From 50b348c4fa7079dcb008d3d5cf8ebc18e5200874 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Thu, 12 Nov 2020 18:57:02 -0500 Subject: [PATCH] [router] Fix + test routing via next/last-hop hints only We had code in the router to support sending a payment via a single hop across channels exclusively provided by the next-/last-hop hints. However, in updating the fuzzer, I noted that this case not only didn't work, but paniced in some cases. Here, we both fix the panic, as well as write a new test which ensures we don't break support for such routing in the future. --- lightning/src/routing/router.rs | 92 ++++++++++++++++++++++++++------- 1 file changed, 73 insertions(+), 19 deletions(-) diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs index 56beb2ea0..526d26b56 100644 --- a/lightning/src/routing/router.rs +++ b/lightning/src/routing/router.rs @@ -236,13 +236,12 @@ pub fn get_route(our_node_id: &PublicKey, network: &NetworkGraph, targ let mut total_fee = $starting_fee_msat as u64; let hm_entry = dist.entry(&$src_node_id); let old_entry = hm_entry.or_insert_with(|| { - let node = network.get_nodes().get(&$src_node_id).unwrap(); let mut fee_base_msat = u32::max_value(); let mut fee_proportional_millionths = u32::max_value(); - if let Some(fees) = node.lowest_inbound_channel_fees { + if let Some(fees) = network.get_nodes().get(&$src_node_id).and_then(|node| node.lowest_inbound_channel_fees) { fee_base_msat = fees.base_msat; fee_proportional_millionths = fees.proportional_millionths; - }; + } (u64::max_value(), fee_base_msat, fee_proportional_millionths, @@ -341,21 +340,26 @@ pub fn get_route(our_node_id: &PublicKey, network: &NetworkGraph, targ } for hop in last_hops.iter() { - if first_hops.is_none() || hop.src_node_id != *our_node_id { // first_hop overrules last_hops - if network.get_nodes().get(&hop.src_node_id).is_some() { - if first_hops.is_some() { - if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&hop.src_node_id) { - // 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, features.to_context(), 0); - } - } - // BOLT 11 doesn't allow inclusion of features for the last hop hints, which - // really sucks, cause we're gonna need that eventually. - add_entry!(hop.short_channel_id, hop.src_node_id, target, hop, ChannelFeatures::empty(), 0); - } + 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, 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. + add_entry!(hop.short_channel_id, hop.src_node_id, target, hop, ChannelFeatures::empty(), 0); } } @@ -411,7 +415,7 @@ pub fn get_route(our_node_id: &PublicKey, network: &NetworkGraph, targ #[cfg(test)] mod tests { use routing::router::{get_route, RouteHint, RoutingFees}; - use routing::network_graph::NetGraphMsgHandler; + use routing::network_graph::{NetworkGraph, NetGraphMsgHandler}; use ln::features::{ChannelFeatures, InitFeatures, NodeFeatures}; use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler, NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate}; @@ -1221,4 +1225,54 @@ mod tests { assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::::new()); // We dont pass flags in from invoices yet assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::::new()); // We can't learn any flags from invoices, sadly } + + #[test] + fn unannounced_path_test() { + // We should be able to send a payment to a destination without any help of a routing graph + // if we have a channel with a common counterparty that appears in the first and last hop + // hints. + let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap()); + let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap()); + let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap()); + + // If we specify a channel to a middle hop, that overrides our local channel view and that gets used + let last_hops = vec![RouteHint { + src_node_id: middle_node_id, + short_channel_id: 8, + fees: RoutingFees { + base_msat: 1000, + proportional_millionths: 0, + }, + cltv_expiry_delta: (8 << 8) | 1, + htlc_minimum_msat: 0, + }]; + let our_chans = vec![channelmanager::ChannelDetails { + channel_id: [0; 32], + short_channel_id: Some(42), + remote_network_id: middle_node_id, + counterparty_features: InitFeatures::from_le_bytes(vec![0b11]), + channel_value_satoshis: 100000, + user_id: 0, + outbound_capacity_msat: 100000, + inbound_capacity_msat: 100000, + is_live: true, + }]; + let route = get_route(&source_node_id, &NetworkGraph::new(), &target_node_id, Some(&our_chans.iter().collect::>()), &last_hops.iter().collect::>(), 100, 42, Arc::new(test_utils::TestLogger::new())).unwrap(); + + assert_eq!(route.paths[0].len(), 2); + + assert_eq!(route.paths[0][0].pubkey, middle_node_id); + assert_eq!(route.paths[0][0].short_channel_id, 42); + assert_eq!(route.paths[0][0].fee_msat, 1000); + assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1); + assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]); + assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly + + assert_eq!(route.paths[0][1].pubkey, target_node_id); + assert_eq!(route.paths[0][1].short_channel_id, 8); + assert_eq!(route.paths[0][1].fee_msat, 100); + assert_eq!(route.paths[0][1].cltv_expiry_delta, 42); + assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet + assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly + } } -- 2.39.5