Update to rust-secp256k1 v0.11 and rust-bitcoin v0.14
[rust-lightning] / src / ln / router.rs
index 10432b9a6d83e915a50551cb90bc1a99d5d512df..1ca55fa260004c25e2cfafbe3856f1923257220a 100644 (file)
@@ -1,15 +1,19 @@
 use secp256k1::key::PublicKey;
 use secp256k1::{Secp256k1,Message};
+use secp256k1;
 
 use bitcoin::util::hash::Sha256dHash;
 
+use ln::channelmanager;
 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,MsgEncodable,NetAddress,GlobalFeatures};
 use ln::msgs;
+use util::logger::Logger;
 
 use std::cmp;
-use std::sync::RwLock;
+use std::sync::{RwLock,Arc};
 use std::collections::{HashMap,BinaryHeap};
 use std::collections::hash_map::Entry;
+use std;
 
 /// A hop in a route
 #[derive(Clone)]
@@ -20,7 +24,7 @@ pub struct RouteHop {
        /// The fee taken on this hop. 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, NOT a delta.
+       /// expected at the destination, in excess of the current block height.
        pub cltv_expiry_delta: u32,
 }
 
@@ -43,12 +47,26 @@ struct DirectionalChannelInfo {
        fee_proportional_millionths: u32,
 }
 
+impl std::fmt::Display for DirectionalChannelInfo {
+       fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+               write!(f, "src_node_id {}, last_update {}, enabled {}, cltv_expiry_delta {}, htlc_minimum_msat {}, fee_base_msat {}, fee_proportional_millionths {}", log_pubkey!(self.src_node_id), self.last_update, self.enabled, self.cltv_expiry_delta, self.htlc_minimum_msat, self.fee_base_msat, self.fee_proportional_millionths)?;
+               Ok(())
+       }
+}
+
 struct ChannelInfo {
        features: GlobalFeatures,
        one_to_two: DirectionalChannelInfo,
        two_to_one: DirectionalChannelInfo,
 }
 
+impl std::fmt::Display for ChannelInfo {
+       fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+               write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
+               Ok(())
+       }
+}
+
 struct NodeInfo {
        #[cfg(feature = "non_bitcoin_chain_hash_routing")]
        channels: Vec<(u64, Sha256dHash)>,
@@ -65,6 +83,13 @@ struct NodeInfo {
        addresses: Vec<NetAddress>,
 }
 
+impl std::fmt::Display for NodeInfo {
+       fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+               write!(f, "features: {}, last_update: {}, lowest_inbound_channel_fee_base_msat: {}, lowest_inbound_channel_fee_proportional_millionths: {}, channels: {:?}", log_bytes!(self.features.encode()), self.last_update, self.lowest_inbound_channel_fee_base_msat, self.lowest_inbound_channel_fee_proportional_millionths, &self.channels[..])?;
+               Ok(())
+       }
+}
+
 struct NetworkMap {
        #[cfg(feature = "non_bitcoin_chain_hash_routing")]
        channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
@@ -75,6 +100,20 @@ struct NetworkMap {
        nodes: HashMap<PublicKey, NodeInfo>,
 }
 
+impl std::fmt::Display for NetworkMap {
+       fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+               write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
+               for (key, val) in self.channels.iter() {
+                       write!(f, " {}: {}\n", key, val)?;
+               }
+               write!(f, "[Nodes]\n")?;
+               for (key, val) in self.nodes.iter() {
+                       write!(f, " {}: {}\n", log_pubkey!(key), val)?;
+               }
+               Ok(())
+       }
+}
+
 impl NetworkMap {
        #[cfg(feature = "non_bitcoin_chain_hash_routing")]
        #[inline]
@@ -87,13 +126,25 @@ impl NetworkMap {
        fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
                short_channel_id
        }
+
+       #[cfg(feature = "non_bitcoin_chain_hash_routing")]
+       #[inline]
+       fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
+               &id.0
+       }
+
+       #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
+       #[inline]
+       fn get_short_id(id: &u64) -> &u64 {
+               id
+       }
 }
 
 /// A channel descriptor which provides a last-hop route to get_route
 pub struct RouteHint {
        pub src_node_id: PublicKey,
        pub short_channel_id: u64,
-       pub fee_base_msat: u64,
+       pub fee_base_msat: u32,
        pub fee_proportional_millionths: u32,
        pub cltv_expiry_delta: u16,
        pub htlc_minimum_msat: u64,
@@ -102,8 +153,9 @@ pub struct RouteHint {
 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 /// payment destinations.
 pub struct Router {
-       secp_ctx: Secp256k1,
+       secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
        network_map: RwLock<NetworkMap>,
+       logger: Arc<Logger>,
 }
 
 macro_rules! secp_verify_sig {
@@ -221,7 +273,14 @@ impl RoutingMessageHandler for Router {
                        },
                        &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id } => {
                                let mut network = self.network_map.write().unwrap();
-                               network.channels.remove(short_channel_id);
+                               if let Some(chan) = network.channels.remove(short_channel_id) {
+                                       network.nodes.get_mut(&chan.one_to_two.src_node_id).unwrap().channels.retain(|chan_id| {
+                                               chan_id != NetworkMap::get_short_id(chan_id)
+                                       });
+                                       network.nodes.get_mut(&chan.two_to_one.src_node_id).unwrap().channels.retain(|chan_id| {
+                                               chan_id != NetworkMap::get_short_id(chan_id)
+                                       });
+                               }
                        },
                }
        }
@@ -300,6 +359,7 @@ impl RoutingMessageHandler for Router {
 struct RouteGraphNode {
        pubkey: PublicKey,
        lowest_fee_to_peer_through_node: u64,
+       lowest_fee_to_node: u64,
 }
 
 impl cmp::Ord for RouteGraphNode {
@@ -315,8 +375,16 @@ impl cmp::PartialOrd for RouteGraphNode {
        }
 }
 
+struct DummyDirectionalChannelInfo {
+       src_node_id: PublicKey,
+       cltv_expiry_delta: u32,
+       htlc_minimum_msat: u64,
+       fee_base_msat: u32,
+       fee_proportional_millionths: u32,
+}
+
 impl Router {
-       pub fn new(our_pubkey: PublicKey) -> Router {
+       pub fn new(our_pubkey: PublicKey, logger: Arc<Logger>) -> Router {
                let mut nodes = HashMap::new();
                nodes.insert(our_pubkey.clone(), NodeInfo {
                        channels: Vec::new(),
@@ -329,15 +397,22 @@ impl Router {
                        addresses: Vec::new(),
                });
                Router {
-                       secp_ctx: Secp256k1::new(),
+                       secp_ctx: Secp256k1::verification_only(),
                        network_map: RwLock::new(NetworkMap {
                                channels: HashMap::new(),
                                our_node_id: our_pubkey,
                                nodes: nodes,
                        }),
+                       logger,
                }
        }
 
+       /// Dumps the entire network view of this Router to the logger provided in the constructor at
+       /// level Trace
+       pub fn trace_state(&self) {
+               log_trace!(self, "{}", self.network_map.read().unwrap());
+       }
+
        /// Get network addresses by node id
        pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
                let network = self.network_map.read().unwrap();
@@ -357,10 +432,15 @@ impl Router {
        /// Gets a route from us to the given target node.
        /// 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
+       /// (this Router's) view of our local channels 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(&self, target: &PublicKey, last_hops: &Vec<RouteHint>, final_value_msat: u64, final_cltv: u32) -> Result<Route, HandleError> {
+       pub fn get_route(&self, target: &PublicKey, first_hops: Option<&[channelmanager::ChannelDetails]>, last_hops: &[RouteHint], final_value_msat: u64, final_cltv: u32) -> Result<Route, HandleError> {
                // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
                // uptime/success in using a node in the past.
                let network = self.network_map.read().unwrap();
@@ -369,24 +449,46 @@ impl Router {
                        return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
                }
 
+               if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
+                       return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
+               }
+
                // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
                // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
                // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
                // to use as the A* heuristic beyond just the cost to get one node further than the current
                // one.
 
+               let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
+                       src_node_id: network.our_node_id.clone(),
+                       cltv_expiry_delta: 0,
+                       htlc_minimum_msat: 0,
+                       fee_base_msat: 0,
+                       fee_proportional_millionths: 0,
+               };
+
                let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
                let mut dist = HashMap::with_capacity(network.nodes.len());
-               for (key, node) in network.nodes.iter() {
-                       dist.insert(key.clone(), (u64::max_value(),
-                               node.lowest_inbound_channel_fee_base_msat as u64,
-                               node.lowest_inbound_channel_fee_proportional_millionths as u64,
-                               RouteHop {
-                                       pubkey: PublicKey::new(),
-                                       short_channel_id: 0,
-                                       fee_msat: 0,
-                                       cltv_expiry_delta: 0,
-                       }));
+
+               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 {
+                                       return Ok(Route {
+                                               hops: vec![RouteHop {
+                                                       pubkey: chan.remote_network_id,
+                                                       short_channel_id,
+                                                       fee_msat: final_value_msat,
+                                                       cltv_expiry_delta: final_cltv,
+                                               }],
+                                       });
+                               }
+                               first_hop_targets.insert(chan.remote_network_id, short_channel_id);
+                       }
+                       if first_hop_targets.is_empty() {
+                               return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
+                       }
                }
 
                macro_rules! add_entry {
@@ -396,27 +498,49 @@ impl Router {
                        ( $chan_id: expr, $dest_node_id: expr, $directional_info: 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 new_fee = $directional_info.fee_base_msat as u64 + ($starting_fee_msat + final_value_msat) * ($directional_info.fee_proportional_millionths as u64) / 1000000;
-                                       let mut total_fee = $starting_fee_msat as u64;
-                                       let old_entry = dist.get_mut(&$directional_info.src_node_id).unwrap();
-                                       if $directional_info.src_node_id != network.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;
-                                               total_fee += old_entry.2 * (final_value_msat + total_fee) / 1000000 + old_entry.1;
-                                       }
-                                       let new_graph_node = RouteGraphNode {
-                                               pubkey: $directional_info.src_node_id,
-                                               lowest_fee_to_peer_through_node: total_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(),
-                                                       short_channel_id: $chan_id.clone(),
-                                                       fee_msat: new_fee, // This field is ignored on the last-hop anyway
-                                                       cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
+                                       let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
+                                       if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
+                                                       ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
+                                       {
+                                               let mut total_fee = $starting_fee_msat as u64;
+                                               let hm_entry = dist.entry(&$directional_info.src_node_id);
+                                               let old_entry = hm_entry.or_insert_with(|| {
+                                                       let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
+                                                       (u64::max_value(),
+                                                               node.lowest_inbound_channel_fee_base_msat,
+                                                               node.lowest_inbound_channel_fee_proportional_millionths,
+                                                               RouteHop {
+                                                                       pubkey: $dest_node_id.clone(),
+                                                                       short_channel_id: 0,
+                                                                       fee_msat: 0,
+                                                                       cltv_expiry_delta: 0,
+                                                       })
+                                               });
+                                               if $directional_info.src_node_id != network.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();
+                                                       }
+                                               }
+                                               let new_graph_node = RouteGraphNode {
+                                                       pubkey: $directional_info.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(),
+                                                               short_channel_id: $chan_id.clone(),
+                                                               fee_msat: new_fee, // This field is ignored on the last-hop anyway
+                                                               cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
+                                                       }
                                                }
                                        }
                                }
@@ -425,16 +549,26 @@ impl Router {
 
                macro_rules! add_entries_to_cheapest_to_target_node {
                        ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
+                               if first_hops.is_some() {
+                                       if let Some(first_hop) = first_hop_targets.get(&$node_id) {
+                                               add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
+                                       }
+                               }
+
                                for chan_id in $node.channels.iter() {
                                        let chan = network.channels.get(chan_id).unwrap();
                                        if chan.one_to_two.src_node_id == *$node_id {
                                                // ie $node is one, ie next hop in A* is two, via the two_to_one channel
-                                               if chan.two_to_one.enabled {
-                                                       add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
+                                               if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
+                                                       if chan.two_to_one.enabled {
+                                                               add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
+                                                       }
                                                }
                                        } else {
-                                               if chan.one_to_two.enabled {
-                                                       add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
+                                               if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
+                                                       if chan.one_to_two.enabled {
+                                                               add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
+                                                       }
                                                }
                                        }
                                }
@@ -449,33 +583,41 @@ impl Router {
                }
 
                for hop in last_hops.iter() {
-                       if network.nodes.get(&hop.src_node_id).is_some() {
-                               add_entry!(hop.short_channel_id, target, hop, 0);
+                       if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
+                               if network.nodes.get(&hop.src_node_id).is_some() {
+                                       if first_hops.is_some() {
+                                               if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
+                                                       add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
+                                               }
+                                       }
+                                       add_entry!(hop.short_channel_id, target, hop, 0);
+                               }
                        }
                }
 
-               while let Some(RouteGraphNode { pubkey, lowest_fee_to_peer_through_node }) = targets.pop() {
+               while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
                        if pubkey == network.our_node_id {
                                let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
                                while res.last().unwrap().pubkey != *target {
-                                       let new_entry = dist.remove(&res.last().unwrap().pubkey).unwrap().3;
+                                       let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
+                                               Some(hop) => hop.3,
+                                               None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
+                                       };
                                        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);
                                }
                                res.last_mut().unwrap().fee_msat = final_value_msat;
                                res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
-                               return Ok(Route {
-                                       hops: res
-                               });
+                               let route = Route { hops: res };
+                               log_trace!(self, "Got route: {}", log_route!(route));
+                               return Ok(route);
                        }
 
                        match network.nodes.get(&pubkey) {
                                None => {},
                                Some(node) => {
-                                       let mut fee = lowest_fee_to_peer_through_node - node.lowest_inbound_channel_fee_base_msat as u64;
-                                       fee -= node.lowest_inbound_channel_fee_proportional_millionths as u64 * (fee + final_value_msat) / 1000000;
-                                       add_entries_to_cheapest_to_target_node!(node, &pubkey, fee);
+                                       add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
                                },
                        }
                }
@@ -486,42 +628,54 @@ impl Router {
 
 #[cfg(test)]
 mod tests {
+       use ln::channelmanager;
        use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
        use ln::msgs::GlobalFeatures;
+       use util::test_utils;
+       use util::logger::Logger;
 
-       use bitcoin::util::misc::hex_bytes;
        use bitcoin::util::hash::Sha256dHash;
 
+       use hex;
+
        use secp256k1::key::{PublicKey,SecretKey};
        use secp256k1::Secp256k1;
 
+       use std::sync::Arc;
+
        #[test]
        fn route_test() {
                let secp_ctx = Secp256k1::new();
-               let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap()).unwrap();
-               let router = Router::new(our_id);
+               let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
+               let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
+               let router = Router::new(our_id, Arc::clone(&logger));
 
                // Build network from our_id to node8:
                //
-               //        -1(1)2- node1 -1(3)2-
-               //       /                     \
-               // our_id                       - node3
-               //       \                     /
-               //        -1(2)2- node2 -1(4)2-
+               //        -1(1)2-  node1  -1(3)2-
+               //       /                       \
+               // our_id -1(12)2- node8 -1(13)2--- node3
+               //       \                       /
+               //        -1(2)2-  node2  -1(4)2-
                //
                //
-               // chan1 1-to-2: disabled
-               // chan1 2-to-1: enabled, 0 fee
+               // chan1  1-to-2: disabled
+               // chan1  2-to-1: enabled, 0 fee
                //
-               // chan2 1-to-2: enabled, ignored fee
-               // chan2 2-to-1: enabled, 0 fee
+               // chan2  1-to-2: enabled, ignored fee
+               // chan2  2-to-1: enabled, 0 fee
                //
-               // chan3 1-to-2: enabled, 0 fee
-               // chan3 2-to-1: enabled, 100 msat fee
+               // chan3  1-to-2: enabled, 0 fee
+               // chan3  2-to-1: enabled, 100 msat fee
                //
-               // chan4 1-to-2: enabled, 100% fee
-               // chan4 2-to-1: enabled, 0 fee
+               // chan4  1-to-2: enabled, 100% fee
+               // chan4  2-to-1: enabled, 0 fee
                //
+               // chan12 1-to-2: enabled, ignored fee
+               // chan12 2-to-1: enabled, 0 fee
+               //
+               // chan13 1-to-2: enabled, 200% fee
+               // chan13 2-to-1: enabled, 0 fee
                //
                //
                //       -1(5)2- node4 -1(8)2--
@@ -553,13 +707,14 @@ mod tests {
                // chan11 1-to-2: enabled, 0 fee
                // chan11 2-to-1: enabled, 0 fee
 
-               let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap()).unwrap();
-               let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap()).unwrap();
-               let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap()).unwrap();
-               let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap()).unwrap();
-               let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap()).unwrap();
-               let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap()).unwrap();
-               let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap()).unwrap();
+               let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
+               let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
+               let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
+               let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
+               let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
+               let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
+               let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
+               let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 
                let zero_hash = Sha256dHash::from_data(&[0; 32]);
 
@@ -626,10 +781,41 @@ mod tests {
                                        fee_proportional_millionths: 0,
                                },
                        });
+                       network.nodes.insert(node8.clone(), NodeInfo {
+                               channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
+                               lowest_inbound_channel_fee_base_msat: 0,
+                               lowest_inbound_channel_fee_proportional_millionths: 0,
+                               features: GlobalFeatures::new(),
+                               last_update: 1,
+                               rgb: [0; 3],
+                               alias: [0; 32],
+                               addresses: Vec::new(),
+                       });
+                       network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
+                               features: GlobalFeatures::new(),
+                               one_to_two: DirectionalChannelInfo {
+                                       src_node_id: our_id.clone(),
+                                       last_update: 0,
+                                       enabled: true,
+                                       cltv_expiry_delta: u16::max_value(), // This value should be ignored
+                                       htlc_minimum_msat: 0,
+                                       fee_base_msat: u32::max_value(), // This value should be ignored
+                                       fee_proportional_millionths: u32::max_value(), // This value should be ignored
+                               }, two_to_one: DirectionalChannelInfo {
+                                       src_node_id: node8.clone(),
+                                       last_update: 0,
+                                       enabled: true,
+                                       cltv_expiry_delta: 0,
+                                       htlc_minimum_msat: 0,
+                                       fee_base_msat: 0,
+                                       fee_proportional_millionths: 0,
+                               },
+                       });
                        network.nodes.insert(node3.clone(), NodeInfo {
                                channels: vec!(
                                        NetworkMap::get_key(3, zero_hash.clone()),
                                        NetworkMap::get_key(4, zero_hash.clone()),
+                                       NetworkMap::get_key(13, zero_hash.clone()),
                                        NetworkMap::get_key(5, zero_hash.clone()),
                                        NetworkMap::get_key(6, zero_hash.clone()),
                                        NetworkMap::get_key(7, zero_hash.clone())),
@@ -681,6 +867,26 @@ mod tests {
                                        fee_proportional_millionths: 0,
                                },
                        });
+                       network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
+                               features: GlobalFeatures::new(),
+                               one_to_two: DirectionalChannelInfo {
+                                       src_node_id: node8.clone(),
+                                       last_update: 0,
+                                       enabled: true,
+                                       cltv_expiry_delta: (13 << 8) | 1,
+                                       htlc_minimum_msat: 0,
+                                       fee_base_msat: 0,
+                                       fee_proportional_millionths: 2000000,
+                               }, two_to_one: DirectionalChannelInfo {
+                                       src_node_id: node3.clone(),
+                                       last_update: 0,
+                                       enabled: true,
+                                       cltv_expiry_delta: (13 << 8) | 2,
+                                       htlc_minimum_msat: 0,
+                                       fee_base_msat: 0,
+                                       fee_proportional_millionths: 0,
+                               },
+                       });
                        network.nodes.insert(node4.clone(), NodeInfo {
                                channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
                                lowest_inbound_channel_fee_base_msat: 0,
@@ -794,7 +1000,7 @@ mod tests {
                }
 
                { // Simple route to 3 via 2
-                       let route = router.get_route(&node3, &Vec::new(), 100, 42).unwrap();
+                       let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
                        assert_eq!(route.hops.len(), 2);
 
                        assert_eq!(route.hops[0].pubkey, node2);
@@ -809,7 +1015,7 @@ mod tests {
                }
 
                { // Route to 1 via 2 and 3 because our channel to 1 is disabled
-                       let route = router.get_route(&node1, &Vec::new(), 100, 42).unwrap();
+                       let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
                        assert_eq!(route.hops.len(), 3);
 
                        assert_eq!(route.hops[0].pubkey, node2);
@@ -828,6 +1034,28 @@ mod tests {
                        assert_eq!(route.hops[2].cltv_expiry_delta, 42);
                }
 
+               { // If we specify a channel to node8, 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: node8.clone(),
+                               channel_value_satoshis: 0,
+                               user_id: 0,
+                       }];
+                       let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
+                       assert_eq!(route.hops.len(), 2);
+
+                       assert_eq!(route.hops[0].pubkey, node8);
+                       assert_eq!(route.hops[0].short_channel_id, 42);
+                       assert_eq!(route.hops[0].fee_msat, 200);
+                       assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
+
+                       assert_eq!(route.hops[1].pubkey, node3);
+                       assert_eq!(route.hops[1].short_channel_id, 13);
+                       assert_eq!(route.hops[1].fee_msat, 100);
+                       assert_eq!(route.hops[1].cltv_expiry_delta, 42);
+               }
+
                let mut last_hops = vec!(RouteHint {
                                src_node_id: node4.clone(),
                                short_channel_id: 8,
@@ -852,7 +1080,7 @@ mod tests {
                        });
 
                { // Simple test across 2, 3, 5, and 4 via a last_hop channel
-                       let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
+                       let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
                        assert_eq!(route.hops.len(), 5);
 
                        assert_eq!(route.hops[0].pubkey, node2);
@@ -881,10 +1109,32 @@ mod tests {
                        assert_eq!(route.hops[4].cltv_expiry_delta, 42);
                }
 
+               { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
+                       let our_chans = vec![channelmanager::ChannelDetails {
+                               channel_id: [0; 32],
+                               short_channel_id: Some(42),
+                               remote_network_id: node4.clone(),
+                               channel_value_satoshis: 0,
+                               user_id: 0,
+                       }];
+                       let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
+                       assert_eq!(route.hops.len(), 2);
+
+                       assert_eq!(route.hops[0].pubkey, node4);
+                       assert_eq!(route.hops[0].short_channel_id, 42);
+                       assert_eq!(route.hops[0].fee_msat, 0);
+                       assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
+
+                       assert_eq!(route.hops[1].pubkey, node7);
+                       assert_eq!(route.hops[1].short_channel_id, 8);
+                       assert_eq!(route.hops[1].fee_msat, 100);
+                       assert_eq!(route.hops[1].cltv_expiry_delta, 42);
+               }
+
                last_hops[0].fee_base_msat = 1000;
 
                { // Revert to via 6 as the fee on 8 goes up
-                       let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
+                       let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
                        assert_eq!(route.hops.len(), 4);
 
                        assert_eq!(route.hops[0].pubkey, node2);
@@ -909,7 +1159,7 @@ mod tests {
                }
 
                { // ...but still use 8 for larger payments as 6 has a variable feerate
-                       let route = router.get_route(&node7, &last_hops, 2000, 42).unwrap();
+                       let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
                        assert_eq!(route.hops.len(), 5);
 
                        assert_eq!(route.hops[0].pubkey, node2);