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

   1 use secp256k1::key::PublicKey;
   2 use secp256k1::{Secp256k1,Message};
   3 use secp256k1;
   4
   5 use bitcoin::util::hash::Sha256dHash;
   6
   7 use ln::channelmanager;
   8 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,MsgEncodable,NetAddress,GlobalFeatures};
   9 use ln::msgs;
  10 use util::logger::Logger;
  11
  12 use std::cmp;
  13 use std::sync::{RwLock,Arc};
  14 use std::collections::{HashMap,BinaryHeap};
  15 use std::collections::hash_map::Entry;
  16 use std;
  17
  18 /// A hop in a route
  19 #[derive(Clone)]
  20 pub struct RouteHop {
  21         pub pubkey: PublicKey,
  22         /// The channel that should be used from the previous hop to reach this node.
  23         pub short_channel_id: u64,
  24         /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
  25         pub fee_msat: u64,
  26         /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
  27         /// expected at the destination, in excess of the current block height.
  28         pub cltv_expiry_delta: u32,
  29 }
  30
  31 /// A route from us through the network to a destination
  32 #[derive(Clone)]
  33 pub struct Route {
  34         /// The list of hops, NOT INCLUDING our own, where the last hop is the destination. Thus, this
  35         /// must always be at least length one. By protocol rules, this may not currently exceed 20 in
  36         /// length.
  37         pub hops: Vec<RouteHop>,
  38 }
  39
  40 struct DirectionalChannelInfo {
  41         src_node_id: PublicKey,
  42         last_update: u32,
  43         enabled: bool,
  44         cltv_expiry_delta: u16,
  45         htlc_minimum_msat: u64,
  46         fee_base_msat: u32,
  47         fee_proportional_millionths: u32,
  48 }
  49
  50 impl std::fmt::Display for DirectionalChannelInfo {
  51         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  52                 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)?;
  53                 Ok(())
  54         }
  55 }
  56
  57 struct ChannelInfo {
  58         features: GlobalFeatures,
  59         one_to_two: DirectionalChannelInfo,
  60         two_to_one: DirectionalChannelInfo,
  61 }
  62
  63 impl std::fmt::Display for ChannelInfo {
  64         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  65                 write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
  66                 Ok(())
  67         }
  68 }
  69
  70 struct NodeInfo {
  71         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  72         channels: Vec<(u64, Sha256dHash)>,
  73         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  74         channels: Vec<u64>,
  75
  76         lowest_inbound_channel_fee_base_msat: u32,
  77         lowest_inbound_channel_fee_proportional_millionths: u32,
  78
  79         features: GlobalFeatures,
  80         last_update: u32,
  81         rgb: [u8; 3],
  82         alias: [u8; 32],
  83         addresses: Vec<NetAddress>,
  84 }
  85
  86 impl std::fmt::Display for NodeInfo {
  87         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  88                 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[..])?;
  89                 Ok(())
  90         }
  91 }
  92
  93 struct NetworkMap {
  94         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  95         channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
  96         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  97         channels: HashMap<u64, ChannelInfo>,
  98
  99         our_node_id: PublicKey,
 100         nodes: HashMap<PublicKey, NodeInfo>,
 101 }
 102
 103 impl std::fmt::Display for NetworkMap {
 104         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 105                 write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
 106                 for (key, val) in self.channels.iter() {
 107                         write!(f, " {}: {}\n", key, val)?;
 108                 }
 109                 write!(f, "[Nodes]\n")?;
 110                 for (key, val) in self.nodes.iter() {
 111                         write!(f, " {}: {}\n", log_pubkey!(key), val)?;
 112                 }
 113                 Ok(())
 114         }
 115 }
 116
 117 impl NetworkMap {
 118         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 119         #[inline]
 120         fn get_key(short_channel_id: u64, chain_hash: Sha256dHash) -> (u64, Sha256dHash) {
 121                 (short_channel_id, chain_hash)
 122         }
 123
 124         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 125         #[inline]
 126         fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
 127                 short_channel_id
 128         }
 129
 130         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 131         #[inline]
 132         fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
 133                 &id.0
 134         }
 135
 136         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 137         #[inline]
 138         fn get_short_id(id: &u64) -> &u64 {
 139                 id
 140         }
 141 }
 142
 143 /// A channel descriptor which provides a last-hop route to get_route
 144 pub struct RouteHint {
 145         pub src_node_id: PublicKey,
 146         pub short_channel_id: u64,
 147         pub fee_base_msat: u32,
 148         pub fee_proportional_millionths: u32,
 149         pub cltv_expiry_delta: u16,
 150         pub htlc_minimum_msat: u64,
 151 }
 152
 153 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 154 /// payment destinations.
 155 pub struct Router {
 156         secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
 157         network_map: RwLock<NetworkMap>,
 158         logger: Arc<Logger>,
 159 }
 160
 161 macro_rules! secp_verify_sig {
 162         ( $secp_ctx: expr, $msg: expr, $sig: expr, $pubkey: expr ) => {
 163                 match $secp_ctx.verify($msg, $sig, $pubkey) {
 164                         Ok(_) => {},
 165                         Err(_) => return Err(HandleError{err: "Invalid signature from remote node", action: None}),
 166                 }
 167         };
 168 }
 169
 170 impl RoutingMessageHandler for Router {
 171         fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<(), HandleError> {
 172                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 173                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 174
 175                 let mut network = self.network_map.write().unwrap();
 176                 match network.nodes.get_mut(&msg.contents.node_id) {
 177                         None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
 178                         Some(node) => {
 179                                 if node.last_update >= msg.contents.timestamp {
 180                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 181                                 }
 182
 183                                 node.features = msg.contents.features.clone();
 184                                 node.last_update = msg.contents.timestamp;
 185                                 node.rgb = msg.contents.rgb;
 186                                 node.alias = msg.contents.alias;
 187                                 node.addresses = msg.contents.addresses.clone();
 188                                 Ok(())
 189                         }
 190                 }
 191         }
 192
 193         fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
 194                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 195                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
 196                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
 197                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
 198                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 199
 200                 //TODO: Call blockchain thing to ask if the short_channel_id is valid
 201                 //TODO: Only allow bitcoin chain_hash
 202
 203                 if msg.contents.features.requires_unknown_bits() {
 204                         return Err(HandleError{err: "Channel announcement required unknown feature flags", action: None});
 205                 }
 206
 207                 let mut network = self.network_map.write().unwrap();
 208
 209                 match network.channels.entry(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 210                         Entry::Occupied(_) => {
 211                                 //TODO: because asking the blockchain if short_channel_id is valid is only optional
 212                                 //in the blockchain API, we need to handle it smartly here, though its unclear
 213                                 //exactly how...
 214                                 return Err(HandleError{err: "Already have knowledge of channel", action: Some(ErrorAction::IgnoreError)})
 215                         },
 216                         Entry::Vacant(entry) => {
 217                                 entry.insert(ChannelInfo {
 218                                         features: msg.contents.features.clone(),
 219                                         one_to_two: DirectionalChannelInfo {
 220                                                 src_node_id: msg.contents.node_id_1.clone(),
 221                                                 last_update: 0,
 222                                                 enabled: false,
 223                                                 cltv_expiry_delta: u16::max_value(),
 224                                                 htlc_minimum_msat: u64::max_value(),
 225                                                 fee_base_msat: u32::max_value(),
 226                                                 fee_proportional_millionths: u32::max_value(),
 227                                         },
 228                                         two_to_one: DirectionalChannelInfo {
 229                                                 src_node_id: msg.contents.node_id_2.clone(),
 230                                                 last_update: 0,
 231                                                 enabled: false,
 232                                                 cltv_expiry_delta: u16::max_value(),
 233                                                 htlc_minimum_msat: u64::max_value(),
 234                                                 fee_base_msat: u32::max_value(),
 235                                                 fee_proportional_millionths: u32::max_value(),
 236                                         }
 237                                 });
 238                         }
 239                 };
 240
 241                 macro_rules! add_channel_to_node {
 242                         ( $node_id: expr ) => {
 243                                 match network.nodes.entry($node_id) {
 244                                         Entry::Occupied(node_entry) => {
 245                                                 node_entry.into_mut().channels.push(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash));
 246                                         },
 247                                         Entry::Vacant(node_entry) => {
 248                                                 node_entry.insert(NodeInfo {
 249                                                         channels: vec!(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)),
 250                                                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 251                                                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 252                                                         features: GlobalFeatures::new(),
 253                                                         last_update: 0,
 254                                                         rgb: [0; 3],
 255                                                         alias: [0; 32],
 256                                                         addresses: Vec::new(),
 257                                                 });
 258                                         }
 259                                 }
 260                         };
 261                 }
 262
 263                 add_channel_to_node!(msg.contents.node_id_1);
 264                 add_channel_to_node!(msg.contents.node_id_2);
 265
 266                 Ok(!msg.contents.features.supports_unknown_bits())
 267         }
 268
 269         fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
 270                 match update {
 271                         &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
 272                                 let _ = self.handle_channel_update(msg);
 273                         },
 274                         &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id } => {
 275                                 let mut network = self.network_map.write().unwrap();
 276                                 if let Some(chan) = network.channels.remove(short_channel_id) {
 277                                         network.nodes.get_mut(&chan.one_to_two.src_node_id).unwrap().channels.retain(|chan_id| {
 278                                                 chan_id != NetworkMap::get_short_id(chan_id)
 279                                         });
 280                                         network.nodes.get_mut(&chan.two_to_one.src_node_id).unwrap().channels.retain(|chan_id| {
 281                                                 chan_id != NetworkMap::get_short_id(chan_id)
 282                                         });
 283                                 }
 284                         },
 285                 }
 286         }
 287
 288         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<(), HandleError> {
 289                 let mut network = self.network_map.write().unwrap();
 290                 let dest_node_id;
 291                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 292                 let chan_was_enabled;
 293
 294                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 295                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 296                         Some(channel) => {
 297                                 macro_rules! maybe_update_channel_info {
 298                                         ( $target: expr) => {
 299                                                 if $target.last_update >= msg.contents.timestamp {
 300                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 301                                                 }
 302                                                 chan_was_enabled = $target.enabled;
 303                                                 $target.last_update = msg.contents.timestamp;
 304                                                 $target.enabled = chan_enabled;
 305                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 306                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 307                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 308                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 309                                         }
 310                                 }
 311
 312                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 313                                 if msg.contents.flags & 1 == 1 {
 314                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 315                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 316                                         maybe_update_channel_info!(channel.two_to_one);
 317                                 } else {
 318                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 319                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 320                                         maybe_update_channel_info!(channel.one_to_two);
 321                                 }
 322                         }
 323                 }
 324
 325                 if chan_enabled {
 326                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 327                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 328                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 329                 } else if chan_was_enabled {
 330                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 331                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 332
 333                         {
 334                                 let node = network.nodes.get(&dest_node_id).unwrap();
 335
 336                                 for chan_id in node.channels.iter() {
 337                                         let chan = network.channels.get(chan_id).unwrap();
 338                                         if chan.one_to_two.src_node_id == dest_node_id {
 339                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 340                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 341                                         } else {
 342                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 343                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 344                                         }
 345                                 }
 346                         }
 347
 348                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 349                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 350                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 351                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 352                 }
 353
 354                 Ok(())
 355         }
 356 }
 357
 358 #[derive(Eq, PartialEq)]
 359 struct RouteGraphNode {
 360         pubkey: PublicKey,
 361         lowest_fee_to_peer_through_node: u64,
 362         lowest_fee_to_node: u64,
 363 }
 364
 365 impl cmp::Ord for RouteGraphNode {
 366         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 367                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 368                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 369         }
 370 }
 371
 372 impl cmp::PartialOrd for RouteGraphNode {
 373         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 374                 Some(self.cmp(other))
 375         }
 376 }
 377
 378 struct DummyDirectionalChannelInfo {
 379         src_node_id: PublicKey,
 380         cltv_expiry_delta: u32,
 381         htlc_minimum_msat: u64,
 382         fee_base_msat: u32,
 383         fee_proportional_millionths: u32,
 384 }
 385
 386 impl Router {
 387         pub fn new(our_pubkey: PublicKey, logger: Arc<Logger>) -> Router {
 388                 let mut nodes = HashMap::new();
 389                 nodes.insert(our_pubkey.clone(), NodeInfo {
 390                         channels: Vec::new(),
 391                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 392                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 393                         features: GlobalFeatures::new(),
 394                         last_update: 0,
 395                         rgb: [0; 3],
 396                         alias: [0; 32],
 397                         addresses: Vec::new(),
 398                 });
 399                 Router {
 400                         secp_ctx: Secp256k1::verification_only(),
 401                         network_map: RwLock::new(NetworkMap {
 402                                 channels: HashMap::new(),
 403                                 our_node_id: our_pubkey,
 404                                 nodes: nodes,
 405                         }),
 406                         logger,
 407                 }
 408         }
 409
 410         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 411         /// level Trace
 412         pub fn trace_state(&self) {
 413                 log_trace!(self, "{}", self.network_map.read().unwrap());
 414         }
 415
 416         /// Get network addresses by node id
 417         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 418                 let network = self.network_map.read().unwrap();
 419                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 420         }
 421
 422         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 423         /// with an expotnential decay in node "badness". Note that there is deliberately no
 424         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 425         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 426         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 427         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 428         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 429                 unimplemented!();
 430         }
 431
 432         /// Gets a route from us to the given target node.
 433         /// Extra routing hops between known nodes and the target will be used if they are included in
 434         /// last_hops.
 435         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 436         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 437         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 438         /// will be used. Panics if first_hops contains channels without short_channel_ids
 439         /// (ChannelManager::list_usable_channels will never include such channels).
 440         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 441         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 442         /// *is* checked as they may change based on the receiving node.
 443         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> {
 444                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 445                 // uptime/success in using a node in the past.
 446                 let network = self.network_map.read().unwrap();
 447
 448                 if *target == network.our_node_id {
 449                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 450                 }
 451
 452                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 453                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 454                 }
 455
 456                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 457                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 458                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 459                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 460                 // one.
 461
 462                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 463                         src_node_id: network.our_node_id.clone(),
 464                         cltv_expiry_delta: 0,
 465                         htlc_minimum_msat: 0,
 466                         fee_base_msat: 0,
 467                         fee_proportional_millionths: 0,
 468                 };
 469
 470                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 471                 let mut dist = HashMap::with_capacity(network.nodes.len());
 472
 473                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 474                 if let Some(hops) = first_hops {
 475                         for chan in hops {
 476                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 477                                 if chan.remote_network_id == *target {
 478                                         return Ok(Route {
 479                                                 hops: vec![RouteHop {
 480                                                         pubkey: chan.remote_network_id,
 481                                                         short_channel_id,
 482                                                         fee_msat: final_value_msat,
 483                                                         cltv_expiry_delta: final_cltv,
 484                                                 }],
 485                                         });
 486                                 }
 487                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 488                         }
 489                         if first_hop_targets.is_empty() {
 490                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 491                         }
 492                 }
 493
 494                 macro_rules! add_entry {
 495                         // Adds entry which goes from the node pointed to by $directional_info to
 496                         // $dest_node_id over the channel with id $chan_id with fees described in
 497                         // $directional_info.
 498                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 499                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 500                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 501                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 502                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 503                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 504                                         {
 505                                                 let mut total_fee = $starting_fee_msat as u64;
 506                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 507                                                 let old_entry = hm_entry.or_insert_with(|| {
 508                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 509                                                         (u64::max_value(),
 510                                                                 node.lowest_inbound_channel_fee_base_msat,
 511                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 512                                                                 RouteHop {
 513                                                                         pubkey: $dest_node_id.clone(),
 514                                                                         short_channel_id: 0,
 515                                                                         fee_msat: 0,
 516                                                                         cltv_expiry_delta: 0,
 517                                                         })
 518                                                 });
 519                                                 if $directional_info.src_node_id != network.our_node_id {
 520                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 521                                                         // will have the same effective-fee
 522                                                         total_fee += new_fee;
 523                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 524                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 525                                                         } else {
 526                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 527                                                                 total_fee = u64::max_value();
 528                                                         }
 529                                                 }
 530                                                 let new_graph_node = RouteGraphNode {
 531                                                         pubkey: $directional_info.src_node_id,
 532                                                         lowest_fee_to_peer_through_node: total_fee,
 533                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 534                                                 };
 535                                                 if old_entry.0 > total_fee {
 536                                                         targets.push(new_graph_node);
 537                                                         old_entry.0 = total_fee;
 538                                                         old_entry.3 = RouteHop {
 539                                                                 pubkey: $dest_node_id.clone(),
 540                                                                 short_channel_id: $chan_id.clone(),
 541                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 542                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 543                                                         }
 544                                                 }
 545                                         }
 546                                 }
 547                         };
 548                 }
 549
 550                 macro_rules! add_entries_to_cheapest_to_target_node {
 551                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 552                                 if first_hops.is_some() {
 553                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 554                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 555                                         }
 556                                 }
 557
 558                                 for chan_id in $node.channels.iter() {
 559                                         let chan = network.channels.get(chan_id).unwrap();
 560                                         if chan.one_to_two.src_node_id == *$node_id {
 561                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 562                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 563                                                         if chan.two_to_one.enabled {
 564                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 565                                                         }
 566                                                 }
 567                                         } else {
 568                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 569                                                         if chan.one_to_two.enabled {
 570                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 571                                                         }
 572                                                 }
 573                                         }
 574                                 }
 575                         };
 576                 }
 577
 578                 match network.nodes.get(target) {
 579                         None => {},
 580                         Some(node) => {
 581                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 582                         },
 583                 }
 584
 585                 for hop in last_hops.iter() {
 586                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 587                                 if network.nodes.get(&hop.src_node_id).is_some() {
 588                                         if first_hops.is_some() {
 589                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 590                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 591                                                 }
 592                                         }
 593                                         add_entry!(hop.short_channel_id, target, hop, 0);
 594                                 }
 595                         }
 596                 }
 597
 598                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 599                         if pubkey == network.our_node_id {
 600                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 601                                 while res.last().unwrap().pubkey != *target {
 602                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 603                                                 Some(hop) => hop.3,
 604                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 605                                         };
 606                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 607                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 608                                         res.push(new_entry);
 609                                 }
 610                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 611                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 612                                 let route = Route { hops: res };
 613                                 log_trace!(self, "Got route: {}", log_route!(route));
 614                                 return Ok(route);
 615                         }
 616
 617                         match network.nodes.get(&pubkey) {
 618                                 None => {},
 619                                 Some(node) => {
 620                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 621                                 },
 622                         }
 623                 }
 624
 625                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 626         }
 627 }
 628
 629 #[cfg(test)]
 630 mod tests {
 631         use ln::channelmanager;
 632         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 633         use ln::msgs::GlobalFeatures;
 634         use util::test_utils;
 635         use util::logger::Logger;
 636
 637         use bitcoin::util::hash::Sha256dHash;
 638
 639         use hex;
 640
 641         use secp256k1::key::{PublicKey,SecretKey};
 642         use secp256k1::Secp256k1;
 643
 644         use std::sync::Arc;
 645
 646         #[test]
 647         fn route_test() {
 648                 let secp_ctx = Secp256k1::new();
 649                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 650                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 651                 let router = Router::new(our_id, Arc::clone(&logger));
 652
 653                 // Build network from our_id to node8:
 654                 //
 655                 //        -1(1)2-  node1  -1(3)2-
 656                 //       /                       \
 657                 // our_id -1(12)2- node8 -1(13)2--- node3
 658                 //       \                       /
 659                 //        -1(2)2-  node2  -1(4)2-
 660                 //
 661                 //
 662                 // chan1  1-to-2: disabled
 663                 // chan1  2-to-1: enabled, 0 fee
 664                 //
 665                 // chan2  1-to-2: enabled, ignored fee
 666                 // chan2  2-to-1: enabled, 0 fee
 667                 //
 668                 // chan3  1-to-2: enabled, 0 fee
 669                 // chan3  2-to-1: enabled, 100 msat fee
 670                 //
 671                 // chan4  1-to-2: enabled, 100% fee
 672                 // chan4  2-to-1: enabled, 0 fee
 673                 //
 674                 // chan12 1-to-2: enabled, ignored fee
 675                 // chan12 2-to-1: enabled, 0 fee
 676                 //
 677                 // chan13 1-to-2: enabled, 200% fee
 678                 // chan13 2-to-1: enabled, 0 fee
 679                 //
 680                 //
 681                 //       -1(5)2- node4 -1(8)2--
 682                 //       |         2          |
 683                 //       |       (11)         |
 684                 //      /          1           \
 685                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 686                 //      \                      /
 687                 //       -1(7)2- node6 -1(10)2-
 688                 //
 689                 // chan5  1-to-2: enabled, 100 msat fee
 690                 // chan5  2-to-1: enabled, 0 fee
 691                 //
 692                 // chan6  1-to-2: enabled, 0 fee
 693                 // chan6  2-to-1: enabled, 0 fee
 694                 //
 695                 // chan7  1-to-2: enabled, 100% fee
 696                 // chan7  2-to-1: enabled, 0 fee
 697                 //
 698                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 699                 // chan8  2-to-1: enabled, 0 fee
 700                 //
 701                 // chan9  1-to-2: enabled, 1001 msat fee
 702                 // chan9  2-to-1: enabled, 0 fee
 703                 //
 704                 // chan10 1-to-2: enabled, 0 fee
 705                 // chan10 2-to-1: enabled, 0 fee
 706                 //
 707                 // chan11 1-to-2: enabled, 0 fee
 708                 // chan11 2-to-1: enabled, 0 fee
 709
 710                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 711                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 712                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 713                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 714                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 715                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 716                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 717                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 718
 719                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 720
 721                 {
 722                         let mut network = router.network_map.write().unwrap();
 723
 724                         network.nodes.insert(node1.clone(), NodeInfo {
 725                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 726                                 lowest_inbound_channel_fee_base_msat: 100,
 727                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 728                                 features: GlobalFeatures::new(),
 729                                 last_update: 1,
 730                                 rgb: [0; 3],
 731                                 alias: [0; 32],
 732                                 addresses: Vec::new(),
 733                         });
 734                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 735                                 features: GlobalFeatures::new(),
 736                                 one_to_two: DirectionalChannelInfo {
 737                                         src_node_id: our_id.clone(),
 738                                         last_update: 0,
 739                                         enabled: false,
 740                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 741                                         htlc_minimum_msat: 0,
 742                                         fee_base_msat: u32::max_value(), // This value should be ignored
 743                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 744                                 }, two_to_one: DirectionalChannelInfo {
 745                                         src_node_id: node1.clone(),
 746                                         last_update: 0,
 747                                         enabled: true,
 748                                         cltv_expiry_delta: 0,
 749                                         htlc_minimum_msat: 0,
 750                                         fee_base_msat: 0,
 751                                         fee_proportional_millionths: 0,
 752                                 },
 753                         });
 754                         network.nodes.insert(node2.clone(), NodeInfo {
 755                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 756                                 lowest_inbound_channel_fee_base_msat: 0,
 757                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 758                                 features: GlobalFeatures::new(),
 759                                 last_update: 1,
 760                                 rgb: [0; 3],
 761                                 alias: [0; 32],
 762                                 addresses: Vec::new(),
 763                         });
 764                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 765                                 features: GlobalFeatures::new(),
 766                                 one_to_two: DirectionalChannelInfo {
 767                                         src_node_id: our_id.clone(),
 768                                         last_update: 0,
 769                                         enabled: true,
 770                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 771                                         htlc_minimum_msat: 0,
 772                                         fee_base_msat: u32::max_value(), // This value should be ignored
 773                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 774                                 }, two_to_one: DirectionalChannelInfo {
 775                                         src_node_id: node2.clone(),
 776                                         last_update: 0,
 777                                         enabled: true,
 778                                         cltv_expiry_delta: 0,
 779                                         htlc_minimum_msat: 0,
 780                                         fee_base_msat: 0,
 781                                         fee_proportional_millionths: 0,
 782                                 },
 783                         });
 784                         network.nodes.insert(node8.clone(), NodeInfo {
 785                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 786                                 lowest_inbound_channel_fee_base_msat: 0,
 787                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 788                                 features: GlobalFeatures::new(),
 789                                 last_update: 1,
 790                                 rgb: [0; 3],
 791                                 alias: [0; 32],
 792                                 addresses: Vec::new(),
 793                         });
 794                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 795                                 features: GlobalFeatures::new(),
 796                                 one_to_two: DirectionalChannelInfo {
 797                                         src_node_id: our_id.clone(),
 798                                         last_update: 0,
 799                                         enabled: true,
 800                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 801                                         htlc_minimum_msat: 0,
 802                                         fee_base_msat: u32::max_value(), // This value should be ignored
 803                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 804                                 }, two_to_one: DirectionalChannelInfo {
 805                                         src_node_id: node8.clone(),
 806                                         last_update: 0,
 807                                         enabled: true,
 808                                         cltv_expiry_delta: 0,
 809                                         htlc_minimum_msat: 0,
 810                                         fee_base_msat: 0,
 811                                         fee_proportional_millionths: 0,
 812                                 },
 813                         });
 814                         network.nodes.insert(node3.clone(), NodeInfo {
 815                                 channels: vec!(
 816                                         NetworkMap::get_key(3, zero_hash.clone()),
 817                                         NetworkMap::get_key(4, zero_hash.clone()),
 818                                         NetworkMap::get_key(13, zero_hash.clone()),
 819                                         NetworkMap::get_key(5, zero_hash.clone()),
 820                                         NetworkMap::get_key(6, zero_hash.clone()),
 821                                         NetworkMap::get_key(7, zero_hash.clone())),
 822                                 lowest_inbound_channel_fee_base_msat: 0,
 823                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 824                                 features: GlobalFeatures::new(),
 825                                 last_update: 1,
 826                                 rgb: [0; 3],
 827                                 alias: [0; 32],
 828                                 addresses: Vec::new(),
 829                         });
 830                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 831                                 features: GlobalFeatures::new(),
 832                                 one_to_two: DirectionalChannelInfo {
 833                                         src_node_id: node1.clone(),
 834                                         last_update: 0,
 835                                         enabled: true,
 836                                         cltv_expiry_delta: (3 << 8) | 1,
 837                                         htlc_minimum_msat: 0,
 838                                         fee_base_msat: 0,
 839                                         fee_proportional_millionths: 0,
 840                                 }, two_to_one: DirectionalChannelInfo {
 841                                         src_node_id: node3.clone(),
 842                                         last_update: 0,
 843                                         enabled: true,
 844                                         cltv_expiry_delta: (3 << 8) | 2,
 845                                         htlc_minimum_msat: 0,
 846                                         fee_base_msat: 100,
 847                                         fee_proportional_millionths: 0,
 848                                 },
 849                         });
 850                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 851                                 features: GlobalFeatures::new(),
 852                                 one_to_two: DirectionalChannelInfo {
 853                                         src_node_id: node2.clone(),
 854                                         last_update: 0,
 855                                         enabled: true,
 856                                         cltv_expiry_delta: (4 << 8) | 1,
 857                                         htlc_minimum_msat: 0,
 858                                         fee_base_msat: 0,
 859                                         fee_proportional_millionths: 1000000,
 860                                 }, two_to_one: DirectionalChannelInfo {
 861                                         src_node_id: node3.clone(),
 862                                         last_update: 0,
 863                                         enabled: true,
 864                                         cltv_expiry_delta: (4 << 8) | 2,
 865                                         htlc_minimum_msat: 0,
 866                                         fee_base_msat: 0,
 867                                         fee_proportional_millionths: 0,
 868                                 },
 869                         });
 870                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
 871                                 features: GlobalFeatures::new(),
 872                                 one_to_two: DirectionalChannelInfo {
 873                                         src_node_id: node8.clone(),
 874                                         last_update: 0,
 875                                         enabled: true,
 876                                         cltv_expiry_delta: (13 << 8) | 1,
 877                                         htlc_minimum_msat: 0,
 878                                         fee_base_msat: 0,
 879                                         fee_proportional_millionths: 2000000,
 880                                 }, two_to_one: DirectionalChannelInfo {
 881                                         src_node_id: node3.clone(),
 882                                         last_update: 0,
 883                                         enabled: true,
 884                                         cltv_expiry_delta: (13 << 8) | 2,
 885                                         htlc_minimum_msat: 0,
 886                                         fee_base_msat: 0,
 887                                         fee_proportional_millionths: 0,
 888                                 },
 889                         });
 890                         network.nodes.insert(node4.clone(), NodeInfo {
 891                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 892                                 lowest_inbound_channel_fee_base_msat: 0,
 893                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 894                                 features: GlobalFeatures::new(),
 895                                 last_update: 1,
 896                                 rgb: [0; 3],
 897                                 alias: [0; 32],
 898                                 addresses: Vec::new(),
 899                         });
 900                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
 901                                 features: GlobalFeatures::new(),
 902                                 one_to_two: DirectionalChannelInfo {
 903                                         src_node_id: node3.clone(),
 904                                         last_update: 0,
 905                                         enabled: true,
 906                                         cltv_expiry_delta: (5 << 8) | 1,
 907                                         htlc_minimum_msat: 0,
 908                                         fee_base_msat: 100,
 909                                         fee_proportional_millionths: 0,
 910                                 }, two_to_one: DirectionalChannelInfo {
 911                                         src_node_id: node4.clone(),
 912                                         last_update: 0,
 913                                         enabled: true,
 914                                         cltv_expiry_delta: (5 << 8) | 2,
 915                                         htlc_minimum_msat: 0,
 916                                         fee_base_msat: 0,
 917                                         fee_proportional_millionths: 0,
 918                                 },
 919                         });
 920                         network.nodes.insert(node5.clone(), NodeInfo {
 921                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 922                                 lowest_inbound_channel_fee_base_msat: 0,
 923                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 924                                 features: GlobalFeatures::new(),
 925                                 last_update: 1,
 926                                 rgb: [0; 3],
 927                                 alias: [0; 32],
 928                                 addresses: Vec::new(),
 929                         });
 930                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
 931                                 features: GlobalFeatures::new(),
 932                                 one_to_two: DirectionalChannelInfo {
 933                                         src_node_id: node3.clone(),
 934                                         last_update: 0,
 935                                         enabled: true,
 936                                         cltv_expiry_delta: (6 << 8) | 1,
 937                                         htlc_minimum_msat: 0,
 938                                         fee_base_msat: 0,
 939                                         fee_proportional_millionths: 0,
 940                                 }, two_to_one: DirectionalChannelInfo {
 941                                         src_node_id: node5.clone(),
 942                                         last_update: 0,
 943                                         enabled: true,
 944                                         cltv_expiry_delta: (6 << 8) | 2,
 945                                         htlc_minimum_msat: 0,
 946                                         fee_base_msat: 0,
 947                                         fee_proportional_millionths: 0,
 948                                 },
 949                         });
 950                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
 951                                 features: GlobalFeatures::new(),
 952                                 one_to_two: DirectionalChannelInfo {
 953                                         src_node_id: node5.clone(),
 954                                         last_update: 0,
 955                                         enabled: true,
 956                                         cltv_expiry_delta: (11 << 8) | 1,
 957                                         htlc_minimum_msat: 0,
 958                                         fee_base_msat: 0,
 959                                         fee_proportional_millionths: 0,
 960                                 }, two_to_one: DirectionalChannelInfo {
 961                                         src_node_id: node4.clone(),
 962                                         last_update: 0,
 963                                         enabled: true,
 964                                         cltv_expiry_delta: (11 << 8) | 2,
 965                                         htlc_minimum_msat: 0,
 966                                         fee_base_msat: 0,
 967                                         fee_proportional_millionths: 0,
 968                                 },
 969                         });
 970                         network.nodes.insert(node6.clone(), NodeInfo {
 971                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
 972                                 lowest_inbound_channel_fee_base_msat: 0,
 973                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 974                                 features: GlobalFeatures::new(),
 975                                 last_update: 1,
 976                                 rgb: [0; 3],
 977                                 alias: [0; 32],
 978                                 addresses: Vec::new(),
 979                         });
 980                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
 981                                 features: GlobalFeatures::new(),
 982                                 one_to_two: DirectionalChannelInfo {
 983                                         src_node_id: node3.clone(),
 984                                         last_update: 0,
 985                                         enabled: true,
 986                                         cltv_expiry_delta: (7 << 8) | 1,
 987                                         htlc_minimum_msat: 0,
 988                                         fee_base_msat: 0,
 989                                         fee_proportional_millionths: 1000000,
 990                                 }, two_to_one: DirectionalChannelInfo {
 991                                         src_node_id: node6.clone(),
 992                                         last_update: 0,
 993                                         enabled: true,
 994                                         cltv_expiry_delta: (7 << 8) | 2,
 995                                         htlc_minimum_msat: 0,
 996                                         fee_base_msat: 0,
 997                                         fee_proportional_millionths: 0,
 998                                 },
 999                         });
1000                 }
1001
1002                 { // Simple route to 3 via 2
1003                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1004                         assert_eq!(route.hops.len(), 2);
1005
1006                         assert_eq!(route.hops[0].pubkey, node2);
1007                         assert_eq!(route.hops[0].short_channel_id, 2);
1008                         assert_eq!(route.hops[0].fee_msat, 100);
1009                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1010
1011                         assert_eq!(route.hops[1].pubkey, node3);
1012                         assert_eq!(route.hops[1].short_channel_id, 4);
1013                         assert_eq!(route.hops[1].fee_msat, 100);
1014                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1015                 }
1016
1017                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1018                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1019                         assert_eq!(route.hops.len(), 3);
1020
1021                         assert_eq!(route.hops[0].pubkey, node2);
1022                         assert_eq!(route.hops[0].short_channel_id, 2);
1023                         assert_eq!(route.hops[0].fee_msat, 200);
1024                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1025
1026                         assert_eq!(route.hops[1].pubkey, node3);
1027                         assert_eq!(route.hops[1].short_channel_id, 4);
1028                         assert_eq!(route.hops[1].fee_msat, 100);
1029                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1030
1031                         assert_eq!(route.hops[2].pubkey, node1);
1032                         assert_eq!(route.hops[2].short_channel_id, 3);
1033                         assert_eq!(route.hops[2].fee_msat, 100);
1034                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1035                 }
1036
1037                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1038                         let our_chans = vec![channelmanager::ChannelDetails {
1039                                 channel_id: [0; 32],
1040                                 short_channel_id: Some(42),
1041                                 remote_network_id: node8.clone(),
1042                                 channel_value_satoshis: 0,
1043                                 user_id: 0,
1044                         }];
1045                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1046                         assert_eq!(route.hops.len(), 2);
1047
1048                         assert_eq!(route.hops[0].pubkey, node8);
1049                         assert_eq!(route.hops[0].short_channel_id, 42);
1050                         assert_eq!(route.hops[0].fee_msat, 200);
1051                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1052
1053                         assert_eq!(route.hops[1].pubkey, node3);
1054                         assert_eq!(route.hops[1].short_channel_id, 13);
1055                         assert_eq!(route.hops[1].fee_msat, 100);
1056                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1057                 }
1058
1059                 let mut last_hops = vec!(RouteHint {
1060                                 src_node_id: node4.clone(),
1061                                 short_channel_id: 8,
1062                                 fee_base_msat: 0,
1063                                 fee_proportional_millionths: 0,
1064                                 cltv_expiry_delta: (8 << 8) | 1,
1065                                 htlc_minimum_msat: 0,
1066                         }, RouteHint {
1067                                 src_node_id: node5.clone(),
1068                                 short_channel_id: 9,
1069                                 fee_base_msat: 1001,
1070                                 fee_proportional_millionths: 0,
1071                                 cltv_expiry_delta: (9 << 8) | 1,
1072                                 htlc_minimum_msat: 0,
1073                         }, RouteHint {
1074                                 src_node_id: node6.clone(),
1075                                 short_channel_id: 10,
1076                                 fee_base_msat: 0,
1077                                 fee_proportional_millionths: 0,
1078                                 cltv_expiry_delta: (10 << 8) | 1,
1079                                 htlc_minimum_msat: 0,
1080                         });
1081
1082                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1083                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1084                         assert_eq!(route.hops.len(), 5);
1085
1086                         assert_eq!(route.hops[0].pubkey, node2);
1087                         assert_eq!(route.hops[0].short_channel_id, 2);
1088                         assert_eq!(route.hops[0].fee_msat, 100);
1089                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1090
1091                         assert_eq!(route.hops[1].pubkey, node3);
1092                         assert_eq!(route.hops[1].short_channel_id, 4);
1093                         assert_eq!(route.hops[1].fee_msat, 0);
1094                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1095
1096                         assert_eq!(route.hops[2].pubkey, node5);
1097                         assert_eq!(route.hops[2].short_channel_id, 6);
1098                         assert_eq!(route.hops[2].fee_msat, 0);
1099                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1100
1101                         assert_eq!(route.hops[3].pubkey, node4);
1102                         assert_eq!(route.hops[3].short_channel_id, 11);
1103                         assert_eq!(route.hops[3].fee_msat, 0);
1104                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1105
1106                         assert_eq!(route.hops[4].pubkey, node7);
1107                         assert_eq!(route.hops[4].short_channel_id, 8);
1108                         assert_eq!(route.hops[4].fee_msat, 100);
1109                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1110                 }
1111
1112                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1113                         let our_chans = vec![channelmanager::ChannelDetails {
1114                                 channel_id: [0; 32],
1115                                 short_channel_id: Some(42),
1116                                 remote_network_id: node4.clone(),
1117                                 channel_value_satoshis: 0,
1118                                 user_id: 0,
1119                         }];
1120                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1121                         assert_eq!(route.hops.len(), 2);
1122
1123                         assert_eq!(route.hops[0].pubkey, node4);
1124                         assert_eq!(route.hops[0].short_channel_id, 42);
1125                         assert_eq!(route.hops[0].fee_msat, 0);
1126                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1127
1128                         assert_eq!(route.hops[1].pubkey, node7);
1129                         assert_eq!(route.hops[1].short_channel_id, 8);
1130                         assert_eq!(route.hops[1].fee_msat, 100);
1131                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1132                 }
1133
1134                 last_hops[0].fee_base_msat = 1000;
1135
1136                 { // Revert to via 6 as the fee on 8 goes up
1137                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1138                         assert_eq!(route.hops.len(), 4);
1139
1140                         assert_eq!(route.hops[0].pubkey, node2);
1141                         assert_eq!(route.hops[0].short_channel_id, 2);
1142                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1143                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1144
1145                         assert_eq!(route.hops[1].pubkey, node3);
1146                         assert_eq!(route.hops[1].short_channel_id, 4);
1147                         assert_eq!(route.hops[1].fee_msat, 100);
1148                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1149
1150                         assert_eq!(route.hops[2].pubkey, node6);
1151                         assert_eq!(route.hops[2].short_channel_id, 7);
1152                         assert_eq!(route.hops[2].fee_msat, 0);
1153                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1154
1155                         assert_eq!(route.hops[3].pubkey, node7);
1156                         assert_eq!(route.hops[3].short_channel_id, 10);
1157                         assert_eq!(route.hops[3].fee_msat, 100);
1158                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1159                 }
1160
1161                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1162                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1163                         assert_eq!(route.hops.len(), 5);
1164
1165                         assert_eq!(route.hops[0].pubkey, node2);
1166                         assert_eq!(route.hops[0].short_channel_id, 2);
1167                         assert_eq!(route.hops[0].fee_msat, 3000);
1168                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1169
1170                         assert_eq!(route.hops[1].pubkey, node3);
1171                         assert_eq!(route.hops[1].short_channel_id, 4);
1172                         assert_eq!(route.hops[1].fee_msat, 0);
1173                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1174
1175                         assert_eq!(route.hops[2].pubkey, node5);
1176                         assert_eq!(route.hops[2].short_channel_id, 6);
1177                         assert_eq!(route.hops[2].fee_msat, 0);
1178                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1179
1180                         assert_eq!(route.hops[3].pubkey, node4);
1181                         assert_eq!(route.hops[3].short_channel_id, 11);
1182                         assert_eq!(route.hops[3].fee_msat, 1000);
1183                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1184
1185                         assert_eq!(route.hops[4].pubkey, node7);
1186                         assert_eq!(route.hops[4].short_channel_id, 8);
1187                         assert_eq!(route.hops[4].fee_msat, 2000);
1188                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1189                 }
1190         }
1191 }