1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The top-level routing/network map tracking logic lives here.
12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::network_graph::{NetworkGraph, RoutingFees};
21 use util::ser::{Writeable, Readable};
22 use util::logger::Logger;
26 use alloc::collections::BinaryHeap;
31 #[derive(Clone, Hash, PartialEq, Eq)]
33 /// The node_id of the node at this hop.
34 pub pubkey: PublicKey,
35 /// The node_announcement features of the node at this hop. For the last hop, these may be
36 /// amended to match the features present in the invoice this node generated.
37 pub node_features: NodeFeatures,
38 /// The channel that should be used from the previous hop to reach this node.
39 pub short_channel_id: u64,
40 /// The channel_announcement features of the channel that should be used from the previous hop
41 /// to reach this node.
42 pub channel_features: ChannelFeatures,
43 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
44 /// For the last hop, this should be the full value of the payment (might be more than
45 /// requested if we had to match htlc_minimum_msat).
47 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
48 /// expected at the destination, in excess of the current block height.
49 pub cltv_expiry_delta: u32,
52 impl_writeable_tlv_based!(RouteHop, {
53 (0, pubkey, required),
54 (2, node_features, required),
55 (4, short_channel_id, required),
56 (6, channel_features, required),
57 (8, fee_msat, required),
58 (10, cltv_expiry_delta, required),
61 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
62 /// it can take multiple paths. Each path is composed of one or more hops through the network.
63 #[derive(Clone, Hash, PartialEq, Eq)]
65 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
66 /// last RouteHop in each path must be the same.
67 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
68 /// destination. Thus, this must always be at least length one. While the maximum length of any
69 /// given path is variable, keeping the length of any path to less than 20 should currently
70 /// ensure it is viable.
71 pub paths: Vec<Vec<RouteHop>>,
74 const SERIALIZATION_VERSION: u8 = 1;
75 const MIN_SERIALIZATION_VERSION: u8 = 1;
77 impl Writeable for Route {
78 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
79 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
80 (self.paths.len() as u64).write(writer)?;
81 for hops in self.paths.iter() {
82 (hops.len() as u8).write(writer)?;
83 for hop in hops.iter() {
87 write_tlv_fields!(writer, {});
92 impl Readable for Route {
93 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
94 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
95 let path_count: u64 = Readable::read(reader)?;
96 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
97 for _ in 0..path_count {
98 let hop_count: u8 = Readable::read(reader)?;
99 let mut hops = Vec::with_capacity(hop_count as usize);
100 for _ in 0..hop_count {
101 hops.push(Readable::read(reader)?);
105 read_tlv_fields!(reader, {});
110 /// A list of hops along a payment path terminating with a channel to the recipient.
111 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
112 pub struct RouteHint(pub Vec<RouteHintHop>);
114 /// A channel descriptor for a hop along a payment path.
115 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
116 pub struct RouteHintHop {
117 /// The node_id of the non-target end of the route
118 pub src_node_id: PublicKey,
119 /// The short_channel_id of this channel
120 pub short_channel_id: u64,
121 /// The fees which must be paid to use this channel
122 pub fees: RoutingFees,
123 /// The difference in CLTV values between this node and the next node.
124 pub cltv_expiry_delta: u16,
125 /// The minimum value, in msat, which must be relayed to the next hop.
126 pub htlc_minimum_msat: Option<u64>,
127 /// The maximum value in msat available for routing with a single HTLC.
128 pub htlc_maximum_msat: Option<u64>,
131 #[derive(Eq, PartialEq)]
132 struct RouteGraphNode {
134 lowest_fee_to_peer_through_node: u64,
135 lowest_fee_to_node: u64,
136 // The maximum value a yet-to-be-constructed payment path might flow through this node.
137 // This value is upper-bounded by us by:
138 // - how much is needed for a path being constructed
139 // - how much value can channels following this node (up to the destination) can contribute,
140 // considering their capacity and fees
141 value_contribution_msat: u64,
142 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
143 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
144 path_htlc_minimum_msat: u64,
147 impl cmp::Ord for RouteGraphNode {
148 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
149 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat);
150 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat);
151 other_score.cmp(&self_score).then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
155 impl cmp::PartialOrd for RouteGraphNode {
156 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
157 Some(self.cmp(other))
161 struct DummyDirectionalChannelInfo {
162 cltv_expiry_delta: u32,
163 htlc_minimum_msat: u64,
164 htlc_maximum_msat: Option<u64>,
168 /// It's useful to keep track of the hops associated with the fees required to use them,
169 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
170 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
171 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
172 #[derive(Clone, Debug)]
173 struct PathBuildingHop<'a> {
174 // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
175 // Note that node_features is calculated separately after our initial graph walk.
177 short_channel_id: u64,
178 channel_features: &'a ChannelFeatures,
180 cltv_expiry_delta: u32,
182 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
183 src_lowest_inbound_fees: RoutingFees,
184 /// Fees of the channel used in this hop.
185 channel_fees: RoutingFees,
186 /// All the fees paid *after* this channel on the way to the destination
187 next_hops_fee_msat: u64,
188 /// Fee paid for the use of the current channel (see channel_fees).
189 /// The value will be actually deducted from the counterparty balance on the previous link.
190 hop_use_fee_msat: u64,
191 /// Used to compare channels when choosing the for routing.
192 /// Includes paying for the use of a hop and the following hops, as well as
193 /// an estimated cost of reaching this hop.
194 /// Might get stale when fees are recomputed. Primarily for internal use.
196 /// This is useful for update_value_and_recompute_fees to make sure
197 /// we don't fall below the minimum. Should not be updated manually and
198 /// generally should not be accessed.
199 htlc_minimum_msat: u64,
200 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
201 /// walk and may be invalid thereafter.
202 path_htlc_minimum_msat: u64,
203 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
204 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
205 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
206 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
207 /// avoid processing them again.
209 #[cfg(any(test, feature = "fuzztarget"))]
210 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
211 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
212 // value_contribution_msat, which requires tracking it here. See comments below where it is
213 // used for more info.
214 value_contribution_msat: u64,
217 // Instantiated with a list of hops with correct data in them collected during path finding,
218 // an instance of this struct should be further modified only via given methods.
220 struct PaymentPath<'a> {
221 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
224 impl<'a> PaymentPath<'a> {
225 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
226 fn get_value_msat(&self) -> u64 {
227 self.hops.last().unwrap().0.fee_msat
230 fn get_total_fee_paid_msat(&self) -> u64 {
231 if self.hops.len() < 1 {
235 // Can't use next_hops_fee_msat because it gets outdated.
236 for (i, (hop, _)) in self.hops.iter().enumerate() {
237 if i != self.hops.len() - 1 {
238 result += hop.fee_msat;
244 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
245 // to change fees may result in an inconsistency.
247 // Sometimes we call this function right after constructing a path which is inconsistent in
248 // that it the value being transferred has decreased while we were doing path finding, leading
249 // to the fees being paid not lining up with the actual limits.
251 // Note that this function is not aware of the available_liquidity limit, and thus does not
252 // support increasing the value being transferred.
253 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
254 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
256 let mut total_fee_paid_msat = 0 as u64;
257 for i in (0..self.hops.len()).rev() {
258 let last_hop = i == self.hops.len() - 1;
260 // For non-last-hop, this value will represent the fees paid on the current hop. It
261 // will consist of the fees for the use of the next hop, and extra fees to match
262 // htlc_minimum_msat of the current channel. Last hop is handled separately.
263 let mut cur_hop_fees_msat = 0;
265 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
268 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
269 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
270 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
271 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
272 // set it too high just to maliciously take more fees by exploiting this
273 // match htlc_minimum_msat logic.
274 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
275 if let Some(extra_fees_msat) = cur_hop.htlc_minimum_msat.checked_sub(cur_hop_transferred_amount_msat) {
276 // Note that there is a risk that *previous hops* (those closer to us, as we go
277 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
279 // This might make us end up with a broken route, although this should be super-rare
280 // in practice, both because of how healthy channels look like, and how we pick
281 // channels in add_entry.
282 // Also, this can't be exploited more heavily than *announce a free path and fail
284 cur_hop_transferred_amount_msat += extra_fees_msat;
285 total_fee_paid_msat += extra_fees_msat;
286 cur_hop_fees_msat += extra_fees_msat;
290 // Final hop is a special case: it usually has just value_msat (by design), but also
291 // it still could overpay for the htlc_minimum_msat.
292 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
294 // Propagate updated fees for the use of the channels to one hop back, where they
295 // will be actually paid (fee_msat). The last hop is handled above separately.
296 cur_hop.fee_msat = cur_hop_fees_msat;
299 // Fee for the use of the current hop which will be deducted on the previous hop.
300 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
301 // this channel is free for us.
303 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.channel_fees) {
304 cur_hop.hop_use_fee_msat = new_fee;
305 total_fee_paid_msat += new_fee;
307 // It should not be possible because this function is called only to reduce the
308 // value. In that case, compute_fee was already called with the same fees for
309 // larger amount and there was no overflow.
317 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
318 let proportional_fee_millions =
319 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
320 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
321 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
325 // This function may be (indirectly) called without any verification,
326 // with channel_fees provided by a caller. We should handle it gracefully.
331 /// Gets a keysend route from us (payer) to the given target node (payee). This is needed because
332 /// keysend payments do not have an invoice from which to pull the payee's supported features, which
333 /// makes it tricky to otherwise supply the `payee_features` parameter of `get_route`.
334 pub fn get_keysend_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee:
335 &PublicKey, first_hops: Option<&[&ChannelDetails]>, last_hops: &[&RouteHint],
336 final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route,
337 LightningError> where L::Target: Logger {
338 let invoice_features = InvoiceFeatures::for_keysend();
339 get_route(our_node_id, network, payee, Some(invoice_features), first_hops, last_hops,
340 final_value_msat, final_cltv, logger)
343 /// Gets a route from us (payer) to the given target node (payee).
345 /// If the payee provided features in their invoice, they should be provided via payee_features.
346 /// Without this, MPP will only be used if the payee's features are available in the network graph.
348 /// Private routing paths between a public node and the target may be included in `last_hops`.
349 /// Currently, only the last hop in each path is considered.
351 /// If some channels aren't announced, it may be useful to fill in a first_hops with the
352 /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
353 /// view of our local channels (from net_graph_msg_handler) will be ignored, and only those
354 /// in first_hops will be used.
356 /// Panics if first_hops contains channels without short_channel_ids
357 /// (ChannelManager::list_usable_channels will never include such channels).
359 /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
360 /// equal), however the enabled/disabled bit on such channels as well as the
361 /// htlc_minimum_msat/htlc_maximum_msat *are* checked as they may change based on the receiving node.
362 pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee: &PublicKey, payee_features: Option<InvoiceFeatures>, first_hops: Option<&[&ChannelDetails]>,
363 last_hops: &[&RouteHint], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
364 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
365 // uptime/success in using a node in the past.
366 if *payee == *our_node_id {
367 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
370 if final_value_msat > MAX_VALUE_MSAT {
371 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
374 if final_value_msat == 0 {
375 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
378 let last_hops = last_hops.iter().filter_map(|hops| hops.0.last()).collect::<Vec<_>>();
379 for last_hop in last_hops.iter() {
380 if last_hop.src_node_id == *payee {
381 return Err(LightningError{err: "Last hop cannot have a payee as a source.".to_owned(), action: ErrorAction::IgnoreError});
385 // The general routing idea is the following:
386 // 1. Fill first/last hops communicated by the caller.
387 // 2. Attempt to construct a path from payer to payee for transferring
388 // any ~sufficient (described later) value.
389 // If succeed, remember which channels were used and how much liquidity they have available,
390 // so that future paths don't rely on the same liquidity.
391 // 3. Prooceed to the next step if:
392 // - we hit the recommended target value;
393 // - OR if we could not construct a new path. Any next attempt will fail too.
394 // Otherwise, repeat step 2.
395 // 4. See if we managed to collect paths which aggregately are able to transfer target value
396 // (not recommended value). If yes, proceed. If not, fail routing.
397 // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
398 // 6. Of all the found paths, select only those with the lowest total fee.
399 // 7. The last path in every selected route is likely to be more than we need.
400 // Reduce its value-to-transfer and recompute fees.
401 // 8. Choose the best route by the lowest total fee.
403 // As for the actual search algorithm,
404 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
405 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
407 // We are not a faithful Dijkstra's implementation because we can change values which impact
408 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
409 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) then
410 // the value we are currently attempting to send over a path, we simply reduce the value being
411 // sent along the path for any hops after that channel. This may imply that later fees (which
412 // we've already tabulated) are lower because a smaller value is passing through the channels
413 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
414 // channels which were selected earlier (and which may still be used for other paths without a
415 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
418 // One potentially problematic case for this algorithm would be if there are many
419 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
420 // graph walking), we may never find a path which is not liquidity-limited and has lower
421 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
422 // Because we only consider paths with at least 5% of the total value being sent, the damage
423 // from such a case should be limited, however this could be further reduced in the future by
424 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
425 // limits for the purposes of fee calculation.
427 // Alternatively, we could store more detailed path information in the heap (targets, below)
428 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
429 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
430 // and practically (as we would need to store dynamically-allocated path information in heap
431 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
432 // results of such an algorithm would likely be biased towards lower-value paths.
434 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
435 // outside of our current search value, running a path search more times to gather candidate
436 // paths at different values. While this may be acceptable, further path searches may increase
437 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
438 // graph for candidate paths, calculating the maximum value which can realistically be sent at
439 // the same time, remaining generic across different payment values.
441 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
442 // to use as the A* heuristic beyond just the cost to get one node further than the current
445 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
446 cltv_expiry_delta: 0,
447 htlc_minimum_msat: 0,
448 htlc_maximum_msat: None,
451 proportional_millionths: 0,
455 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
456 // it. If the payee supports it they're supposed to include it in the invoice, so that should
458 let allow_mpp = if let Some(features) = &payee_features {
459 features.supports_basic_mpp()
460 } else if let Some(node) = network.get_nodes().get(&payee) {
461 if let Some(node_info) = node.announcement_info.as_ref() {
462 node_info.features.supports_basic_mpp()
467 // Prepare the data we'll use for payee-to-payer search by
468 // inserting first hops suggested by the caller as targets.
469 // Our search will then attempt to reach them while traversing from the payee node.
470 let mut first_hop_targets: HashMap<_, (_, ChannelFeatures, _, NodeFeatures)> =
471 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
472 if let Some(hops) = first_hops {
474 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
475 if chan.counterparty.node_id == *our_node_id {
476 return Err(LightningError{err: "First hop cannot have our_node_id as a destination.".to_owned(), action: ErrorAction::IgnoreError});
478 first_hop_targets.insert(chan.counterparty.node_id, (short_channel_id, chan.counterparty.features.to_context(), chan.outbound_capacity_msat, chan.counterparty.features.to_context()));
480 if first_hop_targets.is_empty() {
481 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
485 let empty_channel_features = ChannelFeatures::empty();
487 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
488 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
489 // adding duplicate entries when we find a better path to a given node.
490 let mut targets = BinaryHeap::new();
492 // Map from node_id to information about the best current path to that node, including feerate
494 let mut dist = HashMap::with_capacity(network.get_nodes().len());
496 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
497 // indicating that we may wish to try again with a higher value, potentially paying to meet an
498 // htlc_minimum with extra fees while still finding a cheaper path.
499 let mut hit_minimum_limit;
501 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
502 // We start with a path_value of the exact amount we want, and if that generates a route we may
503 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
504 // amount we want in total across paths, selecting the best subset at the end.
505 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
506 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
507 let mut path_value_msat = final_value_msat;
509 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
510 // This map allows paths to be aware of the channel use by other paths in the same call.
511 // This would help to make a better path finding decisions and not "overbook" channels.
512 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
513 let mut bookkeeped_channels_liquidity_available_msat = HashMap::with_capacity(network.get_nodes().len());
515 // Keeping track of how much value we already collected across other paths. Helps to decide:
516 // - how much a new path should be transferring (upper bound);
517 // - whether a channel should be disregarded because
518 // it's available liquidity is too small comparing to how much more we need to collect;
519 // - when we want to stop looking for new paths.
520 let mut already_collected_value_msat = 0;
522 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee, our_node_id, final_value_msat);
524 macro_rules! add_entry {
525 // Adds entry which goes from $src_node_id to $dest_node_id
526 // over the channel with id $chan_id with fees described in
527 // $directional_info.
528 // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one,
529 // since that value has to be transferred over this channel.
530 // Returns whether this channel caused an update to `targets`.
531 ( $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,
532 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => { {
533 // We "return" whether we updated the path at the end, via this:
534 let mut did_add_update_path_to_src_node = false;
535 // Channels to self should not be used. This is more of belt-and-suspenders, because in
536 // practice these cases should be caught earlier:
537 // - for regular channels at channel announcement (TODO)
538 // - for first and last hops early in get_route
539 if $src_node_id != $dest_node_id.clone() {
540 let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
541 let mut initial_liquidity_available_msat = None;
542 if let Some(capacity_sats) = $capacity_sats {
543 initial_liquidity_available_msat = Some(capacity_sats * 1000);
546 if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
547 if let Some(available_msat) = initial_liquidity_available_msat {
548 initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
550 initial_liquidity_available_msat = Some(htlc_maximum_msat);
554 match initial_liquidity_available_msat {
555 Some(available_msat) => available_msat,
556 // We assume channels with unknown balance have
557 // a capacity of 0.0025 BTC (or 250_000 sats).
558 None => 250_000 * 1000
562 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
563 // It may be misleading because we might later choose to reduce the value transferred
564 // over these channels, and the channel which was insufficient might become sufficient.
565 // Worst case: we drop a good channel here because it can't cover the high following
566 // fees caused by one expensive channel, but then this channel could have been used
567 // if the amount being transferred over this path is lower.
568 // We do this for now, but this is a subject for removal.
569 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
571 // Routing Fragmentation Mitigation heuristic:
573 // Routing fragmentation across many payment paths increases the overall routing
574 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
575 // Taking too many smaller paths also increases the chance of payment failure.
576 // Thus to avoid this effect, we require from our collected links to provide
577 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
579 // This requirement is currently 5% of the remaining-to-be-collected value.
580 // This means as we successfully advance in our collection,
581 // the absolute liquidity contribution is lowered,
582 // thus increasing the number of potential channels to be selected.
584 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
585 // or 100% if we're not allowed to do multipath payments.
586 let minimal_value_contribution_msat: u64 = if allow_mpp {
587 (recommended_value_msat - already_collected_value_msat + 19) / 20
591 // Verify the liquidity offered by this channel complies to the minimal contribution.
592 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
594 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
595 // Includes paying fees for the use of the following channels.
596 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
597 Some(result) => result,
598 // Can't overflow due to how the values were computed right above.
599 None => unreachable!(),
601 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
602 let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
603 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
605 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
606 // bother considering this channel.
607 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
608 // be only reduced later (not increased), so this channel should just be skipped
609 // as not sufficient.
610 if !over_path_minimum_msat {
611 hit_minimum_limit = true;
612 } else if contributes_sufficient_value {
613 // Note that low contribution here (limited by available_liquidity_msat)
614 // might violate htlc_minimum_msat on the hops which are next along the
615 // payment path (upstream to the payee). To avoid that, we recompute path
616 // path fees knowing the final path contribution after constructing it.
617 let path_htlc_minimum_msat = match compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
618 .map(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) {
619 Some(Some(value_msat)) => cmp::max(value_msat, $directional_info.htlc_minimum_msat),
620 _ => u64::max_value()
622 let hm_entry = dist.entry(&$src_node_id);
623 let old_entry = hm_entry.or_insert_with(|| {
624 // If there was previously no known way to access
625 // the source node (recall it goes payee-to-payer) of $chan_id, first add
626 // a semi-dummy record just to compute the fees to reach the source node.
627 // This will affect our decision on selecting $chan_id
628 // as a way to reach the $dest_node_id.
629 let mut fee_base_msat = u32::max_value();
630 let mut fee_proportional_millionths = u32::max_value();
631 if let Some(Some(fees)) = network.get_nodes().get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
632 fee_base_msat = fees.base_msat;
633 fee_proportional_millionths = fees.proportional_millionths;
636 pubkey: $dest_node_id.clone(),
638 channel_features: $chan_features,
640 cltv_expiry_delta: 0,
641 src_lowest_inbound_fees: RoutingFees {
642 base_msat: fee_base_msat,
643 proportional_millionths: fee_proportional_millionths,
645 channel_fees: $directional_info.fees,
646 next_hops_fee_msat: u64::max_value(),
647 hop_use_fee_msat: u64::max_value(),
648 total_fee_msat: u64::max_value(),
649 htlc_minimum_msat: $directional_info.htlc_minimum_msat,
650 path_htlc_minimum_msat,
651 was_processed: false,
652 #[cfg(any(test, feature = "fuzztarget"))]
653 value_contribution_msat,
657 #[allow(unused_mut)] // We only use the mut in cfg(test)
658 let mut should_process = !old_entry.was_processed;
659 #[cfg(any(test, feature = "fuzztarget"))]
661 // In test/fuzzing builds, we do extra checks to make sure the skipping
662 // of already-seen nodes only happens in cases we expect (see below).
663 if !should_process { should_process = true; }
667 let mut hop_use_fee_msat = 0;
668 let mut total_fee_msat = $next_hops_fee_msat;
670 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
671 // will have the same effective-fee
672 if $src_node_id != *our_node_id {
673 match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
674 // max_value means we'll always fail
675 // the old_entry.total_fee_msat > total_fee_msat check
676 None => total_fee_msat = u64::max_value(),
678 hop_use_fee_msat = fee_msat;
679 total_fee_msat += hop_use_fee_msat;
680 // When calculating the lowest inbound fees to a node, we
681 // calculate fees here not based on the actual value we think
682 // will flow over this channel, but on the minimum value that
683 // we'll accept flowing over it. The minimum accepted value
684 // is a constant through each path collection run, ensuring
685 // consistent basis. Otherwise we may later find a
686 // different path to the source node that is more expensive,
687 // but which we consider to be cheaper because we are capacity
688 // constrained and the relative fee becomes lower.
689 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
690 .map(|a| a.checked_add(total_fee_msat)) {
695 total_fee_msat = u64::max_value();
702 let new_graph_node = RouteGraphNode {
703 pubkey: $src_node_id,
704 lowest_fee_to_peer_through_node: total_fee_msat,
705 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
706 value_contribution_msat: value_contribution_msat,
707 path_htlc_minimum_msat,
710 // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
711 // if this way is cheaper than the already known
712 // (considering the cost to "reach" this channel from the route destination,
713 // the cost of using this channel,
714 // and the cost of routing to the source node of this channel).
715 // Also, consider that htlc_minimum_msat_difference, because we might end up
716 // paying it. Consider the following exploit:
717 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
718 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
719 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
720 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
722 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
723 // but it may require additional tracking - we don't want to double-count
724 // the fees included in $next_hops_path_htlc_minimum_msat, but also
725 // can't use something that may decrease on future hops.
726 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat);
727 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat);
729 if !old_entry.was_processed && new_cost < old_cost {
730 targets.push(new_graph_node);
731 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
732 old_entry.hop_use_fee_msat = hop_use_fee_msat;
733 old_entry.total_fee_msat = total_fee_msat;
734 old_entry.pubkey = $dest_node_id.clone();
735 old_entry.short_channel_id = $chan_id.clone();
736 old_entry.channel_features = $chan_features;
737 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
738 old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
739 old_entry.channel_fees = $directional_info.fees;
740 old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
741 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
742 #[cfg(any(test, feature = "fuzztarget"))]
744 old_entry.value_contribution_msat = value_contribution_msat;
746 did_add_update_path_to_src_node = true;
747 } else if old_entry.was_processed && new_cost < old_cost {
748 #[cfg(any(test, feature = "fuzztarget"))]
750 // If we're skipping processing a node which was previously
751 // processed even though we found another path to it with a
752 // cheaper fee, check that it was because the second path we
753 // found (which we are processing now) has a lower value
754 // contribution due to an HTLC minimum limit.
756 // e.g. take a graph with two paths from node 1 to node 2, one
757 // through channel A, and one through channel B. Channel A and
758 // B are both in the to-process heap, with their scores set by
759 // a higher htlc_minimum than fee.
760 // Channel A is processed first, and the channels onwards from
761 // node 1 are added to the to-process heap. Thereafter, we pop
762 // Channel B off of the heap, note that it has a much more
763 // restrictive htlc_maximum_msat, and recalculate the fees for
764 // all of node 1's channels using the new, reduced, amount.
766 // This would be bogus - we'd be selecting a higher-fee path
767 // with a lower htlc_maximum_msat instead of the one we'd
768 // already decided to use.
769 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
770 debug_assert!(value_contribution_msat < old_entry.value_contribution_msat);
777 did_add_update_path_to_src_node
781 let empty_node_features = NodeFeatures::empty();
782 // Find ways (channels with destination) to reach a given node and store them
783 // in the corresponding data structures (routing graph etc).
784 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
785 // meaning how much will be paid in fees after this node (to the best of our knowledge).
786 // This data can later be helpful to optimize routing (pay lower fees).
787 macro_rules! add_entries_to_cheapest_to_target_node {
788 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
789 let skip_node = if let Some(elem) = dist.get_mut($node_id) {
790 let was_processed = elem.was_processed;
791 elem.was_processed = true;
794 // Entries are added to dist in add_entry!() when there is a channel from a node.
795 // Because there are no channels from payee, it will not have a dist entry at this point.
796 // If we're processing any other node, it is always be the result of a channel from it.
797 assert_eq!($node_id, payee);
802 if first_hops.is_some() {
803 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&$node_id) {
804 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);
808 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
814 if !features.requires_unknown_bits() {
815 for chan_id in $node.channels.iter() {
816 let chan = network.get_channels().get(chan_id).unwrap();
817 if !chan.features.requires_unknown_bits() {
818 if chan.node_one == *$node_id {
819 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
820 if first_hops.is_none() || chan.node_two != *our_node_id {
821 if let Some(two_to_one) = chan.two_to_one.as_ref() {
822 if two_to_one.enabled {
823 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);
828 if first_hops.is_none() || chan.node_one != *our_node_id {
829 if let Some(one_to_two) = chan.one_to_two.as_ref() {
830 if one_to_two.enabled {
831 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);
843 let mut payment_paths = Vec::<PaymentPath>::new();
845 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
846 'paths_collection: loop {
847 // For every new path, start from scratch, except
848 // bookkeeped_channels_liquidity_available_msat, which will improve
849 // the further iterations of path finding. Also don't erase first_hop_targets.
852 hit_minimum_limit = false;
854 // If first hop is a private channel and the only way to reach the payee, this is the only
855 // place where it could be added.
856 if first_hops.is_some() {
857 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&payee) {
858 add_entry!(first_hop, *our_node_id, payee, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
862 // Add the payee as a target, so that the payee-to-payer
863 // search algorithm knows what to start with.
864 match network.get_nodes().get(payee) {
865 // The payee is not in our network graph, so nothing to add here.
866 // There is still a chance of reaching them via last_hops though,
867 // so don't yet fail the payment here.
868 // If not, targets.pop() will not even let us enter the loop in step 2.
871 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0);
876 // If a caller provided us with last hops, add them to routing targets. Since this happens
877 // earlier than general path finding, they will be somewhat prioritized, although currently
878 // it matters only if the fees are exactly the same.
879 for hop in last_hops.iter() {
880 let have_hop_src_in_graph =
881 // Only add the last hop to our candidate set if either we have a direct channel or
882 // they are in the regular network graph.
883 first_hop_targets.get(&hop.src_node_id).is_some() ||
884 network.get_nodes().get(&hop.src_node_id).is_some();
885 if have_hop_src_in_graph {
886 // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
887 // really sucks, cause we're gonna need that eventually.
888 let last_hop_htlc_minimum_msat: u64 = match hop.htlc_minimum_msat {
889 Some(htlc_minimum_msat) => htlc_minimum_msat,
892 let directional_info = DummyDirectionalChannelInfo {
893 cltv_expiry_delta: hop.cltv_expiry_delta as u32,
894 htlc_minimum_msat: last_hop_htlc_minimum_msat,
895 htlc_maximum_msat: hop.htlc_maximum_msat,
898 // We assume that the recipient only included route hints for routes which had
899 // sufficient value to route `final_value_msat`. Note that in the case of "0-value"
900 // invoices where the invoice does not specify value this may not be the case, but
901 // better to include the hints than not.
902 if add_entry!(hop.short_channel_id, hop.src_node_id, payee, directional_info, Some((final_value_msat + 999) / 1000), &empty_channel_features, 0, path_value_msat, 0) {
903 // If this hop connects to a node with which we have a direct channel,
904 // ignore the network graph and, if the last hop was added, add our
905 // direct channel to the candidate set.
907 // Note that we *must* check if the last hop was added as `add_entry`
908 // always assumes that the third argument is a node to which we have a
910 if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&hop.src_node_id) {
911 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);
917 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
919 // At this point, targets are filled with the data from first and
920 // last hops communicated by the caller, and the payment receiver.
921 let mut found_new_path = false;
924 // If this loop terminates due the exhaustion of targets, two situations are possible:
925 // - not enough outgoing liquidity:
926 // 0 < already_collected_value_msat < final_value_msat
927 // - enough outgoing liquidity:
928 // final_value_msat <= already_collected_value_msat < recommended_value_msat
929 // Both these cases (and other cases except reaching recommended_value_msat) mean that
930 // paths_collection will be stopped because found_new_path==false.
931 // This is not necessarily a routing failure.
932 'path_construction: while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, .. }) = targets.pop() {
934 // Since we're going payee-to-payer, hitting our node as a target means we should stop
935 // traversing the graph and arrange the path out of what we found.
936 if pubkey == *our_node_id {
937 let mut new_entry = dist.remove(&our_node_id).unwrap();
938 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
941 if let Some(&(_, _, _, ref features)) = first_hop_targets.get(&ordered_hops.last().unwrap().0.pubkey) {
942 ordered_hops.last_mut().unwrap().1 = features.clone();
943 } else if let Some(node) = network.get_nodes().get(&ordered_hops.last().unwrap().0.pubkey) {
944 if let Some(node_info) = node.announcement_info.as_ref() {
945 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
947 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
950 // We should be able to fill in features for everything except the last
951 // hop, if the last hop was provided via a BOLT 11 invoice (though we
952 // should be able to extend it further as BOLT 11 does have feature
953 // flags for the last hop node itself).
954 assert!(ordered_hops.last().unwrap().0.pubkey == *payee);
957 // Means we succesfully traversed from the payer to the payee, now
958 // save this path for the payment route. Also, update the liquidity
959 // remaining on the used hops, so that we take them into account
960 // while looking for more paths.
961 if ordered_hops.last().unwrap().0.pubkey == *payee {
965 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.pubkey) {
966 Some(payment_hop) => payment_hop,
967 // We can't arrive at None because, if we ever add an entry to targets,
968 // we also fill in the entry in dist (see add_entry!).
969 None => unreachable!(),
971 // We "propagate" the fees one hop backward (topologically) here,
972 // so that fees paid for a HTLC forwarding on the current channel are
973 // associated with the previous channel (where they will be subtracted).
974 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
975 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = new_entry.cltv_expiry_delta;
976 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
978 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
979 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
980 ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = final_cltv;
982 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: {:?}",
983 ordered_hops.len(), value_contribution_msat, ordered_hops);
985 let mut payment_path = PaymentPath {hops: ordered_hops};
987 // We could have possibly constructed a slightly inconsistent path: since we reduce
988 // value being transferred along the way, we could have violated htlc_minimum_msat
989 // on some channels we already passed (assuming dest->source direction). Here, we
990 // recompute the fees again, so that if that's the case, we match the currently
991 // underpaid htlc_minimum_msat with fees.
992 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
994 // Since a path allows to transfer as much value as
995 // the smallest channel it has ("bottleneck"), we should recompute
996 // the fees so sender HTLC don't overpay fees when traversing
997 // larger channels than the bottleneck. This may happen because
998 // when we were selecting those channels we were not aware how much value
999 // this path will transfer, and the relative fee for them
1000 // might have been computed considering a larger value.
1001 // Remember that we used these channels so that we don't rely
1002 // on the same liquidity in future paths.
1003 let mut prevented_redundant_path_selection = false;
1004 for (payment_hop, _) in payment_path.hops.iter() {
1005 let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.short_channel_id).unwrap();
1006 let mut spent_on_hop_msat = value_contribution_msat;
1007 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
1008 spent_on_hop_msat += next_hops_fee_msat;
1009 if spent_on_hop_msat == *channel_liquidity_available_msat {
1010 // If this path used all of this channel's available liquidity, we know
1011 // this path will not be selected again in the next loop iteration.
1012 prevented_redundant_path_selection = true;
1014 *channel_liquidity_available_msat -= spent_on_hop_msat;
1016 if !prevented_redundant_path_selection {
1017 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1018 // we'll probably end up picking the same path again on the next iteration.
1019 // Decrease the available liquidity of a hop in the middle of the path.
1020 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.short_channel_id;
1021 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1022 let victim_liquidity = bookkeeped_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1023 *victim_liquidity = 0;
1026 // Track the total amount all our collected paths allow to send so that we:
1027 // - know when to stop looking for more paths
1028 // - know which of the hops are useless considering how much more sats we need
1029 // (contributes_sufficient_value)
1030 already_collected_value_msat += value_contribution_msat;
1032 payment_paths.push(payment_path);
1033 found_new_path = true;
1034 break 'path_construction;
1037 // If we found a path back to the payee, we shouldn't try to process it again. This is
1038 // the equivalent of the `elem.was_processed` check in
1039 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1040 if pubkey == *payee { continue 'path_construction; }
1042 // Otherwise, since the current target node is not us,
1043 // keep "unrolling" the payment graph from payee to payer by
1044 // finding a way to reach the current target from the payer side.
1045 match network.get_nodes().get(&pubkey) {
1048 add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat);
1054 // If we don't support MPP, no use trying to gather more value ever.
1055 break 'paths_collection;
1059 // Stop either when the recommended value is reached or if no new path was found in this
1061 // In the latter case, making another path finding attempt won't help,
1062 // because we deterministically terminated the search due to low liquidity.
1063 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1064 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1065 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1066 break 'paths_collection;
1067 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1068 // Further, if this was our first walk of the graph, and we weren't limited by an
1069 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1070 // limited by an htlc_minimum_msat value, find another path with a higher value,
1071 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1072 // still keeping a lower total fee than this path.
1073 if !hit_minimum_limit {
1074 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1075 break 'paths_collection;
1077 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1078 path_value_msat = recommended_value_msat;
1083 if payment_paths.len() == 0 {
1084 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1087 if already_collected_value_msat < final_value_msat {
1088 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1091 // Sort by total fees and take the best paths.
1092 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1093 if payment_paths.len() > 50 {
1094 payment_paths.truncate(50);
1097 // Draw multiple sufficient routes by randomly combining the selected paths.
1098 let mut drawn_routes = Vec::new();
1099 for i in 0..payment_paths.len() {
1100 let mut cur_route = Vec::<PaymentPath>::new();
1101 let mut aggregate_route_value_msat = 0;
1104 // TODO: real random shuffle
1105 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1106 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1109 for payment_path in cur_payment_paths {
1110 cur_route.push(payment_path.clone());
1111 aggregate_route_value_msat += payment_path.get_value_msat();
1112 if aggregate_route_value_msat > final_value_msat {
1113 // Last path likely overpaid. Substract it from the most expensive
1114 // (in terms of proportional fee) path in this route and recompute fees.
1115 // This might be not the most economically efficient way, but fewer paths
1116 // also makes routing more reliable.
1117 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1119 // First, drop some expensive low-value paths entirely if possible.
1120 // Sort by value so that we drop many really-low values first, since
1121 // fewer paths is better: the payment is less likely to fail.
1122 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1123 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1124 cur_route.sort_by_key(|path| path.get_value_msat());
1125 // We should make sure that at least 1 path left.
1126 let mut paths_left = cur_route.len();
1127 cur_route.retain(|path| {
1128 if paths_left == 1 {
1131 let mut keep = true;
1132 let path_value_msat = path.get_value_msat();
1133 if path_value_msat <= overpaid_value_msat {
1135 overpaid_value_msat -= path_value_msat;
1141 if overpaid_value_msat == 0 {
1145 assert!(cur_route.len() > 0);
1148 // Now, substract the overpaid value from the most-expensive path.
1149 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1150 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1151 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.channel_fees.proportional_millionths as u64).sum::<u64>() });
1152 let expensive_payment_path = cur_route.first_mut().unwrap();
1153 // We already dropped all the small channels above, meaning all the
1154 // remaining channels are larger than remaining overpaid_value_msat.
1155 // Thus, this can't be negative.
1156 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1157 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1161 drawn_routes.push(cur_route);
1165 // Select the best route by lowest total fee.
1166 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1167 let mut selected_paths = Vec::<Vec<RouteHop>>::new();
1168 for payment_path in drawn_routes.first().unwrap() {
1169 selected_paths.push(payment_path.hops.iter().map(|(payment_hop, node_features)| {
1171 pubkey: payment_hop.pubkey,
1172 node_features: node_features.clone(),
1173 short_channel_id: payment_hop.short_channel_id,
1174 channel_features: payment_hop.channel_features.clone(),
1175 fee_msat: payment_hop.fee_msat,
1176 cltv_expiry_delta: payment_hop.cltv_expiry_delta,
1181 if let Some(features) = &payee_features {
1182 for path in selected_paths.iter_mut() {
1183 path.last_mut().unwrap().node_features = features.to_context();
1187 let route = Route { paths: selected_paths };
1188 log_info!(logger, "Got route to {}: {}", payee, log_route!(route));
1194 use routing::router::{get_route, Route, RouteHint, RouteHintHop, RoutingFees};
1195 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
1196 use chain::transaction::OutPoint;
1197 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1198 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1199 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1200 use ln::channelmanager;
1201 use util::test_utils;
1202 use util::ser::Writeable;
1204 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1205 use bitcoin::hashes::Hash;
1206 use bitcoin::network::constants::Network;
1207 use bitcoin::blockdata::constants::genesis_block;
1208 use bitcoin::blockdata::script::Builder;
1209 use bitcoin::blockdata::opcodes;
1210 use bitcoin::blockdata::transaction::TxOut;
1214 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1215 use bitcoin::secp256k1::{Secp256k1, All};
1218 use sync::{self, Arc};
1220 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1221 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1222 channelmanager::ChannelDetails {
1223 channel_id: [0; 32],
1224 counterparty: channelmanager::ChannelCounterparty {
1227 unspendable_punishment_reserve: 0,
1228 forwarding_info: None,
1230 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1232 channel_value_satoshis: 0,
1234 outbound_capacity_msat,
1235 inbound_capacity_msat: 42,
1236 unspendable_punishment_reserve: None,
1237 confirmations_required: None,
1238 force_close_spend_delay: None,
1239 is_outbound: true, is_funding_locked: true,
1240 is_usable: true, is_public: true,
1244 // Using the same keys for LN and BTC ids
1245 fn add_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey,
1246 node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64) {
1247 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1248 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1250 let unsigned_announcement = UnsignedChannelAnnouncement {
1252 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1256 bitcoin_key_1: node_id_1,
1257 bitcoin_key_2: node_id_2,
1258 excess_data: Vec::new(),
1261 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1262 let valid_announcement = ChannelAnnouncement {
1263 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1264 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1265 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1266 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1267 contents: unsigned_announcement.clone(),
1269 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1270 Ok(res) => assert!(res),
1275 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) {
1276 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1277 let valid_channel_update = ChannelUpdate {
1278 signature: secp_ctx.sign(&msghash, node_privkey),
1279 contents: update.clone()
1282 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1283 Ok(res) => assert!(res),
1288 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,
1289 features: NodeFeatures, timestamp: u32) {
1290 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1291 let unsigned_announcement = UnsignedNodeAnnouncement {
1297 addresses: Vec::new(),
1298 excess_address_data: Vec::new(),
1299 excess_data: Vec::new(),
1301 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1302 let valid_announcement = NodeAnnouncement {
1303 signature: secp_ctx.sign(&msghash, node_privkey),
1304 contents: unsigned_announcement.clone()
1307 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1313 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1314 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1315 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1318 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1320 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1321 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1323 (our_privkey, our_id, privkeys, pubkeys)
1326 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1327 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1328 // test for it later.
1329 let idx = (id - 1) * 2 + 1;
1331 vec![1 << (idx - 8*3), 0, 0, 0]
1332 } else if idx > 8*2 {
1333 vec![1 << (idx - 8*2), 0, 0]
1334 } else if idx > 8*1 {
1335 vec![1 << (idx - 8*1), 0]
1341 fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>) {
1342 let secp_ctx = Secp256k1::new();
1343 let logger = Arc::new(test_utils::TestLogger::new());
1344 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1345 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
1346 // Build network from our_id to node7:
1348 // -1(1)2- node0 -1(3)2-
1350 // our_id -1(12)2- node7 -1(13)2--- node2
1352 // -1(2)2- node1 -1(4)2-
1355 // chan1 1-to-2: disabled
1356 // chan1 2-to-1: enabled, 0 fee
1358 // chan2 1-to-2: enabled, ignored fee
1359 // chan2 2-to-1: enabled, 0 fee
1361 // chan3 1-to-2: enabled, 0 fee
1362 // chan3 2-to-1: enabled, 100 msat fee
1364 // chan4 1-to-2: enabled, 100% fee
1365 // chan4 2-to-1: enabled, 0 fee
1367 // chan12 1-to-2: enabled, ignored fee
1368 // chan12 2-to-1: enabled, 0 fee
1370 // chan13 1-to-2: enabled, 200% fee
1371 // chan13 2-to-1: enabled, 0 fee
1374 // -1(5)2- node3 -1(8)2--
1378 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1380 // -1(7)2- node5 -1(10)2-
1382 // chan5 1-to-2: enabled, 100 msat fee
1383 // chan5 2-to-1: enabled, 0 fee
1385 // chan6 1-to-2: enabled, 0 fee
1386 // chan6 2-to-1: enabled, 0 fee
1388 // chan7 1-to-2: enabled, 100% fee
1389 // chan7 2-to-1: enabled, 0 fee
1391 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1392 // chan8 2-to-1: enabled, 0 fee
1394 // chan9 1-to-2: enabled, 1001 msat fee
1395 // chan9 2-to-1: enabled, 0 fee
1397 // chan10 1-to-2: enabled, 0 fee
1398 // chan10 2-to-1: enabled, 0 fee
1400 // chan11 1-to-2: enabled, 0 fee
1401 // chan11 2-to-1: enabled, 0 fee
1403 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1405 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1406 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1407 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1408 short_channel_id: 1,
1411 cltv_expiry_delta: 0,
1412 htlc_minimum_msat: 0,
1413 htlc_maximum_msat: OptionalField::Absent,
1415 fee_proportional_millionths: 0,
1416 excess_data: Vec::new()
1419 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1421 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1422 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1423 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1424 short_channel_id: 2,
1427 cltv_expiry_delta: u16::max_value(),
1428 htlc_minimum_msat: 0,
1429 htlc_maximum_msat: OptionalField::Absent,
1430 fee_base_msat: u32::max_value(),
1431 fee_proportional_millionths: u32::max_value(),
1432 excess_data: Vec::new()
1434 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1435 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1436 short_channel_id: 2,
1439 cltv_expiry_delta: 0,
1440 htlc_minimum_msat: 0,
1441 htlc_maximum_msat: OptionalField::Absent,
1443 fee_proportional_millionths: 0,
1444 excess_data: Vec::new()
1447 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1449 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1450 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1451 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1452 short_channel_id: 12,
1455 cltv_expiry_delta: u16::max_value(),
1456 htlc_minimum_msat: 0,
1457 htlc_maximum_msat: OptionalField::Absent,
1458 fee_base_msat: u32::max_value(),
1459 fee_proportional_millionths: u32::max_value(),
1460 excess_data: Vec::new()
1462 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1464 short_channel_id: 12,
1467 cltv_expiry_delta: 0,
1468 htlc_minimum_msat: 0,
1469 htlc_maximum_msat: OptionalField::Absent,
1471 fee_proportional_millionths: 0,
1472 excess_data: Vec::new()
1475 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1477 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1478 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1479 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1480 short_channel_id: 3,
1483 cltv_expiry_delta: (3 << 8) | 1,
1484 htlc_minimum_msat: 0,
1485 htlc_maximum_msat: OptionalField::Absent,
1487 fee_proportional_millionths: 0,
1488 excess_data: Vec::new()
1490 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1491 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1492 short_channel_id: 3,
1495 cltv_expiry_delta: (3 << 8) | 2,
1496 htlc_minimum_msat: 0,
1497 htlc_maximum_msat: OptionalField::Absent,
1499 fee_proportional_millionths: 0,
1500 excess_data: Vec::new()
1503 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1504 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1505 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1506 short_channel_id: 4,
1509 cltv_expiry_delta: (4 << 8) | 1,
1510 htlc_minimum_msat: 0,
1511 htlc_maximum_msat: OptionalField::Absent,
1513 fee_proportional_millionths: 1000000,
1514 excess_data: Vec::new()
1516 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1517 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1518 short_channel_id: 4,
1521 cltv_expiry_delta: (4 << 8) | 2,
1522 htlc_minimum_msat: 0,
1523 htlc_maximum_msat: OptionalField::Absent,
1525 fee_proportional_millionths: 0,
1526 excess_data: Vec::new()
1529 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1530 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1531 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1532 short_channel_id: 13,
1535 cltv_expiry_delta: (13 << 8) | 1,
1536 htlc_minimum_msat: 0,
1537 htlc_maximum_msat: OptionalField::Absent,
1539 fee_proportional_millionths: 2000000,
1540 excess_data: Vec::new()
1542 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1543 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1544 short_channel_id: 13,
1547 cltv_expiry_delta: (13 << 8) | 2,
1548 htlc_minimum_msat: 0,
1549 htlc_maximum_msat: OptionalField::Absent,
1551 fee_proportional_millionths: 0,
1552 excess_data: Vec::new()
1555 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1557 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1558 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1559 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1560 short_channel_id: 6,
1563 cltv_expiry_delta: (6 << 8) | 1,
1564 htlc_minimum_msat: 0,
1565 htlc_maximum_msat: OptionalField::Absent,
1567 fee_proportional_millionths: 0,
1568 excess_data: Vec::new()
1570 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1571 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1572 short_channel_id: 6,
1575 cltv_expiry_delta: (6 << 8) | 2,
1576 htlc_minimum_msat: 0,
1577 htlc_maximum_msat: OptionalField::Absent,
1579 fee_proportional_millionths: 0,
1580 excess_data: Vec::new(),
1583 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1584 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1585 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1586 short_channel_id: 11,
1589 cltv_expiry_delta: (11 << 8) | 1,
1590 htlc_minimum_msat: 0,
1591 htlc_maximum_msat: OptionalField::Absent,
1593 fee_proportional_millionths: 0,
1594 excess_data: Vec::new()
1596 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
1597 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1598 short_channel_id: 11,
1601 cltv_expiry_delta: (11 << 8) | 2,
1602 htlc_minimum_msat: 0,
1603 htlc_maximum_msat: OptionalField::Absent,
1605 fee_proportional_millionths: 0,
1606 excess_data: Vec::new()
1609 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
1611 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
1613 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
1614 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1615 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1616 short_channel_id: 7,
1619 cltv_expiry_delta: (7 << 8) | 1,
1620 htlc_minimum_msat: 0,
1621 htlc_maximum_msat: OptionalField::Absent,
1623 fee_proportional_millionths: 1000000,
1624 excess_data: Vec::new()
1626 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
1627 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1628 short_channel_id: 7,
1631 cltv_expiry_delta: (7 << 8) | 2,
1632 htlc_minimum_msat: 0,
1633 htlc_maximum_msat: OptionalField::Absent,
1635 fee_proportional_millionths: 0,
1636 excess_data: Vec::new()
1639 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
1641 (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
1645 fn simple_route_test() {
1646 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1647 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1649 // Simple route to 2 via 1
1651 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)) {
1652 assert_eq!(err, "Cannot send a payment of 0 msat");
1653 } else { panic!(); }
1655 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();
1656 assert_eq!(route.paths[0].len(), 2);
1658 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1659 assert_eq!(route.paths[0][0].short_channel_id, 2);
1660 assert_eq!(route.paths[0][0].fee_msat, 100);
1661 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1662 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1663 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1665 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1666 assert_eq!(route.paths[0][1].short_channel_id, 4);
1667 assert_eq!(route.paths[0][1].fee_msat, 100);
1668 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1669 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1670 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1674 fn invalid_first_hop_test() {
1675 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1676 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1678 // Simple route to 2 via 1
1680 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
1682 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)) {
1683 assert_eq!(err, "First hop cannot have our_node_id as a destination.");
1684 } else { panic!(); }
1686 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();
1687 assert_eq!(route.paths[0].len(), 2);
1691 fn htlc_minimum_test() {
1692 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1693 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1695 // Simple route to 2 via 1
1697 // Disable other paths
1698 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1699 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1700 short_channel_id: 12,
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[0], UnsignedChannelUpdate {
1711 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1712 short_channel_id: 3,
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[7], UnsignedChannelUpdate {
1723 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1724 short_channel_id: 13,
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()
1734 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1735 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1736 short_channel_id: 6,
1738 flags: 2, // to disable
1739 cltv_expiry_delta: 0,
1740 htlc_minimum_msat: 0,
1741 htlc_maximum_msat: OptionalField::Absent,
1743 fee_proportional_millionths: 0,
1744 excess_data: Vec::new()
1746 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1747 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1748 short_channel_id: 7,
1750 flags: 2, // to disable
1751 cltv_expiry_delta: 0,
1752 htlc_minimum_msat: 0,
1753 htlc_maximum_msat: OptionalField::Absent,
1755 fee_proportional_millionths: 0,
1756 excess_data: Vec::new()
1759 // Check against amount_to_transfer_over_msat.
1760 // Set minimal HTLC of 200_000_000 msat.
1761 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1762 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1763 short_channel_id: 2,
1766 cltv_expiry_delta: 0,
1767 htlc_minimum_msat: 200_000_000,
1768 htlc_maximum_msat: OptionalField::Absent,
1770 fee_proportional_millionths: 0,
1771 excess_data: Vec::new()
1774 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
1776 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1777 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1778 short_channel_id: 4,
1781 cltv_expiry_delta: 0,
1782 htlc_minimum_msat: 0,
1783 htlc_maximum_msat: OptionalField::Present(199_999_999),
1785 fee_proportional_millionths: 0,
1786 excess_data: Vec::new()
1789 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
1790 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)) {
1791 assert_eq!(err, "Failed to find a path to the given destination");
1792 } else { panic!(); }
1794 // Lift the restriction on the first hop.
1795 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1796 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1797 short_channel_id: 2,
1800 cltv_expiry_delta: 0,
1801 htlc_minimum_msat: 0,
1802 htlc_maximum_msat: OptionalField::Absent,
1804 fee_proportional_millionths: 0,
1805 excess_data: Vec::new()
1808 // A payment above the minimum should pass
1809 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();
1810 assert_eq!(route.paths[0].len(), 2);
1814 fn htlc_minimum_overpay_test() {
1815 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1816 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1818 // A route to node#2 via two paths.
1819 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
1820 // Thus, they can't send 60 without overpaying.
1821 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1822 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1823 short_channel_id: 2,
1826 cltv_expiry_delta: 0,
1827 htlc_minimum_msat: 35_000,
1828 htlc_maximum_msat: OptionalField::Present(40_000),
1830 fee_proportional_millionths: 0,
1831 excess_data: Vec::new()
1833 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1834 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1835 short_channel_id: 12,
1838 cltv_expiry_delta: 0,
1839 htlc_minimum_msat: 35_000,
1840 htlc_maximum_msat: OptionalField::Present(40_000),
1842 fee_proportional_millionths: 0,
1843 excess_data: Vec::new()
1847 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1848 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1849 short_channel_id: 13,
1852 cltv_expiry_delta: 0,
1853 htlc_minimum_msat: 0,
1854 htlc_maximum_msat: OptionalField::Absent,
1856 fee_proportional_millionths: 0,
1857 excess_data: Vec::new()
1859 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1860 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1861 short_channel_id: 4,
1864 cltv_expiry_delta: 0,
1865 htlc_minimum_msat: 0,
1866 htlc_maximum_msat: OptionalField::Absent,
1868 fee_proportional_millionths: 0,
1869 excess_data: Vec::new()
1872 // Disable other paths
1873 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1874 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1875 short_channel_id: 1,
1877 flags: 2, // to disable
1878 cltv_expiry_delta: 0,
1879 htlc_minimum_msat: 0,
1880 htlc_maximum_msat: OptionalField::Absent,
1882 fee_proportional_millionths: 0,
1883 excess_data: Vec::new()
1886 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1887 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1888 // Overpay fees to hit htlc_minimum_msat.
1889 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
1890 // TODO: this could be better balanced to overpay 10k and not 15k.
1891 assert_eq!(overpaid_fees, 15_000);
1893 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
1894 // while taking even more fee to match htlc_minimum_msat.
1895 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1896 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1897 short_channel_id: 12,
1900 cltv_expiry_delta: 0,
1901 htlc_minimum_msat: 65_000,
1902 htlc_maximum_msat: OptionalField::Present(80_000),
1904 fee_proportional_millionths: 0,
1905 excess_data: Vec::new()
1907 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1908 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1909 short_channel_id: 2,
1912 cltv_expiry_delta: 0,
1913 htlc_minimum_msat: 0,
1914 htlc_maximum_msat: OptionalField::Absent,
1916 fee_proportional_millionths: 0,
1917 excess_data: Vec::new()
1919 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1920 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1921 short_channel_id: 4,
1924 cltv_expiry_delta: 0,
1925 htlc_minimum_msat: 0,
1926 htlc_maximum_msat: OptionalField::Absent,
1928 fee_proportional_millionths: 100_000,
1929 excess_data: Vec::new()
1932 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1933 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
1934 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
1935 assert_eq!(route.paths.len(), 1);
1936 assert_eq!(route.paths[0][0].short_channel_id, 12);
1937 let fees = route.paths[0][0].fee_msat;
1938 assert_eq!(fees, 5_000);
1940 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
1941 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
1942 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
1943 // the other channel.
1944 assert_eq!(route.paths.len(), 1);
1945 assert_eq!(route.paths[0][0].short_channel_id, 2);
1946 let fees = route.paths[0][0].fee_msat;
1947 assert_eq!(fees, 5_000);
1951 fn disable_channels_test() {
1952 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
1953 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
1955 // // Disable channels 4 and 12 by flags=2
1956 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1957 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1958 short_channel_id: 4,
1960 flags: 2, // to disable
1961 cltv_expiry_delta: 0,
1962 htlc_minimum_msat: 0,
1963 htlc_maximum_msat: OptionalField::Absent,
1965 fee_proportional_millionths: 0,
1966 excess_data: Vec::new()
1968 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1969 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1970 short_channel_id: 12,
1972 flags: 2, // to disable
1973 cltv_expiry_delta: 0,
1974 htlc_minimum_msat: 0,
1975 htlc_maximum_msat: OptionalField::Absent,
1977 fee_proportional_millionths: 0,
1978 excess_data: Vec::new()
1981 // If all the channels require some features we don't understand, route should fail
1982 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)) {
1983 assert_eq!(err, "Failed to find a path to the given destination");
1984 } else { panic!(); }
1986 // If we specify a channel to node7, that overrides our local channel view and that gets used
1987 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
1988 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();
1989 assert_eq!(route.paths[0].len(), 2);
1991 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
1992 assert_eq!(route.paths[0][0].short_channel_id, 42);
1993 assert_eq!(route.paths[0][0].fee_msat, 200);
1994 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
1995 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
1996 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1998 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1999 assert_eq!(route.paths[0][1].short_channel_id, 13);
2000 assert_eq!(route.paths[0][1].fee_msat, 100);
2001 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2002 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2003 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2007 fn disable_node_test() {
2008 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2009 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2011 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2012 let unknown_features = NodeFeatures::known().set_unknown_feature_required();
2013 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2014 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2015 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2017 // If all nodes require some features we don't understand, route should fail
2018 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)) {
2019 assert_eq!(err, "Failed to find a path to the given destination");
2020 } else { panic!(); }
2022 // If we specify a channel to node7, that overrides our local channel view and that gets used
2023 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2024 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();
2025 assert_eq!(route.paths[0].len(), 2);
2027 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2028 assert_eq!(route.paths[0][0].short_channel_id, 42);
2029 assert_eq!(route.paths[0][0].fee_msat, 200);
2030 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2031 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2032 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2034 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2035 assert_eq!(route.paths[0][1].short_channel_id, 13);
2036 assert_eq!(route.paths[0][1].fee_msat, 100);
2037 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2038 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2039 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2041 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2042 // naively) assume that the user checked the feature bits on the invoice, which override
2043 // the node_announcement.
2047 fn our_chans_test() {
2048 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2049 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2051 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2052 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();
2053 assert_eq!(route.paths[0].len(), 3);
2055 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2056 assert_eq!(route.paths[0][0].short_channel_id, 2);
2057 assert_eq!(route.paths[0][0].fee_msat, 200);
2058 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2059 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2060 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2062 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2063 assert_eq!(route.paths[0][1].short_channel_id, 4);
2064 assert_eq!(route.paths[0][1].fee_msat, 100);
2065 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
2066 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2067 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2069 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2070 assert_eq!(route.paths[0][2].short_channel_id, 3);
2071 assert_eq!(route.paths[0][2].fee_msat, 100);
2072 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2073 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2074 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2076 // If we specify a channel to node7, that overrides our local channel view and that gets used
2077 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2078 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
2079 assert_eq!(route.paths[0].len(), 2);
2081 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2082 assert_eq!(route.paths[0][0].short_channel_id, 42);
2083 assert_eq!(route.paths[0][0].fee_msat, 200);
2084 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
2085 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2086 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2088 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2089 assert_eq!(route.paths[0][1].short_channel_id, 13);
2090 assert_eq!(route.paths[0][1].fee_msat, 100);
2091 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2092 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2093 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2096 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2097 let zero_fees = RoutingFees {
2099 proportional_millionths: 0,
2101 vec![RouteHint(vec![RouteHintHop {
2102 src_node_id: nodes[3].clone(),
2103 short_channel_id: 8,
2105 cltv_expiry_delta: (8 << 8) | 1,
2106 htlc_minimum_msat: None,
2107 htlc_maximum_msat: None,
2108 }]), RouteHint(vec![RouteHintHop {
2109 src_node_id: nodes[4].clone(),
2110 short_channel_id: 9,
2113 proportional_millionths: 0,
2115 cltv_expiry_delta: (9 << 8) | 1,
2116 htlc_minimum_msat: None,
2117 htlc_maximum_msat: None,
2118 }]), RouteHint(vec![RouteHintHop {
2119 src_node_id: nodes[5].clone(),
2120 short_channel_id: 10,
2122 cltv_expiry_delta: (10 << 8) | 1,
2123 htlc_minimum_msat: None,
2124 htlc_maximum_msat: None,
2129 fn last_hops_test() {
2130 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2131 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2133 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2135 // First check that last hop can't have its source as the payee.
2136 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2137 src_node_id: nodes[6],
2138 short_channel_id: 8,
2141 proportional_millionths: 0,
2143 cltv_expiry_delta: (8 << 8) | 1,
2144 htlc_minimum_msat: None,
2145 htlc_maximum_msat: None,
2148 let mut invalid_last_hops = last_hops(&nodes);
2149 invalid_last_hops.push(invalid_last_hop);
2151 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &invalid_last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)) {
2152 assert_eq!(err, "Last hop cannot have a payee as a source.");
2153 } else { panic!(); }
2156 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
2157 assert_eq!(route.paths[0].len(), 5);
2159 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2160 assert_eq!(route.paths[0][0].short_channel_id, 2);
2161 assert_eq!(route.paths[0][0].fee_msat, 100);
2162 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2163 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2164 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2166 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2167 assert_eq!(route.paths[0][1].short_channel_id, 4);
2168 assert_eq!(route.paths[0][1].fee_msat, 0);
2169 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2170 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2171 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2173 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2174 assert_eq!(route.paths[0][2].short_channel_id, 6);
2175 assert_eq!(route.paths[0][2].fee_msat, 0);
2176 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2177 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2178 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2180 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2181 assert_eq!(route.paths[0][3].short_channel_id, 11);
2182 assert_eq!(route.paths[0][3].fee_msat, 0);
2183 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2184 // If we have a peer in the node map, we'll use their features here since we don't have
2185 // a way of figuring out their features from the invoice:
2186 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2187 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2189 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2190 assert_eq!(route.paths[0][4].short_channel_id, 8);
2191 assert_eq!(route.paths[0][4].fee_msat, 100);
2192 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2193 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2194 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2198 fn our_chans_last_hop_connect_test() {
2199 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2200 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2202 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2203 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2204 let mut last_hops = last_hops(&nodes);
2205 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();
2206 assert_eq!(route.paths[0].len(), 2);
2208 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2209 assert_eq!(route.paths[0][0].short_channel_id, 42);
2210 assert_eq!(route.paths[0][0].fee_msat, 0);
2211 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2212 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2213 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2215 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2216 assert_eq!(route.paths[0][1].short_channel_id, 8);
2217 assert_eq!(route.paths[0][1].fee_msat, 100);
2218 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2219 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2220 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2222 last_hops[0].0[0].fees.base_msat = 1000;
2224 // Revert to via 6 as the fee on 8 goes up
2225 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();
2226 assert_eq!(route.paths[0].len(), 4);
2228 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2229 assert_eq!(route.paths[0][0].short_channel_id, 2);
2230 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2231 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2232 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2233 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2235 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2236 assert_eq!(route.paths[0][1].short_channel_id, 4);
2237 assert_eq!(route.paths[0][1].fee_msat, 100);
2238 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
2239 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2240 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2242 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2243 assert_eq!(route.paths[0][2].short_channel_id, 7);
2244 assert_eq!(route.paths[0][2].fee_msat, 0);
2245 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
2246 // If we have a peer in the node map, we'll use their features here since we don't have
2247 // a way of figuring out their features from the invoice:
2248 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2249 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2251 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2252 assert_eq!(route.paths[0][3].short_channel_id, 10);
2253 assert_eq!(route.paths[0][3].fee_msat, 100);
2254 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2255 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2256 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2258 // ...but still use 8 for larger payments as 6 has a variable feerate
2259 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();
2260 assert_eq!(route.paths[0].len(), 5);
2262 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2263 assert_eq!(route.paths[0][0].short_channel_id, 2);
2264 assert_eq!(route.paths[0][0].fee_msat, 3000);
2265 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
2266 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2267 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2269 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2270 assert_eq!(route.paths[0][1].short_channel_id, 4);
2271 assert_eq!(route.paths[0][1].fee_msat, 0);
2272 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
2273 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2274 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2276 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2277 assert_eq!(route.paths[0][2].short_channel_id, 6);
2278 assert_eq!(route.paths[0][2].fee_msat, 0);
2279 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
2280 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2281 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2283 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2284 assert_eq!(route.paths[0][3].short_channel_id, 11);
2285 assert_eq!(route.paths[0][3].fee_msat, 1000);
2286 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
2287 // If we have a peer in the node map, we'll use their features here since we don't have
2288 // a way of figuring out their features from the invoice:
2289 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2290 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2292 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2293 assert_eq!(route.paths[0][4].short_channel_id, 8);
2294 assert_eq!(route.paths[0][4].fee_msat, 2000);
2295 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2296 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2297 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2300 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> {
2301 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
2302 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2303 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2305 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
2306 let last_hops = RouteHint(vec![RouteHintHop {
2307 src_node_id: middle_node_id,
2308 short_channel_id: 8,
2311 proportional_millionths: last_hop_fee_prop,
2313 cltv_expiry_delta: (8 << 8) | 1,
2314 htlc_minimum_msat: None,
2315 htlc_maximum_msat: last_hop_htlc_max,
2317 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
2318 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()))
2322 fn unannounced_path_test() {
2323 // We should be able to send a payment to a destination without any help of a routing graph
2324 // if we have a channel with a common counterparty that appears in the first and last hop
2326 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
2328 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
2329 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
2330 assert_eq!(route.paths[0].len(), 2);
2332 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
2333 assert_eq!(route.paths[0][0].short_channel_id, 42);
2334 assert_eq!(route.paths[0][0].fee_msat, 1001);
2335 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
2336 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
2337 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2339 assert_eq!(route.paths[0][1].pubkey, target_node_id);
2340 assert_eq!(route.paths[0][1].short_channel_id, 8);
2341 assert_eq!(route.paths[0][1].fee_msat, 1000000);
2342 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2343 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
2344 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
2348 fn overflow_unannounced_path_test_liquidity_underflow() {
2349 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
2350 // the last-hop had a fee which overflowed a u64, we'd panic.
2351 // This was due to us adding the first-hop from us unconditionally, causing us to think
2352 // we'd built a path (as our node is in the "best candidate" set), when we had not.
2353 // In this test, we previously hit a subtraction underflow due to having less available
2354 // liquidity at the last hop than 0.
2355 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());
2359 fn overflow_unannounced_path_test_feerate_overflow() {
2360 // This tests for the same case as above, except instead of hitting a subtraction
2361 // underflow, we hit a case where the fee charged at a hop overflowed.
2362 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());
2366 fn available_amount_while_routing_test() {
2367 // Tests whether we choose the correct available channel amount while routing.
2369 let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
2370 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2372 // We will use a simple single-path route from
2373 // our node to node2 via node0: channels {1, 3}.
2375 // First disable all other paths.
2376 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2377 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2378 short_channel_id: 2,
2381 cltv_expiry_delta: 0,
2382 htlc_minimum_msat: 0,
2383 htlc_maximum_msat: OptionalField::Present(100_000),
2385 fee_proportional_millionths: 0,
2386 excess_data: Vec::new()
2388 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2390 short_channel_id: 12,
2393 cltv_expiry_delta: 0,
2394 htlc_minimum_msat: 0,
2395 htlc_maximum_msat: OptionalField::Present(100_000),
2397 fee_proportional_millionths: 0,
2398 excess_data: Vec::new()
2401 // Make the first channel (#1) very permissive,
2402 // and we will be testing all limits on the second channel.
2403 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2404 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2405 short_channel_id: 1,
2408 cltv_expiry_delta: 0,
2409 htlc_minimum_msat: 0,
2410 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2412 fee_proportional_millionths: 0,
2413 excess_data: Vec::new()
2416 // First, let's see if routing works if we have absolutely no idea about the available amount.
2417 // In this case, it should be set to 250_000 sats.
2418 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2419 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2420 short_channel_id: 3,
2423 cltv_expiry_delta: 0,
2424 htlc_minimum_msat: 0,
2425 htlc_maximum_msat: OptionalField::Absent,
2427 fee_proportional_millionths: 0,
2428 excess_data: Vec::new()
2432 // Attempt to route more than available results in a failure.
2433 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2434 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
2435 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2436 } else { panic!(); }
2440 // Now, attempt to route an exact amount we have should be fine.
2441 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2442 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
2443 assert_eq!(route.paths.len(), 1);
2444 let path = route.paths.last().unwrap();
2445 assert_eq!(path.len(), 2);
2446 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2447 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
2450 // Check that setting outbound_capacity_msat in first_hops limits the channels.
2451 // Disable channel #1 and use another first hop.
2452 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2453 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2454 short_channel_id: 1,
2457 cltv_expiry_delta: 0,
2458 htlc_minimum_msat: 0,
2459 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2461 fee_proportional_millionths: 0,
2462 excess_data: Vec::new()
2465 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
2466 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
2469 // Attempt to route more than available results in a failure.
2470 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2471 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
2472 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2473 } else { panic!(); }
2477 // Now, attempt to route an exact amount we have should be fine.
2478 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2479 Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
2480 assert_eq!(route.paths.len(), 1);
2481 let path = route.paths.last().unwrap();
2482 assert_eq!(path.len(), 2);
2483 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2484 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
2487 // Enable channel #1 back.
2488 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2489 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2490 short_channel_id: 1,
2493 cltv_expiry_delta: 0,
2494 htlc_minimum_msat: 0,
2495 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
2497 fee_proportional_millionths: 0,
2498 excess_data: Vec::new()
2502 // Now let's see if routing works if we know only htlc_maximum_msat.
2503 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2504 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2505 short_channel_id: 3,
2508 cltv_expiry_delta: 0,
2509 htlc_minimum_msat: 0,
2510 htlc_maximum_msat: OptionalField::Present(15_000),
2512 fee_proportional_millionths: 0,
2513 excess_data: Vec::new()
2517 // Attempt to route more than available results in a failure.
2518 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2519 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2520 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2521 } else { panic!(); }
2525 // Now, attempt to route an exact amount we have should be fine.
2526 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2527 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2528 assert_eq!(route.paths.len(), 1);
2529 let path = route.paths.last().unwrap();
2530 assert_eq!(path.len(), 2);
2531 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2532 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2535 // Now let's see if routing works if we know only capacity from the UTXO.
2537 // We can't change UTXO capacity on the fly, so we'll disable
2538 // the existing channel and add another one with the capacity we need.
2539 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2540 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2541 short_channel_id: 3,
2544 cltv_expiry_delta: 0,
2545 htlc_minimum_msat: 0,
2546 htlc_maximum_msat: OptionalField::Absent,
2548 fee_proportional_millionths: 0,
2549 excess_data: Vec::new()
2552 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
2553 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
2554 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
2555 .push_opcode(opcodes::all::OP_PUSHNUM_2)
2556 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
2558 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
2559 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
2561 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
2562 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2563 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2564 short_channel_id: 333,
2567 cltv_expiry_delta: (3 << 8) | 1,
2568 htlc_minimum_msat: 0,
2569 htlc_maximum_msat: OptionalField::Absent,
2571 fee_proportional_millionths: 0,
2572 excess_data: Vec::new()
2574 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2575 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2576 short_channel_id: 333,
2579 cltv_expiry_delta: (3 << 8) | 2,
2580 htlc_minimum_msat: 0,
2581 htlc_maximum_msat: OptionalField::Absent,
2583 fee_proportional_millionths: 0,
2584 excess_data: Vec::new()
2588 // Attempt to route more than available results in a failure.
2589 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2590 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
2591 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2592 } else { panic!(); }
2596 // Now, attempt to route an exact amount we have should be fine.
2597 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2598 Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
2599 assert_eq!(route.paths.len(), 1);
2600 let path = route.paths.last().unwrap();
2601 assert_eq!(path.len(), 2);
2602 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2603 assert_eq!(path.last().unwrap().fee_msat, 15_000);
2606 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
2607 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2608 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2609 short_channel_id: 333,
2612 cltv_expiry_delta: 0,
2613 htlc_minimum_msat: 0,
2614 htlc_maximum_msat: OptionalField::Present(10_000),
2616 fee_proportional_millionths: 0,
2617 excess_data: Vec::new()
2621 // Attempt to route more than available results in a failure.
2622 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2623 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
2624 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2625 } else { panic!(); }
2629 // Now, attempt to route an exact amount we have should be fine.
2630 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2631 Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
2632 assert_eq!(route.paths.len(), 1);
2633 let path = route.paths.last().unwrap();
2634 assert_eq!(path.len(), 2);
2635 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2636 assert_eq!(path.last().unwrap().fee_msat, 10_000);
2641 fn available_liquidity_last_hop_test() {
2642 // Check that available liquidity properly limits the path even when only
2643 // one of the latter hops is limited.
2644 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2645 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2647 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
2648 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
2649 // Total capacity: 50 sats.
2651 // Disable other potential paths.
2652 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2653 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2654 short_channel_id: 2,
2657 cltv_expiry_delta: 0,
2658 htlc_minimum_msat: 0,
2659 htlc_maximum_msat: OptionalField::Present(100_000),
2661 fee_proportional_millionths: 0,
2662 excess_data: Vec::new()
2664 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2665 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2666 short_channel_id: 7,
2669 cltv_expiry_delta: 0,
2670 htlc_minimum_msat: 0,
2671 htlc_maximum_msat: OptionalField::Present(100_000),
2673 fee_proportional_millionths: 0,
2674 excess_data: Vec::new()
2679 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2680 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2681 short_channel_id: 12,
2684 cltv_expiry_delta: 0,
2685 htlc_minimum_msat: 0,
2686 htlc_maximum_msat: OptionalField::Present(100_000),
2688 fee_proportional_millionths: 0,
2689 excess_data: Vec::new()
2691 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2692 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2693 short_channel_id: 13,
2696 cltv_expiry_delta: 0,
2697 htlc_minimum_msat: 0,
2698 htlc_maximum_msat: OptionalField::Present(100_000),
2700 fee_proportional_millionths: 0,
2701 excess_data: Vec::new()
2704 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2705 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2706 short_channel_id: 6,
2709 cltv_expiry_delta: 0,
2710 htlc_minimum_msat: 0,
2711 htlc_maximum_msat: OptionalField::Present(50_000),
2713 fee_proportional_millionths: 0,
2714 excess_data: Vec::new()
2716 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2717 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2718 short_channel_id: 11,
2721 cltv_expiry_delta: 0,
2722 htlc_minimum_msat: 0,
2723 htlc_maximum_msat: OptionalField::Present(100_000),
2725 fee_proportional_millionths: 0,
2726 excess_data: Vec::new()
2729 // Attempt to route more than available results in a failure.
2730 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2731 Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
2732 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2733 } else { panic!(); }
2737 // Now, attempt to route 49 sats (just a bit below the capacity).
2738 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2739 Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
2740 assert_eq!(route.paths.len(), 1);
2741 let mut total_amount_paid_msat = 0;
2742 for path in &route.paths {
2743 assert_eq!(path.len(), 4);
2744 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2745 total_amount_paid_msat += path.last().unwrap().fee_msat;
2747 assert_eq!(total_amount_paid_msat, 49_000);
2751 // Attempt to route an exact amount is also fine
2752 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
2753 Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2754 assert_eq!(route.paths.len(), 1);
2755 let mut total_amount_paid_msat = 0;
2756 for path in &route.paths {
2757 assert_eq!(path.len(), 4);
2758 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
2759 total_amount_paid_msat += path.last().unwrap().fee_msat;
2761 assert_eq!(total_amount_paid_msat, 50_000);
2766 fn ignore_fee_first_hop_test() {
2767 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2768 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2770 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2771 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2772 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2773 short_channel_id: 1,
2776 cltv_expiry_delta: 0,
2777 htlc_minimum_msat: 0,
2778 htlc_maximum_msat: OptionalField::Present(100_000),
2779 fee_base_msat: 1_000_000,
2780 fee_proportional_millionths: 0,
2781 excess_data: Vec::new()
2783 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2784 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2785 short_channel_id: 3,
2788 cltv_expiry_delta: 0,
2789 htlc_minimum_msat: 0,
2790 htlc_maximum_msat: OptionalField::Present(50_000),
2792 fee_proportional_millionths: 0,
2793 excess_data: Vec::new()
2797 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
2798 assert_eq!(route.paths.len(), 1);
2799 let mut total_amount_paid_msat = 0;
2800 for path in &route.paths {
2801 assert_eq!(path.len(), 2);
2802 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2803 total_amount_paid_msat += path.last().unwrap().fee_msat;
2805 assert_eq!(total_amount_paid_msat, 50_000);
2810 fn simple_mpp_route_test() {
2811 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2812 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2814 // We need a route consisting of 3 paths:
2815 // From our node to node2 via node0, node7, node1 (three paths one hop each).
2816 // To achieve this, the amount being transferred should be around
2817 // the total capacity of these 3 paths.
2819 // First, we set limits on these (previously unlimited) channels.
2820 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
2822 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
2823 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2824 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2825 short_channel_id: 1,
2828 cltv_expiry_delta: 0,
2829 htlc_minimum_msat: 0,
2830 htlc_maximum_msat: OptionalField::Present(100_000),
2832 fee_proportional_millionths: 0,
2833 excess_data: Vec::new()
2835 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2836 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2837 short_channel_id: 3,
2840 cltv_expiry_delta: 0,
2841 htlc_minimum_msat: 0,
2842 htlc_maximum_msat: OptionalField::Present(50_000),
2844 fee_proportional_millionths: 0,
2845 excess_data: Vec::new()
2848 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
2849 // (total limit 60).
2850 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2852 short_channel_id: 12,
2855 cltv_expiry_delta: 0,
2856 htlc_minimum_msat: 0,
2857 htlc_maximum_msat: OptionalField::Present(60_000),
2859 fee_proportional_millionths: 0,
2860 excess_data: Vec::new()
2862 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2863 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2864 short_channel_id: 13,
2867 cltv_expiry_delta: 0,
2868 htlc_minimum_msat: 0,
2869 htlc_maximum_msat: OptionalField::Present(60_000),
2871 fee_proportional_millionths: 0,
2872 excess_data: Vec::new()
2875 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
2876 // (total capacity 180 sats).
2877 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2878 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2879 short_channel_id: 2,
2882 cltv_expiry_delta: 0,
2883 htlc_minimum_msat: 0,
2884 htlc_maximum_msat: OptionalField::Present(200_000),
2886 fee_proportional_millionths: 0,
2887 excess_data: Vec::new()
2889 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2890 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2891 short_channel_id: 4,
2894 cltv_expiry_delta: 0,
2895 htlc_minimum_msat: 0,
2896 htlc_maximum_msat: OptionalField::Present(180_000),
2898 fee_proportional_millionths: 0,
2899 excess_data: Vec::new()
2903 // Attempt to route more than available results in a failure.
2904 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(),
2905 &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
2906 assert_eq!(err, "Failed to find a sufficient route to the given destination");
2907 } else { panic!(); }
2911 // Now, attempt to route 250 sats (just a bit below the capacity).
2912 // Our algorithm should provide us with these 3 paths.
2913 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2914 Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
2915 assert_eq!(route.paths.len(), 3);
2916 let mut total_amount_paid_msat = 0;
2917 for path in &route.paths {
2918 assert_eq!(path.len(), 2);
2919 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2920 total_amount_paid_msat += path.last().unwrap().fee_msat;
2922 assert_eq!(total_amount_paid_msat, 250_000);
2926 // Attempt to route an exact amount is also fine
2927 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
2928 Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
2929 assert_eq!(route.paths.len(), 3);
2930 let mut total_amount_paid_msat = 0;
2931 for path in &route.paths {
2932 assert_eq!(path.len(), 2);
2933 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
2934 total_amount_paid_msat += path.last().unwrap().fee_msat;
2936 assert_eq!(total_amount_paid_msat, 290_000);
2941 fn long_mpp_route_test() {
2942 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
2943 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2945 // We need a route consisting of 3 paths:
2946 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
2947 // Note that these paths overlap (channels 5, 12, 13).
2948 // We will route 300 sats.
2949 // Each path will have 100 sats capacity, those channels which
2950 // are used twice will have 200 sats capacity.
2952 // Disable other potential paths.
2953 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2954 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2955 short_channel_id: 2,
2958 cltv_expiry_delta: 0,
2959 htlc_minimum_msat: 0,
2960 htlc_maximum_msat: OptionalField::Present(100_000),
2962 fee_proportional_millionths: 0,
2963 excess_data: Vec::new()
2965 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2966 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2967 short_channel_id: 7,
2970 cltv_expiry_delta: 0,
2971 htlc_minimum_msat: 0,
2972 htlc_maximum_msat: OptionalField::Present(100_000),
2974 fee_proportional_millionths: 0,
2975 excess_data: Vec::new()
2978 // Path via {node0, node2} is channels {1, 3, 5}.
2979 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2980 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2981 short_channel_id: 1,
2984 cltv_expiry_delta: 0,
2985 htlc_minimum_msat: 0,
2986 htlc_maximum_msat: OptionalField::Present(100_000),
2988 fee_proportional_millionths: 0,
2989 excess_data: Vec::new()
2991 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2992 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2993 short_channel_id: 3,
2996 cltv_expiry_delta: 0,
2997 htlc_minimum_msat: 0,
2998 htlc_maximum_msat: OptionalField::Present(100_000),
3000 fee_proportional_millionths: 0,
3001 excess_data: Vec::new()
3004 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3005 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3006 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3008 short_channel_id: 5,
3011 cltv_expiry_delta: 0,
3012 htlc_minimum_msat: 0,
3013 htlc_maximum_msat: OptionalField::Present(200_000),
3015 fee_proportional_millionths: 0,
3016 excess_data: Vec::new()
3019 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3020 // Add 100 sats to the capacities of {12, 13}, because these channels
3021 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3022 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3023 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3024 short_channel_id: 12,
3027 cltv_expiry_delta: 0,
3028 htlc_minimum_msat: 0,
3029 htlc_maximum_msat: OptionalField::Present(200_000),
3031 fee_proportional_millionths: 0,
3032 excess_data: Vec::new()
3034 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3036 short_channel_id: 13,
3039 cltv_expiry_delta: 0,
3040 htlc_minimum_msat: 0,
3041 htlc_maximum_msat: OptionalField::Present(200_000),
3043 fee_proportional_millionths: 0,
3044 excess_data: Vec::new()
3047 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3048 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3049 short_channel_id: 6,
3052 cltv_expiry_delta: 0,
3053 htlc_minimum_msat: 0,
3054 htlc_maximum_msat: OptionalField::Present(100_000),
3056 fee_proportional_millionths: 0,
3057 excess_data: Vec::new()
3059 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3060 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3061 short_channel_id: 11,
3064 cltv_expiry_delta: 0,
3065 htlc_minimum_msat: 0,
3066 htlc_maximum_msat: OptionalField::Present(100_000),
3068 fee_proportional_millionths: 0,
3069 excess_data: Vec::new()
3072 // Path via {node7, node2} is channels {12, 13, 5}.
3073 // We already limited them to 200 sats (they are used twice for 100 sats).
3074 // Nothing to do here.
3077 // Attempt to route more than available results in a failure.
3078 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3079 Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
3080 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3081 } else { panic!(); }
3085 // Now, attempt to route 300 sats (exact amount we can route).
3086 // Our algorithm should provide us with these 3 paths, 100 sats each.
3087 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3088 Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
3089 assert_eq!(route.paths.len(), 3);
3091 let mut total_amount_paid_msat = 0;
3092 for path in &route.paths {
3093 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3094 total_amount_paid_msat += path.last().unwrap().fee_msat;
3096 assert_eq!(total_amount_paid_msat, 300_000);
3102 fn mpp_cheaper_route_test() {
3103 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3104 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3106 // This test checks that if we have two cheaper paths and one more expensive path,
3107 // so that liquidity-wise any 2 of 3 combination is sufficient,
3108 // two cheaper paths will be taken.
3109 // These paths have equal available liquidity.
3111 // We need a combination of 3 paths:
3112 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3113 // Note that these paths overlap (channels 5, 12, 13).
3114 // Each path will have 100 sats capacity, those channels which
3115 // are used twice will have 200 sats capacity.
3117 // Disable other potential paths.
3118 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3119 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3120 short_channel_id: 2,
3123 cltv_expiry_delta: 0,
3124 htlc_minimum_msat: 0,
3125 htlc_maximum_msat: OptionalField::Present(100_000),
3127 fee_proportional_millionths: 0,
3128 excess_data: Vec::new()
3130 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3131 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3132 short_channel_id: 7,
3135 cltv_expiry_delta: 0,
3136 htlc_minimum_msat: 0,
3137 htlc_maximum_msat: OptionalField::Present(100_000),
3139 fee_proportional_millionths: 0,
3140 excess_data: Vec::new()
3143 // Path via {node0, node2} is channels {1, 3, 5}.
3144 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3145 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3146 short_channel_id: 1,
3149 cltv_expiry_delta: 0,
3150 htlc_minimum_msat: 0,
3151 htlc_maximum_msat: OptionalField::Present(100_000),
3153 fee_proportional_millionths: 0,
3154 excess_data: Vec::new()
3156 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3157 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3158 short_channel_id: 3,
3161 cltv_expiry_delta: 0,
3162 htlc_minimum_msat: 0,
3163 htlc_maximum_msat: OptionalField::Present(100_000),
3165 fee_proportional_millionths: 0,
3166 excess_data: Vec::new()
3169 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3170 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3171 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3172 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3173 short_channel_id: 5,
3176 cltv_expiry_delta: 0,
3177 htlc_minimum_msat: 0,
3178 htlc_maximum_msat: OptionalField::Present(200_000),
3180 fee_proportional_millionths: 0,
3181 excess_data: Vec::new()
3184 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3185 // Add 100 sats to the capacities of {12, 13}, because these channels
3186 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3187 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3188 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3189 short_channel_id: 12,
3192 cltv_expiry_delta: 0,
3193 htlc_minimum_msat: 0,
3194 htlc_maximum_msat: OptionalField::Present(200_000),
3196 fee_proportional_millionths: 0,
3197 excess_data: Vec::new()
3199 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3200 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3201 short_channel_id: 13,
3204 cltv_expiry_delta: 0,
3205 htlc_minimum_msat: 0,
3206 htlc_maximum_msat: OptionalField::Present(200_000),
3208 fee_proportional_millionths: 0,
3209 excess_data: Vec::new()
3212 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3213 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3214 short_channel_id: 6,
3217 cltv_expiry_delta: 0,
3218 htlc_minimum_msat: 0,
3219 htlc_maximum_msat: OptionalField::Present(100_000),
3220 fee_base_msat: 1_000,
3221 fee_proportional_millionths: 0,
3222 excess_data: Vec::new()
3224 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3225 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3226 short_channel_id: 11,
3229 cltv_expiry_delta: 0,
3230 htlc_minimum_msat: 0,
3231 htlc_maximum_msat: OptionalField::Present(100_000),
3233 fee_proportional_millionths: 0,
3234 excess_data: Vec::new()
3237 // Path via {node7, node2} is channels {12, 13, 5}.
3238 // We already limited them to 200 sats (they are used twice for 100 sats).
3239 // Nothing to do here.
3242 // Now, attempt to route 180 sats.
3243 // Our algorithm should provide us with these 2 paths.
3244 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3245 Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
3246 assert_eq!(route.paths.len(), 2);
3248 let mut total_value_transferred_msat = 0;
3249 let mut total_paid_msat = 0;
3250 for path in &route.paths {
3251 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3252 total_value_transferred_msat += path.last().unwrap().fee_msat;
3254 total_paid_msat += hop.fee_msat;
3257 // If we paid fee, this would be higher.
3258 assert_eq!(total_value_transferred_msat, 180_000);
3259 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3260 assert_eq!(total_fees_paid, 0);
3265 fn fees_on_mpp_route_test() {
3266 // This test makes sure that MPP algorithm properly takes into account
3267 // fees charged on the channels, by making the fees impactful:
3268 // if the fee is not properly accounted for, the behavior is different.
3269 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3270 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3272 // We need a route consisting of 2 paths:
3273 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
3274 // We will route 200 sats, Each path will have 100 sats capacity.
3276 // This test is not particularly stable: e.g.,
3277 // there's a way to route via {node0, node2, node4}.
3278 // It works while pathfinding is deterministic, but can be broken otherwise.
3279 // It's fine to ignore this concern for now.
3281 // Disable other potential paths.
3282 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3283 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3284 short_channel_id: 2,
3287 cltv_expiry_delta: 0,
3288 htlc_minimum_msat: 0,
3289 htlc_maximum_msat: OptionalField::Present(100_000),
3291 fee_proportional_millionths: 0,
3292 excess_data: Vec::new()
3295 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3296 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3297 short_channel_id: 7,
3300 cltv_expiry_delta: 0,
3301 htlc_minimum_msat: 0,
3302 htlc_maximum_msat: OptionalField::Present(100_000),
3304 fee_proportional_millionths: 0,
3305 excess_data: Vec::new()
3308 // Path via {node0, node2} is channels {1, 3, 5}.
3309 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3310 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3311 short_channel_id: 1,
3314 cltv_expiry_delta: 0,
3315 htlc_minimum_msat: 0,
3316 htlc_maximum_msat: OptionalField::Present(100_000),
3318 fee_proportional_millionths: 0,
3319 excess_data: Vec::new()
3321 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3323 short_channel_id: 3,
3326 cltv_expiry_delta: 0,
3327 htlc_minimum_msat: 0,
3328 htlc_maximum_msat: OptionalField::Present(100_000),
3330 fee_proportional_millionths: 0,
3331 excess_data: Vec::new()
3334 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3335 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3336 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3337 short_channel_id: 5,
3340 cltv_expiry_delta: 0,
3341 htlc_minimum_msat: 0,
3342 htlc_maximum_msat: OptionalField::Present(100_000),
3344 fee_proportional_millionths: 0,
3345 excess_data: Vec::new()
3348 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3349 // All channels should be 100 sats capacity. But for the fee experiment,
3350 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
3351 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
3352 // 100 sats (and pay 150 sats in fees for the use of channel 6),
3353 // so no matter how large are other channels,
3354 // the whole path will be limited by 100 sats with just these 2 conditions:
3355 // - channel 12 capacity is 250 sats
3356 // - fee for channel 6 is 150 sats
3357 // Let's test this by enforcing these 2 conditions and removing other limits.
3358 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3359 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3360 short_channel_id: 12,
3363 cltv_expiry_delta: 0,
3364 htlc_minimum_msat: 0,
3365 htlc_maximum_msat: OptionalField::Present(250_000),
3367 fee_proportional_millionths: 0,
3368 excess_data: Vec::new()
3370 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3371 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3372 short_channel_id: 13,
3375 cltv_expiry_delta: 0,
3376 htlc_minimum_msat: 0,
3377 htlc_maximum_msat: OptionalField::Absent,
3379 fee_proportional_millionths: 0,
3380 excess_data: Vec::new()
3383 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3384 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3385 short_channel_id: 6,
3388 cltv_expiry_delta: 0,
3389 htlc_minimum_msat: 0,
3390 htlc_maximum_msat: OptionalField::Absent,
3391 fee_base_msat: 150_000,
3392 fee_proportional_millionths: 0,
3393 excess_data: Vec::new()
3395 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3396 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3397 short_channel_id: 11,
3400 cltv_expiry_delta: 0,
3401 htlc_minimum_msat: 0,
3402 htlc_maximum_msat: OptionalField::Absent,
3404 fee_proportional_millionths: 0,
3405 excess_data: Vec::new()
3409 // Attempt to route more than available results in a failure.
3410 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3411 Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
3412 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3413 } else { panic!(); }
3417 // Now, attempt to route 200 sats (exact amount we can route).
3418 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
3419 Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
3420 assert_eq!(route.paths.len(), 2);
3422 let mut total_amount_paid_msat = 0;
3423 for path in &route.paths {
3424 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3425 total_amount_paid_msat += path.last().unwrap().fee_msat;
3427 assert_eq!(total_amount_paid_msat, 200_000);
3433 fn drop_lowest_channel_mpp_route_test() {
3434 // This test checks that low-capacity channel is dropped when after
3435 // path finding we realize that we found more capacity than we need.
3436 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3437 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3439 // We need a route consisting of 3 paths:
3440 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3442 // The first and the second paths should be sufficient, but the third should be
3443 // cheaper, so that we select it but drop later.
3445 // First, we set limits on these (previously unlimited) channels.
3446 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
3448 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
3449 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3451 short_channel_id: 1,
3454 cltv_expiry_delta: 0,
3455 htlc_minimum_msat: 0,
3456 htlc_maximum_msat: OptionalField::Present(100_000),
3458 fee_proportional_millionths: 0,
3459 excess_data: Vec::new()
3461 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3462 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3463 short_channel_id: 3,
3466 cltv_expiry_delta: 0,
3467 htlc_minimum_msat: 0,
3468 htlc_maximum_msat: OptionalField::Present(50_000),
3470 fee_proportional_millionths: 0,
3471 excess_data: Vec::new()
3474 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
3475 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3477 short_channel_id: 12,
3480 cltv_expiry_delta: 0,
3481 htlc_minimum_msat: 0,
3482 htlc_maximum_msat: OptionalField::Present(60_000),
3484 fee_proportional_millionths: 0,
3485 excess_data: Vec::new()
3487 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3488 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3489 short_channel_id: 13,
3492 cltv_expiry_delta: 0,
3493 htlc_minimum_msat: 0,
3494 htlc_maximum_msat: OptionalField::Present(60_000),
3496 fee_proportional_millionths: 0,
3497 excess_data: Vec::new()
3500 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
3501 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3502 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3503 short_channel_id: 2,
3506 cltv_expiry_delta: 0,
3507 htlc_minimum_msat: 0,
3508 htlc_maximum_msat: OptionalField::Present(20_000),
3510 fee_proportional_millionths: 0,
3511 excess_data: Vec::new()
3513 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3514 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3515 short_channel_id: 4,
3518 cltv_expiry_delta: 0,
3519 htlc_minimum_msat: 0,
3520 htlc_maximum_msat: OptionalField::Present(20_000),
3522 fee_proportional_millionths: 0,
3523 excess_data: Vec::new()
3527 // Attempt to route more than available results in a failure.
3528 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3529 Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
3530 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3531 } else { panic!(); }
3535 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
3536 // Our algorithm should provide us with these 3 paths.
3537 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3538 Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
3539 assert_eq!(route.paths.len(), 3);
3540 let mut total_amount_paid_msat = 0;
3541 for path in &route.paths {
3542 assert_eq!(path.len(), 2);
3543 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3544 total_amount_paid_msat += path.last().unwrap().fee_msat;
3546 assert_eq!(total_amount_paid_msat, 125_000);
3550 // Attempt to route without the last small cheap channel
3551 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
3552 Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3553 assert_eq!(route.paths.len(), 2);
3554 let mut total_amount_paid_msat = 0;
3555 for path in &route.paths {
3556 assert_eq!(path.len(), 2);
3557 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3558 total_amount_paid_msat += path.last().unwrap().fee_msat;
3560 assert_eq!(total_amount_paid_msat, 90_000);
3565 fn min_criteria_consistency() {
3566 // Test that we don't use an inconsistent metric between updating and walking nodes during
3567 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
3568 // was updated with a different criterion from the heap sorting, resulting in loops in
3569 // calculated paths. We test for that specific case here.
3571 // We construct a network that looks like this:
3573 // node2 -1(3)2- node3
3577 // node1 -1(5)2- node4 -1(1)2- node6
3583 // We create a loop on the side of our real path - our destination is node 6, with a
3584 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
3585 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
3586 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
3587 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
3588 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
3589 // "previous hop" being set to node 3, creating a loop in the path.
3590 let secp_ctx = Secp256k1::new();
3591 let logger = Arc::new(test_utils::TestLogger::new());
3592 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
3593 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3595 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
3596 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3597 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3598 short_channel_id: 6,
3601 cltv_expiry_delta: (6 << 8) | 0,
3602 htlc_minimum_msat: 0,
3603 htlc_maximum_msat: OptionalField::Absent,
3605 fee_proportional_millionths: 0,
3606 excess_data: Vec::new()
3608 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
3610 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3611 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3612 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3613 short_channel_id: 5,
3616 cltv_expiry_delta: (5 << 8) | 0,
3617 htlc_minimum_msat: 0,
3618 htlc_maximum_msat: OptionalField::Absent,
3620 fee_proportional_millionths: 0,
3621 excess_data: Vec::new()
3623 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
3625 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
3626 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3627 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3628 short_channel_id: 4,
3631 cltv_expiry_delta: (4 << 8) | 0,
3632 htlc_minimum_msat: 0,
3633 htlc_maximum_msat: OptionalField::Absent,
3635 fee_proportional_millionths: 0,
3636 excess_data: Vec::new()
3638 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
3640 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
3641 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
3642 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3643 short_channel_id: 3,
3646 cltv_expiry_delta: (3 << 8) | 0,
3647 htlc_minimum_msat: 0,
3648 htlc_maximum_msat: OptionalField::Absent,
3650 fee_proportional_millionths: 0,
3651 excess_data: Vec::new()
3653 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
3655 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
3656 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3657 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3658 short_channel_id: 2,
3661 cltv_expiry_delta: (2 << 8) | 0,
3662 htlc_minimum_msat: 0,
3663 htlc_maximum_msat: OptionalField::Absent,
3665 fee_proportional_millionths: 0,
3666 excess_data: Vec::new()
3669 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
3670 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3671 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3672 short_channel_id: 1,
3675 cltv_expiry_delta: (1 << 8) | 0,
3676 htlc_minimum_msat: 100,
3677 htlc_maximum_msat: OptionalField::Absent,
3679 fee_proportional_millionths: 0,
3680 excess_data: Vec::new()
3682 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
3685 // Now ensure the route flows simply over nodes 1 and 4 to 6.
3686 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
3687 assert_eq!(route.paths.len(), 1);
3688 assert_eq!(route.paths[0].len(), 3);
3690 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3691 assert_eq!(route.paths[0][0].short_channel_id, 6);
3692 assert_eq!(route.paths[0][0].fee_msat, 100);
3693 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
3694 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
3695 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
3697 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
3698 assert_eq!(route.paths[0][1].short_channel_id, 5);
3699 assert_eq!(route.paths[0][1].fee_msat, 0);
3700 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
3701 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
3702 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
3704 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
3705 assert_eq!(route.paths[0][2].short_channel_id, 1);
3706 assert_eq!(route.paths[0][2].fee_msat, 10_000);
3707 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
3708 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3709 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
3715 fn exact_fee_liquidity_limit() {
3716 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
3717 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
3718 // we calculated fees on a higher value, resulting in us ignoring such paths.
3719 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3720 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
3722 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
3724 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3725 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3726 short_channel_id: 2,
3729 cltv_expiry_delta: 0,
3730 htlc_minimum_msat: 0,
3731 htlc_maximum_msat: OptionalField::Present(85_000),
3733 fee_proportional_millionths: 0,
3734 excess_data: Vec::new()
3737 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3739 short_channel_id: 12,
3742 cltv_expiry_delta: (4 << 8) | 1,
3743 htlc_minimum_msat: 0,
3744 htlc_maximum_msat: OptionalField::Present(270_000),
3746 fee_proportional_millionths: 1000000,
3747 excess_data: Vec::new()
3751 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
3752 // 200% fee charged channel 13 in the 1-to-2 direction.
3753 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3754 assert_eq!(route.paths.len(), 1);
3755 assert_eq!(route.paths[0].len(), 2);
3757 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3758 assert_eq!(route.paths[0][0].short_channel_id, 12);
3759 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3760 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3761 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3762 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3764 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3765 assert_eq!(route.paths[0][1].short_channel_id, 13);
3766 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3767 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3768 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3769 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3774 fn htlc_max_reduction_below_min() {
3775 // Test that if, while walking the graph, we reduce the value being sent to meet an
3776 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
3777 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
3778 // resulting in us thinking there is no possible path, even if other paths exist.
3779 let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
3780 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3782 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
3783 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
3784 // then try to send 90_000.
3785 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3786 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3787 short_channel_id: 2,
3790 cltv_expiry_delta: 0,
3791 htlc_minimum_msat: 0,
3792 htlc_maximum_msat: OptionalField::Present(80_000),
3794 fee_proportional_millionths: 0,
3795 excess_data: Vec::new()
3797 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3798 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3799 short_channel_id: 4,
3802 cltv_expiry_delta: (4 << 8) | 1,
3803 htlc_minimum_msat: 90_000,
3804 htlc_maximum_msat: OptionalField::Absent,
3806 fee_proportional_millionths: 0,
3807 excess_data: Vec::new()
3811 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
3812 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
3813 // expensive) channels 12-13 path.
3814 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 90_000, 42, Arc::clone(&logger)).unwrap();
3815 assert_eq!(route.paths.len(), 1);
3816 assert_eq!(route.paths[0].len(), 2);
3818 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
3819 assert_eq!(route.paths[0][0].short_channel_id, 12);
3820 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
3821 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
3822 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
3823 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
3825 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3826 assert_eq!(route.paths[0][1].short_channel_id, 13);
3827 assert_eq!(route.paths[0][1].fee_msat, 90_000);
3828 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3829 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
3830 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
3834 #[cfg(not(feature = "no-std"))]
3835 pub(super) fn random_init_seed() -> u64 {
3836 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
3837 use core::hash::{BuildHasher, Hasher};
3838 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
3839 println!("Using seed of {}", seed);
3842 #[cfg(not(feature = "no-std"))]
3843 use util::ser::Readable;
3846 #[cfg(not(feature = "no-std"))]
3847 fn generate_routes() {
3848 let mut d = match super::test_utils::get_route_file() {
3855 let graph = NetworkGraph::read(&mut d).unwrap();
3857 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3858 let mut seed = random_init_seed() as usize;
3859 'load_endpoints: for _ in 0..10 {
3861 seed = seed.overflowing_mul(0xdeadbeef).0;
3862 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3863 seed = seed.overflowing_mul(0xdeadbeef).0;
3864 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3865 let amt = seed as u64 % 200_000_000;
3866 if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3867 continue 'load_endpoints;
3874 #[cfg(not(feature = "no-std"))]
3875 fn generate_routes_mpp() {
3876 let mut d = match super::test_utils::get_route_file() {
3883 let graph = NetworkGraph::read(&mut d).unwrap();
3885 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3886 let mut seed = random_init_seed() as usize;
3887 'load_endpoints: for _ in 0..10 {
3889 seed = seed.overflowing_mul(0xdeadbeef).0;
3890 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3891 seed = seed.overflowing_mul(0xdeadbeef).0;
3892 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3893 let amt = seed as u64 % 200_000_000;
3894 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
3895 continue 'load_endpoints;
3902 #[cfg(all(test, not(feature = "no-std")))]
3903 pub(crate) mod test_utils {
3905 /// Tries to open a network graph file, or panics with a URL to fetch it.
3906 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
3907 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
3908 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
3909 .or_else(|_| { // Fall back to guessing based on the binary location
3910 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
3911 let mut path = std::env::current_exe().unwrap();
3912 path.pop(); // lightning-...
3914 path.pop(); // debug
3915 path.pop(); // target
3916 path.push("lightning");
3917 path.push("net_graph-2021-05-31.bin");
3918 eprintln!("{}", path.to_str().unwrap());
3921 .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");
3922 #[cfg(require_route_graph_test)]
3923 return Ok(res.unwrap());
3924 #[cfg(not(require_route_graph_test))]
3929 #[cfg(all(test, feature = "unstable", not(feature = "no-std")))]
3932 use util::logger::{Logger, Record};
3936 struct DummyLogger {}
3937 impl Logger for DummyLogger {
3938 fn log(&self, _record: &Record) {}
3942 fn generate_routes(bench: &mut Bencher) {
3943 let mut d = test_utils::get_route_file().unwrap();
3944 let graph = NetworkGraph::read(&mut d).unwrap();
3946 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3947 let mut path_endpoints = Vec::new();
3948 let mut seed: usize = 0xdeadbeef;
3949 'load_endpoints: for _ in 0..100 {
3952 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3954 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3955 let amt = seed as u64 % 1_000_000;
3956 if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
3957 path_endpoints.push((src, dst, amt));
3958 continue 'load_endpoints;
3963 // ...then benchmark finding paths between the nodes we learned.
3966 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
3967 assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
3973 fn generate_mpp_routes(bench: &mut Bencher) {
3974 let mut d = test_utils::get_route_file().unwrap();
3975 let graph = NetworkGraph::read(&mut d).unwrap();
3977 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
3978 let mut path_endpoints = Vec::new();
3979 let mut seed: usize = 0xdeadbeef;
3980 'load_endpoints: for _ in 0..100 {
3983 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3985 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
3986 let amt = seed as u64 % 1_000_000;
3987 if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
3988 path_endpoints.push((src, dst, amt));
3989 continue 'load_endpoints;
3994 // ...then benchmark finding paths between the nodes we learned.
3997 let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
3998 assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());