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