use util::logger::Logger;
use std::cmp;
-use std::collections::{HashMap,BinaryHeap};
+use std::collections::{HashMap, BinaryHeap};
use std::ops::Deref;
/// A hop in a route
/// 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.
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.
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
}
impl cmp::Ord for RouteGraphNode {
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)]
+struct PathBuildingHop {
+ /// Hop-specific details unrelated to the path during the routing phase,
+ /// but rather relevant to the LN graph.
+ route_hop: RouteHop,
+ /// 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,
+}
+
+// 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 {
+ hops: Vec<PathBuildingHop>,
+}
+
+impl PaymentPath {
+
+ // 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().route_hop.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.route_hop.fee_msat;
+ }
+ }
+ return result;
+ }
+
+ // If an amount transferred by the path is updated, the fees should be adjusted.
+ // Any other way to change fees may result in an inconsistency.
+ // The caller should make sure values don't fall below htlc_minimum_msat of the used channels.
+ fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
+ let mut total_fee_paid_msat = 0 as u64;
+ for i in (1..self.hops.len()).rev() {
+ let cur_hop_amount_msat = total_fee_paid_msat + value_msat;
+ let mut cur_hop = self.hops.get_mut(i).unwrap();
+ cur_hop.next_hops_fee_msat = total_fee_paid_msat;
+ if let Some(new_fee) = compute_fees(cur_hop_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!();
+ }
+ }
+
+ // Propagate updated fees for the use of the channels to one hop back,
+ // where they will be actually paid (fee_msat).
+ // For the last hop it will represent the value being transferred over this path.
+ for i in 0..self.hops.len() - 1 {
+ let next_hop_use_fee_msat = self.hops.get(i + 1).unwrap().hop_use_fee_msat;
+ self.hops.get_mut(i).unwrap().route_hop.fee_msat = next_hop_use_fee_msat;
+ }
+ self.hops.last_mut().unwrap().route_hop.fee_msat = value_msat;
+ self.hops.last_mut().unwrap().hop_use_fee_msat = 0;
+ }
+}
+
+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).
///
/// Extra routing hops between known nodes and the target will be used if they are included in
/// last_hops.
///
/// 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, 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
+ if final_value_msat == 0 {
+ return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
+ }
+
+ for last_hop in last_hops {
+ 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 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 A*").
// 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
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());
+ // When arranging a route, we select multiple paths so that we can make a multi-path payment.
+ // Don't stop searching for paths when we think they're
+ // sufficient to transfer a given value aggregately.
+ // Search for higher value, so that we collect many more paths,
+ // and then select the best combination among them.
+ const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
+ let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
+
+ // 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::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 {
+ if chan.remote_network_id == *payee {
return Ok(Route {
paths: vec![vec![RouteHop {
pubkey: chan.remote_network_id,
cltv_expiry_delta: final_cltv,
}]],
});
+ } else 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()));
}
}
}
+ // 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.
+ // TODO: we could let a caller specify this. Definitely useful when considering our own channels.
+ let mut bookkeeped_channels_liquidity_available_msat = HashMap::new();
+
+ // 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;
+
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.
+ ( $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 ) => {
+ // 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;
+ 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).
+ let minimal_value_contribution_msat: u64 = (recommended_value_msat - already_collected_value_msat + 19) / 20;
+ // 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!(),
+ };
+
+ // If HTLC minimum is larger than the whole value we're going to transfer, we shouldn't bother
+ // even considering this channel, because it won't be useful.
+ // TODO: Explore simply adding fee to hit htlc_minimum_msat
+ // This is separate from checking amount_to_transfer_over_msat, which also should be
+ // lower-bounded by htlc_minimum_msat. Since we're choosing it as maximum possible,
+ // this channel should just be skipped if it's not sufficient.
+ // amount_to_transfer_over_msat can be both larger and smaller than final_value_msat,
+ // so this can't be derived.
+ let final_value_satisfies_htlc_minimum_msat = final_value_msat >= $directional_info.htlc_minimum_msat;
+ if final_value_satisfies_htlc_minimum_msat &&
+ contributes_sufficient_value && amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat {
+ let hm_entry = dist.entry(&$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 {
+ route_hop: RouteHop {
+ pubkey: $dest_node_id.clone(),
+ node_features: NodeFeatures::empty(),
+ short_channel_id: 0,
+ channel_features: $chan_features.clone(),
+ fee_msat: 0,
+ cltv_expiry_delta: 0,
+ },
+ 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(),
+ }
+ });
+
+ 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;
+ if let Some(prev_hop_fee_msat) = compute_fees(total_fee_msat + amount_to_transfer_over_msat,
+ old_entry.src_lowest_inbound_fees) {
+ if let Some(incremented_total_fee_msat) = total_fee_msat.checked_add(prev_hop_fee_msat) {
+ total_fee_msat = incremented_total_fee_msat;
+ }
+ else {
+ // max_value means we'll always fail
+ // the old_entry.total_fee_msat > total_fee_msat check
+ total_fee_msat = u64::max_value();
+ }
+ } else {
+ // max_value means we'll always fail
+ // the old_entry.total_fee_msat > total_fee_msat check
+ total_fee_msat = u64::max_value();
+ }
+ }
+ }
}
- (u64::max_value(),
- fee_base_msat,
- fee_proportional_millionths,
- RouteHop {
+
+ 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,
+ };
+
+ // 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).
+ if old_entry.total_fee_msat > total_fee_msat {
+ 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.route_hop = RouteHop {
pubkey: $dest_node_id.clone(),
node_features: NodeFeatures::empty(),
- short_channel_id: 0,
+ short_channel_id: $chan_id.clone(),
channel_features: $chan_features.clone(),
- 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();
+ fee_msat: 0, // This value will be later filled with hop_use_fee_msat of the following channel
+ cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
+ };
+ old_entry.channel_fees = $directional_info.fees;
}
}
- 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;
- }
}
}
};
}
+ // 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 ) => {
+ ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr ) => {
if first_hops.is_some() {
if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&$node_id) {
- add_entry!(first_hop, *our_node_id, $node_id, dummy_directional_info, None::<u64>, features.to_context(), $fee_to_target_msat);
+ add_entry!(first_hop, *our_node_id, $node_id, dummy_directional_info, None::<u64>, features.to_context(), $fee_to_target_msat, $next_hops_value_contribution);
}
}
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);
+ 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);
}
}
}
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);
+ 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);
}
}
};
}
- 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();
+
+ // 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, recommended_value_msat);
+ },
+ }
- 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);
+ // 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 =
+ 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, recommended_value_msat);
+ 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, payee, directional_info, None::<u64>, ChannelFeatures::empty(), 0, recommended_value_msat);
+ }
}
- }
- 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();
+ // 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, .. }) = 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());
+
+ 'path_walk: loop {
+ if let Some(&(_, ref features)) = first_hop_targets.get(&ordered_hops.last().unwrap().route_hop.pubkey) {
+ ordered_hops.last_mut().unwrap().route_hop.node_features = features.to_context();
+ } else if let Some(node) = network.get_nodes().get(&ordered_hops.last().unwrap().route_hop.pubkey) {
+ if let Some(node_info) = node.announcement_info.as_ref() {
+ ordered_hops.last_mut().unwrap().route_hop.node_features = node_info.features.clone();
+ } else {
+ ordered_hops.last_mut().unwrap().route_hop.node_features = 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().route_hop.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().route_hop.pubkey == *payee {
+ break 'path_walk;
+ }
+
+ new_entry = match dist.remove(&ordered_hops.last().unwrap().route_hop.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().route_hop.fee_msat = new_entry.hop_use_fee_msat;
+ ordered_hops.last_mut().unwrap().route_hop.cltv_expiry_delta = new_entry.route_hop.cltv_expiry_delta;
+ ordered_hops.push(new_entry.clone());
}
- if res.last().unwrap().pubkey == *target {
- break;
+ ordered_hops.last_mut().unwrap().route_hop.fee_msat = value_contribution_msat;
+ ordered_hops.last_mut().unwrap().hop_use_fee_msat = 0;
+ ordered_hops.last_mut().unwrap().route_hop.cltv_expiry_delta = final_cltv;
+
+ let payment_path = PaymentPath {hops: ordered_hops};
+ // 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.
+ for (i, payment_hop) in payment_path.hops.iter().enumerate() {
+ let channel_liquidity_available_msat = bookkeeped_channels_liquidity_available_msat.get_mut(&payment_hop.route_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 *channel_liquidity_available_msat < spent_on_hop_msat {
+ // This should not happen because we do recompute fees right before,
+ // trying to avoid cases when a hop is not usable due to the fee situation.
+ break 'path_construction;
+ }
+ *channel_liquidity_available_msat -= spent_on_hop_msat;
}
+ // 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;
+ }
- 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);
+ // 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);
+ },
}
- 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);
}
- match network.get_nodes().get(&pubkey) {
- None => {},
- Some(node) => {
- add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
- },
+ // Step (3).
+ // Stop either when recommended value is reached,
+ // or if during last iteration no new path was found.
+ // In the latter case, making another path finding attempt could not help,
+ // because we deterministically terminate the search due to low liquidity.
+ if already_collected_value_msat >= recommended_value_msat || !found_new_path {
+ break 'paths_collection;
+ }
+ }
+
+ // 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.
+ 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;
+ }
+
+ assert!(cur_route.len() > 0);
+
+ // Step (7).
+ // Now, substract the overpaid value from the most-expensive path.
+ cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.channel_fees.proportional_millionths as u64).sum::<u64>() });
+ let expensive_payment_path = cur_route.last_mut().unwrap();
+ let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
+ // TODO: make sure expensive_path_new_value_msat doesn't cause to fall behind htlc_minimum_msat.
+ expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
+ break;
+ }
}
+ drawn_routes.push(cur_route);
+ }
+
+ // 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| payment_hop.route_hop.clone()).collect());
}
- Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError})
+ let route = Route { paths: selected_paths };
+ log_trace!(logger, "Got route: {}", log_route!(route));
+ return Ok(route);
}
#[cfg(test)]
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;
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
+ // 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, &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, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
assert_eq!(route.paths[0].len(), 2);
}
#[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],
+ 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_live: true,
+ }];
+
+ if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = 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)) {
+ 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, &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
+ // Simple route to 2 via 1
+ // Should fail if htlc_minimum can't be reached
+
+ 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: 50_000,
+ htlc_maximum_msat: OptionalField::Absent,
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ excess_data: Vec::new()
+ });
+ // Make 0 fee.
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
+ flags: 0,
cltv_expiry_delta: 0,
htlc_minimum_msat: 0,
htlc_maximum_msat: OptionalField::Absent,
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: 12,
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: 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,
+ 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, &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, &Vec::new(), 49_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],
- 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,
- inbound_capacity_msat: 0,
- is_live: true,
- }];
- 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();
+ // A payment above the minimum should pass
+ let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[2], None, &Vec::new(), 50_000, 42, Arc::clone(&logger)).unwrap();
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, 42);
- assert_eq!(route.paths[0][0].fee_msat, 200);
- assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
- assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
- assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
-
- 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, 100);
- 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 disable_node_test() {
- let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
- let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
+ // This was a check against final_value_msat.
+ // Now let's 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()
+ });
- // Disable nodes 1, 2, and 8 by requiring unknown feature bits
- let mut unknown_features = NodeFeatures::known();
- unknown_features.set_required_unknown_bits();
- add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
- add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
- add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
+ // 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()
+ });
- // 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)) {
+ // 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, &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],
- short_channel_id: Some(42),
- remote_network_id: nodes[7].clone(),
+ // 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, &Vec::new(), 199_999_999, 42, Arc::clone(&logger)).unwrap();
+ assert_eq!(route.paths[0].len(), 2);
+ }
+
+ #[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, &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],
+ 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,
+ inbound_capacity_msat: 0,
+ is_live: true,
+ }];
+ 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();
+ 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, 42);
+ assert_eq!(route.paths[0][0].fee_msat, 200);
+ assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
+ assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
+ assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
+
+ 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, 100);
+ 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 disable_node_test() {
+ 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
+ let mut unknown_features = NodeFeatures::known();
+ unknown_features.set_required_unknown_bits();
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
+ add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
+ 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)) {
+ 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],
+ 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,
#[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
#[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
+
+ // First check that lst hop can't have its source as the payee.
+ let invalid_last_hop = RouteHint {
+ 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, &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, &last_hops(&nodes).iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
assert_eq!(route.paths[0].len(), 5);
#[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
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 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], 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], 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);
+ }
+
+ // 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], 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], 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], 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], 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], 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], 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], 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], 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], 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, &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], 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], 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], 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], 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], 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], 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], 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], 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], 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], 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], 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);
+ }
+ }
+
}
projects / rust-lightning / commitdiff