_ 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 use bitcoin::blockdata::constants::genesis_block;
   7 use bitcoin::network::serialize::BitcoinHash;
   8
   9 use chain::chaininterface::ChainWatchInterface;
  10 use ln::channelmanager;
  11 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,MsgEncodable,NetAddress,GlobalFeatures};
  12 use ln::msgs;
  13 use util::logger::Logger;
  14
  15 use std::cmp;
  16 use std::sync::{RwLock,Arc};
  17 use std::collections::{HashMap,BinaryHeap};
  18 use std::collections::hash_map::Entry;
  19 use std;
  20
  21 /// A hop in a route
  22 #[derive(Clone)]
  23 pub struct RouteHop {
  24         pub pubkey: PublicKey,
  25         /// The channel that should be used from the previous hop to reach this node.
  26         pub short_channel_id: u64,
  27         /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
  28         pub fee_msat: u64,
  29         /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
  30         /// expected at the destination, in excess of the current block height.
  31         pub cltv_expiry_delta: u32,
  32 }
  33
  34 /// A route from us through the network to a destination
  35 #[derive(Clone)]
  36 pub struct Route {
  37         /// The list of hops, NOT INCLUDING our own, where the last hop is the destination. Thus, this
  38         /// must always be at least length one. By protocol rules, this may not currently exceed 20 in
  39         /// length.
  40         pub hops: Vec<RouteHop>,
  41 }
  42
  43 struct DirectionalChannelInfo {
  44         src_node_id: PublicKey,
  45         last_update: u32,
  46         enabled: bool,
  47         cltv_expiry_delta: u16,
  48         htlc_minimum_msat: u64,
  49         fee_base_msat: u32,
  50         fee_proportional_millionths: u32,
  51 }
  52
  53 impl std::fmt::Display for DirectionalChannelInfo {
  54         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  55                 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)?;
  56                 Ok(())
  57         }
  58 }
  59
  60 struct ChannelInfo {
  61         features: GlobalFeatures,
  62         one_to_two: DirectionalChannelInfo,
  63         two_to_one: DirectionalChannelInfo,
  64 }
  65
  66 impl std::fmt::Display for ChannelInfo {
  67         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  68                 write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
  69                 Ok(())
  70         }
  71 }
  72
  73 struct NodeInfo {
  74         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  75         channels: Vec<(u64, Sha256dHash)>,
  76         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  77         channels: Vec<u64>,
  78
  79         lowest_inbound_channel_fee_base_msat: u32,
  80         lowest_inbound_channel_fee_proportional_millionths: u32,
  81
  82         features: GlobalFeatures,
  83         last_update: u32,
  84         rgb: [u8; 3],
  85         alias: [u8; 32],
  86         addresses: Vec<NetAddress>,
  87 }
  88
  89 impl std::fmt::Display for NodeInfo {
  90         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  91                 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[..])?;
  92                 Ok(())
  93         }
  94 }
  95
  96 struct NetworkMap {
  97         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  98         channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
  99         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 100         channels: HashMap<u64, ChannelInfo>,
 101
 102         our_node_id: PublicKey,
 103         nodes: HashMap<PublicKey, NodeInfo>,
 104 }
 105
 106 impl std::fmt::Display for NetworkMap {
 107         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 108                 write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
 109                 for (key, val) in self.channels.iter() {
 110                         write!(f, " {}: {}\n", key, val)?;
 111                 }
 112                 write!(f, "[Nodes]\n")?;
 113                 for (key, val) in self.nodes.iter() {
 114                         write!(f, " {}: {}\n", log_pubkey!(key), val)?;
 115                 }
 116                 Ok(())
 117         }
 118 }
 119
 120 impl NetworkMap {
 121         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 122         #[inline]
 123         fn get_key(short_channel_id: u64, chain_hash: Sha256dHash) -> (u64, Sha256dHash) {
 124                 (short_channel_id, chain_hash)
 125         }
 126
 127         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 128         #[inline]
 129         fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
 130                 short_channel_id
 131         }
 132
 133         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 134         #[inline]
 135         fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
 136                 &id.0
 137         }
 138
 139         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 140         #[inline]
 141         fn get_short_id(id: &u64) -> &u64 {
 142                 id
 143         }
 144 }
 145
 146 /// A channel descriptor which provides a last-hop route to get_route
 147 pub struct RouteHint {
 148         pub src_node_id: PublicKey,
 149         pub short_channel_id: u64,
 150         pub fee_base_msat: u32,
 151         pub fee_proportional_millionths: u32,
 152         pub cltv_expiry_delta: u16,
 153         pub htlc_minimum_msat: u64,
 154 }
 155
 156 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 157 /// payment destinations.
 158 pub struct Router {
 159         secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
 160         network_map: RwLock<NetworkMap>,
 161         chain_monitor: Arc<ChainWatchInterface>,
 162         logger: Arc<Logger>,
 163 }
 164
 165 macro_rules! secp_verify_sig {
 166         ( $secp_ctx: expr, $msg: expr, $sig: expr, $pubkey: expr ) => {
 167                 match $secp_ctx.verify($msg, $sig, $pubkey) {
 168                         Ok(_) => {},
 169                         Err(_) => return Err(HandleError{err: "Invalid signature from remote node", action: None}),
 170                 }
 171         };
 172 }
 173
 174 impl RoutingMessageHandler for Router {
 175         fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, HandleError> {
 176                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 177                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 178
 179                 if msg.contents.features.requires_unknown_bits() {
 180                         panic!("Unknown-required-features NodeAnnouncements should never deserialize!");
 181                 }
 182
 183                 let mut network = self.network_map.write().unwrap();
 184                 match network.nodes.get_mut(&msg.contents.node_id) {
 185                         None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
 186                         Some(node) => {
 187                                 if node.last_update >= msg.contents.timestamp {
 188                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 189                                 }
 190
 191                                 node.features = msg.contents.features.clone();
 192                                 node.last_update = msg.contents.timestamp;
 193                                 node.rgb = msg.contents.rgb;
 194                                 node.alias = msg.contents.alias;
 195                                 node.addresses = msg.contents.addresses.clone();
 196                                 Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 197                         }
 198                 }
 199         }
 200
 201         fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
 202                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 203                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
 204                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
 205                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
 206                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 207
 208                 if msg.contents.features.requires_unknown_bits() {
 209                         panic!("Unknown-required-features ChannelAnnouncements should never deserialize!");
 210                 }
 211
 212                 //TODO: Call blockchain thing to ask if the short_channel_id is valid
 213                 if msg.contents.chain_hash != genesis_block(self.chain_monitor.get_network()).header.bitcoin_hash() {
 214                         return Err(HandleError{err: "Channel announced on an unknown chain", action: Some(ErrorAction::IgnoreError)});
 215                 }
 216
 217                 let mut network = self.network_map.write().unwrap();
 218
 219                 match network.channels.entry(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 220                         Entry::Occupied(_) => {
 221                                 //TODO: because asking the blockchain if short_channel_id is valid is only optional
 222                                 //in the blockchain API, we need to handle it smartly here, though its unclear
 223                                 //exactly how...
 224                                 return Err(HandleError{err: "Already have knowledge of channel", action: Some(ErrorAction::IgnoreError)})
 225                         },
 226                         Entry::Vacant(entry) => {
 227                                 entry.insert(ChannelInfo {
 228                                         features: msg.contents.features.clone(),
 229                                         one_to_two: DirectionalChannelInfo {
 230                                                 src_node_id: msg.contents.node_id_1.clone(),
 231                                                 last_update: 0,
 232                                                 enabled: false,
 233                                                 cltv_expiry_delta: u16::max_value(),
 234                                                 htlc_minimum_msat: u64::max_value(),
 235                                                 fee_base_msat: u32::max_value(),
 236                                                 fee_proportional_millionths: u32::max_value(),
 237                                         },
 238                                         two_to_one: DirectionalChannelInfo {
 239                                                 src_node_id: msg.contents.node_id_2.clone(),
 240                                                 last_update: 0,
 241                                                 enabled: false,
 242                                                 cltv_expiry_delta: u16::max_value(),
 243                                                 htlc_minimum_msat: u64::max_value(),
 244                                                 fee_base_msat: u32::max_value(),
 245                                                 fee_proportional_millionths: u32::max_value(),
 246                                         }
 247                                 });
 248                         }
 249                 };
 250
 251                 macro_rules! add_channel_to_node {
 252                         ( $node_id: expr ) => {
 253                                 match network.nodes.entry($node_id) {
 254                                         Entry::Occupied(node_entry) => {
 255                                                 node_entry.into_mut().channels.push(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash));
 256                                         },
 257                                         Entry::Vacant(node_entry) => {
 258                                                 node_entry.insert(NodeInfo {
 259                                                         channels: vec!(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)),
 260                                                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 261                                                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 262                                                         features: GlobalFeatures::new(),
 263                                                         last_update: 0,
 264                                                         rgb: [0; 3],
 265                                                         alias: [0; 32],
 266                                                         addresses: Vec::new(),
 267                                                 });
 268                                         }
 269                                 }
 270                         };
 271                 }
 272
 273                 add_channel_to_node!(msg.contents.node_id_1);
 274                 add_channel_to_node!(msg.contents.node_id_2);
 275
 276                 Ok(msg.contents.excess_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 277         }
 278
 279         fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
 280                 match update {
 281                         &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
 282                                 let _ = self.handle_channel_update(msg);
 283                         },
 284                         &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id } => {
 285                                 let mut network = self.network_map.write().unwrap();
 286                                 if let Some(chan) = network.channels.remove(short_channel_id) {
 287                                         network.nodes.get_mut(&chan.one_to_two.src_node_id).unwrap().channels.retain(|chan_id| {
 288                                                 chan_id != NetworkMap::get_short_id(chan_id)
 289                                         });
 290                                         network.nodes.get_mut(&chan.two_to_one.src_node_id).unwrap().channels.retain(|chan_id| {
 291                                                 chan_id != NetworkMap::get_short_id(chan_id)
 292                                         });
 293                                 }
 294                         },
 295                 }
 296         }
 297
 298         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
 299                 let mut network = self.network_map.write().unwrap();
 300                 let dest_node_id;
 301                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 302                 let chan_was_enabled;
 303
 304                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 305                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 306                         Some(channel) => {
 307                                 macro_rules! maybe_update_channel_info {
 308                                         ( $target: expr) => {
 309                                                 if $target.last_update >= msg.contents.timestamp {
 310                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 311                                                 }
 312                                                 chan_was_enabled = $target.enabled;
 313                                                 $target.last_update = msg.contents.timestamp;
 314                                                 $target.enabled = chan_enabled;
 315                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 316                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 317                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 318                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 319                                         }
 320                                 }
 321
 322                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 323                                 if msg.contents.flags & 1 == 1 {
 324                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 325                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 326                                         maybe_update_channel_info!(channel.two_to_one);
 327                                 } else {
 328                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 329                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 330                                         maybe_update_channel_info!(channel.one_to_two);
 331                                 }
 332                         }
 333                 }
 334
 335                 if chan_enabled {
 336                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 337                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 338                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 339                 } else if chan_was_enabled {
 340                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 341                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 342
 343                         {
 344                                 let node = network.nodes.get(&dest_node_id).unwrap();
 345
 346                                 for chan_id in node.channels.iter() {
 347                                         let chan = network.channels.get(chan_id).unwrap();
 348                                         if chan.one_to_two.src_node_id == dest_node_id {
 349                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 350                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 351                                         } else {
 352                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 353                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 354                                         }
 355                                 }
 356                         }
 357
 358                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 359                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 360                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 361                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 362                 }
 363
 364                 Ok(msg.contents.excess_data.is_empty())
 365         }
 366 }
 367
 368 #[derive(Eq, PartialEq)]
 369 struct RouteGraphNode {
 370         pubkey: PublicKey,
 371         lowest_fee_to_peer_through_node: u64,
 372         lowest_fee_to_node: u64,
 373 }
 374
 375 impl cmp::Ord for RouteGraphNode {
 376         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 377                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 378                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 379         }
 380 }
 381
 382 impl cmp::PartialOrd for RouteGraphNode {
 383         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 384                 Some(self.cmp(other))
 385         }
 386 }
 387
 388 struct DummyDirectionalChannelInfo {
 389         src_node_id: PublicKey,
 390         cltv_expiry_delta: u32,
 391         htlc_minimum_msat: u64,
 392         fee_base_msat: u32,
 393         fee_proportional_millionths: u32,
 394 }
 395
 396 impl Router {
 397         pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
 398                 let mut nodes = HashMap::new();
 399                 nodes.insert(our_pubkey.clone(), NodeInfo {
 400                         channels: Vec::new(),
 401                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 402                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 403                         features: GlobalFeatures::new(),
 404                         last_update: 0,
 405                         rgb: [0; 3],
 406                         alias: [0; 32],
 407                         addresses: Vec::new(),
 408                 });
 409                 Router {
 410                         secp_ctx: Secp256k1::verification_only(),
 411                         network_map: RwLock::new(NetworkMap {
 412                                 channels: HashMap::new(),
 413                                 our_node_id: our_pubkey,
 414                                 nodes: nodes,
 415                         }),
 416                         chain_monitor,
 417                         logger,
 418                 }
 419         }
 420
 421         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 422         /// level Trace
 423         pub fn trace_state(&self) {
 424                 log_trace!(self, "{}", self.network_map.read().unwrap());
 425         }
 426
 427         /// Get network addresses by node id
 428         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 429                 let network = self.network_map.read().unwrap();
 430                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 431         }
 432
 433         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 434         /// with an expotnential decay in node "badness". Note that there is deliberately no
 435         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 436         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 437         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 438         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 439         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 440                 unimplemented!();
 441         }
 442
 443         /// Gets a route from us to the given target node.
 444         /// Extra routing hops between known nodes and the target will be used if they are included in
 445         /// last_hops.
 446         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 447         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 448         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 449         /// will be used. Panics if first_hops contains channels without short_channel_ids
 450         /// (ChannelManager::list_usable_channels will never include such channels).
 451         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 452         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 453         /// *is* checked as they may change based on the receiving node.
 454         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> {
 455                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 456                 // uptime/success in using a node in the past.
 457                 let network = self.network_map.read().unwrap();
 458
 459                 if *target == network.our_node_id {
 460                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 461                 }
 462
 463                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 464                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 465                 }
 466
 467                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 468                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 469                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 470                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 471                 // one.
 472
 473                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 474                         src_node_id: network.our_node_id.clone(),
 475                         cltv_expiry_delta: 0,
 476                         htlc_minimum_msat: 0,
 477                         fee_base_msat: 0,
 478                         fee_proportional_millionths: 0,
 479                 };
 480
 481                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 482                 let mut dist = HashMap::with_capacity(network.nodes.len());
 483
 484                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 485                 if let Some(hops) = first_hops {
 486                         for chan in hops {
 487                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 488                                 if chan.remote_network_id == *target {
 489                                         return Ok(Route {
 490                                                 hops: vec![RouteHop {
 491                                                         pubkey: chan.remote_network_id,
 492                                                         short_channel_id,
 493                                                         fee_msat: final_value_msat,
 494                                                         cltv_expiry_delta: final_cltv,
 495                                                 }],
 496                                         });
 497                                 }
 498                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 499                         }
 500                         if first_hop_targets.is_empty() {
 501                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 502                         }
 503                 }
 504
 505                 macro_rules! add_entry {
 506                         // Adds entry which goes from the node pointed to by $directional_info to
 507                         // $dest_node_id over the channel with id $chan_id with fees described in
 508                         // $directional_info.
 509                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 510                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 511                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 512                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 513                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 514                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 515                                         {
 516                                                 let mut total_fee = $starting_fee_msat as u64;
 517                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 518                                                 let old_entry = hm_entry.or_insert_with(|| {
 519                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 520                                                         (u64::max_value(),
 521                                                                 node.lowest_inbound_channel_fee_base_msat,
 522                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 523                                                                 RouteHop {
 524                                                                         pubkey: $dest_node_id.clone(),
 525                                                                         short_channel_id: 0,
 526                                                                         fee_msat: 0,
 527                                                                         cltv_expiry_delta: 0,
 528                                                         })
 529                                                 });
 530                                                 if $directional_info.src_node_id != network.our_node_id {
 531                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 532                                                         // will have the same effective-fee
 533                                                         total_fee += new_fee;
 534                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 535                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 536                                                         } else {
 537                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 538                                                                 total_fee = u64::max_value();
 539                                                         }
 540                                                 }
 541                                                 let new_graph_node = RouteGraphNode {
 542                                                         pubkey: $directional_info.src_node_id,
 543                                                         lowest_fee_to_peer_through_node: total_fee,
 544                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 545                                                 };
 546                                                 if old_entry.0 > total_fee {
 547                                                         targets.push(new_graph_node);
 548                                                         old_entry.0 = total_fee;
 549                                                         old_entry.3 = RouteHop {
 550                                                                 pubkey: $dest_node_id.clone(),
 551                                                                 short_channel_id: $chan_id.clone(),
 552                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 553                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 554                                                         }
 555                                                 }
 556                                         }
 557                                 }
 558                         };
 559                 }
 560
 561                 macro_rules! add_entries_to_cheapest_to_target_node {
 562                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 563                                 if first_hops.is_some() {
 564                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 565                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 566                                         }
 567                                 }
 568
 569                                 for chan_id in $node.channels.iter() {
 570                                         let chan = network.channels.get(chan_id).unwrap();
 571                                         if chan.one_to_two.src_node_id == *$node_id {
 572                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 573                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 574                                                         if chan.two_to_one.enabled {
 575                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 576                                                         }
 577                                                 }
 578                                         } else {
 579                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 580                                                         if chan.one_to_two.enabled {
 581                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 582                                                         }
 583                                                 }
 584                                         }
 585                                 }
 586                         };
 587                 }
 588
 589                 match network.nodes.get(target) {
 590                         None => {},
 591                         Some(node) => {
 592                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 593                         },
 594                 }
 595
 596                 for hop in last_hops.iter() {
 597                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 598                                 if network.nodes.get(&hop.src_node_id).is_some() {
 599                                         if first_hops.is_some() {
 600                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 601                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 602                                                 }
 603                                         }
 604                                         add_entry!(hop.short_channel_id, target, hop, 0);
 605                                 }
 606                         }
 607                 }
 608
 609                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 610                         if pubkey == network.our_node_id {
 611                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 612                                 while res.last().unwrap().pubkey != *target {
 613                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 614                                                 Some(hop) => hop.3,
 615                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 616                                         };
 617                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 618                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 619                                         res.push(new_entry);
 620                                 }
 621                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 622                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 623                                 let route = Route { hops: res };
 624                                 log_trace!(self, "Got route: {}", log_route!(route));
 625                                 return Ok(route);
 626                         }
 627
 628                         match network.nodes.get(&pubkey) {
 629                                 None => {},
 630                                 Some(node) => {
 631                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 632                                 },
 633                         }
 634                 }
 635
 636                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 637         }
 638 }
 639
 640 #[cfg(test)]
 641 mod tests {
 642         use chain::chaininterface;
 643         use ln::channelmanager;
 644         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 645         use ln::msgs::GlobalFeatures;
 646         use util::test_utils;
 647         use util::logger::Logger;
 648
 649         use bitcoin::util::hash::Sha256dHash;
 650         use bitcoin::network::constants::Network;
 651
 652         use hex;
 653
 654         use secp256k1::key::{PublicKey,SecretKey};
 655         use secp256k1::Secp256k1;
 656
 657         use std::sync::Arc;
 658
 659         #[test]
 660         fn route_test() {
 661                 let secp_ctx = Secp256k1::new();
 662                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 663                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 664                 let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
 665                 let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 666
 667                 // Build network from our_id to node8:
 668                 //
 669                 //        -1(1)2-  node1  -1(3)2-
 670                 //       /                       \
 671                 // our_id -1(12)2- node8 -1(13)2--- node3
 672                 //       \                       /
 673                 //        -1(2)2-  node2  -1(4)2-
 674                 //
 675                 //
 676                 // chan1  1-to-2: disabled
 677                 // chan1  2-to-1: enabled, 0 fee
 678                 //
 679                 // chan2  1-to-2: enabled, ignored fee
 680                 // chan2  2-to-1: enabled, 0 fee
 681                 //
 682                 // chan3  1-to-2: enabled, 0 fee
 683                 // chan3  2-to-1: enabled, 100 msat fee
 684                 //
 685                 // chan4  1-to-2: enabled, 100% fee
 686                 // chan4  2-to-1: enabled, 0 fee
 687                 //
 688                 // chan12 1-to-2: enabled, ignored fee
 689                 // chan12 2-to-1: enabled, 0 fee
 690                 //
 691                 // chan13 1-to-2: enabled, 200% fee
 692                 // chan13 2-to-1: enabled, 0 fee
 693                 //
 694                 //
 695                 //       -1(5)2- node4 -1(8)2--
 696                 //       |         2          |
 697                 //       |       (11)         |
 698                 //      /          1           \
 699                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 700                 //      \                      /
 701                 //       -1(7)2- node6 -1(10)2-
 702                 //
 703                 // chan5  1-to-2: enabled, 100 msat fee
 704                 // chan5  2-to-1: enabled, 0 fee
 705                 //
 706                 // chan6  1-to-2: enabled, 0 fee
 707                 // chan6  2-to-1: enabled, 0 fee
 708                 //
 709                 // chan7  1-to-2: enabled, 100% fee
 710                 // chan7  2-to-1: enabled, 0 fee
 711                 //
 712                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 713                 // chan8  2-to-1: enabled, 0 fee
 714                 //
 715                 // chan9  1-to-2: enabled, 1001 msat fee
 716                 // chan9  2-to-1: enabled, 0 fee
 717                 //
 718                 // chan10 1-to-2: enabled, 0 fee
 719                 // chan10 2-to-1: enabled, 0 fee
 720                 //
 721                 // chan11 1-to-2: enabled, 0 fee
 722                 // chan11 2-to-1: enabled, 0 fee
 723
 724                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 725                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 726                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 727                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 728                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 729                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 730                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 731                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 732
 733                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 734
 735                 {
 736                         let mut network = router.network_map.write().unwrap();
 737
 738                         network.nodes.insert(node1.clone(), NodeInfo {
 739                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 740                                 lowest_inbound_channel_fee_base_msat: 100,
 741                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 742                                 features: GlobalFeatures::new(),
 743                                 last_update: 1,
 744                                 rgb: [0; 3],
 745                                 alias: [0; 32],
 746                                 addresses: Vec::new(),
 747                         });
 748                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 749                                 features: GlobalFeatures::new(),
 750                                 one_to_two: DirectionalChannelInfo {
 751                                         src_node_id: our_id.clone(),
 752                                         last_update: 0,
 753                                         enabled: false,
 754                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 755                                         htlc_minimum_msat: 0,
 756                                         fee_base_msat: u32::max_value(), // This value should be ignored
 757                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 758                                 }, two_to_one: DirectionalChannelInfo {
 759                                         src_node_id: node1.clone(),
 760                                         last_update: 0,
 761                                         enabled: true,
 762                                         cltv_expiry_delta: 0,
 763                                         htlc_minimum_msat: 0,
 764                                         fee_base_msat: 0,
 765                                         fee_proportional_millionths: 0,
 766                                 },
 767                         });
 768                         network.nodes.insert(node2.clone(), NodeInfo {
 769                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 770                                 lowest_inbound_channel_fee_base_msat: 0,
 771                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 772                                 features: GlobalFeatures::new(),
 773                                 last_update: 1,
 774                                 rgb: [0; 3],
 775                                 alias: [0; 32],
 776                                 addresses: Vec::new(),
 777                         });
 778                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 779                                 features: GlobalFeatures::new(),
 780                                 one_to_two: DirectionalChannelInfo {
 781                                         src_node_id: our_id.clone(),
 782                                         last_update: 0,
 783                                         enabled: true,
 784                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 785                                         htlc_minimum_msat: 0,
 786                                         fee_base_msat: u32::max_value(), // This value should be ignored
 787                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 788                                 }, two_to_one: DirectionalChannelInfo {
 789                                         src_node_id: node2.clone(),
 790                                         last_update: 0,
 791                                         enabled: true,
 792                                         cltv_expiry_delta: 0,
 793                                         htlc_minimum_msat: 0,
 794                                         fee_base_msat: 0,
 795                                         fee_proportional_millionths: 0,
 796                                 },
 797                         });
 798                         network.nodes.insert(node8.clone(), NodeInfo {
 799                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 800                                 lowest_inbound_channel_fee_base_msat: 0,
 801                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 802                                 features: GlobalFeatures::new(),
 803                                 last_update: 1,
 804                                 rgb: [0; 3],
 805                                 alias: [0; 32],
 806                                 addresses: Vec::new(),
 807                         });
 808                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 809                                 features: GlobalFeatures::new(),
 810                                 one_to_two: DirectionalChannelInfo {
 811                                         src_node_id: our_id.clone(),
 812                                         last_update: 0,
 813                                         enabled: true,
 814                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 815                                         htlc_minimum_msat: 0,
 816                                         fee_base_msat: u32::max_value(), // This value should be ignored
 817                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 818                                 }, two_to_one: DirectionalChannelInfo {
 819                                         src_node_id: node8.clone(),
 820                                         last_update: 0,
 821                                         enabled: true,
 822                                         cltv_expiry_delta: 0,
 823                                         htlc_minimum_msat: 0,
 824                                         fee_base_msat: 0,
 825                                         fee_proportional_millionths: 0,
 826                                 },
 827                         });
 828                         network.nodes.insert(node3.clone(), NodeInfo {
 829                                 channels: vec!(
 830                                         NetworkMap::get_key(3, zero_hash.clone()),
 831                                         NetworkMap::get_key(4, zero_hash.clone()),
 832                                         NetworkMap::get_key(13, zero_hash.clone()),
 833                                         NetworkMap::get_key(5, zero_hash.clone()),
 834                                         NetworkMap::get_key(6, zero_hash.clone()),
 835                                         NetworkMap::get_key(7, zero_hash.clone())),
 836                                 lowest_inbound_channel_fee_base_msat: 0,
 837                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 838                                 features: GlobalFeatures::new(),
 839                                 last_update: 1,
 840                                 rgb: [0; 3],
 841                                 alias: [0; 32],
 842                                 addresses: Vec::new(),
 843                         });
 844                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 845                                 features: GlobalFeatures::new(),
 846                                 one_to_two: DirectionalChannelInfo {
 847                                         src_node_id: node1.clone(),
 848                                         last_update: 0,
 849                                         enabled: true,
 850                                         cltv_expiry_delta: (3 << 8) | 1,
 851                                         htlc_minimum_msat: 0,
 852                                         fee_base_msat: 0,
 853                                         fee_proportional_millionths: 0,
 854                                 }, two_to_one: DirectionalChannelInfo {
 855                                         src_node_id: node3.clone(),
 856                                         last_update: 0,
 857                                         enabled: true,
 858                                         cltv_expiry_delta: (3 << 8) | 2,
 859                                         htlc_minimum_msat: 0,
 860                                         fee_base_msat: 100,
 861                                         fee_proportional_millionths: 0,
 862                                 },
 863                         });
 864                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 865                                 features: GlobalFeatures::new(),
 866                                 one_to_two: DirectionalChannelInfo {
 867                                         src_node_id: node2.clone(),
 868                                         last_update: 0,
 869                                         enabled: true,
 870                                         cltv_expiry_delta: (4 << 8) | 1,
 871                                         htlc_minimum_msat: 0,
 872                                         fee_base_msat: 0,
 873                                         fee_proportional_millionths: 1000000,
 874                                 }, two_to_one: DirectionalChannelInfo {
 875                                         src_node_id: node3.clone(),
 876                                         last_update: 0,
 877                                         enabled: true,
 878                                         cltv_expiry_delta: (4 << 8) | 2,
 879                                         htlc_minimum_msat: 0,
 880                                         fee_base_msat: 0,
 881                                         fee_proportional_millionths: 0,
 882                                 },
 883                         });
 884                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
 885                                 features: GlobalFeatures::new(),
 886                                 one_to_two: DirectionalChannelInfo {
 887                                         src_node_id: node8.clone(),
 888                                         last_update: 0,
 889                                         enabled: true,
 890                                         cltv_expiry_delta: (13 << 8) | 1,
 891                                         htlc_minimum_msat: 0,
 892                                         fee_base_msat: 0,
 893                                         fee_proportional_millionths: 2000000,
 894                                 }, two_to_one: DirectionalChannelInfo {
 895                                         src_node_id: node3.clone(),
 896                                         last_update: 0,
 897                                         enabled: true,
 898                                         cltv_expiry_delta: (13 << 8) | 2,
 899                                         htlc_minimum_msat: 0,
 900                                         fee_base_msat: 0,
 901                                         fee_proportional_millionths: 0,
 902                                 },
 903                         });
 904                         network.nodes.insert(node4.clone(), NodeInfo {
 905                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 906                                 lowest_inbound_channel_fee_base_msat: 0,
 907                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 908                                 features: GlobalFeatures::new(),
 909                                 last_update: 1,
 910                                 rgb: [0; 3],
 911                                 alias: [0; 32],
 912                                 addresses: Vec::new(),
 913                         });
 914                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
 915                                 features: GlobalFeatures::new(),
 916                                 one_to_two: DirectionalChannelInfo {
 917                                         src_node_id: node3.clone(),
 918                                         last_update: 0,
 919                                         enabled: true,
 920                                         cltv_expiry_delta: (5 << 8) | 1,
 921                                         htlc_minimum_msat: 0,
 922                                         fee_base_msat: 100,
 923                                         fee_proportional_millionths: 0,
 924                                 }, two_to_one: DirectionalChannelInfo {
 925                                         src_node_id: node4.clone(),
 926                                         last_update: 0,
 927                                         enabled: true,
 928                                         cltv_expiry_delta: (5 << 8) | 2,
 929                                         htlc_minimum_msat: 0,
 930                                         fee_base_msat: 0,
 931                                         fee_proportional_millionths: 0,
 932                                 },
 933                         });
 934                         network.nodes.insert(node5.clone(), NodeInfo {
 935                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 936                                 lowest_inbound_channel_fee_base_msat: 0,
 937                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 938                                 features: GlobalFeatures::new(),
 939                                 last_update: 1,
 940                                 rgb: [0; 3],
 941                                 alias: [0; 32],
 942                                 addresses: Vec::new(),
 943                         });
 944                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
 945                                 features: GlobalFeatures::new(),
 946                                 one_to_two: DirectionalChannelInfo {
 947                                         src_node_id: node3.clone(),
 948                                         last_update: 0,
 949                                         enabled: true,
 950                                         cltv_expiry_delta: (6 << 8) | 1,
 951                                         htlc_minimum_msat: 0,
 952                                         fee_base_msat: 0,
 953                                         fee_proportional_millionths: 0,
 954                                 }, two_to_one: DirectionalChannelInfo {
 955                                         src_node_id: node5.clone(),
 956                                         last_update: 0,
 957                                         enabled: true,
 958                                         cltv_expiry_delta: (6 << 8) | 2,
 959                                         htlc_minimum_msat: 0,
 960                                         fee_base_msat: 0,
 961                                         fee_proportional_millionths: 0,
 962                                 },
 963                         });
 964                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
 965                                 features: GlobalFeatures::new(),
 966                                 one_to_two: DirectionalChannelInfo {
 967                                         src_node_id: node5.clone(),
 968                                         last_update: 0,
 969                                         enabled: true,
 970                                         cltv_expiry_delta: (11 << 8) | 1,
 971                                         htlc_minimum_msat: 0,
 972                                         fee_base_msat: 0,
 973                                         fee_proportional_millionths: 0,
 974                                 }, two_to_one: DirectionalChannelInfo {
 975                                         src_node_id: node4.clone(),
 976                                         last_update: 0,
 977                                         enabled: true,
 978                                         cltv_expiry_delta: (11 << 8) | 2,
 979                                         htlc_minimum_msat: 0,
 980                                         fee_base_msat: 0,
 981                                         fee_proportional_millionths: 0,
 982                                 },
 983                         });
 984                         network.nodes.insert(node6.clone(), NodeInfo {
 985                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
 986                                 lowest_inbound_channel_fee_base_msat: 0,
 987                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 988                                 features: GlobalFeatures::new(),
 989                                 last_update: 1,
 990                                 rgb: [0; 3],
 991                                 alias: [0; 32],
 992                                 addresses: Vec::new(),
 993                         });
 994                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
 995                                 features: GlobalFeatures::new(),
 996                                 one_to_two: DirectionalChannelInfo {
 997                                         src_node_id: node3.clone(),
 998                                         last_update: 0,
 999                                         enabled: true,
1000                                         cltv_expiry_delta: (7 << 8) | 1,
1001                                         htlc_minimum_msat: 0,
1002                                         fee_base_msat: 0,
1003                                         fee_proportional_millionths: 1000000,
1004                                 }, two_to_one: DirectionalChannelInfo {
1005                                         src_node_id: node6.clone(),
1006                                         last_update: 0,
1007                                         enabled: true,
1008                                         cltv_expiry_delta: (7 << 8) | 2,
1009                                         htlc_minimum_msat: 0,
1010                                         fee_base_msat: 0,
1011                                         fee_proportional_millionths: 0,
1012                                 },
1013                         });
1014                 }
1015
1016                 { // Simple route to 3 via 2
1017                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1018                         assert_eq!(route.hops.len(), 2);
1019
1020                         assert_eq!(route.hops[0].pubkey, node2);
1021                         assert_eq!(route.hops[0].short_channel_id, 2);
1022                         assert_eq!(route.hops[0].fee_msat, 100);
1023                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1024
1025                         assert_eq!(route.hops[1].pubkey, node3);
1026                         assert_eq!(route.hops[1].short_channel_id, 4);
1027                         assert_eq!(route.hops[1].fee_msat, 100);
1028                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1029                 }
1030
1031                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1032                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1033                         assert_eq!(route.hops.len(), 3);
1034
1035                         assert_eq!(route.hops[0].pubkey, node2);
1036                         assert_eq!(route.hops[0].short_channel_id, 2);
1037                         assert_eq!(route.hops[0].fee_msat, 200);
1038                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1039
1040                         assert_eq!(route.hops[1].pubkey, node3);
1041                         assert_eq!(route.hops[1].short_channel_id, 4);
1042                         assert_eq!(route.hops[1].fee_msat, 100);
1043                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1044
1045                         assert_eq!(route.hops[2].pubkey, node1);
1046                         assert_eq!(route.hops[2].short_channel_id, 3);
1047                         assert_eq!(route.hops[2].fee_msat, 100);
1048                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1049                 }
1050
1051                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1052                         let our_chans = vec![channelmanager::ChannelDetails {
1053                                 channel_id: [0; 32],
1054                                 short_channel_id: Some(42),
1055                                 remote_network_id: node8.clone(),
1056                                 channel_value_satoshis: 0,
1057                                 user_id: 0,
1058                         }];
1059                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1060                         assert_eq!(route.hops.len(), 2);
1061
1062                         assert_eq!(route.hops[0].pubkey, node8);
1063                         assert_eq!(route.hops[0].short_channel_id, 42);
1064                         assert_eq!(route.hops[0].fee_msat, 200);
1065                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1066
1067                         assert_eq!(route.hops[1].pubkey, node3);
1068                         assert_eq!(route.hops[1].short_channel_id, 13);
1069                         assert_eq!(route.hops[1].fee_msat, 100);
1070                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1071                 }
1072
1073                 let mut last_hops = vec!(RouteHint {
1074                                 src_node_id: node4.clone(),
1075                                 short_channel_id: 8,
1076                                 fee_base_msat: 0,
1077                                 fee_proportional_millionths: 0,
1078                                 cltv_expiry_delta: (8 << 8) | 1,
1079                                 htlc_minimum_msat: 0,
1080                         }, RouteHint {
1081                                 src_node_id: node5.clone(),
1082                                 short_channel_id: 9,
1083                                 fee_base_msat: 1001,
1084                                 fee_proportional_millionths: 0,
1085                                 cltv_expiry_delta: (9 << 8) | 1,
1086                                 htlc_minimum_msat: 0,
1087                         }, RouteHint {
1088                                 src_node_id: node6.clone(),
1089                                 short_channel_id: 10,
1090                                 fee_base_msat: 0,
1091                                 fee_proportional_millionths: 0,
1092                                 cltv_expiry_delta: (10 << 8) | 1,
1093                                 htlc_minimum_msat: 0,
1094                         });
1095
1096                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1097                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1098                         assert_eq!(route.hops.len(), 5);
1099
1100                         assert_eq!(route.hops[0].pubkey, node2);
1101                         assert_eq!(route.hops[0].short_channel_id, 2);
1102                         assert_eq!(route.hops[0].fee_msat, 100);
1103                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1104
1105                         assert_eq!(route.hops[1].pubkey, node3);
1106                         assert_eq!(route.hops[1].short_channel_id, 4);
1107                         assert_eq!(route.hops[1].fee_msat, 0);
1108                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1109
1110                         assert_eq!(route.hops[2].pubkey, node5);
1111                         assert_eq!(route.hops[2].short_channel_id, 6);
1112                         assert_eq!(route.hops[2].fee_msat, 0);
1113                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1114
1115                         assert_eq!(route.hops[3].pubkey, node4);
1116                         assert_eq!(route.hops[3].short_channel_id, 11);
1117                         assert_eq!(route.hops[3].fee_msat, 0);
1118                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1119
1120                         assert_eq!(route.hops[4].pubkey, node7);
1121                         assert_eq!(route.hops[4].short_channel_id, 8);
1122                         assert_eq!(route.hops[4].fee_msat, 100);
1123                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1124                 }
1125
1126                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1127                         let our_chans = vec![channelmanager::ChannelDetails {
1128                                 channel_id: [0; 32],
1129                                 short_channel_id: Some(42),
1130                                 remote_network_id: node4.clone(),
1131                                 channel_value_satoshis: 0,
1132                                 user_id: 0,
1133                         }];
1134                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1135                         assert_eq!(route.hops.len(), 2);
1136
1137                         assert_eq!(route.hops[0].pubkey, node4);
1138                         assert_eq!(route.hops[0].short_channel_id, 42);
1139                         assert_eq!(route.hops[0].fee_msat, 0);
1140                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1141
1142                         assert_eq!(route.hops[1].pubkey, node7);
1143                         assert_eq!(route.hops[1].short_channel_id, 8);
1144                         assert_eq!(route.hops[1].fee_msat, 100);
1145                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1146                 }
1147
1148                 last_hops[0].fee_base_msat = 1000;
1149
1150                 { // Revert to via 6 as the fee on 8 goes up
1151                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1152                         assert_eq!(route.hops.len(), 4);
1153
1154                         assert_eq!(route.hops[0].pubkey, node2);
1155                         assert_eq!(route.hops[0].short_channel_id, 2);
1156                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1157                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1158
1159                         assert_eq!(route.hops[1].pubkey, node3);
1160                         assert_eq!(route.hops[1].short_channel_id, 4);
1161                         assert_eq!(route.hops[1].fee_msat, 100);
1162                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1163
1164                         assert_eq!(route.hops[2].pubkey, node6);
1165                         assert_eq!(route.hops[2].short_channel_id, 7);
1166                         assert_eq!(route.hops[2].fee_msat, 0);
1167                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1168
1169                         assert_eq!(route.hops[3].pubkey, node7);
1170                         assert_eq!(route.hops[3].short_channel_id, 10);
1171                         assert_eq!(route.hops[3].fee_msat, 100);
1172                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1173                 }
1174
1175                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1176                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1177                         assert_eq!(route.hops.len(), 5);
1178
1179                         assert_eq!(route.hops[0].pubkey, node2);
1180                         assert_eq!(route.hops[0].short_channel_id, 2);
1181                         assert_eq!(route.hops[0].fee_msat, 3000);
1182                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1183
1184                         assert_eq!(route.hops[1].pubkey, node3);
1185                         assert_eq!(route.hops[1].short_channel_id, 4);
1186                         assert_eq!(route.hops[1].fee_msat, 0);
1187                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1188
1189                         assert_eq!(route.hops[2].pubkey, node5);
1190                         assert_eq!(route.hops[2].short_channel_id, 6);
1191                         assert_eq!(route.hops[2].fee_msat, 0);
1192                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1193
1194                         assert_eq!(route.hops[3].pubkey, node4);
1195                         assert_eq!(route.hops[3].short_channel_id, 11);
1196                         assert_eq!(route.hops[3].fee_msat, 1000);
1197                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1198
1199                         assert_eq!(route.hops[4].pubkey, node7);
1200                         assert_eq!(route.hops[4].short_channel_id, 8);
1201                         assert_eq!(route.hops[4].fee_msat, 2000);
1202                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1203                 }
1204         }
1205 }