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

   1 //! The top-level routing/network map tracking logic lives here.
   2 //!
   3 //! You probably want to create a Router and use that as your RoutingMessageHandler and then
   4 //! interrogate it to get routes for your own payments.
   5
   6 use secp256k1::key::PublicKey;
   7 use secp256k1::{Secp256k1,Message};
   8 use secp256k1;
   9
  10 use bitcoin::util::hash::Sha256dHash;
  11 use bitcoin::blockdata::script::Builder;
  12 use bitcoin::blockdata::opcodes;
  13
  14 use chain::chaininterface::{ChainError, ChainWatchInterface};
  15 use ln::channelmanager;
  16 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,NetAddress,GlobalFeatures};
  17 use ln::msgs;
  18 use util::ser::Writeable;
  19 use util::logger::Logger;
  20
  21 use std::cmp;
  22 use std::sync::{RwLock,Arc};
  23 use std::collections::{HashMap,BinaryHeap};
  24 use std::collections::hash_map::Entry;
  25 use std;
  26
  27 /// A hop in a route
  28 #[derive(Clone)]
  29 pub struct RouteHop {
  30         /// The node_id of the node at this hop.
  31         pub pubkey: PublicKey,
  32         /// The channel that should be used from the previous hop to reach this node.
  33         pub short_channel_id: u64,
  34         /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
  35         pub fee_msat: u64,
  36         /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
  37         /// expected at the destination, in excess of the current block height.
  38         pub cltv_expiry_delta: u32,
  39         /// channel update timestamp of the outbound channel of each hop when this route is
  40         /// calculated
  41         pub channel_update_timestamp: u32,
  42 }
  43
  44 /// A route from us through the network to a destination
  45 #[derive(Clone)]
  46 pub struct Route {
  47         /// The list of hops, NOT INCLUDING our own, where the last hop is the destination. Thus, this
  48         /// must always be at least length one. By protocol rules, this may not currently exceed 20 in
  49         /// length.
  50         pub hops: Vec<RouteHop>,
  51 }
  52
  53 struct DirectionalChannelInfo {
  54         src_node_id: PublicKey,
  55         last_update: u32,
  56         enabled: bool,
  57         cltv_expiry_delta: u16,
  58         htlc_minimum_msat: u64,
  59         fee_base_msat: u32,
  60         fee_proportional_millionths: u32,
  61 }
  62
  63 impl std::fmt::Display for DirectionalChannelInfo {
  64         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  65                 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)?;
  66                 Ok(())
  67         }
  68 }
  69
  70 struct ChannelInfo {
  71         features: GlobalFeatures,
  72         one_to_two: DirectionalChannelInfo,
  73         two_to_one: DirectionalChannelInfo,
  74 }
  75
  76 impl std::fmt::Display for ChannelInfo {
  77         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  78                 write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
  79                 Ok(())
  80         }
  81 }
  82
  83 struct NodeInfo {
  84         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  85         channels: Vec<(u64, Sha256dHash)>,
  86         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  87         channels: Vec<u64>,
  88
  89         lowest_inbound_channel_fee_base_msat: u32,
  90         lowest_inbound_channel_fee_proportional_millionths: u32,
  91
  92         features: GlobalFeatures,
  93         last_update: u32,
  94         rgb: [u8; 3],
  95         alias: [u8; 32],
  96         addresses: Vec<NetAddress>,
  97 }
  98
  99 impl std::fmt::Display for NodeInfo {
 100         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 101                 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[..])?;
 102                 Ok(())
 103         }
 104 }
 105
 106 struct NetworkMap {
 107         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 108         channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
 109         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 110         channels: HashMap<u64, ChannelInfo>,
 111
 112         our_node_id: PublicKey,
 113         nodes: HashMap<PublicKey, NodeInfo>,
 114 }
 115 struct MutNetworkMap<'a> {
 116         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 117         channels: &'a mut HashMap<(u64, Sha256dHash), ChannelInfo>,
 118         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 119         channels: &'a mut HashMap<u64, ChannelInfo>,
 120         nodes: &'a mut HashMap<PublicKey, NodeInfo>,
 121 }
 122 impl NetworkMap {
 123         fn borrow_parts(&mut self) -> MutNetworkMap {
 124                 MutNetworkMap {
 125                         channels: &mut self.channels,
 126                         nodes: &mut self.nodes,
 127                 }
 128         }
 129 }
 130 impl std::fmt::Display for NetworkMap {
 131         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 132                 write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
 133                 for (key, val) in self.channels.iter() {
 134                         write!(f, " {}: {}\n", key, val)?;
 135                 }
 136                 write!(f, "[Nodes]\n")?;
 137                 for (key, val) in self.nodes.iter() {
 138                         write!(f, " {}: {}\n", log_pubkey!(key), val)?;
 139                 }
 140                 Ok(())
 141         }
 142 }
 143
 144 impl NetworkMap {
 145         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 146         #[inline]
 147         fn get_key(short_channel_id: u64, chain_hash: Sha256dHash) -> (u64, Sha256dHash) {
 148                 (short_channel_id, chain_hash)
 149         }
 150
 151         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 152         #[inline]
 153         fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
 154                 short_channel_id
 155         }
 156
 157         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 158         #[inline]
 159         fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
 160                 &id.0
 161         }
 162
 163         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 164         #[inline]
 165         fn get_short_id(id: &u64) -> &u64 {
 166                 id
 167         }
 168 }
 169
 170 /// A channel descriptor which provides a last-hop route to get_route
 171 pub struct RouteHint {
 172         /// The node_id of the non-target end of the route
 173         pub src_node_id: PublicKey,
 174         /// last update
 175         pub last_update: u32,
 176         /// The short_channel_id of this channel
 177         pub short_channel_id: u64,
 178         /// The static msat-denominated fee which must be paid to use this channel
 179         pub fee_base_msat: u32,
 180         /// The dynamic proportional fee which must be paid to use this channel, denominated in
 181         /// millionths of the value being forwarded to the next hop.
 182         pub fee_proportional_millionths: u32,
 183         /// The difference in CLTV values between this node and the next node.
 184         pub cltv_expiry_delta: u16,
 185         /// The minimum value, in msat, which must be relayed to the next hop.
 186         pub htlc_minimum_msat: u64,
 187 }
 188
 189 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 190 /// payment destinations.
 191 pub struct Router {
 192         secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
 193         network_map: RwLock<NetworkMap>,
 194         chain_monitor: Arc<ChainWatchInterface>,
 195         logger: Arc<Logger>,
 196 }
 197
 198 macro_rules! secp_verify_sig {
 199         ( $secp_ctx: expr, $msg: expr, $sig: expr, $pubkey: expr ) => {
 200                 match $secp_ctx.verify($msg, $sig, $pubkey) {
 201                         Ok(_) => {},
 202                         Err(_) => return Err(HandleError{err: "Invalid signature from remote node", action: None}),
 203                 }
 204         };
 205 }
 206
 207 impl RoutingMessageHandler for Router {
 208         fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, HandleError> {
 209                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 210                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 211
 212                 if msg.contents.features.requires_unknown_bits() {
 213                         panic!("Unknown-required-features NodeAnnouncements should never deserialize!");
 214                 }
 215
 216                 let mut network = self.network_map.write().unwrap();
 217                 match network.nodes.get_mut(&msg.contents.node_id) {
 218                         None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
 219                         Some(node) => {
 220                                 if node.last_update >= msg.contents.timestamp {
 221                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 222                                 }
 223
 224                                 node.features = msg.contents.features.clone();
 225                                 node.last_update = msg.contents.timestamp;
 226                                 node.rgb = msg.contents.rgb;
 227                                 node.alias = msg.contents.alias;
 228                                 node.addresses = msg.contents.addresses.clone();
 229                                 Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 230                         }
 231                 }
 232         }
 233
 234         fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
 235                 if msg.contents.node_id_1 == msg.contents.node_id_2 || msg.contents.bitcoin_key_1 == msg.contents.bitcoin_key_2 {
 236                         return Err(HandleError{err: "Channel announcement node had a channel with itself", action: Some(ErrorAction::IgnoreError)});
 237                 }
 238
 239                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 240                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
 241                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
 242                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
 243                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 244
 245                 if msg.contents.features.requires_unknown_bits() {
 246                         panic!("Unknown-required-features ChannelAnnouncements should never deserialize!");
 247                 }
 248
 249                 let checked_utxo = match self.chain_monitor.get_chain_utxo(msg.contents.chain_hash, msg.contents.short_channel_id) {
 250                         Ok((script_pubkey, _value)) => {
 251                                 let expected_script = Builder::new().push_opcode(opcodes::All::OP_PUSHNUM_2)
 252                                                                     .push_slice(&msg.contents.bitcoin_key_1.serialize())
 253                                                                     .push_slice(&msg.contents.bitcoin_key_2.serialize())
 254                                                                     .push_opcode(opcodes::All::OP_PUSHNUM_2).push_opcode(opcodes::All::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
 255                                 if script_pubkey != expected_script {
 256                                         return Err(HandleError{err: "Channel announcement keys didn't match on-chain script", action: Some(ErrorAction::IgnoreError)});
 257                                 }
 258                                 //TODO: Check if value is worth storing, use it to inform routing, and compare it
 259                                 //to the new HTLC max field in channel_update
 260                                 true
 261                         },
 262                         Err(ChainError::NotSupported) => {
 263                                 // Tentatively accept, potentially exposing us to DoS attacks
 264                                 false
 265                         },
 266                         Err(ChainError::NotWatched) => {
 267                                 return Err(HandleError{err: "Channel announced on an unknown chain", action: Some(ErrorAction::IgnoreError)});
 268                         },
 269                         Err(ChainError::UnknownTx) => {
 270                                 return Err(HandleError{err: "Channel announced without corresponding UTXO entry", action: Some(ErrorAction::IgnoreError)});
 271                         },
 272                 };
 273
 274                 let mut network_lock = self.network_map.write().unwrap();
 275                 let network = network_lock.borrow_parts();
 276
 277                 let chan_info = ChannelInfo {
 278                                 features: msg.contents.features.clone(),
 279                                 one_to_two: DirectionalChannelInfo {
 280                                         src_node_id: msg.contents.node_id_1.clone(),
 281                                         last_update: 0,
 282                                         enabled: false,
 283                                         cltv_expiry_delta: u16::max_value(),
 284                                         htlc_minimum_msat: u64::max_value(),
 285                                         fee_base_msat: u32::max_value(),
 286                                         fee_proportional_millionths: u32::max_value(),
 287                                 },
 288                                 two_to_one: DirectionalChannelInfo {
 289                                         src_node_id: msg.contents.node_id_2.clone(),
 290                                         last_update: 0,
 291                                         enabled: false,
 292                                         cltv_expiry_delta: u16::max_value(),
 293                                         htlc_minimum_msat: u64::max_value(),
 294                                         fee_base_msat: u32::max_value(),
 295                                         fee_proportional_millionths: u32::max_value(),
 296                                 }
 297                         };
 298
 299                 match network.channels.entry(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 300                         Entry::Occupied(mut entry) => {
 301                                 //TODO: because asking the blockchain if short_channel_id is valid is only optional
 302                                 //in the blockchain API, we need to handle it smartly here, though its unclear
 303                                 //exactly how...
 304                                 if checked_utxo {
 305                                         // Either our UTXO provider is busted, there was a reorg, or the UTXO provider
 306                                         // only sometimes returns results. In any case remove the previous entry. Note
 307                                         // that the spec expects us to "blacklist" the node_ids involved, but we can't
 308                                         // do that because
 309                                         // a) we don't *require* a UTXO provider that always returns results.
 310                                         // b) we don't track UTXOs of channels we know about and remove them if they
 311                                         //    get reorg'd out.
 312                                         // c) it's unclear how to do so without exposing ourselves to massive DoS risk.
 313                                         Self::remove_channel_in_nodes(network.nodes, &entry.get(), msg.contents.short_channel_id);
 314                                         *entry.get_mut() = chan_info;
 315                                 } else {
 316                                         return Err(HandleError{err: "Already have knowledge of channel", action: Some(ErrorAction::IgnoreError)})
 317                                 }
 318                         },
 319                         Entry::Vacant(entry) => {
 320                                 entry.insert(chan_info);
 321                         }
 322                 };
 323
 324                 macro_rules! add_channel_to_node {
 325                         ( $node_id: expr ) => {
 326                                 match network.nodes.entry($node_id) {
 327                                         Entry::Occupied(node_entry) => {
 328                                                 node_entry.into_mut().channels.push(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash));
 329                                         },
 330                                         Entry::Vacant(node_entry) => {
 331                                                 node_entry.insert(NodeInfo {
 332                                                         channels: vec!(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)),
 333                                                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 334                                                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 335                                                         features: GlobalFeatures::new(),
 336                                                         last_update: 0,
 337                                                         rgb: [0; 3],
 338                                                         alias: [0; 32],
 339                                                         addresses: Vec::new(),
 340                                                 });
 341                                         }
 342                                 }
 343                         };
 344                 }
 345
 346                 add_channel_to_node!(msg.contents.node_id_1);
 347                 add_channel_to_node!(msg.contents.node_id_2);
 348
 349                 Ok(msg.contents.excess_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 350         }
 351
 352         fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
 353                 match update {
 354                         &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
 355                                 let _ = self.handle_channel_update(msg);
 356                         },
 357                         &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id, is_permanent:_ } => {
 358                                 let mut network = self.network_map.write().unwrap();
 359                                 if let Some(chan) = network.channels.remove(short_channel_id) {
 360                                         Self::remove_channel_in_nodes(&mut network.nodes, &chan, *short_channel_id);
 361                                 }
 362                         },
 363                         &msgs::HTLCFailChannelUpdate::NodeFailure { ref node_id, is_permanent:_ } => {
 364                                 //let mut network = self.network_map.write().unwrap();
 365                                 //TODO: check _blamed_upstream_node
 366                                 self.mark_node_bad(node_id, false);
 367                         },
 368                 }
 369         }
 370
 371         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
 372                 let mut network = self.network_map.write().unwrap();
 373                 let dest_node_id;
 374                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 375                 let chan_was_enabled;
 376
 377                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 378                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 379                         Some(channel) => {
 380                                 macro_rules! maybe_update_channel_info {
 381                                         ( $target: expr) => {
 382                                                 if $target.last_update >= msg.contents.timestamp {
 383                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 384                                                 }
 385                                                 chan_was_enabled = $target.enabled;
 386                                                 $target.last_update = msg.contents.timestamp;
 387                                                 $target.enabled = chan_enabled;
 388                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 389                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 390                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 391                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 392                                         }
 393                                 }
 394
 395                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 396                                 if msg.contents.flags & 1 == 1 {
 397                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 398                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 399                                         maybe_update_channel_info!(channel.two_to_one);
 400                                 } else {
 401                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 402                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 403                                         maybe_update_channel_info!(channel.one_to_two);
 404                                 }
 405                         }
 406                 }
 407
 408                 if chan_enabled {
 409                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 410                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 411                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 412                 } else if chan_was_enabled {
 413                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 414                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 415
 416                         {
 417                                 let node = network.nodes.get(&dest_node_id).unwrap();
 418
 419                                 for chan_id in node.channels.iter() {
 420                                         let chan = network.channels.get(chan_id).unwrap();
 421                                         if chan.one_to_two.src_node_id == dest_node_id {
 422                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 423                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 424                                         } else {
 425                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 426                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 427                                         }
 428                                 }
 429                         }
 430
 431                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 432                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 433                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 434                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 435                 }
 436
 437                 Ok(msg.contents.excess_data.is_empty())
 438         }
 439 }
 440
 441 #[derive(Eq, PartialEq)]
 442 struct RouteGraphNode {
 443         pubkey: PublicKey,
 444         lowest_fee_to_peer_through_node: u64,
 445         lowest_fee_to_node: u64,
 446 }
 447
 448 impl cmp::Ord for RouteGraphNode {
 449         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 450                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 451                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 452         }
 453 }
 454
 455 impl cmp::PartialOrd for RouteGraphNode {
 456         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 457                 Some(self.cmp(other))
 458         }
 459 }
 460
 461 struct DummyDirectionalChannelInfo {
 462         src_node_id: PublicKey,
 463         last_update: u32,
 464         cltv_expiry_delta: u32,
 465         htlc_minimum_msat: u64,
 466         fee_base_msat: u32,
 467         fee_proportional_millionths: u32,
 468 }
 469
 470 impl Router {
 471         /// Creates a new router with the given node_id to be used as the source for get_route()
 472         pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
 473                 let mut nodes = HashMap::new();
 474                 nodes.insert(our_pubkey.clone(), NodeInfo {
 475                         channels: Vec::new(),
 476                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 477                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 478                         features: GlobalFeatures::new(),
 479                         last_update: 0,
 480                         rgb: [0; 3],
 481                         alias: [0; 32],
 482                         addresses: Vec::new(),
 483                 });
 484                 Router {
 485                         secp_ctx: Secp256k1::verification_only(),
 486                         network_map: RwLock::new(NetworkMap {
 487                                 channels: HashMap::new(),
 488                                 our_node_id: our_pubkey,
 489                                 nodes: nodes,
 490                         }),
 491                         chain_monitor,
 492                         logger,
 493                 }
 494         }
 495
 496         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 497         /// level Trace
 498         pub fn trace_state(&self) {
 499                 log_trace!(self, "{}", self.network_map.read().unwrap());
 500         }
 501
 502         /// Get network addresses by node id
 503         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 504                 let network = self.network_map.read().unwrap();
 505                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 506         }
 507
 508         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 509         /// with an expotnential decay in node "badness". Note that there is deliberately no
 510         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 511         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 512         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 513         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 514         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 515                 unimplemented!();
 516         }
 517
 518         fn remove_channel_in_nodes(nodes: &mut HashMap<PublicKey, NodeInfo>, chan: &ChannelInfo, short_channel_id: u64) {
 519                 macro_rules! remove_from_node {
 520                         ($node_id: expr) => {
 521                                 if let Entry::Occupied(mut entry) = nodes.entry($node_id) {
 522                                         entry.get_mut().channels.retain(|chan_id| {
 523                                                 short_channel_id != *NetworkMap::get_short_id(chan_id)
 524                                         });
 525                                         if entry.get().channels.is_empty() {
 526                                                 entry.remove_entry();
 527                                         }
 528                                 } else {
 529                                         panic!("Had channel that pointed to unknown node (ie inconsistent network map)!");
 530                                 }
 531                         }
 532                 }
 533                 remove_from_node!(chan.one_to_two.src_node_id);
 534                 remove_from_node!(chan.two_to_one.src_node_id);
 535         }
 536
 537         /// Gets a route from us to the given target node.
 538         ///
 539         /// Extra routing hops between known nodes and the target will be used if they are included in
 540         /// last_hops.
 541         ///
 542         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 543         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 544         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 545         /// will be used.
 546         ///
 547         /// Panics if first_hops contains channels without short_channel_ids
 548         /// (ChannelManager::list_usable_channels will never include such channels).
 549         ///
 550         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 551         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 552         /// *is* checked as they may change based on the receiving node.
 553         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> {
 554                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 555                 // uptime/success in using a node in the past.
 556                 let network = self.network_map.read().unwrap();
 557
 558                 if *target == network.our_node_id {
 559                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 560                 }
 561
 562                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 563                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 564                 }
 565
 566                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 567                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 568                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 569                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 570                 // one.
 571
 572                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 573                         src_node_id: network.our_node_id.clone(),
 574                         last_update: 0,
 575                         cltv_expiry_delta: 0,
 576                         htlc_minimum_msat: 0,
 577                         fee_base_msat: 0,
 578                         fee_proportional_millionths: 0,
 579                 };
 580
 581                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 582                 let mut dist = HashMap::with_capacity(network.nodes.len());
 583
 584                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 585                 if let Some(hops) = first_hops {
 586                         for chan in hops {
 587                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 588                                 if chan.remote_network_id == *target {
 589                                         return Ok(Route {
 590                                                 hops: vec![RouteHop {
 591                                                         pubkey: chan.remote_network_id,
 592                                                         short_channel_id,
 593                                                         fee_msat: final_value_msat,
 594                                                         cltv_expiry_delta: final_cltv,
 595                                                         channel_update_timestamp: 0, //TODO: related to local channel_update_handling?
 596                                                 }],
 597                                         });
 598                                 }
 599                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 600                         }
 601                         if first_hop_targets.is_empty() {
 602                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 603                         }
 604                 }
 605
 606                 macro_rules! add_entry {
 607                         // Adds entry which goes from the node pointed to by $directional_info to
 608                         // $dest_node_id over the channel with id $chan_id with fees described in
 609                         // $directional_info.
 610                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 611                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 612                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 613                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 614                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 615                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 616                                         {
 617                                                 let mut total_fee = $starting_fee_msat as u64;
 618                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 619                                                 let old_entry = hm_entry.or_insert_with(|| {
 620                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 621                                                         (u64::max_value(),
 622                                                                 node.lowest_inbound_channel_fee_base_msat,
 623                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 624                                                                 RouteHop {
 625                                                                         pubkey: $dest_node_id.clone(),
 626                                                                         short_channel_id: 0,
 627                                                                         fee_msat: 0,
 628                                                                         cltv_expiry_delta: 0,
 629                                                                         channel_update_timestamp: $directional_info.last_update,
 630                                                         })
 631                                                 });
 632                                                 if $directional_info.src_node_id != network.our_node_id {
 633                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 634                                                         // will have the same effective-fee
 635                                                         total_fee += new_fee;
 636                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 637                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 638                                                         } else {
 639                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 640                                                                 total_fee = u64::max_value();
 641                                                         }
 642                                                 }
 643                                                 let new_graph_node = RouteGraphNode {
 644                                                         pubkey: $directional_info.src_node_id,
 645                                                         lowest_fee_to_peer_through_node: total_fee,
 646                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 647                                                 };
 648                                                 if old_entry.0 > total_fee {
 649                                                         targets.push(new_graph_node);
 650                                                         old_entry.0 = total_fee;
 651                                                         old_entry.3 = RouteHop {
 652                                                                 pubkey: $dest_node_id.clone(),
 653                                                                 short_channel_id: $chan_id.clone(),
 654                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 655                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 656                                                                 channel_update_timestamp: $directional_info.last_update,
 657                                                         }
 658                                                 }
 659                                         }
 660                                 }
 661                         };
 662                 }
 663
 664                 macro_rules! add_entries_to_cheapest_to_target_node {
 665                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 666                                 if first_hops.is_some() {
 667                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 668                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 669                                         }
 670                                 }
 671
 672                                 for chan_id in $node.channels.iter() {
 673                                         let chan = network.channels.get(chan_id).unwrap();
 674                                         if chan.one_to_two.src_node_id == *$node_id {
 675                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 676                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 677                                                         if chan.two_to_one.enabled {
 678                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 679                                                         }
 680                                                 }
 681                                         } else {
 682                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 683                                                         if chan.one_to_two.enabled {
 684                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 685                                                         }
 686                                                 }
 687                                         }
 688                                 }
 689                         };
 690                 }
 691
 692                 match network.nodes.get(target) {
 693                         None => {},
 694                         Some(node) => {
 695                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 696                         },
 697                 }
 698
 699                 for hop in last_hops.iter() {
 700                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 701                                 if network.nodes.get(&hop.src_node_id).is_some() {
 702                                         if first_hops.is_some() {
 703                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 704                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 705                                                 }
 706                                         }
 707                                         add_entry!(hop.short_channel_id, target, hop, 0);
 708                                 }
 709                         }
 710                 }
 711
 712                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 713                         if pubkey == network.our_node_id {
 714                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 715                                 while res.last().unwrap().pubkey != *target {
 716                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 717                                                 Some(hop) => hop.3,
 718                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 719                                         };
 720                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 721                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 722                                         res.push(new_entry);
 723                                 }
 724                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 725                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 726                                 let route = Route { hops: res };
 727                                 log_trace!(self, "Got route: {}", log_route!(route));
 728                                 return Ok(route);
 729                         }
 730
 731                         match network.nodes.get(&pubkey) {
 732                                 None => {},
 733                                 Some(node) => {
 734                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 735                                 },
 736                         }
 737                 }
 738
 739                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 740         }
 741 }
 742
 743 #[cfg(test)]
 744 mod tests {
 745         use chain::chaininterface;
 746         use ln::channelmanager;
 747         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 748         use ln::msgs::GlobalFeatures;
 749         use util::test_utils;
 750         use util::logger::Logger;
 751
 752         use bitcoin::util::hash::Sha256dHash;
 753         use bitcoin::network::constants::Network;
 754
 755         use hex;
 756
 757         use secp256k1::key::{PublicKey,SecretKey};
 758         use secp256k1::Secp256k1;
 759
 760         use std::sync::Arc;
 761
 762         #[test]
 763         fn route_test() {
 764                 let secp_ctx = Secp256k1::new();
 765                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 766                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 767                 let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
 768                 let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 769
 770                 // Build network from our_id to node8:
 771                 //
 772                 //        -1(1)2-  node1  -1(3)2-
 773                 //       /                       \
 774                 // our_id -1(12)2- node8 -1(13)2--- node3
 775                 //       \                       /
 776                 //        -1(2)2-  node2  -1(4)2-
 777                 //
 778                 //
 779                 // chan1  1-to-2: disabled
 780                 // chan1  2-to-1: enabled, 0 fee
 781                 //
 782                 // chan2  1-to-2: enabled, ignored fee
 783                 // chan2  2-to-1: enabled, 0 fee
 784                 //
 785                 // chan3  1-to-2: enabled, 0 fee
 786                 // chan3  2-to-1: enabled, 100 msat fee
 787                 //
 788                 // chan4  1-to-2: enabled, 100% fee
 789                 // chan4  2-to-1: enabled, 0 fee
 790                 //
 791                 // chan12 1-to-2: enabled, ignored fee
 792                 // chan12 2-to-1: enabled, 0 fee
 793                 //
 794                 // chan13 1-to-2: enabled, 200% fee
 795                 // chan13 2-to-1: enabled, 0 fee
 796                 //
 797                 //
 798                 //       -1(5)2- node4 -1(8)2--
 799                 //       |         2          |
 800                 //       |       (11)         |
 801                 //      /          1           \
 802                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 803                 //      \                      /
 804                 //       -1(7)2- node6 -1(10)2-
 805                 //
 806                 // chan5  1-to-2: enabled, 100 msat fee
 807                 // chan5  2-to-1: enabled, 0 fee
 808                 //
 809                 // chan6  1-to-2: enabled, 0 fee
 810                 // chan6  2-to-1: enabled, 0 fee
 811                 //
 812                 // chan7  1-to-2: enabled, 100% fee
 813                 // chan7  2-to-1: enabled, 0 fee
 814                 //
 815                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 816                 // chan8  2-to-1: enabled, 0 fee
 817                 //
 818                 // chan9  1-to-2: enabled, 1001 msat fee
 819                 // chan9  2-to-1: enabled, 0 fee
 820                 //
 821                 // chan10 1-to-2: enabled, 0 fee
 822                 // chan10 2-to-1: enabled, 0 fee
 823                 //
 824                 // chan11 1-to-2: enabled, 0 fee
 825                 // chan11 2-to-1: enabled, 0 fee
 826
 827                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 828                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 829                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 830                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 831                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 832                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 833                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 834                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 835
 836                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 837
 838                 {
 839                         let mut network = router.network_map.write().unwrap();
 840
 841                         network.nodes.insert(node1.clone(), NodeInfo {
 842                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 843                                 lowest_inbound_channel_fee_base_msat: 100,
 844                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 845                                 features: GlobalFeatures::new(),
 846                                 last_update: 1,
 847                                 rgb: [0; 3],
 848                                 alias: [0; 32],
 849                                 addresses: Vec::new(),
 850                         });
 851                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 852                                 features: GlobalFeatures::new(),
 853                                 one_to_two: DirectionalChannelInfo {
 854                                         src_node_id: our_id.clone(),
 855                                         last_update: 0,
 856                                         enabled: false,
 857                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 858                                         htlc_minimum_msat: 0,
 859                                         fee_base_msat: u32::max_value(), // This value should be ignored
 860                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 861                                 }, two_to_one: DirectionalChannelInfo {
 862                                         src_node_id: node1.clone(),
 863                                         last_update: 0,
 864                                         enabled: true,
 865                                         cltv_expiry_delta: 0,
 866                                         htlc_minimum_msat: 0,
 867                                         fee_base_msat: 0,
 868                                         fee_proportional_millionths: 0,
 869                                 },
 870                         });
 871                         network.nodes.insert(node2.clone(), NodeInfo {
 872                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 873                                 lowest_inbound_channel_fee_base_msat: 0,
 874                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 875                                 features: GlobalFeatures::new(),
 876                                 last_update: 1,
 877                                 rgb: [0; 3],
 878                                 alias: [0; 32],
 879                                 addresses: Vec::new(),
 880                         });
 881                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 882                                 features: GlobalFeatures::new(),
 883                                 one_to_two: DirectionalChannelInfo {
 884                                         src_node_id: our_id.clone(),
 885                                         last_update: 0,
 886                                         enabled: true,
 887                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 888                                         htlc_minimum_msat: 0,
 889                                         fee_base_msat: u32::max_value(), // This value should be ignored
 890                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 891                                 }, two_to_one: DirectionalChannelInfo {
 892                                         src_node_id: node2.clone(),
 893                                         last_update: 0,
 894                                         enabled: true,
 895                                         cltv_expiry_delta: 0,
 896                                         htlc_minimum_msat: 0,
 897                                         fee_base_msat: 0,
 898                                         fee_proportional_millionths: 0,
 899                                 },
 900                         });
 901                         network.nodes.insert(node8.clone(), NodeInfo {
 902                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 903                                 lowest_inbound_channel_fee_base_msat: 0,
 904                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 905                                 features: GlobalFeatures::new(),
 906                                 last_update: 1,
 907                                 rgb: [0; 3],
 908                                 alias: [0; 32],
 909                                 addresses: Vec::new(),
 910                         });
 911                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 912                                 features: GlobalFeatures::new(),
 913                                 one_to_two: DirectionalChannelInfo {
 914                                         src_node_id: our_id.clone(),
 915                                         last_update: 0,
 916                                         enabled: true,
 917                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 918                                         htlc_minimum_msat: 0,
 919                                         fee_base_msat: u32::max_value(), // This value should be ignored
 920                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 921                                 }, two_to_one: DirectionalChannelInfo {
 922                                         src_node_id: node8.clone(),
 923                                         last_update: 0,
 924                                         enabled: true,
 925                                         cltv_expiry_delta: 0,
 926                                         htlc_minimum_msat: 0,
 927                                         fee_base_msat: 0,
 928                                         fee_proportional_millionths: 0,
 929                                 },
 930                         });
 931                         network.nodes.insert(node3.clone(), NodeInfo {
 932                                 channels: vec!(
 933                                         NetworkMap::get_key(3, zero_hash.clone()),
 934                                         NetworkMap::get_key(4, zero_hash.clone()),
 935                                         NetworkMap::get_key(13, zero_hash.clone()),
 936                                         NetworkMap::get_key(5, zero_hash.clone()),
 937                                         NetworkMap::get_key(6, zero_hash.clone()),
 938                                         NetworkMap::get_key(7, zero_hash.clone())),
 939                                 lowest_inbound_channel_fee_base_msat: 0,
 940                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 941                                 features: GlobalFeatures::new(),
 942                                 last_update: 1,
 943                                 rgb: [0; 3],
 944                                 alias: [0; 32],
 945                                 addresses: Vec::new(),
 946                         });
 947                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 948                                 features: GlobalFeatures::new(),
 949                                 one_to_two: DirectionalChannelInfo {
 950                                         src_node_id: node1.clone(),
 951                                         last_update: 0,
 952                                         enabled: true,
 953                                         cltv_expiry_delta: (3 << 8) | 1,
 954                                         htlc_minimum_msat: 0,
 955                                         fee_base_msat: 0,
 956                                         fee_proportional_millionths: 0,
 957                                 }, two_to_one: DirectionalChannelInfo {
 958                                         src_node_id: node3.clone(),
 959                                         last_update: 0,
 960                                         enabled: true,
 961                                         cltv_expiry_delta: (3 << 8) | 2,
 962                                         htlc_minimum_msat: 0,
 963                                         fee_base_msat: 100,
 964                                         fee_proportional_millionths: 0,
 965                                 },
 966                         });
 967                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 968                                 features: GlobalFeatures::new(),
 969                                 one_to_two: DirectionalChannelInfo {
 970                                         src_node_id: node2.clone(),
 971                                         last_update: 0,
 972                                         enabled: true,
 973                                         cltv_expiry_delta: (4 << 8) | 1,
 974                                         htlc_minimum_msat: 0,
 975                                         fee_base_msat: 0,
 976                                         fee_proportional_millionths: 1000000,
 977                                 }, two_to_one: DirectionalChannelInfo {
 978                                         src_node_id: node3.clone(),
 979                                         last_update: 0,
 980                                         enabled: true,
 981                                         cltv_expiry_delta: (4 << 8) | 2,
 982                                         htlc_minimum_msat: 0,
 983                                         fee_base_msat: 0,
 984                                         fee_proportional_millionths: 0,
 985                                 },
 986                         });
 987                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
 988                                 features: GlobalFeatures::new(),
 989                                 one_to_two: DirectionalChannelInfo {
 990                                         src_node_id: node8.clone(),
 991                                         last_update: 0,
 992                                         enabled: true,
 993                                         cltv_expiry_delta: (13 << 8) | 1,
 994                                         htlc_minimum_msat: 0,
 995                                         fee_base_msat: 0,
 996                                         fee_proportional_millionths: 2000000,
 997                                 }, two_to_one: DirectionalChannelInfo {
 998                                         src_node_id: node3.clone(),
 999                                         last_update: 0,
1000                                         enabled: true,
1001                                         cltv_expiry_delta: (13 << 8) | 2,
1002                                         htlc_minimum_msat: 0,
1003                                         fee_base_msat: 0,
1004                                         fee_proportional_millionths: 0,
1005                                 },
1006                         });
1007                         network.nodes.insert(node4.clone(), NodeInfo {
1008                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
1009                                 lowest_inbound_channel_fee_base_msat: 0,
1010                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1011                                 features: GlobalFeatures::new(),
1012                                 last_update: 1,
1013                                 rgb: [0; 3],
1014                                 alias: [0; 32],
1015                                 addresses: Vec::new(),
1016                         });
1017                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
1018                                 features: GlobalFeatures::new(),
1019                                 one_to_two: DirectionalChannelInfo {
1020                                         src_node_id: node3.clone(),
1021                                         last_update: 0,
1022                                         enabled: true,
1023                                         cltv_expiry_delta: (5 << 8) | 1,
1024                                         htlc_minimum_msat: 0,
1025                                         fee_base_msat: 100,
1026                                         fee_proportional_millionths: 0,
1027                                 }, two_to_one: DirectionalChannelInfo {
1028                                         src_node_id: node4.clone(),
1029                                         last_update: 0,
1030                                         enabled: true,
1031                                         cltv_expiry_delta: (5 << 8) | 2,
1032                                         htlc_minimum_msat: 0,
1033                                         fee_base_msat: 0,
1034                                         fee_proportional_millionths: 0,
1035                                 },
1036                         });
1037                         network.nodes.insert(node5.clone(), NodeInfo {
1038                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
1039                                 lowest_inbound_channel_fee_base_msat: 0,
1040                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1041                                 features: GlobalFeatures::new(),
1042                                 last_update: 1,
1043                                 rgb: [0; 3],
1044                                 alias: [0; 32],
1045                                 addresses: Vec::new(),
1046                         });
1047                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
1048                                 features: GlobalFeatures::new(),
1049                                 one_to_two: DirectionalChannelInfo {
1050                                         src_node_id: node3.clone(),
1051                                         last_update: 0,
1052                                         enabled: true,
1053                                         cltv_expiry_delta: (6 << 8) | 1,
1054                                         htlc_minimum_msat: 0,
1055                                         fee_base_msat: 0,
1056                                         fee_proportional_millionths: 0,
1057                                 }, two_to_one: DirectionalChannelInfo {
1058                                         src_node_id: node5.clone(),
1059                                         last_update: 0,
1060                                         enabled: true,
1061                                         cltv_expiry_delta: (6 << 8) | 2,
1062                                         htlc_minimum_msat: 0,
1063                                         fee_base_msat: 0,
1064                                         fee_proportional_millionths: 0,
1065                                 },
1066                         });
1067                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
1068                                 features: GlobalFeatures::new(),
1069                                 one_to_two: DirectionalChannelInfo {
1070                                         src_node_id: node5.clone(),
1071                                         last_update: 0,
1072                                         enabled: true,
1073                                         cltv_expiry_delta: (11 << 8) | 1,
1074                                         htlc_minimum_msat: 0,
1075                                         fee_base_msat: 0,
1076                                         fee_proportional_millionths: 0,
1077                                 }, two_to_one: DirectionalChannelInfo {
1078                                         src_node_id: node4.clone(),
1079                                         last_update: 0,
1080                                         enabled: true,
1081                                         cltv_expiry_delta: (11 << 8) | 2,
1082                                         htlc_minimum_msat: 0,
1083                                         fee_base_msat: 0,
1084                                         fee_proportional_millionths: 0,
1085                                 },
1086                         });
1087                         network.nodes.insert(node6.clone(), NodeInfo {
1088                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
1089                                 lowest_inbound_channel_fee_base_msat: 0,
1090                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1091                                 features: GlobalFeatures::new(),
1092                                 last_update: 1,
1093                                 rgb: [0; 3],
1094                                 alias: [0; 32],
1095                                 addresses: Vec::new(),
1096                         });
1097                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
1098                                 features: GlobalFeatures::new(),
1099                                 one_to_two: DirectionalChannelInfo {
1100                                         src_node_id: node3.clone(),
1101                                         last_update: 0,
1102                                         enabled: true,
1103                                         cltv_expiry_delta: (7 << 8) | 1,
1104                                         htlc_minimum_msat: 0,
1105                                         fee_base_msat: 0,
1106                                         fee_proportional_millionths: 1000000,
1107                                 }, two_to_one: DirectionalChannelInfo {
1108                                         src_node_id: node6.clone(),
1109                                         last_update: 0,
1110                                         enabled: true,
1111                                         cltv_expiry_delta: (7 << 8) | 2,
1112                                         htlc_minimum_msat: 0,
1113                                         fee_base_msat: 0,
1114                                         fee_proportional_millionths: 0,
1115                                 },
1116                         });
1117                 }
1118
1119                 { // Simple route to 3 via 2
1120                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1121                         assert_eq!(route.hops.len(), 2);
1122
1123                         assert_eq!(route.hops[0].pubkey, node2);
1124                         assert_eq!(route.hops[0].short_channel_id, 2);
1125                         assert_eq!(route.hops[0].fee_msat, 100);
1126                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1127
1128                         assert_eq!(route.hops[1].pubkey, node3);
1129                         assert_eq!(route.hops[1].short_channel_id, 4);
1130                         assert_eq!(route.hops[1].fee_msat, 100);
1131                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1132                 }
1133
1134                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1135                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1136                         assert_eq!(route.hops.len(), 3);
1137
1138                         assert_eq!(route.hops[0].pubkey, node2);
1139                         assert_eq!(route.hops[0].short_channel_id, 2);
1140                         assert_eq!(route.hops[0].fee_msat, 200);
1141                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1142
1143                         assert_eq!(route.hops[1].pubkey, node3);
1144                         assert_eq!(route.hops[1].short_channel_id, 4);
1145                         assert_eq!(route.hops[1].fee_msat, 100);
1146                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1147
1148                         assert_eq!(route.hops[2].pubkey, node1);
1149                         assert_eq!(route.hops[2].short_channel_id, 3);
1150                         assert_eq!(route.hops[2].fee_msat, 100);
1151                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1152                 }
1153
1154                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1155                         let our_chans = vec![channelmanager::ChannelDetails {
1156                                 channel_id: [0; 32],
1157                                 short_channel_id: Some(42),
1158                                 remote_network_id: node8.clone(),
1159                                 channel_value_satoshis: 0,
1160                                 user_id: 0,
1161                         }];
1162                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1163                         assert_eq!(route.hops.len(), 2);
1164
1165                         assert_eq!(route.hops[0].pubkey, node8);
1166                         assert_eq!(route.hops[0].short_channel_id, 42);
1167                         assert_eq!(route.hops[0].fee_msat, 200);
1168                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1169
1170                         assert_eq!(route.hops[1].pubkey, node3);
1171                         assert_eq!(route.hops[1].short_channel_id, 13);
1172                         assert_eq!(route.hops[1].fee_msat, 100);
1173                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1174                 }
1175
1176                 let mut last_hops = vec!(RouteHint {
1177                                 src_node_id: node4.clone(),
1178                                 short_channel_id: 8,
1179                                 last_update: 0,
1180                                 fee_base_msat: 0,
1181                                 fee_proportional_millionths: 0,
1182                                 cltv_expiry_delta: (8 << 8) | 1,
1183                                 htlc_minimum_msat: 0,
1184                         }, RouteHint {
1185                                 src_node_id: node5.clone(),
1186                                 short_channel_id: 9,
1187                                 last_update: 0,
1188                                 fee_base_msat: 1001,
1189                                 fee_proportional_millionths: 0,
1190                                 cltv_expiry_delta: (9 << 8) | 1,
1191                                 htlc_minimum_msat: 0,
1192                         }, RouteHint {
1193                                 src_node_id: node6.clone(),
1194                                 short_channel_id: 10,
1195                                 last_update: 0,
1196                                 fee_base_msat: 0,
1197                                 fee_proportional_millionths: 0,
1198                                 cltv_expiry_delta: (10 << 8) | 1,
1199                                 htlc_minimum_msat: 0,
1200                         });
1201
1202                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1203                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1204                         assert_eq!(route.hops.len(), 5);
1205
1206                         assert_eq!(route.hops[0].pubkey, node2);
1207                         assert_eq!(route.hops[0].short_channel_id, 2);
1208                         assert_eq!(route.hops[0].fee_msat, 100);
1209                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1210
1211                         assert_eq!(route.hops[1].pubkey, node3);
1212                         assert_eq!(route.hops[1].short_channel_id, 4);
1213                         assert_eq!(route.hops[1].fee_msat, 0);
1214                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1215
1216                         assert_eq!(route.hops[2].pubkey, node5);
1217                         assert_eq!(route.hops[2].short_channel_id, 6);
1218                         assert_eq!(route.hops[2].fee_msat, 0);
1219                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1220
1221                         assert_eq!(route.hops[3].pubkey, node4);
1222                         assert_eq!(route.hops[3].short_channel_id, 11);
1223                         assert_eq!(route.hops[3].fee_msat, 0);
1224                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1225
1226                         assert_eq!(route.hops[4].pubkey, node7);
1227                         assert_eq!(route.hops[4].short_channel_id, 8);
1228                         assert_eq!(route.hops[4].fee_msat, 100);
1229                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1230                 }
1231
1232                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1233                         let our_chans = vec![channelmanager::ChannelDetails {
1234                                 channel_id: [0; 32],
1235                                 short_channel_id: Some(42),
1236                                 remote_network_id: node4.clone(),
1237                                 channel_value_satoshis: 0,
1238                                 user_id: 0,
1239                         }];
1240                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1241                         assert_eq!(route.hops.len(), 2);
1242
1243                         assert_eq!(route.hops[0].pubkey, node4);
1244                         assert_eq!(route.hops[0].short_channel_id, 42);
1245                         assert_eq!(route.hops[0].fee_msat, 0);
1246                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1247
1248                         assert_eq!(route.hops[1].pubkey, node7);
1249                         assert_eq!(route.hops[1].short_channel_id, 8);
1250                         assert_eq!(route.hops[1].fee_msat, 100);
1251                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1252                 }
1253
1254                 last_hops[0].fee_base_msat = 1000;
1255
1256                 { // Revert to via 6 as the fee on 8 goes up
1257                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1258                         assert_eq!(route.hops.len(), 4);
1259
1260                         assert_eq!(route.hops[0].pubkey, node2);
1261                         assert_eq!(route.hops[0].short_channel_id, 2);
1262                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1263                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1264
1265                         assert_eq!(route.hops[1].pubkey, node3);
1266                         assert_eq!(route.hops[1].short_channel_id, 4);
1267                         assert_eq!(route.hops[1].fee_msat, 100);
1268                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1269
1270                         assert_eq!(route.hops[2].pubkey, node6);
1271                         assert_eq!(route.hops[2].short_channel_id, 7);
1272                         assert_eq!(route.hops[2].fee_msat, 0);
1273                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1274
1275                         assert_eq!(route.hops[3].pubkey, node7);
1276                         assert_eq!(route.hops[3].short_channel_id, 10);
1277                         assert_eq!(route.hops[3].fee_msat, 100);
1278                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1279                 }
1280
1281                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1282                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1283                         assert_eq!(route.hops.len(), 5);
1284
1285                         assert_eq!(route.hops[0].pubkey, node2);
1286                         assert_eq!(route.hops[0].short_channel_id, 2);
1287                         assert_eq!(route.hops[0].fee_msat, 3000);
1288                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1289
1290                         assert_eq!(route.hops[1].pubkey, node3);
1291                         assert_eq!(route.hops[1].short_channel_id, 4);
1292                         assert_eq!(route.hops[1].fee_msat, 0);
1293                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1294
1295                         assert_eq!(route.hops[2].pubkey, node5);
1296                         assert_eq!(route.hops[2].short_channel_id, 6);
1297                         assert_eq!(route.hops[2].fee_msat, 0);
1298                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1299
1300                         assert_eq!(route.hops[3].pubkey, node4);
1301                         assert_eq!(route.hops[3].short_channel_id, 11);
1302                         assert_eq!(route.hops[3].fee_msat, 1000);
1303                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1304
1305                         assert_eq!(route.hops[4].pubkey, node7);
1306                         assert_eq!(route.hops[4].short_channel_id, 8);
1307                         assert_eq!(route.hops[4].fee_msat, 2000);
1308                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1309                 }
1310         }
1311 }