Merge pull request #3132 from jkczyz/2024-06-bolt12-unannounced

[rust-lightning] / lightning / src / routing / router.rs

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 9a88d913896778dfc3b70ee0d97179c56e43c806..28aaba0513fb45de1e9ba9b24d42b463bd548ba4 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -100,16 +100,31 @@ impl<G: Deref<Target = NetworkGraph<L>> + Clone, L: Deref, ES: Deref, S: Deref,
                // recipient's node_id.
                const MIN_PEER_CHANNELS: usize = 3;
 
+               let has_one_peer = first_hops
+                       .first()
+                       .map(|details| details.counterparty.node_id)
+                       .map(|node_id| first_hops
+                               .iter()
+                               .skip(1)
+                               .all(|details| details.counterparty.node_id == node_id)
+                       )
+                       .unwrap_or(false);
+
                let network_graph = self.network_graph.deref().read_only();
+               let is_recipient_announced =
+                       network_graph.nodes().contains_key(&NodeId::from_pubkey(&recipient));
+
                let paths = first_hops.into_iter()
                        .filter(|details| details.counterparty.features.supports_route_blinding())
                        .filter(|details| amount_msats <= details.inbound_capacity_msat)
                        .filter(|details| amount_msats >= details.inbound_htlc_minimum_msat.unwrap_or(0))
                        .filter(|details| amount_msats <= details.inbound_htlc_maximum_msat.unwrap_or(u64::MAX))
+                       // Limit to peers with announced channels unless the recipient is unannounced.
                        .filter(|details| network_graph
                                        .node(&NodeId::from_pubkey(&details.counterparty.node_id))
-                                       .map(|node_info| node_info.channels.len() >= MIN_PEER_CHANNELS)
-                                       .unwrap_or(false)
+                                       .map(|node| !is_recipient_announced || node.channels.len() >= MIN_PEER_CHANNELS)
+                                       // Allow payments directly with the only peer when unannounced.
+                                       .unwrap_or(!is_recipient_announced && has_one_peer)
                        )
                        .filter_map(|details| {
                                let short_channel_id = match details.get_inbound_payment_scid() {
@@ -1031,6 +1046,13 @@ impl Payee {
                }
        }
 
+       pub(crate) fn blinded_route_hints_mut(&mut self) -> &mut [(BlindedPayInfo, BlindedPath)] {
+               match self {
+                       Self::Blinded { route_hints, .. } => &mut route_hints[..],
+                       Self::Clear { .. } => &mut []
+               }
+       }
+
        fn unblinded_route_hints(&self) -> &[RouteHint] {
                match self {
                        Self::Blinded { .. } => &[],