use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
use routing::scoring::{ChannelUsage, Score};
use routing::network_graph::{DirectedChannelInfoWithUpdate, EffectiveCapacity, NetworkGraph, ReadOnlyNetworkGraph, NodeId, RoutingFees};
-use util::ser::{Writeable, Readable};
+use util::ser::{Writeable, Readable, Writer};
use util::logger::{Level, Logger};
use util::chacha20::ChaCha20;
/// Parameters needed to find a [`Route`].
///
-/// Passed to [`find_route`] and also provided in [`Event::PaymentPathFailed`] for retrying a failed
-/// payment path.
+/// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
+/// [`Event::PaymentPathFailed`] for retrying a failed payment path.
///
/// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
#[derive(Clone, Debug)]
) -> Result<Route, LightningError>
where L::Target: Logger {
let network_graph = network.read_only();
- match get_route(
- our_node_pubkey, &route_params.payment_params, &network_graph, first_hops, route_params.final_value_msat,
- route_params.final_cltv_expiry_delta, logger, scorer, random_seed_bytes
- ) {
- Ok(mut route) => {
- add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
- Ok(route)
- },
- Err(err) => Err(err),
- }
+ let mut route = get_route(our_node_pubkey, &route_params.payment_params, &network_graph, first_hops,
+ route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, scorer,
+ random_seed_bytes)?;
+ add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
+ Ok(route)
}
pub(crate) fn get_route<L: Deref, S: Score>(
// destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
// graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
// payment path by adding a randomized 'shadow route' offset to the final hop.
-fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]) {
+fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
+ network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
+) {
let network_channels = network_graph.channels();
let network_nodes = network_graph.nodes();
}
}
+/// Construct a route from us (payer) to the target node (payee) via the given hops (which should
+/// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
+///
+/// Re-uses logic from `find_route`, so the restrictions described there also apply here.
+pub fn build_route_from_hops<L: Deref>(
+ our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters, network: &NetworkGraph,
+ logger: L, random_seed_bytes: &[u8; 32]
+) -> Result<Route, LightningError>
+where L::Target: Logger {
+ let network_graph = network.read_only();
+ let mut route = build_route_from_hops_internal(
+ our_node_pubkey, hops, &route_params.payment_params, &network_graph,
+ route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, random_seed_bytes)?;
+ add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
+ Ok(route)
+}
+
+fn build_route_from_hops_internal<L: Deref>(
+ our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
+ network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
+ logger: L, random_seed_bytes: &[u8; 32]
+) -> Result<Route, LightningError> where L::Target: Logger {
+
+ struct HopScorer {
+ our_node_id: NodeId,
+ hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
+ }
+
+ impl Score for HopScorer {
+ fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
+ _usage: ChannelUsage) -> u64
+ {
+ let mut cur_id = self.our_node_id;
+ for i in 0..self.hop_ids.len() {
+ if let Some(next_id) = self.hop_ids[i] {
+ if cur_id == *source && next_id == *target {
+ return 0;
+ }
+ cur_id = next_id;
+ } else {
+ break;
+ }
+ }
+ u64::max_value()
+ }
+
+ fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+
+ fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
+ }
+
+ impl<'a> Writeable for HopScorer {
+ #[inline]
+ fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
+ unreachable!();
+ }
+ }
+
+ if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
+ return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
+ }
+
+ let our_node_id = NodeId::from_pubkey(our_node_pubkey);
+ let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
+ for i in 0..hops.len() {
+ hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
+ }
+
+ let scorer = HopScorer { our_node_id, hop_ids };
+
+ get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
+ final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
+}
+
#[cfg(test)]
mod tests {
use routing::network_graph::{NetworkGraph, NetGraphMsgHandler, NodeId};
- use routing::router::{get_route, add_random_cltv_offset, default_node_features,
+ use routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
use routing::scoring::{ChannelUsage, Score};
assert!(path_plausibility.iter().all(|x| *x));
}
+ #[test]
+ fn builds_correct_path_from_hops() {
+ let (secp_ctx, network, _, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+ let network_graph = network.read_only();
+
+ let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+ let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+ let payment_params = PaymentParameters::from_node_id(nodes[3]);
+ let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
+ let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
+ &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
+ let route_hop_pubkeys = route.paths[0].iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
+ assert_eq!(hops.len(), route.paths[0].len());
+ for (idx, hop_pubkey) in hops.iter().enumerate() {
+ assert!(*hop_pubkey == route_hop_pubkeys[idx]);
+ }
+ }
+
#[cfg(not(feature = "no-std"))]
pub(super) fn random_init_seed() -> u64 {
// Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.