_ Git - rust-lightning/blob - lightning/src/routing/router.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! The top-level routing/network map tracking logic lives here.
  11 //!
  12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
  13 //! interrogate it to get routes for your own payments.
  14
  15 use bitcoin::secp256k1::key::PublicKey;
  16
  17 use ln::channelmanager::ChannelDetails;
  18 use ln::features::{ChannelFeatures, NodeFeatures};
  19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
  20 use routing::network_graph::{NetworkGraph, RoutingFees};
  21 use util::ser::{Writeable, Readable};
  22 use util::logger::Logger;
  23
  24 use std::cmp;
  25 use std::collections::{HashMap,BinaryHeap};
  26 use std::ops::Deref;
  27
  28 /// A hop in a route
  29 #[derive(Clone, PartialEq)]
  30 pub struct RouteHop {
  31         /// The node_id of the node at this hop.
  32         pub pubkey: PublicKey,
  33         /// The node_announcement features of the node at this hop. For the last hop, these may be
  34         /// amended to match the features present in the invoice this node generated.
  35         pub node_features: NodeFeatures,
  36         /// The channel that should be used from the previous hop to reach this node.
  37         pub short_channel_id: u64,
  38         /// The channel_announcement features of the channel that should be used from the previous hop
  39         /// to reach this node.
  40         pub channel_features: ChannelFeatures,
  41         /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
  42         pub fee_msat: u64,
  43         /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
  44         /// expected at the destination, in excess of the current block height.
  45         pub cltv_expiry_delta: u32,
  46 }
  47
  48 /// (C-not exported)
  49 impl Writeable for Vec<RouteHop> {
  50         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  51                 (self.len() as u8).write(writer)?;
  52                 for hop in self.iter() {
  53                         hop.pubkey.write(writer)?;
  54                         hop.node_features.write(writer)?;
  55                         hop.short_channel_id.write(writer)?;
  56                         hop.channel_features.write(writer)?;
  57                         hop.fee_msat.write(writer)?;
  58                         hop.cltv_expiry_delta.write(writer)?;
  59                 }
  60                 Ok(())
  61         }
  62 }
  63
  64 /// (C-not exported)
  65 impl Readable for Vec<RouteHop> {
  66         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Vec<RouteHop>, DecodeError> {
  67                 let hops_count: u8 = Readable::read(reader)?;
  68                 let mut hops = Vec::with_capacity(hops_count as usize);
  69                 for _ in 0..hops_count {
  70                         hops.push(RouteHop {
  71                                 pubkey: Readable::read(reader)?,
  72                                 node_features: Readable::read(reader)?,
  73                                 short_channel_id: Readable::read(reader)?,
  74                                 channel_features: Readable::read(reader)?,
  75                                 fee_msat: Readable::read(reader)?,
  76                                 cltv_expiry_delta: Readable::read(reader)?,
  77                         });
  78                 }
  79                 Ok(hops)
  80         }
  81 }
  82
  83 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
  84 /// it can take multiple paths. Each path is composed of one or more hops through the network.
  85 #[derive(Clone, PartialEq)]
  86 pub struct Route {
  87         /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
  88         /// last RouteHop in each path must be the same.
  89         /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
  90         /// destination. Thus, this must always be at least length one. While the maximum length of any
  91         /// given path is variable, keeping the length of any path to less than 20 should currently
  92         /// ensure it is viable.
  93         pub paths: Vec<Vec<RouteHop>>,
  94 }
  95
  96 impl Writeable for Route {
  97         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  98                 (self.paths.len() as u64).write(writer)?;
  99                 for hops in self.paths.iter() {
 100                         hops.write(writer)?;
 101                 }
 102                 Ok(())
 103         }
 104 }
 105
 106 impl Readable for Route {
 107         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
 108                 let path_count: u64 = Readable::read(reader)?;
 109                 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
 110                 for _ in 0..path_count {
 111                         paths.push(Readable::read(reader)?);
 112                 }
 113                 Ok(Route { paths })
 114         }
 115 }
 116
 117 /// A channel descriptor which provides a last-hop route to get_route
 118 #[derive(Clone)]
 119 pub struct RouteHint {
 120         /// The node_id of the non-target end of the route
 121         pub src_node_id: PublicKey,
 122         /// The short_channel_id of this channel
 123         pub short_channel_id: u64,
 124         /// The fees which must be paid to use this channel
 125         pub fees: RoutingFees,
 126         /// The difference in CLTV values between this node and the next node.
 127         pub cltv_expiry_delta: u16,
 128         /// The minimum value, in msat, which must be relayed to the next hop.
 129         pub htlc_minimum_msat: u64,
 130 }
 131
 132 #[derive(Eq, PartialEq)]
 133 struct RouteGraphNode {
 134         pubkey: PublicKey,
 135         lowest_fee_to_peer_through_node: u64,
 136         lowest_fee_to_node: u64,
 137 }
 138
 139 impl cmp::Ord for RouteGraphNode {
 140         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 141                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 142                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 143         }
 144 }
 145
 146 impl cmp::PartialOrd for RouteGraphNode {
 147         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 148                 Some(self.cmp(other))
 149         }
 150 }
 151
 152 struct DummyDirectionalChannelInfo {
 153         cltv_expiry_delta: u32,
 154         htlc_minimum_msat: u64,
 155         fees: RoutingFees,
 156 }
 157
 158
 159 /// Gets a route from us to the given target node.
 160 ///
 161 /// Extra routing hops between known nodes and the target will be used if they are included in
 162 /// last_hops.
 163 ///
 164 /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 165 /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 166 /// view of our local channels (from net_graph_msg_handler) will be ignored, and only those in first_hops
 167 /// will be used.
 168 ///
 169 /// Panics if first_hops contains channels without short_channel_ids
 170 /// (ChannelManager::list_usable_channels will never include such channels).
 171 ///
 172 /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 173 /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 174 /// *is* checked as they may change based on the receiving node.
 175 pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, target: &PublicKey, first_hops: Option<&[&ChannelDetails]>,
 176         last_hops: &[&RouteHint], final_value_msat: u64, final_cltv: u32, logger: L) -> Result<Route, LightningError> where L::Target: Logger {
 177         // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 178         // uptime/success in using a node in the past.
 179         if *target == *our_node_id {
 180                 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
 181         }
 182
 183         if final_value_msat > MAX_VALUE_MSAT {
 184                 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
 185         }
 186
 187         // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 188         // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 189         // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 190         // to use as the A* heuristic beyond just the cost to get one node further than the current
 191         // one.
 192
 193         let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 194                 cltv_expiry_delta: 0,
 195                 htlc_minimum_msat: 0,
 196                 fees: RoutingFees {
 197                         base_msat: 0,
 198                         proportional_millionths: 0,
 199                 }
 200         };
 201
 202         let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 203         let mut dist = HashMap::with_capacity(network.get_nodes().len());
 204
 205         let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 206         if let Some(hops) = first_hops {
 207                 for chan in hops {
 208                         let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 209                         if chan.remote_network_id == *target {
 210                                 return Ok(Route {
 211                                         paths: vec![vec![RouteHop {
 212                                                 pubkey: chan.remote_network_id,
 213                                                 node_features: chan.counterparty_features.to_context(),
 214                                                 short_channel_id,
 215                                                 channel_features: chan.counterparty_features.to_context(),
 216                                                 fee_msat: final_value_msat,
 217                                                 cltv_expiry_delta: final_cltv,
 218                                         }]],
 219                                 });
 220                         }
 221                         first_hop_targets.insert(chan.remote_network_id, (short_channel_id, chan.counterparty_features.clone()));
 222                 }
 223                 if first_hop_targets.is_empty() {
 224                         return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
 225                 }
 226         }
 227
 228         macro_rules! add_entry {
 229                 // Adds entry which goes from $src_node_id to $dest_node_id
 230                 // over the channel with id $chan_id with fees described in
 231                 // $directional_info.
 232                 ( $chan_id: expr, $src_node_id: expr, $dest_node_id: expr, $directional_info: expr, $chan_features: expr, $starting_fee_msat: expr ) => {
 233                         //TODO: Explore simply adding fee to hit htlc_minimum_msat
 234                         if $starting_fee_msat as u64 + final_value_msat >= $directional_info.htlc_minimum_msat {
 235                                 let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fees.proportional_millionths as u64);
 236                                 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 237                                                 ($directional_info.fees.base_msat as u64).checked_add(part / 1000000) })
 238                                 {
 239                                         let mut total_fee = $starting_fee_msat as u64;
 240                                         let hm_entry = dist.entry(&$src_node_id);
 241                                         let old_entry = hm_entry.or_insert_with(|| {
 242                                                 let mut fee_base_msat = u32::max_value();
 243                                                 let mut fee_proportional_millionths = u32::max_value();
 244                                                 if let Some(fees) = network.get_nodes().get(&$src_node_id).and_then(|node| node.lowest_inbound_channel_fees) {
 245                                                         fee_base_msat = fees.base_msat;
 246                                                         fee_proportional_millionths = fees.proportional_millionths;
 247                                                 }
 248                                                 (u64::max_value(),
 249                                                         fee_base_msat,
 250                                                         fee_proportional_millionths,
 251                                                         RouteHop {
 252                                                                 pubkey: $dest_node_id.clone(),
 253                                                                 node_features: NodeFeatures::empty(),
 254                                                                 short_channel_id: 0,
 255                                                                 channel_features: $chan_features.clone(),
 256                                                                 fee_msat: 0,
 257                                                                 cltv_expiry_delta: 0,
 258                                                         },
 259                                                 )
 260                                         });
 261                                         if $src_node_id != *our_node_id {
 262                                                 // Ignore new_fee for channel-from-us as we assume all channels-from-us
 263                                                 // will have the same effective-fee
 264                                                 total_fee += new_fee;
 265                                                 if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 266                                                         total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 267                                                 } else {
 268                                                         // max_value means we'll always fail the old_entry.0 > total_fee check
 269                                                         total_fee = u64::max_value();
 270                                                 }
 271                                         }
 272                                         let new_graph_node = RouteGraphNode {
 273                                                 pubkey: $src_node_id,
 274                                                 lowest_fee_to_peer_through_node: total_fee,
 275                                                 lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 276                                         };
 277                                         if old_entry.0 > total_fee {
 278                                                 targets.push(new_graph_node);
 279                                                 old_entry.0 = total_fee;
 280                                                 old_entry.3 = RouteHop {
 281                                                         pubkey: $dest_node_id.clone(),
 282                                                         node_features: NodeFeatures::empty(),
 283                                                         short_channel_id: $chan_id.clone(),
 284                                                         channel_features: $chan_features.clone(),
 285                                                         fee_msat: new_fee, // This field is ignored on the last-hop anyway
 286                                                         cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 287                                                 }
 288                                         }
 289                                 }
 290                         }
 291                 };
 292         }
 293
 294         macro_rules! add_entries_to_cheapest_to_target_node {
 295                 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 296                         if first_hops.is_some() {
 297                                 if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&$node_id) {
 298                                         add_entry!(first_hop, *our_node_id, $node_id, dummy_directional_info, features.to_context(), $fee_to_target_msat);
 299                                 }
 300                         }
 301
 302                         let features;
 303                         if let Some(node_info) = $node.announcement_info.as_ref() {
 304                                 features = node_info.features.clone();
 305                         } else {
 306                                 features = NodeFeatures::empty();
 307                         }
 308
 309                         if !features.requires_unknown_bits() {
 310                                 for chan_id in $node.channels.iter() {
 311                                         let chan = network.get_channels().get(chan_id).unwrap();
 312                                         if !chan.features.requires_unknown_bits() {
 313                                                 if chan.node_one == *$node_id {
 314                                                         // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 315                                                         if first_hops.is_none() || chan.node_two != *our_node_id {
 316                                                                 if let Some(two_to_one) = chan.two_to_one.as_ref() {
 317                                                                         if two_to_one.enabled {
 318                                                                                 add_entry!(chan_id, chan.node_two, chan.node_one, two_to_one, chan.features, $fee_to_target_msat);
 319                                                                         }
 320                                                                 }
 321                                                         }
 322                                                 } else {
 323                                                         if first_hops.is_none() || chan.node_one != *our_node_id {
 324                                                                 if let Some(one_to_two) = chan.one_to_two.as_ref() {
 325                                                                         if one_to_two.enabled {
 326                                                                                 add_entry!(chan_id, chan.node_one, chan.node_two, one_to_two, chan.features, $fee_to_target_msat);
 327                                                                         }
 328                                                                 }
 329
 330                                                         }
 331                                                 }
 332                                         }
 333                                 }
 334                         }
 335                 };
 336         }
 337
 338         match network.get_nodes().get(target) {
 339                 None => {},
 340                 Some(node) => {
 341                         add_entries_to_cheapest_to_target_node!(node, target, 0);
 342                 },
 343         }
 344
 345         for hop in last_hops.iter() {
 346                 let have_hop_src_in_graph =
 347                         if let Some(&(ref first_hop, ref features)) = first_hop_targets.get(&hop.src_node_id) {
 348                                 // If this hop connects to a node with which we have a direct channel, ignore the
 349                                 // network graph and add both the hop and our direct channel to the candidate set:
 350                                 //
 351                                 // Currently there are no channel-context features defined, so we are a
 352                                 // bit lazy here. In the future, we should pull them out via our
 353                                 // ChannelManager, but there's no reason to waste the space until we
 354                                 // need them.
 355                                 add_entry!(first_hop, *our_node_id , hop.src_node_id, dummy_directional_info, features.to_context(), 0);
 356                                 true
 357                         } else {
 358                                 // In any other case, only add the hop if the source is in the regular network
 359                                 // graph:
 360                                 network.get_nodes().get(&hop.src_node_id).is_some()
 361                         };
 362                 if have_hop_src_in_graph {
 363                         // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
 364                         // really sucks, cause we're gonna need that eventually.
 365                         add_entry!(hop.short_channel_id, hop.src_node_id, target, hop, ChannelFeatures::empty(), 0);
 366                 }
 367         }
 368
 369         while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 370                 if pubkey == *our_node_id {
 371                         let mut res = vec!(dist.remove(&our_node_id).unwrap().3);
 372                         loop {
 373                                 if let Some(&(_, ref features)) = first_hop_targets.get(&res.last().unwrap().pubkey) {
 374                                         res.last_mut().unwrap().node_features = features.to_context();
 375                                 } else if let Some(node) = network.get_nodes().get(&res.last().unwrap().pubkey) {
 376                                         if let Some(node_info) = node.announcement_info.as_ref() {
 377                                                 res.last_mut().unwrap().node_features = node_info.features.clone();
 378                                         } else {
 379                                                 res.last_mut().unwrap().node_features = NodeFeatures::empty();
 380                                         }
 381                                 } else {
 382                                         // We should be able to fill in features for everything except the last
 383                                         // hop, if the last hop was provided via a BOLT 11 invoice (though we
 384                                         // should be able to extend it further as BOLT 11 does have feature
 385                                         // flags for the last hop node itself).
 386                                         assert!(res.last().unwrap().pubkey == *target);
 387                                 }
 388                                 if res.last().unwrap().pubkey == *target {
 389                                         break;
 390                                 }
 391
 392                                 let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 393                                         Some(hop) => hop.3,
 394                                         None => return Err(LightningError{err: "Failed to find a non-fee-overflowing path to the given destination".to_owned(), action: ErrorAction::IgnoreError}),
 395                                 };
 396                                 res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 397                                 res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 398                                 res.push(new_entry);
 399                         }
 400                         res.last_mut().unwrap().fee_msat = final_value_msat;
 401                         res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 402                         let route = Route { paths: vec![res] };
 403                         log_trace!(logger, "Got route: {}", log_route!(route));
 404                         return Ok(route);
 405                 }
 406
 407                 match network.get_nodes().get(&pubkey) {
 408                         None => {},
 409                         Some(node) => {
 410                                 add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 411                         },
 412                 }
 413         }
 414
 415         Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError})
 416 }
 417
 418 #[cfg(test)]
 419 mod tests {
 420         use routing::router::{get_route, RouteHint, RoutingFees};
 421         use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
 422         use ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
 423         use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
 424            NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
 425         use ln::channelmanager;
 426         use util::test_utils;
 427         use util::ser::Writeable;
 428
 429         use bitcoin::hashes::sha256d::Hash as Sha256dHash;
 430         use bitcoin::hashes::Hash;
 431         use bitcoin::network::constants::Network;
 432         use bitcoin::blockdata::constants::genesis_block;
 433
 434         use hex;
 435
 436         use bitcoin::secp256k1::key::{PublicKey,SecretKey};
 437         use bitcoin::secp256k1::{Secp256k1, All};
 438
 439         use std::sync::Arc;
 440
 441         // Using the same keys for LN and BTC ids
 442         fn add_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey,
 443            node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64) {
 444                 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
 445                 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
 446
 447                 let unsigned_announcement = UnsignedChannelAnnouncement {
 448                         features,
 449                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 450                         short_channel_id,
 451                         node_id_1,
 452                         node_id_2,
 453                         bitcoin_key_1: node_id_1,
 454                         bitcoin_key_2: node_id_2,
 455                         excess_data: Vec::new(),
 456                 };
 457
 458                 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
 459                 let valid_announcement = ChannelAnnouncement {
 460                         node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
 461                         node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
 462                         bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
 463                         bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
 464                         contents: unsigned_announcement.clone(),
 465                 };
 466                 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
 467                         Ok(res) => assert!(res),
 468                         _ => panic!()
 469                 };
 470         }
 471
 472         fn update_channel(net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>, secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate) {
 473                 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
 474                 let valid_channel_update = ChannelUpdate {
 475                         signature: secp_ctx.sign(&msghash, node_privkey),
 476                         contents: update.clone()
 477                 };
 478
 479                 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
 480                         Ok(res) => assert!(res),
 481                         // Err(_) => panic!()
 482                         Err(e) => println!("{:?}", e.err)
 483                 };
 484         }
 485
 486
 487         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,
 488            features: NodeFeatures, timestamp: u32) {
 489                 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
 490                 let unsigned_announcement = UnsignedNodeAnnouncement {
 491                         features,
 492                         timestamp,
 493                         node_id,
 494                         rgb: [0; 3],
 495                         alias: [0; 32],
 496                         addresses: Vec::new(),
 497                         excess_address_data: Vec::new(),
 498                         excess_data: Vec::new(),
 499                 };
 500                 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
 501                 let valid_announcement = NodeAnnouncement {
 502                         signature: secp_ctx.sign(&msghash, node_privkey),
 503                         contents: unsigned_announcement.clone()
 504                 };
 505
 506                 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
 507                         Ok(_) => (),
 508                         Err(_) => panic!()
 509                 };
 510         }
 511
 512         fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
 513                 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
 514                         SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
 515                 }).collect();
 516
 517                 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
 518
 519                 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
 520                 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
 521
 522                 (our_privkey, our_id, privkeys, pubkeys)
 523         }
 524
 525         fn id_to_feature_flags(id: u8) -> Vec<u8> {
 526                 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
 527                 // test for it later.
 528                 let idx = (id - 1) * 2 + 1;
 529                 if idx > 8*3 {
 530                         vec![1 << (idx - 8*3), 0, 0, 0]
 531                 } else if idx > 8*2 {
 532                         vec![1 << (idx - 8*2), 0, 0]
 533                 } else if idx > 8*1 {
 534                         vec![1 << (idx - 8*1), 0]
 535                 } else {
 536                         vec![1 << idx]
 537                 }
 538         }
 539
 540         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>) {
 541                 let secp_ctx = Secp256k1::new();
 542                 let logger = Arc::new(test_utils::TestLogger::new());
 543                 let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
 544                 // Build network from our_id to node7:
 545                 //
 546                 //        -1(1)2-  node0  -1(3)2-
 547                 //       /                       \
 548                 // our_id -1(12)2- node7 -1(13)2--- node2
 549                 //       \                       /
 550                 //        -1(2)2-  node1  -1(4)2-
 551                 //
 552                 //
 553                 // chan1  1-to-2: disabled
 554                 // chan1  2-to-1: enabled, 0 fee
 555                 //
 556                 // chan2  1-to-2: enabled, ignored fee
 557                 // chan2  2-to-1: enabled, 0 fee
 558                 //
 559                 // chan3  1-to-2: enabled, 0 fee
 560                 // chan3  2-to-1: enabled, 100 msat fee
 561                 //
 562                 // chan4  1-to-2: enabled, 100% fee
 563                 // chan4  2-to-1: enabled, 0 fee
 564                 //
 565                 // chan12 1-to-2: enabled, ignored fee
 566                 // chan12 2-to-1: enabled, 0 fee
 567                 //
 568                 // chan13 1-to-2: enabled, 200% fee
 569                 // chan13 2-to-1: enabled, 0 fee
 570                 //
 571                 //
 572                 //       -1(5)2- node3 -1(8)2--
 573                 //       |         2          |
 574                 //       |       (11)         |
 575                 //      /          1           \
 576                 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
 577                 //      \                      /
 578                 //       -1(7)2- node5 -1(10)2-
 579                 //
 580                 // chan5  1-to-2: enabled, 100 msat fee
 581                 // chan5  2-to-1: enabled, 0 fee
 582                 //
 583                 // chan6  1-to-2: enabled, 0 fee
 584                 // chan6  2-to-1: enabled, 0 fee
 585                 //
 586                 // chan7  1-to-2: enabled, 100% fee
 587                 // chan7  2-to-1: enabled, 0 fee
 588                 //
 589                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 590                 // chan8  2-to-1: enabled, 0 fee
 591                 //
 592                 // chan9  1-to-2: enabled, 1001 msat fee
 593                 // chan9  2-to-1: enabled, 0 fee
 594                 //
 595                 // chan10 1-to-2: enabled, 0 fee
 596                 // chan10 2-to-1: enabled, 0 fee
 597                 //
 598                 // chan11 1-to-2: enabled, 0 fee
 599                 // chan11 2-to-1: enabled, 0 fee
 600
 601                 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
 602
 603                 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
 604                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
 605                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 606                         short_channel_id: 1,
 607                         timestamp: 1,
 608                         flags: 1,
 609                         cltv_expiry_delta: 0,
 610                         htlc_minimum_msat: 0,
 611                         htlc_maximum_msat: OptionalField::Absent,
 612                         fee_base_msat: 0,
 613                         fee_proportional_millionths: 0,
 614                         excess_data: Vec::new()
 615                 });
 616
 617                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
 618
 619                 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
 620                 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
 621                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 622                         short_channel_id: 2,
 623                         timestamp: 1,
 624                         flags: 0,
 625                         cltv_expiry_delta: u16::max_value(),
 626                         htlc_minimum_msat: 0,
 627                         htlc_maximum_msat: OptionalField::Absent,
 628                         fee_base_msat: u32::max_value(),
 629                         fee_proportional_millionths: u32::max_value(),
 630                         excess_data: Vec::new()
 631                 });
 632                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
 633                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 634                         short_channel_id: 2,
 635                         timestamp: 1,
 636                         flags: 1,
 637                         cltv_expiry_delta: 0,
 638                         htlc_minimum_msat: 0,
 639                         htlc_maximum_msat: OptionalField::Absent,
 640                         fee_base_msat: 0,
 641                         fee_proportional_millionths: 0,
 642                         excess_data: Vec::new()
 643                 });
 644
 645                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
 646
 647                 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
 648                 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
 649                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 650                         short_channel_id: 12,
 651                         timestamp: 1,
 652                         flags: 0,
 653                         cltv_expiry_delta: u16::max_value(),
 654                         htlc_minimum_msat: 0,
 655                         htlc_maximum_msat: OptionalField::Absent,
 656                         fee_base_msat: u32::max_value(),
 657                         fee_proportional_millionths: u32::max_value(),
 658                         excess_data: Vec::new()
 659                 });
 660                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
 661                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 662                         short_channel_id: 12,
 663                         timestamp: 1,
 664                         flags: 1,
 665                         cltv_expiry_delta: 0,
 666                         htlc_minimum_msat: 0,
 667                         htlc_maximum_msat: OptionalField::Absent,
 668                         fee_base_msat: 0,
 669                         fee_proportional_millionths: 0,
 670                         excess_data: Vec::new()
 671                 });
 672
 673                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
 674
 675                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
 676                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
 677                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 678                         short_channel_id: 3,
 679                         timestamp: 1,
 680                         flags: 0,
 681                         cltv_expiry_delta: (3 << 8) | 1,
 682                         htlc_minimum_msat: 0,
 683                         htlc_maximum_msat: OptionalField::Absent,
 684                         fee_base_msat: 0,
 685                         fee_proportional_millionths: 0,
 686                         excess_data: Vec::new()
 687                 });
 688                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
 689                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 690                         short_channel_id: 3,
 691                         timestamp: 1,
 692                         flags: 1,
 693                         cltv_expiry_delta: (3 << 8) | 2,
 694                         htlc_minimum_msat: 0,
 695                         htlc_maximum_msat: OptionalField::Absent,
 696                         fee_base_msat: 100,
 697                         fee_proportional_millionths: 0,
 698                         excess_data: Vec::new()
 699                 });
 700
 701                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
 702                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
 703                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 704                         short_channel_id: 4,
 705                         timestamp: 1,
 706                         flags: 0,
 707                         cltv_expiry_delta: (4 << 8) | 1,
 708                         htlc_minimum_msat: 0,
 709                         htlc_maximum_msat: OptionalField::Absent,
 710                         fee_base_msat: 0,
 711                         fee_proportional_millionths: 1000000,
 712                         excess_data: Vec::new()
 713                 });
 714                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
 715                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 716                         short_channel_id: 4,
 717                         timestamp: 1,
 718                         flags: 1,
 719                         cltv_expiry_delta: (4 << 8) | 2,
 720                         htlc_minimum_msat: 0,
 721                         htlc_maximum_msat: OptionalField::Absent,
 722                         fee_base_msat: 0,
 723                         fee_proportional_millionths: 0,
 724                         excess_data: Vec::new()
 725                 });
 726
 727                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
 728                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
 729                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 730                         short_channel_id: 13,
 731                         timestamp: 1,
 732                         flags: 0,
 733                         cltv_expiry_delta: (13 << 8) | 1,
 734                         htlc_minimum_msat: 0,
 735                         htlc_maximum_msat: OptionalField::Absent,
 736                         fee_base_msat: 0,
 737                         fee_proportional_millionths: 2000000,
 738                         excess_data: Vec::new()
 739                 });
 740                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
 741                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 742                         short_channel_id: 13,
 743                         timestamp: 1,
 744                         flags: 1,
 745                         cltv_expiry_delta: (13 << 8) | 2,
 746                         htlc_minimum_msat: 0,
 747                         htlc_maximum_msat: OptionalField::Absent,
 748                         fee_base_msat: 0,
 749                         fee_proportional_millionths: 0,
 750                         excess_data: Vec::new()
 751                 });
 752
 753                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
 754
 755                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
 756                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
 757                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 758                         short_channel_id: 6,
 759                         timestamp: 1,
 760                         flags: 0,
 761                         cltv_expiry_delta: (6 << 8) | 1,
 762                         htlc_minimum_msat: 0,
 763                         htlc_maximum_msat: OptionalField::Absent,
 764                         fee_base_msat: 0,
 765                         fee_proportional_millionths: 0,
 766                         excess_data: Vec::new()
 767                 });
 768                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
 769                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 770                         short_channel_id: 6,
 771                         timestamp: 1,
 772                         flags: 1,
 773                         cltv_expiry_delta: (6 << 8) | 2,
 774                         htlc_minimum_msat: 0,
 775                         htlc_maximum_msat: OptionalField::Absent,
 776                         fee_base_msat: 0,
 777                         fee_proportional_millionths: 0,
 778                         excess_data: Vec::new(),
 779                 });
 780
 781                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
 782                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
 783                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 784                         short_channel_id: 11,
 785                         timestamp: 1,
 786                         flags: 0,
 787                         cltv_expiry_delta: (11 << 8) | 1,
 788                         htlc_minimum_msat: 0,
 789                         htlc_maximum_msat: OptionalField::Absent,
 790                         fee_base_msat: 0,
 791                         fee_proportional_millionths: 0,
 792                         excess_data: Vec::new()
 793                 });
 794                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
 795                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 796                         short_channel_id: 11,
 797                         timestamp: 1,
 798                         flags: 1,
 799                         cltv_expiry_delta: (11 << 8) | 2,
 800                         htlc_minimum_msat: 0,
 801                         htlc_maximum_msat: OptionalField::Absent,
 802                         fee_base_msat: 0,
 803                         fee_proportional_millionths: 0,
 804                         excess_data: Vec::new()
 805                 });
 806
 807                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
 808
 809                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
 810
 811                 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
 812                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
 813                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 814                         short_channel_id: 7,
 815                         timestamp: 1,
 816                         flags: 0,
 817                         cltv_expiry_delta: (7 << 8) | 1,
 818                         htlc_minimum_msat: 0,
 819                         htlc_maximum_msat: OptionalField::Absent,
 820                         fee_base_msat: 0,
 821                         fee_proportional_millionths: 1000000,
 822                         excess_data: Vec::new()
 823                 });
 824                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
 825                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 826                         short_channel_id: 7,
 827                         timestamp: 1,
 828                         flags: 1,
 829                         cltv_expiry_delta: (7 << 8) | 2,
 830                         htlc_minimum_msat: 0,
 831                         htlc_maximum_msat: OptionalField::Absent,
 832                         fee_base_msat: 0,
 833                         fee_proportional_millionths: 0,
 834                         excess_data: Vec::new()
 835                 });
 836
 837                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
 838
 839                 (secp_ctx, net_graph_msg_handler, logger)
 840         }
 841
 842         #[test]
 843         fn simple_route_test() {
 844                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
 845                 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
 846
 847                 // Simple route to 3 via 2
 848                 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();
 849                 assert_eq!(route.paths[0].len(), 2);
 850
 851                 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
 852                 assert_eq!(route.paths[0][0].short_channel_id, 2);
 853                 assert_eq!(route.paths[0][0].fee_msat, 100);
 854                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
 855                 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
 856                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
 857
 858                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
 859                 assert_eq!(route.paths[0][1].short_channel_id, 4);
 860                 assert_eq!(route.paths[0][1].fee_msat, 100);
 861                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
 862                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
 863                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
 864         }
 865
 866         #[test]
 867         fn disable_channels_test() {
 868                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
 869                 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
 870
 871                 // // Disable channels 4 and 12 by flags=2
 872                 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
 873                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 874                         short_channel_id: 4,
 875                         timestamp: 2,
 876                         flags: 2, // to disable
 877                         cltv_expiry_delta: 0,
 878                         htlc_minimum_msat: 0,
 879                         htlc_maximum_msat: OptionalField::Absent,
 880                         fee_base_msat: 0,
 881                         fee_proportional_millionths: 0,
 882                         excess_data: Vec::new()
 883                 });
 884                 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
 885                         chain_hash: genesis_block(Network::Testnet).header.block_hash(),
 886                         short_channel_id: 12,
 887                         timestamp: 2,
 888                         flags: 2, // to disable
 889                         cltv_expiry_delta: 0,
 890                         htlc_minimum_msat: 0,
 891                         htlc_maximum_msat: OptionalField::Absent,
 892                         fee_base_msat: 0,
 893                         fee_proportional_millionths: 0,
 894                         excess_data: Vec::new()
 895                 });
 896
 897                 // If all the channels require some features we don't understand, route should fail
 898                 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)) {
 899                         assert_eq!(err, "Failed to find a path to the given destination");
 900                 } else { panic!(); }
 901
 902                 // If we specify a channel to node7, that overrides our local channel view and that gets used
 903                 let our_chans = vec![channelmanager::ChannelDetails {
 904                         channel_id: [0; 32],
 905                         short_channel_id: Some(42),
 906                         remote_network_id: nodes[7].clone(),
 907                         counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
 908                         channel_value_satoshis: 0,
 909                         user_id: 0,
 910                         outbound_capacity_msat: 0,
 911                         inbound_capacity_msat: 0,
 912                         is_live: true,
 913                 }];
 914                 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();
 915                 assert_eq!(route.paths[0].len(), 2);
 916
 917                 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
 918                 assert_eq!(route.paths[0][0].short_channel_id, 42);
 919                 assert_eq!(route.paths[0][0].fee_msat, 200);
 920                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
 921                 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
 922                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
 923
 924                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
 925                 assert_eq!(route.paths[0][1].short_channel_id, 13);
 926                 assert_eq!(route.paths[0][1].fee_msat, 100);
 927                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
 928                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
 929                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
 930         }
 931
 932         #[test]
 933         fn disable_node_test() {
 934                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
 935                 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
 936
 937                 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
 938                 let mut unknown_features = NodeFeatures::known();
 939                 unknown_features.set_required_unknown_bits();
 940                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
 941                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
 942                 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
 943
 944                 // If all nodes require some features we don't understand, route should fail
 945                 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)) {
 946                         assert_eq!(err, "Failed to find a path to the given destination");
 947                 } else { panic!(); }
 948
 949                 // If we specify a channel to node7, that overrides our local channel view and that gets used
 950                 let our_chans = vec![channelmanager::ChannelDetails {
 951                         channel_id: [0; 32],
 952                         short_channel_id: Some(42),
 953                         remote_network_id: nodes[7].clone(),
 954                         counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
 955                         channel_value_satoshis: 0,
 956                         user_id: 0,
 957                         outbound_capacity_msat: 0,
 958                         inbound_capacity_msat: 0,
 959                         is_live: true,
 960                 }];
 961                 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();
 962                 assert_eq!(route.paths[0].len(), 2);
 963
 964                 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
 965                 assert_eq!(route.paths[0][0].short_channel_id, 42);
 966                 assert_eq!(route.paths[0][0].fee_msat, 200);
 967                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
 968                 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
 969                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
 970
 971                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
 972                 assert_eq!(route.paths[0][1].short_channel_id, 13);
 973                 assert_eq!(route.paths[0][1].fee_msat, 100);
 974                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
 975                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
 976                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
 977
 978                 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
 979                 // naively) assume that the user checked the feature bits on the invoice, which override
 980                 // the node_announcement.
 981         }
 982
 983         #[test]
 984         fn our_chans_test() {
 985                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
 986                 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
 987
 988                 // Route to 1 via 2 and 3 because our channel to 1 is disabled
 989                 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[0], None, &Vec::new(), 100, 42, Arc::clone(&logger)).unwrap();
 990                 assert_eq!(route.paths[0].len(), 3);
 991
 992                 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
 993                 assert_eq!(route.paths[0][0].short_channel_id, 2);
 994                 assert_eq!(route.paths[0][0].fee_msat, 200);
 995                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
 996                 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
 997                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
 998
 999                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1000                 assert_eq!(route.paths[0][1].short_channel_id, 4);
1001                 assert_eq!(route.paths[0][1].fee_msat, 100);
1002                 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 8) | 2);
1003                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1004                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1005
1006                 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
1007                 assert_eq!(route.paths[0][2].short_channel_id, 3);
1008                 assert_eq!(route.paths[0][2].fee_msat, 100);
1009                 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
1010                 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
1011                 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
1012
1013                 // If we specify a channel to node7, that overrides our local channel view and that gets used
1014                 let our_chans = vec![channelmanager::ChannelDetails {
1015                         channel_id: [0; 32],
1016                         short_channel_id: Some(42),
1017                         remote_network_id: nodes[7].clone(),
1018                         counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1019                         channel_value_satoshis: 0,
1020                         user_id: 0,
1021                         outbound_capacity_msat: 0,
1022                         inbound_capacity_msat: 0,
1023                         is_live: true,
1024                 }];
1025                 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();
1026                 assert_eq!(route.paths[0].len(), 2);
1027
1028                 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
1029                 assert_eq!(route.paths[0][0].short_channel_id, 42);
1030                 assert_eq!(route.paths[0][0].fee_msat, 200);
1031                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 8) | 1);
1032                 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
1033                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1034
1035                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1036                 assert_eq!(route.paths[0][1].short_channel_id, 13);
1037                 assert_eq!(route.paths[0][1].fee_msat, 100);
1038                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1039                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1040                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
1041         }
1042
1043         fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
1044                 let zero_fees = RoutingFees {
1045                         base_msat: 0,
1046                         proportional_millionths: 0,
1047                 };
1048                 vec!(RouteHint {
1049                         src_node_id: nodes[3].clone(),
1050                         short_channel_id: 8,
1051                         fees: zero_fees,
1052                         cltv_expiry_delta: (8 << 8) | 1,
1053                         htlc_minimum_msat: 0,
1054                 }, RouteHint {
1055                         src_node_id: nodes[4].clone(),
1056                         short_channel_id: 9,
1057                         fees: RoutingFees {
1058                                 base_msat: 1001,
1059                                 proportional_millionths: 0,
1060                         },
1061                         cltv_expiry_delta: (9 << 8) | 1,
1062                         htlc_minimum_msat: 0,
1063                 }, RouteHint {
1064                         src_node_id: nodes[5].clone(),
1065                         short_channel_id: 10,
1066                         fees: zero_fees,
1067                         cltv_expiry_delta: (10 << 8) | 1,
1068                         htlc_minimum_msat: 0,
1069                 })
1070         }
1071
1072         #[test]
1073         fn last_hops_test() {
1074                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
1075                 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1076
1077                 // Simple test across 2, 3, 5, and 4 via a last_hop channel
1078                 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();
1079                 assert_eq!(route.paths[0].len(), 5);
1080
1081                 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1082                 assert_eq!(route.paths[0][0].short_channel_id, 2);
1083                 assert_eq!(route.paths[0][0].fee_msat, 100);
1084                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1085                 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1086                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1087
1088                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1089                 assert_eq!(route.paths[0][1].short_channel_id, 4);
1090                 assert_eq!(route.paths[0][1].fee_msat, 0);
1091                 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
1092                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1093                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1094
1095                 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
1096                 assert_eq!(route.paths[0][2].short_channel_id, 6);
1097                 assert_eq!(route.paths[0][2].fee_msat, 0);
1098                 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
1099                 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
1100                 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
1101
1102                 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
1103                 assert_eq!(route.paths[0][3].short_channel_id, 11);
1104                 assert_eq!(route.paths[0][3].fee_msat, 0);
1105                 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
1106                 // If we have a peer in the node map, we'll use their features here since we don't have
1107                 // a way of figuring out their features from the invoice:
1108                 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
1109                 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
1110
1111                 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
1112                 assert_eq!(route.paths[0][4].short_channel_id, 8);
1113                 assert_eq!(route.paths[0][4].fee_msat, 100);
1114                 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
1115                 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
1116                 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
1117         }
1118
1119         #[test]
1120         fn our_chans_last_hop_connect_test() {
1121                 let (secp_ctx, net_graph_msg_handler, logger) = build_graph();
1122                 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
1123
1124                 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1125                 let our_chans = vec![channelmanager::ChannelDetails {
1126                         channel_id: [0; 32],
1127                         short_channel_id: Some(42),
1128                         remote_network_id: nodes[3].clone(),
1129                         counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1130                         channel_value_satoshis: 0,
1131                         user_id: 0,
1132                         outbound_capacity_msat: 0,
1133                         inbound_capacity_msat: 0,
1134                         is_live: true,
1135                 }];
1136                 let mut last_hops = last_hops(&nodes);
1137                 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
1138                 assert_eq!(route.paths[0].len(), 2);
1139
1140                 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
1141                 assert_eq!(route.paths[0][0].short_channel_id, 42);
1142                 assert_eq!(route.paths[0][0].fee_msat, 0);
1143                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
1144                 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
1145                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
1146
1147                 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
1148                 assert_eq!(route.paths[0][1].short_channel_id, 8);
1149                 assert_eq!(route.paths[0][1].fee_msat, 100);
1150                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1151                 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
1152                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
1153
1154                 last_hops[0].fees.base_msat = 1000;
1155
1156                 // Revert to via 6 as the fee on 8 goes up
1157                 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::clone(&logger)).unwrap();
1158                 assert_eq!(route.paths[0].len(), 4);
1159
1160                 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1161                 assert_eq!(route.paths[0][0].short_channel_id, 2);
1162                 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
1163                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1164                 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1165                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1166
1167                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1168                 assert_eq!(route.paths[0][1].short_channel_id, 4);
1169                 assert_eq!(route.paths[0][1].fee_msat, 100);
1170                 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 8) | 1);
1171                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1172                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1173
1174                 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
1175                 assert_eq!(route.paths[0][2].short_channel_id, 7);
1176                 assert_eq!(route.paths[0][2].fee_msat, 0);
1177                 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 8) | 1);
1178                 // If we have a peer in the node map, we'll use their features here since we don't have
1179                 // a way of figuring out their features from the invoice:
1180                 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
1181                 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
1182
1183                 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
1184                 assert_eq!(route.paths[0][3].short_channel_id, 10);
1185                 assert_eq!(route.paths[0][3].fee_msat, 100);
1186                 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
1187                 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
1188                 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
1189
1190                 // ...but still use 8 for larger payments as 6 has a variable feerate
1191                 let route = get_route(&our_id, &net_graph_msg_handler.network_graph.read().unwrap(), &nodes[6], None, &last_hops.iter().collect::<Vec<_>>(), 2000, 42, Arc::clone(&logger)).unwrap();
1192                 assert_eq!(route.paths[0].len(), 5);
1193
1194                 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
1195                 assert_eq!(route.paths[0][0].short_channel_id, 2);
1196                 assert_eq!(route.paths[0][0].fee_msat, 3000);
1197                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 8) | 1);
1198                 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
1199                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
1200
1201                 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
1202                 assert_eq!(route.paths[0][1].short_channel_id, 4);
1203                 assert_eq!(route.paths[0][1].fee_msat, 0);
1204                 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 8) | 1);
1205                 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
1206                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
1207
1208                 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
1209                 assert_eq!(route.paths[0][2].short_channel_id, 6);
1210                 assert_eq!(route.paths[0][2].fee_msat, 0);
1211                 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 8) | 1);
1212                 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
1213                 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
1214
1215                 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
1216                 assert_eq!(route.paths[0][3].short_channel_id, 11);
1217                 assert_eq!(route.paths[0][3].fee_msat, 1000);
1218                 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 8) | 1);
1219                 // If we have a peer in the node map, we'll use their features here since we don't have
1220                 // a way of figuring out their features from the invoice:
1221                 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
1222                 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
1223
1224                 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
1225                 assert_eq!(route.paths[0][4].short_channel_id, 8);
1226                 assert_eq!(route.paths[0][4].fee_msat, 2000);
1227                 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
1228                 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
1229                 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
1230         }
1231
1232         #[test]
1233         fn unannounced_path_test() {
1234                 // We should be able to send a payment to a destination without any help of a routing graph
1235                 // if we have a channel with a common counterparty that appears in the first and last hop
1236                 // hints.
1237                 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
1238                 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
1239                 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
1240
1241                 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
1242                 let last_hops = vec![RouteHint {
1243                         src_node_id: middle_node_id,
1244                         short_channel_id: 8,
1245                         fees: RoutingFees {
1246                                 base_msat: 1000,
1247                                 proportional_millionths: 0,
1248                         },
1249                         cltv_expiry_delta: (8 << 8) | 1,
1250                         htlc_minimum_msat: 0,
1251                 }];
1252                 let our_chans = vec![channelmanager::ChannelDetails {
1253                         channel_id: [0; 32],
1254                         short_channel_id: Some(42),
1255                         remote_network_id: middle_node_id,
1256                         counterparty_features: InitFeatures::from_le_bytes(vec![0b11]),
1257                         channel_value_satoshis: 100000,
1258                         user_id: 0,
1259                         outbound_capacity_msat: 100000,
1260                         inbound_capacity_msat: 100000,
1261                         is_live: true,
1262                 }];
1263                 let route = get_route(&source_node_id, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()), &target_node_id, Some(&our_chans.iter().collect::<Vec<_>>()), &last_hops.iter().collect::<Vec<_>>(), 100, 42, Arc::new(test_utils::TestLogger::new())).unwrap();
1264
1265                 assert_eq!(route.paths[0].len(), 2);
1266
1267                 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
1268                 assert_eq!(route.paths[0][0].short_channel_id, 42);
1269                 assert_eq!(route.paths[0][0].fee_msat, 1000);
1270                 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 8) | 1);
1271                 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
1272                 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
1273
1274                 assert_eq!(route.paths[0][1].pubkey, target_node_id);
1275                 assert_eq!(route.paths[0][1].short_channel_id, 8);
1276                 assert_eq!(route.paths[0][1].fee_msat, 100);
1277                 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
1278                 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
1279                 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
1280         }
1281 }
1282
1283 #[cfg(all(test, feature = "unstable"))]
1284 mod benches {
1285         use super::*;
1286         use util::logger::{Logger, Record};
1287
1288         use std::fs::File;
1289         use test::Bencher;
1290
1291         struct DummyLogger {}
1292         impl Logger for DummyLogger {
1293                 fn log(&self, _record: &Record) {}
1294         }
1295
1296         #[bench]
1297         fn generate_routes(bench: &mut Bencher) {
1298                 let mut d = File::open("net_graph-2021-02-12.bin").expect("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
1299                 let graph = NetworkGraph::read(&mut d).unwrap();
1300
1301                 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
1302                 let mut path_endpoints = Vec::new();
1303                 let mut seed: usize = 0xdeadbeef;
1304                 'load_endpoints: for _ in 0..100 {
1305                         loop {
1306                                 seed *= 0xdeadbeef;
1307                                 let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
1308                                 seed *= 0xdeadbeef;
1309                                 let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
1310                                 let amt = seed as u64 % 1_000_000;
1311                                 if get_route(src, &graph, dst, None, &[], amt, 42, &DummyLogger{}).is_ok() {
1312                                         path_endpoints.push((src, dst, amt));
1313                                         continue 'load_endpoints;
1314                                 }
1315                         }
1316                 }
1317
1318                 // ...then benchmark finding paths between the nodes we learned.
1319                 let mut idx = 0;
1320                 bench.iter(|| {
1321                         let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
1322                         assert!(get_route(src, &graph, dst, None, &[], amt, 42, &DummyLogger{}).is_ok());
1323                         idx += 1;
1324                 });
1325         }
1326 }