3672 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3674 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
3675 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3676 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3677 short_channel_id: 6,
3680 cltv_expiry_delta: (6 << 8) | 0,
3681 htlc_minimum_msat: 0,
3682 htlc_maximum_msat: OptionalField::Absent,
3684 fee_proportional_millionths: 0,
3685 excess_data: Vec::new()
3687 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
3689 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3690 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3691 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3692 short_channel_id: 5,
3695 cltv_expiry_delta: (5 << 8) | 0,
3696 htlc_minimum_msat: 0,
3697 htlc_maximum_msat: OptionalField::Absent,
3699 fee_proportional_millionths: 0,
3700 excess_data: Vec::new()
3702 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
3704 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
3705 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3706 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3707 short_channel_id: 4,
3710 cltv_expiry_delta: (4 << 8) | 0,
3711 htlc_minimum_msat: 0,
3712 htlc_maximum_msat: OptionalField::Absent,
3714 fee_proportional_millionths: 0,
3715 excess_data: Vec::new()
3717 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
3719 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
3720 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
3721 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3722 short_channel_id: 3,
3725 cltv_expiry_delta: (3 << 8) | 0,
3726 htlc_minimum_msat: 0,
3727 htlc_maximum_msat: OptionalField::Absent,
3729 fee_proportional_millionths: 0,
3730 excess_data: Vec::new()
3732 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
3734 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
3735 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3736 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3737 short_channel_id: 2,
3740 cltv_expiry_delta: (2 << 8) | 0,
3741 htlc_minimum_msat: 0,
3742 htlc_maximum_msat: OptionalField::Absent,
3744 fee_proportional_millionths: 0,
3745 excess_data: Vec::new()
3748 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
3749 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3750 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3751 short_channel_id: 1,
3754 cltv_expiry_delta: (1 << 8) | 0,
3755 htlc_minimum_msat: 100,
3756 htlc_maximum_msat: OptionalField::Absent,
3758 fee_proportional_millionths: 0,
3759 excess_data: Vec::new()
3761 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
3764 // Now ensure the route flows simply over nodes 1 and 4 to 6.
3765 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
3766 assert_eq!(route.paths.len(), 1);
3767 assert_eq!(route.paths[0].len(), 3);
3769 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3770 assert_eq!(route.paths[0][0].short_channel_id, 6);
3771 assert_eq!(route.paths[0][0].fee_msat, 100);
3772 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
3773 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
3774 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
3776 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
3777 assert_eq!(route.paths[0][1].short_channel_id, 5);
3778 assert_eq!(route.paths[0][1].fee_msat, 0);
3779 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
3780 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
3781 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
3783 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
3784 assert_eq!(route.paths[0][2].short_channel_id, 1);
3785 assert_eq!(route.paths[0][2].fee_msat, 10_000);
3786 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
3787 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3788 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
3794 fn exact_fee_liquidity_limit() {
3795 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
3796 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
3797 // we calculated fees on a higher value, resulting in us ignoring such paths.
3798 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3799 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
3801 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
3803 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3804 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3805 short_channel_id: 2,
3808 cltv_expiry_delta: 0,
3809 htlc_minimum_msat: 0,
3810 htlc_maximum_msat: OptionalField::Present(85_000),
3812 fee_proportional_millionths: 0,
3813 excess_data: Vec::new()
3816 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3817 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3818 short_channel_id: 12,
3821 cltv_expiry_delta: (4 << 8) | 1,
3822 htlc_minimum_msat: 0,
3823 htlc_maximum_msat: OptionalField::Present(270_000),
3825 fee_proportional_millionths: 1000000,
3826 excess_data: Vec::new()
3830 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
3831 // 200% fee charged channel 13 in the 1-to-2 direction.
3832 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3833 assert_eq!(route.paths.len(), 1);
3834 assert_eq!(route.paths[0].len(), 2);
3836 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3837 assert_eq!(route.paths[0][0].short_channel_id, 12);
3838 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3839 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3840 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3841 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3843 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3844 assert_eq!(route.paths[0][1].short_channel_id, 13);
3845 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3846 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3847 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3848 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3853 fn htlc_max_reduction_below_min() {
3854 // Test that if, while walking the graph, we reduce the value being sent to meet an
3855 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
3856 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
3857 // resulting in us thinking there is no possible path, even if other paths exist.
3858 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3859 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3861 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
3862 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
3863 // then try to send 90_000.
3864 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3865 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3866 short_channel_id: 2,
3869 cltv_expiry_delta: 0,
3870 htlc_minimum_msat: 0,
3871 htlc_maximum_msat: OptionalField::Present(80_000),
3873 fee_proportional_millionths: 0,
3874 excess_data: Vec::new()
3876 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3877 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3878 short_channel_id: 4,
3881 cltv_expiry_delta: (4 << 8) | 1,
3882 htlc_minimum_msat: 90_000,
3883 htlc_maximum_msat: OptionalField::Absent,
3885 fee_proportional_millionths: 0,
3886 excess_data: Vec::new()
3890 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
3891 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
3892 // expensive) channels 12-13 path.
3893 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3894 assert_eq!(route.paths.len(), 1);
3895 assert_eq!(route.paths[0].len(), 2);
3897 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3898 assert_eq!(route.paths[0][0].short_channel_id, 12);
3899 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3900 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3901 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3902 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3904 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3905 assert_eq!(route.paths[0][1].short_channel_id, 13);
3906 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3907 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3908 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
3909 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3913 #[cfg(not(feature = "no_std"))]
3914 pub(super) fn random_init_seed() -> u64 {
3915 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
3916 use core::hash::{BuildHasher, Hasher};
3917 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
3918 println!("Using seed of {}", seed);
3921 #[cfg(not(feature = "no_std"))]
3922 use util::ser::Readable;
3925 #[cfg(not(feature = "no_std"))]
3926 fn generate_routes() {
3927 let mut d = match super::test_utils::get_route_file() {
3934 let graph = NetworkGraph::read(&mut d).unwrap();
3936 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3937 let mut seed = random_init_seed() as usize;
3938 'load_endpoints: for _ in 0..10 {
3940 seed = seed.overflowing_mul(0xdeadbeef).0;
3941 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3942 seed = seed.overflowing_mul(0xdeadbeef).0;
3943 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3944 let amt = seed as u64 % 200_000_000;
3945 if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3946 continue 'load_endpoints;
3953 #[cfg(not(feature = "no_std"))]
3954 fn generate_routes_mpp() {
3955 let mut d = match super::test_utils::get_route_file() {
3962 let graph = NetworkGraph::read(&mut d).unwrap();
3964 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3965 let mut seed = random_init_seed() as usize;
3966 'load_endpoints: for _ in 0..10 {
3968 seed = seed.overflowing_mul(0xdeadbeef).0;
3969 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3970 seed = seed.overflowing_mul(0xdeadbeef).0;
3971 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3972 let amt = seed as u64 % 200_000_000;
3973 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3974 continue 'load_endpoints;
3981 #[cfg(all(test, not(feature = "no_std")))]
3982 pub(crate) mod test_utils {
3984 /// Tries to open a network graph file, or panics with a URL to fetch it.
3985 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
3986 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
3987 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
3988 .or_else(|_| { // Fall back to guessing based on the binary location
3989 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
3990 let mut path = std::env::current_exe().unwrap();
3991 path.pop(); // lightning-...
3993 path.pop(); // debug
3994 path.pop(); // target
3995 path.push("lightning");
3996 path.push("net_graph-2021-05-31.bin");
3997 eprintln!("{}", path.to_str().unwrap());
4000 .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");
4001 #[cfg(require_route_graph_test)]
4002 return Ok(res.unwrap());
4003 #[cfg(not(require_route_graph_test))]
4008 #[cfg(all(test, feature = "unstable", not(feature = "no_std")))]
4011 use util::logger::{Logger, Record};
4015 struct DummyLogger {}
4016 impl Logger for DummyLogger {
4017 fn log(&self, _record: &Record) {}
4021 fn generate_routes(bench: &mut Bencher) {
4022 let mut d = test_utils::get_route_file().unwrap();
4023 let graph = NetworkGraph::read(&mut d).unwrap();
4025 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4026 let mut path_endpoints = Vec::new();
4027 let mut seed: usize = 0xdeadbeef;
4028 'load_endpoints: for _ in 0..100 {
4031 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
4033 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
4034 let amt = seed as u64 % 1_000_000;
4035 if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
4036 path_endpoints.push((src, dst, amt));
4037 continue 'load_endpoints;
4042 // ...then benchmark finding paths between the nodes we learned.
4045 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
4046 assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
4052 fn generate_mpp_routes(bench: &mut Bencher) {
4053 let mut d = test_utils::get_route_file().unwrap();
4054 let graph = NetworkGraph::read(&mut d).unwrap();
4056 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4057 let mut path_endpoints = Vec::new();
4058 let mut seed: usize = 0xdeadbeef;
4059 'load_endpoints: for _ in 0..100 {
4062 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
4064 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
4065 let amt = seed as u64 % 1_000_000;
4066 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
4067 path_endpoints.push((src, dst, amt));
4068 continue 'load_endpoints;
4073 // ...then benchmark finding paths between the nodes we learned.
4076 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
4077 assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());