use bitcoin::secp256k1::key::PublicKey;
use ln::channelmanager::ChannelDetails;
-use ln::features::{ChannelFeatures, NodeFeatures};
+use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
use routing::network_graph::{NetworkGraph, RoutingFees};
use util::ser::{Writeable, Readable};
use util::logger::Logger;
-use std::cmp;
-use std::collections::{HashMap,BinaryHeap};
-use std::ops::Deref;
+use prelude::*;
+use alloc::collections::BinaryHeap;
+use core::cmp;
+use core::ops::Deref;
/// A hop in a route
#[derive(Clone, PartialEq)]
/// The channel_announcement features of the channel that should be used from the previous hop
/// to reach this node.
pub channel_features: ChannelFeatures,
- /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
+ /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
+ /// For the last hop, this should be the full value of the payment (might be more than
+ /// requested if we had to match htlc_minimum_msat).
pub fee_msat: u64,
/// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
/// expected at the destination, in excess of the current block height.
pub cltv_expiry_delta: u32,
}
-impl Writeable for Vec<RouteHop> {
- fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
- (self.len() as u8).write(writer)?;
- for hop in self.iter() {
- hop.pubkey.write(writer)?;
- hop.node_features.write(writer)?;
- hop.short_channel_id.write(writer)?;
- hop.channel_features.write(writer)?;
- hop.fee_msat.write(writer)?;
- hop.cltv_expiry_delta.write(writer)?;
- }
- Ok(())
- }
-}
-
-impl Readable for Vec<RouteHop> {
- fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Vec<RouteHop>, DecodeError> {
- let hops_count: u8 = Readable::read(reader)?;
- let mut hops = Vec::with_capacity(hops_count as usize);
- for _ in 0..hops_count {
- hops.push(RouteHop {
- pubkey: Readable::read(reader)?,
- node_features: Readable::read(reader)?,
- short_channel_id: Readable::read(reader)?,
- channel_features: Readable::read(reader)?,
- fee_msat: Readable::read(reader)?,
- cltv_expiry_delta: Readable::read(reader)?,
- });
- }
- Ok(hops)
- }
-}
+impl_writeable_tlv_based!(RouteHop, {
+ (0, pubkey, required),
+ (2, node_features, required),
+ (4, short_channel_id, required),
+ (6, channel_features, required),
+ (8, fee_msat, required),
+ (10, cltv_expiry_delta, required),
+});
/// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
/// it can take multiple paths. Each path is composed of one or more hops through the network.
pub paths: Vec<Vec<RouteHop>>,
}
+const SERIALIZATION_VERSION: u8 = 1;
+const MIN_SERIALIZATION_VERSION: u8 = 1;
+
impl Writeable for Route {
fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
(self.paths.len() as u64).write(writer)?;
for hops in self.paths.iter() {
- hops.write(writer)?;
+ (hops.len() as u8).write(writer)?;
+ for hop in hops.iter() {
+ hop.write(writer)?;
+ }
}
+ write_tlv_fields!(writer, {});
Ok(())
}
}
impl Readable for Route {
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
+ let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
let path_count: u64 = Readable::read(reader)?;
let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
for _ in 0..path_count {
- paths.push(Readable::read(reader)?);
+ let hop_count: u8 = Readable::read(reader)?;
+ let mut hops = Vec::with_capacity(hop_count as usize);
+ for _ in 0..hop_count {
+ hops.push(Readable::read(reader)?);
+ }
+ paths.push(hops);
}
+ read_tlv_fields!(reader, {});
Ok(Route { paths })
}
}
-/// A channel descriptor which provides a last-hop route to get_route
-#[derive(Clone)]
-pub struct RouteHint {
+/// A list of hops along a payment path terminating with a channel to the recipient.
+#[derive(Eq, PartialEq, Debug, Clone)]
+pub struct RouteHint(pub Vec<RouteHintHop>);
+
+/// A channel descriptor for a hop along a payment path.
+#[derive(Eq, PartialEq, Debug, Clone)]
+pub struct RouteHintHop {
/// The node_id of the non-target end of the route
pub src_node_id: PublicKey,
/// The short_channel_id of this channel
pubkey: PublicKey,
lowest_fee_to_peer_through_node: u64,
lowest_fee_to_node: u64,
+ // The maximum value a yet-to-be-constructed payment path might flow through this node.
+ // This value is upper-bounded by us by:
+ // - how much is needed for a path being constructed
+ // - how much value can channels following this node (up to the destination) can contribute,
+ // considering their capacity and fees
+ value_contribution_msat: u64,
+ /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
+ /// minimum, we use it, plus the fees required at each earlier hop to meet it.
+ path_htlc_minimum_msat: u64,
}
impl cmp::Ord for RouteGraphNode {
fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
- other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
- .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
+ let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat);
+ let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat);
+ other_score.cmp(&self_score).then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
}
}
fees: RoutingFees,
}
+/// It's useful to keep track of the hops associated with the fees required to use them,
+/// so that we can choose cheaper paths (as per Dijkstra's algorithm).
+/// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
+/// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
+#[derive(Clone, Debug)]
+struct PathBuildingHop<'a> {
+ // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
+ // Note that node_features is calculated separately after our initial graph walk.
+ pubkey: PublicKey,
+ short_channel_id: u64,
+ channel_features: &'a ChannelFeatures,
+ fee_msat: u64,
+ cltv_expiry_delta: u32,
+
+ /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
+ src_lowest_inbound_fees: RoutingFees,
+ /// Fees of the channel used in this hop.
+ channel_fees: RoutingFees,
+ /// All the fees paid *after* this channel on the way to the destination
+ next_hops_fee_msat: u64,
+ /// Fee paid for the use of the current channel (see channel_fees).
+ /// The value will be actually deducted from the counterparty balance on the previous link.
+ hop_use_fee_msat: u64,
+ /// Used to compare channels when choosing the for routing.
+ /// Includes paying for the use of a hop and the following hops, as well as
+ /// an estimated cost of reaching this hop.
+ /// Might get stale when fees are recomputed. Primarily for internal use.
+ total_fee_msat: u64,
+ /// This is useful for update_value_and_recompute_fees to make sure
+ /// we don't fall below the minimum. Should not be updated manually and
+ /// generally should not be accessed.
+ htlc_minimum_msat: u64,
+ /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
+ /// walk and may be invalid thereafter.
+ path_htlc_minimum_msat: u64,
+ /// If we've already processed a node as the best node, we shouldn't process it again. Normally
+ /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
+ /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
+ /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
+ /// avoid processing them again.
+ was_processed: bool,
+ #[cfg(any(test, feature = "fuzztarget"))]
+ // In tests, we apply further sanity checks on cases where we skip nodes we already processed
+ // to ensure it is specifically in cases where the fee has gone down because of a decrease in
+ // value_contribution_msat, which requires tracking it here. See comments below where it is
+ // used for more info.
+ value_contribution_msat: u64,
+}
+
+// Instantiated with a list of hops with correct data in them collected during path finding,
+// an instance of this struct should be further modified only via given methods.
+#[derive(Clone)]
+struct PaymentPath<'a> {
+ hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
+}
+
+impl<'a> PaymentPath<'a> {
+ // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
+ fn get_value_msat(&self) -> u64 {
+ self.hops.last().unwrap().0.fee_msat
+ }
+
+ fn get_total_fee_paid_msat(&self) -> u64 {
+ if self.hops.len() < 1 {
+ return 0;
+ }
+ let mut result = 0;
+ // Can't use next_hops_fee_msat because it gets outdated.
+ for (i, (hop, _)) in self.hops.iter().enumerate() {
+ if i != self.hops.len() - 1 {
+ result += hop.fee_msat;
+ }
+ }
+ return result;
+ }
+
+ // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
+ // to change fees may result in an inconsistency.
+ //
+ // Sometimes we call this function right after constructing a path which is inconsistent in
+ // that it the value being transferred has decreased while we were doing path finding, leading
+ // to the fees being paid not lining up with the actual limits.
+ //
+ // Note that this function is not aware of the available_liquidity limit, and thus does not
+ // support increasing the value being transferred.
+ fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
+ assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
+
+ let mut total_fee_paid_msat = 0 as u64;
+ for i in (0..self.hops.len()).rev() {
+ let last_hop = i == self.hops.len() - 1;
+
+ // For non-last-hop, this value will represent the fees paid on the current hop. It
+ // will consist of the fees for the use of the next hop, and extra fees to match
+ // htlc_minimum_msat of the current channel. Last hop is handled separately.
+ let mut cur_hop_fees_msat = 0;
+ if !last_hop {
+ cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
+ }
+
+ let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
+ cur_hop.next_hops_fee_msat = total_fee_paid_msat;
+ // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
+ // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
+ // set it too high just to maliciously take more fees by exploiting this
+ // match htlc_minimum_msat logic.
+ let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
+ if let Some(extra_fees_msat) = cur_hop.htlc_minimum_msat.checked_sub(cur_hop_transferred_amount_msat) {
+ // Note that there is a risk that *previous hops* (those closer to us, as we go
+ // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
+ //
+ // This might make us end up with a broken route, although this should be super-rare
+ // in practice, both because of how healthy channels look like, and how we pick
+ // channels in add_entry.
+ // Also, this can't be exploited more heavily than *announce a free path and fail
+ // all payments*.
+ cur_hop_transferred_amount_msat += extra_fees_msat;
+ total_fee_paid_msat += extra_fees_msat;
+ cur_hop_fees_msat += extra_fees_msat;
+ }
+
+ if last_hop {
+ // Final hop is a special case: it usually has just value_msat (by design), but also
+ // it still could overpay for the htlc_minimum_msat.
+ cur_hop.fee_msat = cur_hop_transferred_amount_msat;
+ } else {
+ // Propagate updated fees for the use of the channels to one hop back, where they
+ // will be actually paid (fee_msat). The last hop is handled above separately.
+ cur_hop.fee_msat = cur_hop_fees_msat;
+ }
+
+ // Fee for the use of the current hop which will be deducted on the previous hop.
+ // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
+ // this channel is free for us.
+ if i != 0 {
+ if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.channel_fees) {
+ cur_hop.hop_use_fee_msat = new_fee;
+ total_fee_paid_msat += new_fee;
+ } else {
+ // It should not be possible because this function is called only to reduce the
+ // value. In that case, compute_fee was already called with the same fees for
+ // larger amount and there was no overflow.
+ unreachable!();
+ }
+ }
+ }
+ }
+}
+
+fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
+ let proportional_fee_millions =
+ amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
+ if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
+ (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
+
+ Some(new_fee)
+ } else {
+ // This function may be (indirectly) called without any verification,
+ // with channel_fees provided by a caller. We should handle it gracefully.
+ None
+ }
+}
-/// Gets a route from us to the given target node.
+/// Gets a route from us (payer) to the given target node (payee).
+///
+/// If the payee provided features in their invoice, they should be provided via payee_features.
+/// Without this, MPP will only be used if the payee's features are available in the network graph.
///
-/// Extra routing hops between known nodes and the target will be used if they are included in
-/// last_hops.
+/// Private routing paths between a public node and the target may be included in `last_hops`.
+/// Currently, only the last hop in each path is considered.
///
/// If some channels aren't announced, it may be useful to fill in a first_hops with the
/// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
-/// view of our local channels (from net_graph_msg_handler) will be ignored, and only those in first_hops
-/// will be used.
+/// view of our local channels (from net_graph_msg_handler) will be ignored, and only those
+/// in first_hops will be used.
///
/// Panics if first_hops contains channels without short_channel_ids
/// (ChannelManager::list_usable_channels will never include such channels).
///
/// The fees on channels from us to next-hops are ignored (as they are assumed to all be
-/// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
-/// *is* checked as they may change based on the receiving node.
-pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, target: &PublicKey, first_hops: Option<&[&ChannelDetails]>,
+/// equal), however the enabled/disabled bit on such channels as well as the
+/// htlc_minimum_msat/htlc_maximum_msat *are* checked as they may change based on the receiving node.
+pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, payee: &PublicKey, payee_features: Option<InvoiceFeatures>, first_hops: Option<&[&ChannelDetails]>,
last_hops: &[&RouteHint], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
// TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
// uptime/success in using a node in the past.
- if *target == *our_node_id {
+ if *payee == *our_node_id {
return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
}
return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
}
- // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
- // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
+ if final_value_msat == 0 {
+ return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
+ }
+
+ let last_hops = last_hops.iter().filter_map(|hops| hops.0.last()).collect::<Vec<_>>();
+ for last_hop in last_hops.iter() {
+ if last_hop.src_node_id == *payee {
+ return Err(LightningError{err: "Last hop cannot have a payee as a source.".to_owned(), action: ErrorAction::IgnoreError});
+ }
+ }
+
+ // The general routing idea is the following:
+ // 1. Fill first/last hops communicated by the caller.
+ // 2. Attempt to construct a path from payer to payee for transferring
+ // any ~sufficient (described later) value.
+ // If succeed, remember which channels were used and how much liquidity they have available,
+ // so that future paths don't rely on the same liquidity.
+ // 3. Prooceed to the next step if:
+ // - we hit the recommended target value;
+ // - OR if we could not construct a new path. Any next attempt will fail too.
+ // Otherwise, repeat step 2.
+ // 4. See if we managed to collect paths which aggregately are able to transfer target value
+ // (not recommended value). If yes, proceed. If not, fail routing.
+ // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
+ // 6. Of all the found paths, select only those with the lowest total fee.
+ // 7. The last path in every selected route is likely to be more than we need.
+ // Reduce its value-to-transfer and recompute fees.
+ // 8. Choose the best route by the lowest total fee.
+
+ // As for the actual search algorithm,
+ // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
+ // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
+ //
+ // We are not a faithful Dijkstra's implementation because we can change values which impact
+ // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
+ // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) then
+ // the value we are currently attempting to send over a path, we simply reduce the value being
+ // sent along the path for any hops after that channel. This may imply that later fees (which
+ // we've already tabulated) are lower because a smaller value is passing through the channels
+ // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
+ // channels which were selected earlier (and which may still be used for other paths without a
+ // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
+ // de-preferenced.
+ //
+ // One potentially problematic case for this algorithm would be if there are many
+ // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
+ // graph walking), we may never find a path which is not liquidity-limited and has lower
+ // proportional fee (and only lower absolute fee when considering the ultimate value sent).
+ // Because we only consider paths with at least 5% of the total value being sent, the damage
+ // from such a case should be limited, however this could be further reduced in the future by
+ // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
+ // limits for the purposes of fee calculation.
+ //
+ // Alternatively, we could store more detailed path information in the heap (targets, below)
+ // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
+ // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
+ // and practically (as we would need to store dynamically-allocated path information in heap
+ // objects, increasing malloc traffic and indirect memory access significantly). Further, the
+ // results of such an algorithm would likely be biased towards lower-value paths.
+ //
+ // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
+ // outside of our current search value, running a path search more times to gather candidate
+ // paths at different values. While this may be acceptable, further path searches may increase
+ // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
+ // graph for candidate paths, calculating the maximum value which can realistically be sent at
+ // the same time, remaining generic across different payment values.
+ //
// TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
// to use as the A* heuristic beyond just the cost to get one node further than the current
// one.
}
};
- let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
- let mut dist = HashMap::with_capacity(network.get_nodes().len());
-
- let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
+ // Allow MPP only if we have a features set from somewhere that indicates the payee supports
+ // it. If the payee supports it they're supposed to include it in the invoice, so that should
+ // work reliably.
+ let allow_mpp = if let Some(features) = &payee_features {
+ features.supports_basic_mpp()
+ } else if let Some(node) = network.get_nodes().get(&payee) {
+ if let Some(node_info) = node.announcement_info.as_ref() {
+ node_info.features.supports_basic_mpp()
+ } else { false }
+ } else { false };
+
+ // Step (1).
+ // Prepare the data we'll use for payee-to-payer search by
+ // inserting first hops suggested by the caller as targets.
+ // Our search will then attempt to reach them while traversing from the payee node.
+ let mut first_hop_targets: HashMap<_, (_, ChannelFeatures, _, NodeFeatures)> =
+ HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
if let Some(hops) = first_hops {
for chan in hops {
let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
- if chan.remote_network_id == *target {
- return Ok(Route {
- paths: vec![vec![RouteHop {
- pubkey: chan.remote_network_id,
- node_features: chan.counterparty_features.to_context(),
- short_channel_id,
- channel_features: chan.counterparty_features.to_context(),
- fee_msat: final_value_msat,
- cltv_expiry_delta: final_cltv,
- }]],
- });
+ if chan.remote_network_id == *our_node_id {
+ return Err(LightningError{err: "First hop cannot have our_node_id as a destination.".to_owned(), action: ErrorAction::IgnoreError});
}
- first_hop_targets.insert(chan.remote_network_id, (short_channel_id, chan.counterparty_features.clone()));
+ first_hop_targets.insert(chan.remote_network_id, (short_channel_id, chan.counterparty_features.to_context(), chan.outbound_capacity_msat, chan.counterparty_features.to_context()));
}
if first_hop_targets.is_empty() {
return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
}
}
+ let empty_channel_features = ChannelFeatures::empty();
+
+ // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
+ // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
+ // adding duplicate entries when we find a better path to a given node.
+ let mut targets = BinaryHeap::new();
+
+ // Map from node_id to information about the best current path to that node, including feerate
+ // information.
+ let mut dist = HashMap::with_capacity(network.get_nodes().len());
+
+ // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
+ // indicating that we may wish to try again with a higher value, potentially paying to meet an
+ // htlc_minimum with extra fees while still finding a cheaper path.
+ let mut hit_minimum_limit;
+
+ // When arranging a route, we select multiple paths so that we can make a multi-path payment.
+ // We start with a path_value of the exact amount we want, and if that generates a route we may
+ // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
+ // amount we want in total across paths, selecting the best subset at the end.
+ const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
+ let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
+ let mut path_value_msat = final_value_msat;
+
+ // We don't want multiple paths (as per MPP) share liquidity of the same channels.
+ // This map allows paths to be aware of the channel use by other paths in the same call.
+ // This would help to make a better path finding decisions and not "overbook" channels.
+ // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
+ let mut bookkeeped_channels_liquidity_available_msat = HashMap::with_capacity(network.get_nodes().len());
+
+ // Keeping track of how much value we already collected across other paths. Helps to decide:
+ // - how much a new path should be transferring (upper bound);
+ // - whether a channel should be disregarded because
+ // it's available liquidity is too small comparing to how much more we need to collect;
+ // - when we want to stop looking for new paths.
+ let mut already_collected_value_msat = 0;
+
+ log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee, our_node_id, final_value_msat);
+
macro_rules! add_entry {
// Adds entry which goes from $src_node_id to $dest_node_id
// over the channel with id $chan_id with fees described in
// $directional_info.
- ( $chan_id: expr, $src_node_id: expr, $dest_node_id: expr, $directional_info: expr, $capacity_sats: expr, $chan_features: expr, $starting_fee_msat: expr ) => {
- //TODO: Explore simply adding fee to hit htlc_minimum_msat
- if $starting_fee_msat as u64 + final_value_msat >= $directional_info.htlc_minimum_msat {
- let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fees.proportional_millionths as u64);
- if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
- ($directional_info.fees.base_msat as u64).checked_add(part / 1000000) })
- {
- let mut total_fee = $starting_fee_msat as u64;
-
- let mut available_msat = $capacity_sats;
+ // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one,
+ // since that value has to be transferred over this channel.
+ // Returns whether this channel caused an update to `targets`.
+ ( $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,
+ $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => { {
+ // We "return" whether we updated the path at the end, via this:
+ let mut did_add_update_path_to_src_node = false;
+ // Channels to self should not be used. This is more of belt-and-suspenders, because in
+ // practice these cases should be caught earlier:
+ // - for regular channels at channel announcement (TODO)
+ // - for first and last hops early in get_route
+ if $src_node_id != $dest_node_id.clone() {
+ let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
+ let mut initial_liquidity_available_msat = None;
+ if let Some(capacity_sats) = $capacity_sats {
+ initial_liquidity_available_msat = Some(capacity_sats * 1000);
+ }
+
if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
- if let Some(capacity_sats) = $capacity_sats {
- available_msat = Some(cmp::min(capacity_sats * 1000, htlc_maximum_msat));
+ if let Some(available_msat) = initial_liquidity_available_msat {
+ initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
} else {
- available_msat = Some(htlc_maximum_msat);
+ initial_liquidity_available_msat = Some(htlc_maximum_msat);
}
}
- let hm_entry = dist.entry(&$src_node_id);
- let old_entry = hm_entry.or_insert_with(|| {
- let mut fee_base_msat = u32::max_value();
- let mut fee_proportional_millionths = u32::max_value();
- if let Some(fees) = network.get_nodes().get(&$src_node_id).and_then(|node| node.lowest_inbound_channel_fees) {
- fee_base_msat = fees.base_msat;
- fee_proportional_millionths = fees.proportional_millionths;
- }
- (u64::max_value(),
- fee_base_msat,
- fee_proportional_millionths,
- RouteHop {
+ match initial_liquidity_available_msat {
+ Some(available_msat) => available_msat,
+ // We assume channels with unknown balance have
+ // a capacity of 0.0025 BTC (or 250_000 sats).
+ None => 250_000 * 1000
+ }
+ });
+
+ // It is tricky to substract $next_hops_fee_msat from available liquidity here.
+ // It may be misleading because we might later choose to reduce the value transferred
+ // over these channels, and the channel which was insufficient might become sufficient.
+ // Worst case: we drop a good channel here because it can't cover the high following
+ // fees caused by one expensive channel, but then this channel could have been used
+ // if the amount being transferred over this path is lower.
+ // We do this for now, but this is a subject for removal.
+ if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
+
+ // Routing Fragmentation Mitigation heuristic:
+ //
+ // Routing fragmentation across many payment paths increases the overall routing
+ // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
+ // Taking too many smaller paths also increases the chance of payment failure.
+ // Thus to avoid this effect, we require from our collected links to provide
+ // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
+ //
+ // This requirement is currently 5% of the remaining-to-be-collected value.
+ // This means as we successfully advance in our collection,
+ // the absolute liquidity contribution is lowered,
+ // thus increasing the number of potential channels to be selected.
+
+ // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
+ // or 100% if we're not allowed to do multipath payments.
+ let minimal_value_contribution_msat: u64 = if allow_mpp {
+ (recommended_value_msat - already_collected_value_msat + 19) / 20
+ } else {
+ final_value_msat
+ };
+ // Verify the liquidity offered by this channel complies to the minimal contribution.
+ let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
+
+ let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
+ // Includes paying fees for the use of the following channels.
+ let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
+ Some(result) => result,
+ // Can't overflow due to how the values were computed right above.
+ None => unreachable!(),
+ };
+ #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
+ let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
+ amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
+
+ // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
+ // bother considering this channel.
+ // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
+ // be only reduced later (not increased), so this channel should just be skipped
+ // as not sufficient.
+ if !over_path_minimum_msat {
+ hit_minimum_limit = true;
+ } else if contributes_sufficient_value {
+ // Note that low contribution here (limited by available_liquidity_msat)
+ // might violate htlc_minimum_msat on the hops which are next along the
+ // payment path (upstream to the payee). To avoid that, we recompute path
+ // path fees knowing the final path contribution after constructing it.
+ let path_htlc_minimum_msat = match compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
+ .map(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) {
+ Some(Some(value_msat)) => cmp::max(value_msat, $directional_info.htlc_minimum_msat),
+ _ => u64::max_value()
+ };
+ let hm_entry = dist.entry(&$src_node_id);
+ let old_entry = hm_entry.or_insert_with(|| {
+ // If there was previously no known way to access
+ // the source node (recall it goes payee-to-payer) of $chan_id, first add
+ // a semi-dummy record just to compute the fees to reach the source node.
+ // This will affect our decision on selecting $chan_id
+ // as a way to reach the $dest_node_id.
+ let mut fee_base_msat = u32::max_value();
+ let mut fee_proportional_millionths = u32::max_value();
+ if let Some(Some(fees)) = network.get_nodes().get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
+ fee_base_msat = fees.base_msat;
+ fee_proportional_millionths = fees.proportional_millionths;
+ }
+ PathBuildingHop {
pubkey: $dest_node_id.clone(),
- node_features: NodeFeatures::empty(),
short_channel_id: 0,
- channel_features: $chan_features.clone(),
+ channel_features: $chan_features,
fee_msat: 0,
cltv_expiry_delta: 0,
- },
- None,
- )
- });
- if $src_node_id != *our_node_id {
- // Ignore new_fee for channel-from-us as we assume all channels-from-us
- // will have the same effective-fee
- total_fee += new_fee;
- if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
- total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
- } else {
- // max_value means we'll always fail the old_entry.0 > total_fee check
- total_fee = u64::max_value();
+ src_lowest_inbound_fees: RoutingFees {
+ base_msat: fee_base_msat,
+ proportional_millionths: fee_proportional_millionths,
+ },
+ channel_fees: $directional_info.fees,
+ next_hops_fee_msat: u64::max_value(),
+ hop_use_fee_msat: u64::max_value(),
+ total_fee_msat: u64::max_value(),
+ htlc_minimum_msat: $directional_info.htlc_minimum_msat,
+ path_htlc_minimum_msat,
+ was_processed: false,
+ #[cfg(any(test, feature = "fuzztarget"))]
+ value_contribution_msat,
+ }
+ });
+
+ #[allow(unused_mut)] // We only use the mut in cfg(test)
+ let mut should_process = !old_entry.was_processed;
+ #[cfg(any(test, feature = "fuzztarget"))]
+ {
+ // In test/fuzzing builds, we do extra checks to make sure the skipping
+ // of already-seen nodes only happens in cases we expect (see below).
+ if !should_process { should_process = true; }
+ }
+
+ if should_process {
+ let mut hop_use_fee_msat = 0;
+ let mut total_fee_msat = $next_hops_fee_msat;
+
+ // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
+ // will have the same effective-fee
+ if $src_node_id != *our_node_id {
+ match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
+ // max_value means we'll always fail
+ // the old_entry.total_fee_msat > total_fee_msat check
+ None => total_fee_msat = u64::max_value(),
+ Some(fee_msat) => {
+ hop_use_fee_msat = fee_msat;
+ total_fee_msat += hop_use_fee_msat;
+ // When calculating the lowest inbound fees to a node, we
+ // calculate fees here not based on the actual value we think
+ // will flow over this channel, but on the minimum value that
+ // we'll accept flowing over it. The minimum accepted value
+ // is a constant through each path collection run, ensuring
+ // consistent basis. Otherwise we may later find a
+ // different path to the source node that is more expensive,
+ // but which we consider to be cheaper because we are capacity
+ // constrained and the relative fee becomes lower.
+ match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
+ .map(|a| a.checked_add(total_fee_msat)) {
+ Some(Some(v)) => {
+ total_fee_msat = v;
+ },
+ _ => {
+ total_fee_msat = u64::max_value();
+ }
+ };
+ }
+ }
+ }
+
+ let new_graph_node = RouteGraphNode {
+ pubkey: $src_node_id,
+ lowest_fee_to_peer_through_node: total_fee_msat,
+ lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
+ value_contribution_msat: value_contribution_msat,
+ path_htlc_minimum_msat,
+ };
+
+ // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
+ // if this way is cheaper than the already known
+ // (considering the cost to "reach" this channel from the route destination,
+ // the cost of using this channel,
+ // and the cost of routing to the source node of this channel).
+ // Also, consider that htlc_minimum_msat_difference, because we might end up
+ // paying it. Consider the following exploit:
+ // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
+ // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
+ // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
+ // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
+ // to this channel.
+ // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
+ // but it may require additional tracking - we don't want to double-count
+ // the fees included in $next_hops_path_htlc_minimum_msat, but also
+ // can't use something that may decrease on future hops.
+ let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat);
+ let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat);
+
+ if !old_entry.was_processed && new_cost < old_cost {
+ targets.push(new_graph_node);
+ old_entry.next_hops_fee_msat = $next_hops_fee_msat;
+ old_entry.hop_use_fee_msat = hop_use_fee_msat;
+ old_entry.total_fee_msat = total_fee_msat;
+ old_entry.pubkey = $dest_node_id.clone();
+ old_entry.short_channel_id = $chan_id.clone();
+ old_entry.channel_features = $chan_features;
+ old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
+ old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
+ old_entry.channel_fees = $directional_info.fees;
+ old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
+ old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
+ #[cfg(any(test, feature = "fuzztarget"))]
+ {
+ old_entry.value_contribution_msat = value_contribution_msat;
+ }
+ did_add_update_path_to_src_node = true;
+ } else if old_entry.was_processed && new_cost < old_cost {
+ #[cfg(any(test, feature = "fuzztarget"))]
+ {
+ // If we're skipping processing a node which was previously
+ // processed even though we found another path to it with a
+ // cheaper fee, check that it was because the second path we
+ // found (which we are processing now) has a lower value
+ // contribution due to an HTLC minimum limit.
+ //
+ // e.g. take a graph with two paths from node 1 to node 2, one
+ // through channel A, and one through channel B. Channel A and
+ // B are both in the to-process heap, with their scores set by
+ // a higher htlc_minimum than fee.
+ // Channel A is processed first, and the channels onwards from
+ // node 1 are added to the to-process heap. Thereafter, we pop
+ // Channel B off of the heap, note that it has a much more
+ // restrictive htlc_maximum_msat, and recalculate the fees for
+ // all of node 1's channels using the new, reduced, amount.
+ //
+ // This would be bogus - we'd be selecting a higher-fee path
+ // with a lower htlc_maximum_msat instead of the one we'd
+ // already decided to use.
+ debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
+ debug_assert!(value_contribution_msat < old_entry.value_contribution_msat);
+ }
+ }
}
- }
- let new_graph_node = RouteGraphNode {
- pubkey: $src_node_id,
- lowest_fee_to_peer_through_node: total_fee,
- lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
- };
- if old_entry.0 > total_fee {
- targets.push(new_graph_node);
- old_entry.0 = total_fee;
- old_entry.3 = RouteHop {
- pubkey: $dest_node_id.clone(),
- node_features: NodeFeatures::empty(),
- short_channel_id: $chan_id.clone(),
- channel_features: $chan_features.clone(),
- fee_msat: new_fee, // This field is ignored on the last-hop anyway
- cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
- };
- old_entry.4 = available_msat;
}
}
}
- };
+ did_add_update_path_to_src_node
+ } }
}
+ let empty_node_features = NodeFeatures::empty();
+ // Find ways (channels with destination) to reach a given node and store them
+ // in the corresponding data structures (routing graph etc).
+ // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
+ // meaning how much will be paid in fees after this node (to the best of our knowledge).
+ // This data can later be helpful to optimize routing (pay lower fees).
macro_rules! add_entries_to_cheapest_to_target_node {
- ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
- if first_hops.is_some() {
- if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&$node_id) {
- add_entry!(first_hop, *our_node_id, $node_id, dummy_directional_info, None::<u64>, features.to_context(), $fee_to_target_msat);
+ ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr ) => {
+ let skip_node = if let Some(elem) = dist.get_mut($node_id) {
+ let was_processed = elem.was_processed;
+ elem.was_processed = true;
+ was_processed
+ } else {
+ // Entries are added to dist in add_entry!() when there is a channel from a node.
+ // Because there are no channels from payee, it will not have a dist entry at this point.
+ // If we're processing any other node, it is always be the result of a channel from it.
+ assert_eq!($node_id, payee);
+ false
+ };
+
+ if !skip_node {
+ if first_hops.is_some() {
+ if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&$node_id) {
+ 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);
+ }
}
- }
- let features;
- if let Some(node_info) = $node.announcement_info.as_ref() {
- features = node_info.features.clone();
- } else {
- features = NodeFeatures::empty();
- }
+ let features = if let Some(node_info) = $node.announcement_info.as_ref() {
+ &node_info.features
+ } else {
+ &empty_node_features
+ };
- if !features.requires_unknown_bits() {
- for chan_id in $node.channels.iter() {
- let chan = network.get_channels().get(chan_id).unwrap();
- if !chan.features.requires_unknown_bits() {
- if chan.node_one == *$node_id {
- // ie $node is one, ie next hop in A* is two, via the two_to_one channel
- if first_hops.is_none() || chan.node_two != *our_node_id {
- if let Some(two_to_one) = chan.two_to_one.as_ref() {
- if two_to_one.enabled {
- add_entry!(chan_id, chan.node_two, chan.node_one, two_to_one, chan.capacity_sats, chan.features, $fee_to_target_msat);
+ if !features.requires_unknown_bits() {
+ for chan_id in $node.channels.iter() {
+ let chan = network.get_channels().get(chan_id).unwrap();
+ if !chan.features.requires_unknown_bits() {
+ if chan.node_one == *$node_id {
+ // ie $node is one, ie next hop in A* is two, via the two_to_one channel
+ if first_hops.is_none() || chan.node_two != *our_node_id {
+ if let Some(two_to_one) = chan.two_to_one.as_ref() {
+ if two_to_one.enabled {
+ 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);
+ }
}
}
- }
- } else {
- if first_hops.is_none() || chan.node_one != *our_node_id {
- if let Some(one_to_two) = chan.one_to_two.as_ref() {
- if one_to_two.enabled {
- add_entry!(chan_id, chan.node_one, chan.node_two, one_to_two, chan.capacity_sats, chan.features, $fee_to_target_msat);
+ } else {
+ if first_hops.is_none() || chan.node_one != *our_node_id {
+ if let Some(one_to_two) = chan.one_to_two.as_ref() {
+ if one_to_two.enabled {
+ 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);
+ }
}
}
-
}
}
}
};
}
- match network.get_nodes().get(target) {
- None => {},
- Some(node) => {
- add_entries_to_cheapest_to_target_node!(node, target, 0);
- },
- }
+ let mut payment_paths = Vec::<PaymentPath>::new();
+
+ // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
+ 'paths_collection: loop {
+ // For every new path, start from scratch, except
+ // bookkeeped_channels_liquidity_available_msat, which will improve
+ // the further iterations of path finding. Also don't erase first_hop_targets.
+ targets.clear();
+ dist.clear();
+ hit_minimum_limit = false;
+
+ // If first hop is a private channel and the only way to reach the payee, this is the only
+ // place where it could be added.
+ if first_hops.is_some() {
+ if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&payee) {
+ add_entry!(first_hop, *our_node_id, payee, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0);
+ }
+ }
- for hop in last_hops.iter() {
- let have_hop_src_in_graph =
- if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&hop.src_node_id) {
- // If this hop connects to a node with which we have a direct channel, ignore the
- // network graph and add both the hop and our direct channel to the candidate set:
- //
- // Currently there are no channel-context features defined, so we are a
- // bit lazy here. In the future, we should pull them out via our
- // ChannelManager, but there's no reason to waste the space until we
- // need them.
- add_entry!(first_hop, *our_node_id , hop.src_node_id, dummy_directional_info, None::<u64>, features.to_context(), 0);
- true
- } else {
- // In any other case, only add the hop if the source is in the regular network
- // graph:
- network.get_nodes().get(&hop.src_node_id).is_some()
- };
- if have_hop_src_in_graph {
- // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
- // really sucks, cause we're gonna need that eventually.
- let last_hop_htlc_minimum_msat: u64 = match hop.htlc_minimum_msat {
- Some(htlc_minimum_msat) => htlc_minimum_msat,
- None => 0
- };
- let directional_info = DummyDirectionalChannelInfo {
- cltv_expiry_delta: hop.cltv_expiry_delta as u32,
- htlc_minimum_msat: last_hop_htlc_minimum_msat,
- htlc_maximum_msat: hop.htlc_maximum_msat,
- fees: hop.fees,
- };
- add_entry!(hop.short_channel_id, hop.src_node_id, target, directional_info, None::<u64>, ChannelFeatures::empty(), 0);
+ // Add the payee as a target, so that the payee-to-payer
+ // search algorithm knows what to start with.
+ match network.get_nodes().get(payee) {
+ // The payee is not in our network graph, so nothing to add here.
+ // There is still a chance of reaching them via last_hops though,
+ // so don't yet fail the payment here.
+ // If not, targets.pop() will not even let us enter the loop in step 2.
+ None => {},
+ Some(node) => {
+ add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0);
+ },
}
- }
- while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
- if pubkey == *our_node_id {
- let mut res = vec!(dist.remove(&our_node_id).unwrap().3);
- loop {
- if let Some(&(_, ref features)) = first_hop_targets.get(&res.last().unwrap().pubkey) {
- res.last_mut().unwrap().node_features = features.to_context();
- } else if let Some(node) = network.get_nodes().get(&res.last().unwrap().pubkey) {
- if let Some(node_info) = node.announcement_info.as_ref() {
- res.last_mut().unwrap().node_features = node_info.features.clone();
+ // Step (1).
+ // If a caller provided us with last hops, add them to routing targets. Since this happens
+ // earlier than general path finding, they will be somewhat prioritized, although currently
+ // it matters only if the fees are exactly the same.
+ for hop in last_hops.iter() {
+ let have_hop_src_in_graph =
+ // Only add the last hop to our candidate set if either we have a direct channel or
+ // they are in the regular network graph.
+ first_hop_targets.get(&hop.src_node_id).is_some() ||
+ network.get_nodes().get(&hop.src_node_id).is_some();
+ if have_hop_src_in_graph {
+ // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
+ // really sucks, cause we're gonna need that eventually.
+ let last_hop_htlc_minimum_msat: u64 = match hop.htlc_minimum_msat {
+ Some(htlc_minimum_msat) => htlc_minimum_msat,
+ None => 0
+ };
+ let directional_info = DummyDirectionalChannelInfo {
+ cltv_expiry_delta: hop.cltv_expiry_delta as u32,
+ htlc_minimum_msat: last_hop_htlc_minimum_msat,
+ htlc_maximum_msat: hop.htlc_maximum_msat,
+ fees: hop.fees,
+ };
+ if add_entry!(hop.short_channel_id, hop.src_node_id, payee, directional_info, None::<u64>, &empty_channel_features, 0, path_value_msat, 0) {
+ // If this hop connects to a node with which we have a direct channel,
+ // ignore the network graph and, if the last hop was added, add our
+ // direct channel to the candidate set.
+ //
+ // Note that we *must* check if the last hop was added as `add_entry`
+ // always assumes that the third argument is a node to which we have a
+ // path.
+ if let Some(&(ref first_hop, ref features, ref outbound_capacity_msat, _)) = first_hop_targets.get(&hop.src_node_id) {
+ 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);
+ }
+ }
+ }
+ }
+
+ log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
+
+ // At this point, targets are filled with the data from first and
+ // last hops communicated by the caller, and the payment receiver.
+ let mut found_new_path = false;
+
+ // Step (2).
+ // If this loop terminates due the exhaustion of targets, two situations are possible:
+ // - not enough outgoing liquidity:
+ // 0 < already_collected_value_msat < final_value_msat
+ // - enough outgoing liquidity:
+ // final_value_msat <= already_collected_value_msat < recommended_value_msat
+ // Both these cases (and other cases except reaching recommended_value_msat) mean that
+ // paths_collection will be stopped because found_new_path==false.
+ // This is not necessarily a routing failure.
+ 'path_construction: while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, .. }) = targets.pop() {
+
+ // Since we're going payee-to-payer, hitting our node as a target means we should stop
+ // traversing the graph and arrange the path out of what we found.
+ if pubkey == *our_node_id {
+ let mut new_entry = dist.remove(&our_node_id).unwrap();
+ let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
+
+ 'path_walk: loop {
+ if let Some(&(_, _, _, ref features)) = first_hop_targets.get(&ordered_hops.last().unwrap().0.pubkey) {
+ ordered_hops.last_mut().unwrap().1 = features.clone();
+ } else if let Some(node) = network.get_nodes().get(&ordered_hops.last().unwrap().0.pubkey) {
+ if let Some(node_info) = node.announcement_info.as_ref() {
+ ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
+ } else {
+ ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
+ }
} else {
- res.last_mut().unwrap().node_features = NodeFeatures::empty();
+ // We should be able to fill in features for everything except the last
+ // hop, if the last hop was provided via a BOLT 11 invoice (though we
+ // should be able to extend it further as BOLT 11 does have feature
+ // flags for the last hop node itself).
+ assert!(ordered_hops.last().unwrap().0.pubkey == *payee);
}
- } else {
- // We should be able to fill in features for everything except the last
- // hop, if the last hop was provided via a BOLT 11 invoice (though we
- // should be able to extend it further as BOLT 11 does have feature
- // flags for the last hop node itself).
- assert!(res.last().unwrap().pubkey == *target);
+
+ // Means we succesfully traversed from the payer to the payee, now
+ // save this path for the payment route. Also, update the liquidity
+ // remaining on the used hops, so that we take them into account
+ // while looking for more paths.
+ if ordered_hops.last().unwrap().0.pubkey == *payee {
+ break 'path_walk;
+ }
+
+ new_entry = match dist.remove(&ordered_hops.last().unwrap().0.pubkey) {
+ Some(payment_hop) => payment_hop,
+ // We can't arrive at None because, if we ever add an entry to targets,
+ // we also fill in the entry in dist (see add_entry!).
+ None => unreachable!(),
+ };
+ // We "propagate" the fees one hop backward (topologically) here,
+ // so that fees paid for a HTLC forwarding on the current channel are
+ // associated with the previous channel (where they will be subtracted).
+ ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
+ ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = new_entry.cltv_expiry_delta;
+ ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
+ }
+ ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
+ ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
+ ordered_hops.last_mut().unwrap().0.cltv_expiry_delta = final_cltv;
+
+ log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: {:?}",
+ ordered_hops.len(), value_contribution_msat, ordered_hops);
+
+ let mut payment_path = PaymentPath {hops: ordered_hops};
+
+ // We could have possibly constructed a slightly inconsistent path: since we reduce
+ // value being transferred along the way, we could have violated htlc_minimum_msat
+ // on some channels we already passed (assuming dest->source direction). Here, we
+ // recompute the fees again, so that if that's the case, we match the currently
+ // underpaid htlc_minimum_msat with fees.
+ payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
+
+ // Since a path allows to transfer as much value as
+ // the smallest channel it has ("bottleneck"), we should recompute
+ // the fees so sender HTLC don't overpay fees when traversing
+ // larger channels than the bottleneck. This may happen because
+ // when we were selecting those channels we were not aware how much value
+ // this path will transfer, and the relative fee for them
+ // might have been computed considering a larger value.
+ // Remember that we used these channels so that we don't rely
+ // on the same liquidity in future paths.
+ let mut prevented_redundant_path_selection = false;
+ for (payment_hop, _) in payment_path.hops.iter() {
+ let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.short_channel_id).unwrap();
+ let mut spent_on_hop_msat = value_contribution_msat;
+ let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
+ spent_on_hop_msat += next_hops_fee_msat;
+ if spent_on_hop_msat == *channel_liquidity_available_msat {
+ // If this path used all of this channel's available liquidity, we know
+ // this path will not be selected again in the next loop iteration.
+ prevented_redundant_path_selection = true;
+ }
+ *channel_liquidity_available_msat -= spent_on_hop_msat;
}
- if res.last().unwrap().pubkey == *target {
+ if !prevented_redundant_path_selection {
+ // If we weren't capped by hitting a liquidity limit on a channel in the path,
+ // we'll probably end up picking the same path again on the next iteration.
+ // Decrease the available liquidity of a hop in the middle of the path.
+ let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.short_channel_id;
+ log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
+ let victim_liquidity = bookkeeped_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
+ *victim_liquidity = 0;
+ }
+
+ // Track the total amount all our collected paths allow to send so that we:
+ // - know when to stop looking for more paths
+ // - know which of the hops are useless considering how much more sats we need
+ // (contributes_sufficient_value)
+ already_collected_value_msat += value_contribution_msat;
+
+ payment_paths.push(payment_path);
+ found_new_path = true;
+ break 'path_construction;
+ }
+
+ // If we found a path back to the payee, we shouldn't try to process it again. This is
+ // the equivalent of the `elem.was_processed` check in
+ // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
+ if pubkey == *payee { continue 'path_construction; }
+
+ // Otherwise, since the current target node is not us,
+ // keep "unrolling" the payment graph from payee to payer by
+ // finding a way to reach the current target from the payer side.
+ match network.get_nodes().get(&pubkey) {
+ None => {},
+ Some(node) => {
+ add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat);
+ },
+ }
+ }
+
+ if !allow_mpp {
+ // If we don't support MPP, no use trying to gather more value ever.
+ break 'paths_collection;
+ }
+
+ // Step (3).
+ // Stop either when the recommended value is reached or if no new path was found in this
+ // iteration.
+ // In the latter case, making another path finding attempt won't help,
+ // because we deterministically terminated the search due to low liquidity.
+ if already_collected_value_msat >= recommended_value_msat || !found_new_path {
+ log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
+ already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
+ break 'paths_collection;
+ } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
+ // Further, if this was our first walk of the graph, and we weren't limited by an
+ // htlc_minimum_msat, return immediately because this path should suffice. If we were
+ // limited by an htlc_minimum_msat value, find another path with a higher value,
+ // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
+ // still keeping a lower total fee than this path.
+ if !hit_minimum_limit {
+ log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
+ break 'paths_collection;
+ }
+ log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
+ path_value_msat = recommended_value_msat;
+ }
+ }
+
+ // Step (4).
+ if payment_paths.len() == 0 {
+ return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
+ }
+
+ if already_collected_value_msat < final_value_msat {
+ return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
+ }
+
+ // Sort by total fees and take the best paths.
+ payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
+ if payment_paths.len() > 50 {
+ payment_paths.truncate(50);
+ }
+
+ // Draw multiple sufficient routes by randomly combining the selected paths.
+ let mut drawn_routes = Vec::new();
+ for i in 0..payment_paths.len() {
+ let mut cur_route = Vec::<PaymentPath>::new();
+ let mut aggregate_route_value_msat = 0;
+
+ // Step (5).
+ // TODO: real random shuffle
+ // Currently just starts with i_th and goes up to i-1_th in a looped way.
+ let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
+
+ // Step (6).
+ for payment_path in cur_payment_paths {
+ cur_route.push(payment_path.clone());
+ aggregate_route_value_msat += payment_path.get_value_msat();
+ if aggregate_route_value_msat > final_value_msat {
+ // Last path likely overpaid. Substract it from the most expensive
+ // (in terms of proportional fee) path in this route and recompute fees.
+ // This might be not the most economically efficient way, but fewer paths
+ // also makes routing more reliable.
+ let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
+
+ // First, drop some expensive low-value paths entirely if possible.
+ // Sort by value so that we drop many really-low values first, since
+ // fewer paths is better: the payment is less likely to fail.
+ // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
+ // so that the sender pays less fees overall. And also htlc_minimum_msat.
+ cur_route.sort_by_key(|path| path.get_value_msat());
+ // We should make sure that at least 1 path left.
+ let mut paths_left = cur_route.len();
+ cur_route.retain(|path| {
+ if paths_left == 1 {
+ return true
+ }
+ let mut keep = true;
+ let path_value_msat = path.get_value_msat();
+ if path_value_msat <= overpaid_value_msat {
+ keep = false;
+ overpaid_value_msat -= path_value_msat;
+ paths_left -= 1;
+ }
+ keep
+ });
+
+ if overpaid_value_msat == 0 {
break;
}
- let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
- Some(hop) => hop.3,
- None => return Err(LightningError{err: "Failed to find a non-fee-overflowing path to the given destination".to_owned(), action: ErrorAction::IgnoreError}),
- };
- res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
- res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
- res.push(new_entry);
+ assert!(cur_route.len() > 0);
+
+ // Step (7).
+ // Now, substract the overpaid value from the most-expensive path.
+ // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
+ // so that the sender pays less fees overall. And also htlc_minimum_msat.
+ cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.channel_fees.proportional_millionths as u64).sum::<u64>() });
+ let expensive_payment_path = cur_route.first_mut().unwrap();
+ // We already dropped all the small channels above, meaning all the
+ // remaining channels are larger than remaining overpaid_value_msat.
+ // Thus, this can't be negative.
+ let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
+ expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
+ break;
}
- res.last_mut().unwrap().fee_msat = final_value_msat;
- res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
- let route = Route { paths: vec![res] };
- log_trace!(logger, "Got route: {}", log_route!(route));
- return Ok(route);
}
+ drawn_routes.push(cur_route);
+ }
- match network.get_nodes().get(&pubkey) {
- None => {},
- Some(node) => {
- add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
- },
+ // Step (8).
+ // Select the best route by lowest total fee.
+ drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
+ let mut selected_paths = Vec::<Vec<RouteHop>>::new();
+ for payment_path in drawn_routes.first().unwrap() {
+ selected_paths.push(payment_path.hops.iter().map(|(payment_hop, node_features)| {
+ RouteHop {
+ pubkey: payment_hop.pubkey,
+ node_features: node_features.clone(),
+ short_channel_id: payment_hop.short_channel_id,
+ channel_features: payment_hop.channel_features.clone(),
+ fee_msat: payment_hop.fee_msat,
+ cltv_expiry_delta: payment_hop.cltv_expiry_delta,
+ }
+ }).collect());
+ }
+
+ if let Some(features) = &payee_features {
+ for path in selected_paths.iter_mut() {
+ path.last_mut().unwrap().node_features = features.to_context();
}
}
- Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError})
+ let route = Route { paths: selected_paths };
+ log_info!(logger, "Got route to {}: {}", payee, log_route!(route));
+ Ok(route)
}
#[cfg(test)]
mod tests {
- use routing::router::{get_route, RouteHint, RoutingFees};
+ use routing::router::{get_route, Route, RouteHint, RouteHintHop, RoutingFees};
use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
- use ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
+ use chain::transaction::OutPoint;
+ use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
use ln::channelmanager;
use bitcoin::hashes::Hash;
use bitcoin::network::constants::Network;
use bitcoin::blockdata::constants::genesis_block;
+ use bitcoin::blockdata::script::Builder;
+ use bitcoin::blockdata::opcodes;
+ use bitcoin::blockdata::transaction::TxOut;
use hex;
use bitcoin::secp256k1::key::{PublicKey,SecretKey};
use bitcoin::secp256k1::{Secp256k1, All};
+ use prelude::*;
use std::sync::Arc;
// Using the same keys for LN and BTC ids
match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
Ok(res) => assert!(res),
- // Err(_) => panic!()
- Err(e) => println!("{:?}", e.err)
+ Err(_) => panic!()
};
}
-
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,
features: NodeFeatures, timestamp: u32) {
let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
}
}
- fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<std::sync::Arc<crate::util::test_utils::TestChainSource>, std::sync::Arc<crate::util::test_utils::TestLogger>>, std::sync::Arc<test_utils::TestLogger>) {
+ fn build_graph() -> (Secp256k1<All>, NetGraphMsgHandler<std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<crate::util::test_utils::TestLogger>>, std::sync::Arc<test_utils::TestChainSource>, std::sync::Arc<test_utils::TestLogger>) {
let secp_ctx = Secp256k1::new();
let logger = Arc::new(test_utils::TestLogger::new());
+ let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
// Build network from our_id to node7:
//
add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
- (secp_ctx, net_graph_msg_handler, logger)
+ (secp_ctx, net_graph_msg_handler, chain_monitor, logger)
}
#[test]
fn simple_route_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
- // Simple route to 3 via 2
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
+ // Simple route to 2 via 1
+
+ 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)) {
+ assert_eq!(err, "Cannot send a payment of 0 msat");
+ } else { panic!(); }
+
+ 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();
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, nodes[1]);
}
#[test]
- fn disable_channels_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ fn invalid_first_hop_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+
+ // Simple route to 2 via 1
+
+ let our_chans = vec![channelmanager::ChannelDetails {
+ channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
+ short_channel_id: Some(2),
+ remote_network_id: our_id,
+ counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
+ channel_value_satoshis: 100000,
+ user_id: 0,
+ outbound_capacity_msat: 100000,
+ inbound_capacity_msat: 100000,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
+ }];
+
+ 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)) {
+ assert_eq!(err, "First hop cannot have our_node_id as a destination.");
+ } else { panic!(); }
+
+ 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();
+ assert_eq!(route.paths[0].len(), 2);
+ }
+
+ #[test]
+ fn htlc_minimum_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
- // // Disable channels 4 and 12 by flags=2
- update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ // Simple route to 2 via 1
+
+ // Disable other paths
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
chain_hash: genesis_block(Network::Testnet).header.block_hash(),
- short_channel_id: 4,
+ short_channel_id: 12,
timestamp: 2,
flags: 2, // to disable
cltv_expiry_delta: 0,
fee_proportional_millionths: 0,
excess_data: Vec::new()
});
- update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
chain_hash: genesis_block(Network::Testnet).header.block_hash(),
- short_channel_id: 12,
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 2,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 7,
timestamp: 2,
flags: 2, // to disable
cltv_expiry_delta: 0,
excess_data: Vec::new()
});
- // If all the channels require some features we don't understand, route should fail
- if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
+ // Check against amount_to_transfer_over_msat.
+ // Set minimal HTLC of 200_000_000 msat.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 3,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 200_000_000,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
+ // be used.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 3,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(199_999_999),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
+ 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)) {
assert_eq!(err, "Failed to find a path to the given destination");
} else { panic!(); }
- // If we specify a channel to node7, that overrides our local channel view and that gets used
- let our_chans = vec![channelmanager::ChannelDetails {
- channel_id: [0; 32],
+ // Lift the restriction on the first hop.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 4,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // A payment above the minimum should pass
+ 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();
+ assert_eq!(route.paths[0].len(), 2);
+ }
+
+ #[test]
+ fn htlc_minimum_overpay_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // A route to node#2 via two paths.
+ // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
+ // Thus, they can't send 60 without overpaying.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 35_000,
+ htlc_maximum_msat: OptionalField::Present(40_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 3,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 35_000,
+ htlc_maximum_msat: OptionalField::Present(40_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Make 0 fee.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Disable other paths
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 3,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
+ // Overpay fees to hit htlc_minimum_msat.
+ let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
+ // TODO: this could be better balanced to overpay 10k and not 15k.
+ assert_eq!(overpaid_fees, 15_000);
+
+ // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
+ // while taking even more fee to match htlc_minimum_msat.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 4,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 65_000,
+ htlc_maximum_msat: OptionalField::Present(80_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 3,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 4,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 100_000,
+ excess_data: Vec::new()
+ });
+
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)).unwrap();
+ // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0][0].short_channel_id, 12);
+ let fees = route.paths[0][0].fee_msat;
+ assert_eq!(fees, 5_000);
+
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
+ // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
+ // the other channel.
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0][0].short_channel_id, 2);
+ let fees = route.paths[0][0].fee_msat;
+ assert_eq!(fees, 5_000);
+ }
+
+ #[test]
+ fn disable_channels_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // // Disable channels 4 and 12 by flags=2
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 2,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 2, // to disable
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // If all the channels require some features we don't understand, route should fail
+ 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)) {
+ assert_eq!(err, "Failed to find a path to the given destination");
+ } else { panic!(); }
+
+ // If we specify a channel to node7, that overrides our local channel view and that gets used
+ let our_chans = vec![channelmanager::ChannelDetails {
+ channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
short_channel_id: Some(42),
remote_network_id: nodes[7].clone(),
counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
channel_value_satoshis: 0,
user_id: 0,
- outbound_capacity_msat: 0,
+ outbound_capacity_msat: 250_000_000,
inbound_capacity_msat: 0,
- is_live: true,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
}];
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, nodes[7]);
#[test]
fn disable_node_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
// Disable nodes 1, 2, and 8 by requiring unknown feature bits
add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
// If all nodes require some features we don't understand, route should fail
- if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, &Vec::new(), 100, 42, Arc::clone(&logger)) {
+ 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)) {
assert_eq!(err, "Failed to find a path to the given destination");
} else { panic!(); }
// If we specify a channel to node7, that overrides our local channel view and that gets used
let our_chans = vec![channelmanager::ChannelDetails {
channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
short_channel_id: Some(42),
remote_network_id: nodes[7].clone(),
counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
channel_value_satoshis: 0,
user_id: 0,
- outbound_capacity_msat: 0,
+ outbound_capacity_msat: 250_000_000,
inbound_capacity_msat: 0,
- is_live: true,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
}];
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, nodes[7]);
#[test]
fn our_chans_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
// Route to 1 via 2 and 3 because our channel to 1 is disabled
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[0], None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 3);
assert_eq!(route.paths[0][0].pubkey, nodes[1]);
// If we specify a channel to node7, that overrides our local channel view and that gets used
let our_chans = vec![channelmanager::ChannelDetails {
channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
short_channel_id: Some(42),
remote_network_id: nodes[7].clone(),
counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
channel_value_satoshis: 0,
user_id: 0,
- outbound_capacity_msat: 0,
+ outbound_capacity_msat: 250_000_000,
inbound_capacity_msat: 0,
- is_live: true,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
}];
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, nodes[7]);
base_msat: 0,
proportional_millionths: 0,
};
- vec!(RouteHint {
+ vec![RouteHint(vec![RouteHintHop {
src_node_id: nodes[3].clone(),
short_channel_id: 8,
fees: zero_fees,
cltv_expiry_delta: (8 << 8) | 1,
htlc_minimum_msat: None,
htlc_maximum_msat: None,
- }, RouteHint {
+ }]), RouteHint(vec![RouteHintHop {
src_node_id: nodes[4].clone(),
short_channel_id: 9,
fees: RoutingFees {
cltv_expiry_delta: (9 << 8) | 1,
htlc_minimum_msat: None,
htlc_maximum_msat: None,
- }, RouteHint {
+ }]), RouteHint(vec![RouteHintHop {
src_node_id: nodes[5].clone(),
short_channel_id: 10,
fees: zero_fees,
cltv_expiry_delta: (10 << 8) | 1,
htlc_minimum_msat: None,
htlc_maximum_msat: None,
- })
+ }])]
}
#[test]
fn last_hops_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
// Simple test across 2, 3, 5, and 4 via a last_hop channel
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, &last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
+
+ // First check that last hop can't have its source as the payee.
+ let invalid_last_hop = RouteHint(vec![RouteHintHop {
+ src_node_id: nodes[6],
+ short_channel_id: 8,
+ fees: RoutingFees {
+ base_msat: 1000,
+ proportional_millionths: 0,
+ },
+ cltv_expiry_delta: (8 << 8) | 1,
+ htlc_minimum_msat: None,
+ htlc_maximum_msat: None,
+ }]);
+
+ let mut invalid_last_hops = last_hops(&nodes);
+ invalid_last_hops.push(invalid_last_hop);
+ {
+ 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)) {
+ assert_eq!(err, "Last hop cannot have a payee as a source.");
+ } else { panic!(); }
+ }
+
+ 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();
assert_eq!(route.paths[0].len(), 5);
assert_eq!(route.paths[0][0].pubkey, nodes[1]);
#[test]
fn our_chans_last_hop_connect_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
// Simple test with outbound channel to 4 to test that last_hops and first_hops connect
let our_chans = vec![channelmanager::ChannelDetails {
channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
short_channel_id: Some(42),
remote_network_id: nodes[3].clone(),
counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
channel_value_satoshis: 0,
user_id: 0,
- outbound_capacity_msat: 0,
+ outbound_capacity_msat: 250_000_000,
inbound_capacity_msat: 0,
- is_live: true,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
}];
let mut last_hops = last_hops(&nodes);
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, nodes[3]);
assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
- last_hops[0].fees.base_msat = 1000;
+ last_hops[0].0[0].fees.base_msat = 1000;
// Revert to via 6 as the fee on 8 goes up
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 4);
assert_eq!(route.paths[0][0].pubkey, nodes[1]);
assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
// ...but still use 8 for larger payments as 6 has a variable feerate
- let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, &last_hops.iter().collect::<Vec<_>>(), 2000, 42, Arc::clone(&logger)).unwrap();
+ 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();
assert_eq!(route.paths[0].len(), 5);
assert_eq!(route.paths[0][0].pubkey, nodes[1]);
assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
}
- #[test]
- fn unannounced_path_test() {
- // We should be able to send a payment to a destination without any help of a routing graph
- // if we have a channel with a common counterparty that appears in the first and last hop
- // hints.
+ 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> {
let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
// If we specify a channel to a middle hop, that overrides our local channel view and that gets used
- let last_hops = vec![RouteHint {
+ let last_hops = RouteHint(vec![RouteHintHop {
src_node_id: middle_node_id,
short_channel_id: 8,
fees: RoutingFees {
base_msat: 1000,
- proportional_millionths: 0,
+ proportional_millionths: last_hop_fee_prop,
},
cltv_expiry_delta: (8 << 8) | 1,
htlc_minimum_msat: None,
- htlc_maximum_msat: None,
- }];
+ htlc_maximum_msat: last_hop_htlc_max,
+ }]);
let our_chans = vec![channelmanager::ChannelDetails {
channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
short_channel_id: Some(42),
remote_network_id: middle_node_id,
counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
channel_value_satoshis: 100000,
user_id: 0,
- outbound_capacity_msat: 100000,
+ outbound_capacity_msat: outbound_capacity_msat,
inbound_capacity_msat: 100000,
- is_live: true,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
}];
- let route = get_route(&source_node_id, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()), &target_node_id, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::new(test_utils::TestLogger::new())).unwrap();
+ 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()))
+ }
+ #[test]
+ fn unannounced_path_test() {
+ // We should be able to send a payment to a destination without any help of a routing graph
+ // if we have a channel with a common counterparty that appears in the first and last hop
+ // hints.
+ let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
+
+ let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
+ let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
assert_eq!(route.paths[0].len(), 2);
assert_eq!(route.paths[0][0].pubkey, middle_node_id);
assert_eq!(route.paths[0][0].short_channel_id, 42);
- assert_eq!(route.paths[0][0].fee_msat, 1000);
+ assert_eq!(route.paths[0][0].fee_msat, 1001);
assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
assert_eq!(route.paths[0][1].pubkey, target_node_id);
assert_eq!(route.paths[0][1].short_channel_id, 8);
- assert_eq!(route.paths[0][1].fee_msat, 100);
+ assert_eq!(route.paths[0][1].fee_msat, 1000000);
assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
}
+
+ #[test]
+ fn overflow_unannounced_path_test_liquidity_underflow() {
+ // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
+ // the last-hop had a fee which overflowed a u64, we'd panic.
+ // This was due to us adding the first-hop from us unconditionally, causing us to think
+ // we'd built a path (as our node is in the "best candidate" set), when we had not.
+ // In this test, we previously hit a subtraction underflow due to having less available
+ // liquidity at the last hop than 0.
+ 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());
+ }
+
+ #[test]
+ fn overflow_unannounced_path_test_feerate_overflow() {
+ // This tests for the same case as above, except instead of hitting a subtraction
+ // underflow, we hit a case where the fee charged at a hop overflowed.
+ 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());
+ }
+
+ #[test]
+ fn available_amount_while_routing_test() {
+ // Tests whether we choose the correct available channel amount while routing.
+
+ let (secp_ctx, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We will use a simple single-path route from
+ // our node to node2 via node0: channels {1, 3}.
+
+ // First disable all other paths.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Make the first channel (#1) very permissive,
+ // and we will be testing all limits on the second channel.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(1_000_000_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // First, let's see if routing works if we have absolutely no idea about the available amount.
+ // In this case, it should be set to 250_000 sats.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_001, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route an exact amount we have should be fine.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let path = route.paths.last().unwrap();
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
+ }
+
+ // Check that setting outbound_capacity_msat in first_hops limits the channels.
+ // Disable channel #1 and use another first hop.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 3,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(1_000_000_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
+ let our_chans = vec![channelmanager::ChannelDetails {
+ channel_id: [0; 32],
+ funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
+ short_channel_id: Some(42),
+ remote_network_id: nodes[0].clone(),
+ counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
+ channel_value_satoshis: 0,
+ user_id: 0,
+ outbound_capacity_msat: 200_000_000,
+ inbound_capacity_msat: 0,
+ is_outbound: true, is_funding_locked: true,
+ is_usable: true, is_public: true,
+ counterparty_forwarding_info: None,
+ }];
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_001, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route an exact amount we have should be fine.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), Some(&our_chans.iter().collect::<Vec<_>>()), &Vec::new(), 200_000_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let path = route.paths.last().unwrap();
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
+ }
+
+ // Enable channel #1 back.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 4,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(1_000_000_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+
+ // Now let's see if routing works if we know only htlc_maximum_msat.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 3,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(15_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route an exact amount we have should be fine.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let path = route.paths.last().unwrap();
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ assert_eq!(path.last().unwrap().fee_msat, 15_000);
+ }
+
+ // Now let's see if routing works if we know only capacity from the UTXO.
+
+ // We can't change UTXO capacity on the fly, so we'll disable
+ // the existing channel and add another one with the capacity we need.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 4,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
+ .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
+ .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
+ .push_opcode(opcodes::all::OP_PUSHNUM_2)
+ .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
+
+ *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
+ net_graph_msg_handler.add_chain_access(Some(chain_monitor));
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 333,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (3 << 8) | 1,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 333,
+ timestamp: 1,
+ flags: 1,
+ cltv_expiry_delta: (3 << 8) | 2,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 100,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 15_001, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route an exact amount we have should be fine.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 15_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let path = route.paths.last().unwrap();
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ assert_eq!(path.last().unwrap().fee_msat, 15_000);
+ }
+
+ // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 333,
+ timestamp: 6,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(10_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 10_001, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route an exact amount we have should be fine.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 10_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let path = route.paths.last().unwrap();
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ assert_eq!(path.last().unwrap().fee_msat, 10_000);
+ }
+ }
+
+ #[test]
+ fn available_liquidity_last_hop_test() {
+ // Check that available liquidity properly limits the path even when only
+ // one of the latter hops is limited.
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
+ // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
+ // Total capacity: 50 sats.
+
+ // Disable other potential paths.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 7,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Limit capacities
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(50_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 11,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 60_000, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route 49 sats (just a bit below the capacity).
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 49_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 4);
+ assert_eq!(path.last().unwrap().pubkey, nodes[3]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 49_000);
+ }
+
+ {
+ // Attempt to route an exact amount is also fine
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 4);
+ assert_eq!(path.last().unwrap().pubkey, nodes[3]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 50_000);
+ }
+ }
+
+ #[test]
+ fn ignore_fee_first_hop_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 1_000_000,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(50_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ 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();
+ assert_eq!(route.paths.len(), 1);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 50_000);
+ }
+ }
+
+ #[test]
+ fn simple_mpp_route_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We need a route consisting of 3 paths:
+ // From our node to node2 via node0, node7, node1 (three paths one hop each).
+ // To achieve this, the amount being transferred should be around
+ // the total capacity of these 3 paths.
+
+ // First, we set limits on these (previously unlimited) channels.
+ // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
+
+ // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(50_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
+ // (total limit 60).
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(60_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(60_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
+ // (total capacity 180 sats).
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(180_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(),
+ &nodes[2], Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route 250 sats (just a bit below the capacity).
+ // Our algorithm should provide us with these 3 paths.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 250_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 3);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 250_000);
+ }
+
+ {
+ // Attempt to route an exact amount is also fine
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 290_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 3);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 290_000);
+ }
+ }
+
+ #[test]
+ fn long_mpp_route_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We need a route consisting of 3 paths:
+ // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
+ // Note that these paths overlap (channels 5, 12, 13).
+ // We will route 300 sats.
+ // Each path will have 100 sats capacity, those channels which
+ // are used twice will have 200 sats capacity.
+
+ // Disable other potential paths.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 7,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node0, node2} is channels {1, 3, 5}.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Capacity of 200 sats because this channel will be used by 3rd path as well.
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 5,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
+ // Add 100 sats to the capacities of {12, 13}, because these channels
+ // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 11,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node7, node2} is channels {12, 13, 5}.
+ // We already limited them to 200 sats (they are used twice for 100 sats).
+ // Nothing to do here.
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 350_000, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route 300 sats (exact amount we can route).
+ // Our algorithm should provide us with these 3 paths, 100 sats each.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 300_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 3);
+
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.last().unwrap().pubkey, nodes[3]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 300_000);
+ }
+
+ }
+
+ #[test]
+ fn mpp_cheaper_route_test() {
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // This test checks that if we have two cheaper paths and one more expensive path,
+ // so that liquidity-wise any 2 of 3 combination is sufficient,
+ // two cheaper paths will be taken.
+ // These paths have equal available liquidity.
+
+ // We need a combination of 3 paths:
+ // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
+ // Note that these paths overlap (channels 5, 12, 13).
+ // Each path will have 100 sats capacity, those channels which
+ // are used twice will have 200 sats capacity.
+
+ // Disable other potential paths.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 7,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node0, node2} is channels {1, 3, 5}.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Capacity of 200 sats because this channel will be used by 3rd path as well.
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 5,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
+ // Add 100 sats to the capacities of {12, 13}, because these channels
+ // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(200_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 1_000,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 11,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node7, node2} is channels {12, 13, 5}.
+ // We already limited them to 200 sats (they are used twice for 100 sats).
+ // Nothing to do here.
+
+ {
+ // Now, attempt to route 180 sats.
+ // Our algorithm should provide us with these 2 paths.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 180_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 2);
+
+ let mut total_value_transferred_msat = 0;
+ let mut total_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.last().unwrap().pubkey, nodes[3]);
+ total_value_transferred_msat += path.last().unwrap().fee_msat;
+ for hop in path {
+ total_paid_msat += hop.fee_msat;
+ }
+ }
+ // If we paid fee, this would be higher.
+ assert_eq!(total_value_transferred_msat, 180_000);
+ let total_fees_paid = total_paid_msat - total_value_transferred_msat;
+ assert_eq!(total_fees_paid, 0);
+ }
+ }
+
+ #[test]
+ fn fees_on_mpp_route_test() {
+ // This test makes sure that MPP algorithm properly takes into account
+ // fees charged on the channels, by making the fees impactful:
+ // if the fee is not properly accounted for, the behavior is different.
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We need a route consisting of 2 paths:
+ // From our node to node3 via {node0, node2} and {node7, node2, node4}.
+ // We will route 200 sats, Each path will have 100 sats capacity.
+
+ // This test is not particularly stable: e.g.,
+ // there's a way to route via {node0, node2, node4}.
+ // It works while pathfinding is deterministic, but can be broken otherwise.
+ // It's fine to ignore this concern for now.
+
+ // Disable other potential paths.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 7,
+ timestamp: 2,
+ flags: 2,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node0, node2} is channels {1, 3, 5}.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 5,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
+ // All channels should be 100 sats capacity. But for the fee experiment,
+ // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
+ // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
+ // 100 sats (and pay 150 sats in fees for the use of channel 6),
+ // so no matter how large are other channels,
+ // the whole path will be limited by 100 sats with just these 2 conditions:
+ // - channel 12 capacity is 250 sats
+ // - fee for channel 6 is 150 sats
+ // Let's test this by enforcing these 2 conditions and removing other limits.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(250_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 150_000,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 11,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 210_000, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route 200 sats (exact amount we can route).
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[3],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 200_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 2);
+
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.last().unwrap().pubkey, nodes[3]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 200_000);
+ }
+
+ }
+
+ #[test]
+ fn drop_lowest_channel_mpp_route_test() {
+ // This test checks that low-capacity channel is dropped when after
+ // path finding we realize that we found more capacity than we need.
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We need a route consisting of 3 paths:
+ // From our node to node2 via node0, node7, node1 (three paths one hop each).
+
+ // The first and the second paths should be sufficient, but the third should be
+ // cheaper, so that we select it but drop later.
+
+ // First, we set limits on these (previously unlimited) channels.
+ // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
+
+ // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(100_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(50_000),
+ fee_base_msat: 100,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(60_000),
+ fee_base_msat: 100,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 13,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(60_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(20_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(20_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Attempt to route more than available results in a failure.
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 150_000, 42, Arc::clone(&logger)) {
+ assert_eq!(err, "Failed to find a sufficient route to the given destination");
+ } else { panic!(); }
+ }
+
+ {
+ // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
+ // Our algorithm should provide us with these 3 paths.
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2],
+ Some(InvoiceFeatures::known()), None, &Vec::new(), 125_000, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths.len(), 3);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 125_000);
+ }
+
+ {
+ // Attempt to route without the last small cheap channel
+ 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();
+ assert_eq!(route.paths.len(), 2);
+ let mut total_amount_paid_msat = 0;
+ for path in &route.paths {
+ assert_eq!(path.len(), 2);
+ assert_eq!(path.last().unwrap().pubkey, nodes[2]);
+ total_amount_paid_msat += path.last().unwrap().fee_msat;
+ }
+ assert_eq!(total_amount_paid_msat, 90_000);
+ }
+ }
+
+ #[test]
+ fn min_criteria_consistency() {
+ // Test that we don't use an inconsistent metric between updating and walking nodes during
+ // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
+ // was updated with a different criterion from the heap sorting, resulting in loops in
+ // calculated paths. We test for that specific case here.
+
+ // We construct a network that looks like this:
+ //
+ // node2 -1(3)2- node3
+ // 2 2
+ // (2) (4)
+ // 1 1
+ // node1 -1(5)2- node4 -1(1)2- node6
+ // 2
+ // (6)
+ // 1
+ // our_node
+ //
+ // We create a loop on the side of our real path - our destination is node 6, with a
+ // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
+ // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
+ // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
+ // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
+ // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
+ // "previous hop" being set to node 3, creating a loop in the path.
+ let secp_ctx = Secp256k1::new();
+ let logger = Arc::new(test_utils::TestLogger::new());
+ let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 6,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (6 << 8) | 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 5,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (5 << 8) | 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 100,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (4 << 8) | 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 3,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (3 << 8) | 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (2 << 8) | 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 1,
+ timestamp: 1,
+ flags: 0,
+ cltv_expiry_delta: (1 << 8) | 0,
+ htlc_minimum_msat: 100,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
+
+ {
+ // Now ensure the route flows simply over nodes 1 and 4 to 6.
+ 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();
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0].len(), 3);
+
+ assert_eq!(route.paths[0][0].pubkey, nodes[1]);
+ assert_eq!(route.paths[0][0].short_channel_id, 6);
+ assert_eq!(route.paths[0][0].fee_msat, 100);
+ assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 8) | 0);
+ assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
+ assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
+
+ assert_eq!(route.paths[0][1].pubkey, nodes[4]);
+ assert_eq!(route.paths[0][1].short_channel_id, 5);
+ assert_eq!(route.paths[0][1].fee_msat, 0);
+ assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 8) | 0);
+ assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
+ assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
+
+ assert_eq!(route.paths[0][2].pubkey, nodes[6]);
+ assert_eq!(route.paths[0][2].short_channel_id, 1);
+ assert_eq!(route.paths[0][2].fee_msat, 10_000);
+ assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
+ assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
+ assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
+ }
+ }
+
+
+ #[test]
+ fn exact_fee_liquidity_limit() {
+ // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
+ // for us, including later hop fees, we take it. In the first version of our MPP algorithm
+ // we calculated fees on a higher value, resulting in us ignoring such paths.
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
+
+ // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
+ // send.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(85_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 12,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: (4 << 8) | 1,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(270_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 1000000,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
+ // 200% fee charged channel 13 in the 1-to-2 direction.
+ 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();
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0].len(), 2);
+
+ assert_eq!(route.paths[0][0].pubkey, nodes[7]);
+ assert_eq!(route.paths[0][0].short_channel_id, 12);
+ assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
+ assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
+ assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
+ assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
+
+ assert_eq!(route.paths[0][1].pubkey, nodes[2]);
+ assert_eq!(route.paths[0][1].short_channel_id, 13);
+ assert_eq!(route.paths[0][1].fee_msat, 90_000);
+ assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
+ assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
+ assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
+ }
+ }
+
+ #[test]
+ fn htlc_max_reduction_below_min() {
+ // Test that if, while walking the graph, we reduce the value being sent to meet an
+ // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
+ // initial version of MPP we'd accept such routes but reject them while recalculating fees,
+ // resulting in us thinking there is no possible path, even if other paths exist.
+ let (secp_ctx, net_graph_msg_handler, _, logger) = build_graph();
+ let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+
+ // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
+ // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
+ // then try to send 90_000.
+ update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 2,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: OptionalField::Present(80_000),
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+ chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+ short_channel_id: 4,
+ timestamp: 2,
+ flags: 0,
+ cltv_expiry_delta: (4 << 8) | 1,
+ htlc_minimum_msat: 90_000,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+
+ {
+ // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
+ // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
+ // expensive) channels 12-13 path.
+ 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();
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0].len(), 2);
+
+ assert_eq!(route.paths[0][0].pubkey, nodes[7]);
+ assert_eq!(route.paths[0][0].short_channel_id, 12);
+ assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
+ assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
+ assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
+ assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
+
+ assert_eq!(route.paths[0][1].pubkey, nodes[2]);
+ assert_eq!(route.paths[0][1].short_channel_id, 13);
+ assert_eq!(route.paths[0][1].fee_msat, 90_000);
+ assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
+ assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
+ assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
+ }
+ }
+
+ #[cfg(not(feature = "no_std"))]
+ pub(super) fn random_init_seed() -> u64 {
+ // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
+ use core::hash::{BuildHasher, Hasher};
+ let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
+ println!("Using seed of {}", seed);
+ seed
+ }
+ #[cfg(not(feature = "no_std"))]
+ use util::ser::Readable;
+
+ #[test]
+ #[cfg(not(feature = "no_std"))]
+ fn generate_routes() {
+ let mut d = match super::test_utils::get_route_file() {
+ Ok(f) => f,
+ Err(e) => {
+ eprintln!("{}", e);
+ return;
+ },
+ };
+ let graph = NetworkGraph::read(&mut d).unwrap();
+
+ // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
+ let mut seed = random_init_seed() as usize;
+ 'load_endpoints: for _ in 0..10 {
+ loop {
+ seed = seed.overflowing_mul(0xdeadbeef).0;
+ let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ seed = seed.overflowing_mul(0xdeadbeef).0;
+ let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ let amt = seed as u64 % 200_000_000;
+ if get_route(src, &graph, dst, None, None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
+ continue 'load_endpoints;
+ }
+ }
+ }
+ }
+
+ #[test]
+ #[cfg(not(feature = "no_std"))]
+ fn generate_routes_mpp() {
+ let mut d = match super::test_utils::get_route_file() {
+ Ok(f) => f,
+ Err(e) => {
+ eprintln!("{}", e);
+ return;
+ },
+ };
+ let graph = NetworkGraph::read(&mut d).unwrap();
+
+ // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
+ let mut seed = random_init_seed() as usize;
+ 'load_endpoints: for _ in 0..10 {
+ loop {
+ seed = seed.overflowing_mul(0xdeadbeef).0;
+ let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ seed = seed.overflowing_mul(0xdeadbeef).0;
+ let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ let amt = seed as u64 % 200_000_000;
+ if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &test_utils::TestLogger::new()).is_ok() {
+ continue 'load_endpoints;
+ }
+ }
+ }
+ }
+}
+
+#[cfg(all(test, not(feature = "no_std")))]
+pub(crate) mod test_utils {
+ use std::fs::File;
+ /// Tries to open a network graph file, or panics with a URL to fetch it.
+ pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
+ let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
+ .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
+ .or_else(|_| { // Fall back to guessing based on the binary location
+ // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
+ let mut path = std::env::current_exe().unwrap();
+ path.pop(); // lightning-...
+ path.pop(); // deps
+ path.pop(); // debug
+ path.pop(); // target
+ path.push("lightning");
+ path.push("net_graph-2021-05-31.bin");
+ eprintln!("{}", path.to_str().unwrap());
+ File::open(path)
+ })
+ .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");
+ #[cfg(require_route_graph_test)]
+ return Ok(res.unwrap());
+ #[cfg(not(require_route_graph_test))]
+ return res;
+ }
+}
+
+#[cfg(all(test, feature = "unstable", not(feature = "no_std")))]
+mod benches {
+ use super::*;
+ use util::logger::{Logger, Record};
+
+ use test::Bencher;
+
+ struct DummyLogger {}
+ impl Logger for DummyLogger {
+ fn log(&self, _record: &Record) {}
+ }
+
+ #[bench]
+ fn generate_routes(bench: &mut Bencher) {
+ let mut d = test_utils::get_route_file().unwrap();
+ let graph = NetworkGraph::read(&mut d).unwrap();
+
+ // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
+ let mut path_endpoints = Vec::new();
+ let mut seed: usize = 0xdeadbeef;
+ 'load_endpoints: for _ in 0..100 {
+ loop {
+ seed *= 0xdeadbeef;
+ let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ seed *= 0xdeadbeef;
+ let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ let amt = seed as u64 % 1_000_000;
+ if get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok() {
+ path_endpoints.push((src, dst, amt));
+ continue 'load_endpoints;
+ }
+ }
+ }
+
+ // ...then benchmark finding paths between the nodes we learned.
+ let mut idx = 0;
+ bench.iter(|| {
+ let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
+ assert!(get_route(src, &graph, dst, None, None, &[], amt, 42, &DummyLogger{}).is_ok());
+ idx += 1;
+ });
+ }
+
+ #[bench]
+ fn generate_mpp_routes(bench: &mut Bencher) {
+ let mut d = test_utils::get_route_file().unwrap();
+ let graph = NetworkGraph::read(&mut d).unwrap();
+
+ // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
+ let mut path_endpoints = Vec::new();
+ let mut seed: usize = 0xdeadbeef;
+ 'load_endpoints: for _ in 0..100 {
+ loop {
+ seed *= 0xdeadbeef;
+ let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ seed *= 0xdeadbeef;
+ let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+ let amt = seed as u64 % 1_000_000;
+ if get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok() {
+ path_endpoints.push((src, dst, amt));
+ continue 'load_endpoints;
+ }
+ }
+ }
+
+ // ...then benchmark finding paths between the nodes we learned.
+ let mut idx = 0;
+ bench.iter(|| {
+ let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
+ assert!(get_route(src, &graph, dst, Some(InvoiceFeatures::known()), None, &[], amt, 42, &DummyLogger{}).is_ok());
+ idx += 1;
+ });
+ }
}
projects / rust-lightning / blobdiff