_ 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::{DecodeError,ErrorAction,HandleError,RoutingMessageHandler,NetAddress,GlobalFeatures};
  17 use ln::msgs;
  18 use util::ser::{Writeable, Readable};
  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 impl Writeable for Route {
  51         fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  52                 (self.hops.len() as u8).write(writer)?;
  53                 for hop in self.hops.iter() {
  54                         hop.pubkey.write(writer)?;
  55                         hop.short_channel_id.write(writer)?;
  56                         hop.fee_msat.write(writer)?;
  57                         hop.cltv_expiry_delta.write(writer)?;
  58                 }
  59                 Ok(())
  60         }
  61 }
  62
  63 impl<R: ::std::io::Read> Readable<R> for Route {
  64         fn read(reader: &mut R) -> Result<Route, DecodeError> {
  65                 let hops_count: u8 = Readable::read(reader)?;
  66                 let mut hops = Vec::with_capacity(hops_count as usize);
  67                 for _ in 0..hops_count {
  68                         hops.push(RouteHop {
  69                                 pubkey: Readable::read(reader)?,
  70                                 short_channel_id: Readable::read(reader)?,
  71                                 fee_msat: Readable::read(reader)?,
  72                                 cltv_expiry_delta: Readable::read(reader)?,
  73                         });
  74                 }
  75                 Ok(Route {
  76                         hops
  77                 })
  78         }
  79 }
  80
  81 struct DirectionalChannelInfo {
  82         src_node_id: PublicKey,
  83         last_update: u32,
  84         enabled: bool,
  85         cltv_expiry_delta: u16,
  86         htlc_minimum_msat: u64,
  87         fee_base_msat: u32,
  88         fee_proportional_millionths: u32,
  89 }
  90
  91 impl std::fmt::Display for DirectionalChannelInfo {
  92         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  93                 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)?;
  94                 Ok(())
  95         }
  96 }
  97
  98 struct ChannelInfo {
  99         features: GlobalFeatures,
 100         one_to_two: DirectionalChannelInfo,
 101         two_to_one: DirectionalChannelInfo,
 102 }
 103
 104 impl std::fmt::Display for ChannelInfo {
 105         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 106                 write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
 107                 Ok(())
 108         }
 109 }
 110
 111 struct NodeInfo {
 112         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 113         channels: Vec<(u64, Sha256dHash)>,
 114         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 115         channels: Vec<u64>,
 116
 117         lowest_inbound_channel_fee_base_msat: u32,
 118         lowest_inbound_channel_fee_proportional_millionths: u32,
 119
 120         features: GlobalFeatures,
 121         last_update: u32,
 122         rgb: [u8; 3],
 123         alias: [u8; 32],
 124         addresses: Vec<NetAddress>,
 125 }
 126
 127 impl std::fmt::Display for NodeInfo {
 128         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 129                 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[..])?;
 130                 Ok(())
 131         }
 132 }
 133
 134 struct NetworkMap {
 135         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 136         channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
 137         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 138         channels: HashMap<u64, ChannelInfo>,
 139
 140         our_node_id: PublicKey,
 141         nodes: HashMap<PublicKey, NodeInfo>,
 142 }
 143 struct MutNetworkMap<'a> {
 144         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 145         channels: &'a mut HashMap<(u64, Sha256dHash), ChannelInfo>,
 146         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 147         channels: &'a mut HashMap<u64, ChannelInfo>,
 148         nodes: &'a mut HashMap<PublicKey, NodeInfo>,
 149 }
 150 impl NetworkMap {
 151         fn borrow_parts(&mut self) -> MutNetworkMap {
 152                 MutNetworkMap {
 153                         channels: &mut self.channels,
 154                         nodes: &mut self.nodes,
 155                 }
 156         }
 157 }
 158 impl std::fmt::Display for NetworkMap {
 159         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 160                 write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
 161                 for (key, val) in self.channels.iter() {
 162                         write!(f, " {}: {}\n", key, val)?;
 163                 }
 164                 write!(f, "[Nodes]\n")?;
 165                 for (key, val) in self.nodes.iter() {
 166                         write!(f, " {}: {}\n", log_pubkey!(key), val)?;
 167                 }
 168                 Ok(())
 169         }
 170 }
 171
 172 impl NetworkMap {
 173         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 174         #[inline]
 175         fn get_key(short_channel_id: u64, chain_hash: Sha256dHash) -> (u64, Sha256dHash) {
 176                 (short_channel_id, chain_hash)
 177         }
 178
 179         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 180         #[inline]
 181         fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
 182                 short_channel_id
 183         }
 184
 185         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 186         #[inline]
 187         fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
 188                 &id.0
 189         }
 190
 191         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 192         #[inline]
 193         fn get_short_id(id: &u64) -> &u64 {
 194                 id
 195         }
 196 }
 197
 198 /// A channel descriptor which provides a last-hop route to get_route
 199 pub struct RouteHint {
 200         /// The node_id of the non-target end of the route
 201         pub src_node_id: PublicKey,
 202         /// The short_channel_id of this channel
 203         pub short_channel_id: u64,
 204         /// The static msat-denominated fee which must be paid to use this channel
 205         pub fee_base_msat: u32,
 206         /// The dynamic proportional fee which must be paid to use this channel, denominated in
 207         /// millionths of the value being forwarded to the next hop.
 208         pub fee_proportional_millionths: u32,
 209         /// The difference in CLTV values between this node and the next node.
 210         pub cltv_expiry_delta: u16,
 211         /// The minimum value, in msat, which must be relayed to the next hop.
 212         pub htlc_minimum_msat: u64,
 213 }
 214
 215 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 216 /// payment destinations.
 217 pub struct Router {
 218         secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
 219         network_map: RwLock<NetworkMap>,
 220         chain_monitor: Arc<ChainWatchInterface>,
 221         logger: Arc<Logger>,
 222 }
 223
 224 macro_rules! secp_verify_sig {
 225         ( $secp_ctx: expr, $msg: expr, $sig: expr, $pubkey: expr ) => {
 226                 match $secp_ctx.verify($msg, $sig, $pubkey) {
 227                         Ok(_) => {},
 228                         Err(_) => return Err(HandleError{err: "Invalid signature from remote node", action: None}),
 229                 }
 230         };
 231 }
 232
 233 impl RoutingMessageHandler for Router {
 234         fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, HandleError> {
 235                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 236                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 237
 238                 if msg.contents.features.requires_unknown_bits() {
 239                         panic!("Unknown-required-features NodeAnnouncements should never deserialize!");
 240                 }
 241
 242                 let mut network = self.network_map.write().unwrap();
 243                 match network.nodes.get_mut(&msg.contents.node_id) {
 244                         None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
 245                         Some(node) => {
 246                                 if node.last_update >= msg.contents.timestamp {
 247                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 248                                 }
 249
 250                                 node.features = msg.contents.features.clone();
 251                                 node.last_update = msg.contents.timestamp;
 252                                 node.rgb = msg.contents.rgb;
 253                                 node.alias = msg.contents.alias;
 254                                 node.addresses = msg.contents.addresses.clone();
 255                                 Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 256                         }
 257                 }
 258         }
 259
 260         fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
 261                 if msg.contents.node_id_1 == msg.contents.node_id_2 || msg.contents.bitcoin_key_1 == msg.contents.bitcoin_key_2 {
 262                         return Err(HandleError{err: "Channel announcement node had a channel with itself", action: Some(ErrorAction::IgnoreError)});
 263                 }
 264
 265                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 266                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
 267                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
 268                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
 269                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 270
 271                 if msg.contents.features.requires_unknown_bits() {
 272                         panic!("Unknown-required-features ChannelAnnouncements should never deserialize!");
 273                 }
 274
 275                 let checked_utxo = match self.chain_monitor.get_chain_utxo(msg.contents.chain_hash, msg.contents.short_channel_id) {
 276                         Ok((script_pubkey, _value)) => {
 277                                 let expected_script = Builder::new().push_opcode(opcodes::All::OP_PUSHNUM_2)
 278                                                                     .push_slice(&msg.contents.bitcoin_key_1.serialize())
 279                                                                     .push_slice(&msg.contents.bitcoin_key_2.serialize())
 280                                                                     .push_opcode(opcodes::All::OP_PUSHNUM_2).push_opcode(opcodes::All::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
 281                                 if script_pubkey != expected_script {
 282                                         return Err(HandleError{err: "Channel announcement keys didn't match on-chain script", action: Some(ErrorAction::IgnoreError)});
 283                                 }
 284                                 //TODO: Check if value is worth storing, use it to inform routing, and compare it
 285                                 //to the new HTLC max field in channel_update
 286                                 true
 287                         },
 288                         Err(ChainError::NotSupported) => {
 289                                 // Tentatively accept, potentially exposing us to DoS attacks
 290                                 false
 291                         },
 292                         Err(ChainError::NotWatched) => {
 293                                 return Err(HandleError{err: "Channel announced on an unknown chain", action: Some(ErrorAction::IgnoreError)});
 294                         },
 295                         Err(ChainError::UnknownTx) => {
 296                                 return Err(HandleError{err: "Channel announced without corresponding UTXO entry", action: Some(ErrorAction::IgnoreError)});
 297                         },
 298                 };
 299
 300                 let mut network_lock = self.network_map.write().unwrap();
 301                 let network = network_lock.borrow_parts();
 302
 303                 let chan_info = ChannelInfo {
 304                                 features: msg.contents.features.clone(),
 305                                 one_to_two: DirectionalChannelInfo {
 306                                         src_node_id: msg.contents.node_id_1.clone(),
 307                                         last_update: 0,
 308                                         enabled: false,
 309                                         cltv_expiry_delta: u16::max_value(),
 310                                         htlc_minimum_msat: u64::max_value(),
 311                                         fee_base_msat: u32::max_value(),
 312                                         fee_proportional_millionths: u32::max_value(),
 313                                 },
 314                                 two_to_one: DirectionalChannelInfo {
 315                                         src_node_id: msg.contents.node_id_2.clone(),
 316                                         last_update: 0,
 317                                         enabled: false,
 318                                         cltv_expiry_delta: u16::max_value(),
 319                                         htlc_minimum_msat: u64::max_value(),
 320                                         fee_base_msat: u32::max_value(),
 321                                         fee_proportional_millionths: u32::max_value(),
 322                                 }
 323                         };
 324
 325                 match network.channels.entry(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 326                         Entry::Occupied(mut entry) => {
 327                                 //TODO: because asking the blockchain if short_channel_id is valid is only optional
 328                                 //in the blockchain API, we need to handle it smartly here, though its unclear
 329                                 //exactly how...
 330                                 if checked_utxo {
 331                                         // Either our UTXO provider is busted, there was a reorg, or the UTXO provider
 332                                         // only sometimes returns results. In any case remove the previous entry. Note
 333                                         // that the spec expects us to "blacklist" the node_ids involved, but we can't
 334                                         // do that because
 335                                         // a) we don't *require* a UTXO provider that always returns results.
 336                                         // b) we don't track UTXOs of channels we know about and remove them if they
 337                                         //    get reorg'd out.
 338                                         // c) it's unclear how to do so without exposing ourselves to massive DoS risk.
 339                                         Self::remove_channel_in_nodes(network.nodes, &entry.get(), msg.contents.short_channel_id);
 340                                         *entry.get_mut() = chan_info;
 341                                 } else {
 342                                         return Err(HandleError{err: "Already have knowledge of channel", action: Some(ErrorAction::IgnoreError)})
 343                                 }
 344                         },
 345                         Entry::Vacant(entry) => {
 346                                 entry.insert(chan_info);
 347                         }
 348                 };
 349
 350                 macro_rules! add_channel_to_node {
 351                         ( $node_id: expr ) => {
 352                                 match network.nodes.entry($node_id) {
 353                                         Entry::Occupied(node_entry) => {
 354                                                 node_entry.into_mut().channels.push(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash));
 355                                         },
 356                                         Entry::Vacant(node_entry) => {
 357                                                 node_entry.insert(NodeInfo {
 358                                                         channels: vec!(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)),
 359                                                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 360                                                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 361                                                         features: GlobalFeatures::new(),
 362                                                         last_update: 0,
 363                                                         rgb: [0; 3],
 364                                                         alias: [0; 32],
 365                                                         addresses: Vec::new(),
 366                                                 });
 367                                         }
 368                                 }
 369                         };
 370                 }
 371
 372                 add_channel_to_node!(msg.contents.node_id_1);
 373                 add_channel_to_node!(msg.contents.node_id_2);
 374
 375                 Ok(msg.contents.excess_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 376         }
 377
 378         fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
 379                 match update {
 380                         &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
 381                                 let _ = self.handle_channel_update(msg);
 382                         },
 383                         &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id, ref is_permanent } => {
 384                                 let mut network = self.network_map.write().unwrap();
 385                                 if *is_permanent {
 386                                         if let Some(chan) = network.channels.remove(short_channel_id) {
 387                                                 Self::remove_channel_in_nodes(&mut network.nodes, &chan, *short_channel_id);
 388                                         }
 389                                 } else {
 390                                         if let Some(chan) = network.channels.get_mut(short_channel_id) {
 391                                                 chan.one_to_two.enabled = false;
 392                                                 chan.two_to_one.enabled = false;
 393                                         }
 394                                 }
 395                         },
 396                         &msgs::HTLCFailChannelUpdate::NodeFailure { ref node_id, ref is_permanent } => {
 397                                 if *is_permanent {
 398                                         //TODO: Wholly remove the node
 399                                 } else {
 400                                         self.mark_node_bad(node_id, false);
 401                                 }
 402                         },
 403                 }
 404         }
 405
 406         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
 407                 let mut network = self.network_map.write().unwrap();
 408                 let dest_node_id;
 409                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 410                 let chan_was_enabled;
 411
 412                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 413                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 414                         Some(channel) => {
 415                                 macro_rules! maybe_update_channel_info {
 416                                         ( $target: expr) => {
 417                                                 if $target.last_update >= msg.contents.timestamp {
 418                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 419                                                 }
 420                                                 chan_was_enabled = $target.enabled;
 421                                                 $target.last_update = msg.contents.timestamp;
 422                                                 $target.enabled = chan_enabled;
 423                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 424                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 425                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 426                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 427                                         }
 428                                 }
 429
 430                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 431                                 if msg.contents.flags & 1 == 1 {
 432                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 433                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 434                                         maybe_update_channel_info!(channel.two_to_one);
 435                                 } else {
 436                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 437                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 438                                         maybe_update_channel_info!(channel.one_to_two);
 439                                 }
 440                         }
 441                 }
 442
 443                 if chan_enabled {
 444                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 445                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 446                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 447                 } else if chan_was_enabled {
 448                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 449                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 450
 451                         {
 452                                 let node = network.nodes.get(&dest_node_id).unwrap();
 453
 454                                 for chan_id in node.channels.iter() {
 455                                         let chan = network.channels.get(chan_id).unwrap();
 456                                         if chan.one_to_two.src_node_id == dest_node_id {
 457                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 458                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 459                                         } else {
 460                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 461                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 462                                         }
 463                                 }
 464                         }
 465
 466                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 467                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 468                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 469                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 470                 }
 471
 472                 Ok(msg.contents.excess_data.is_empty())
 473         }
 474 }
 475
 476 #[derive(Eq, PartialEq)]
 477 struct RouteGraphNode {
 478         pubkey: PublicKey,
 479         lowest_fee_to_peer_through_node: u64,
 480         lowest_fee_to_node: u64,
 481 }
 482
 483 impl cmp::Ord for RouteGraphNode {
 484         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 485                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 486                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 487         }
 488 }
 489
 490 impl cmp::PartialOrd for RouteGraphNode {
 491         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 492                 Some(self.cmp(other))
 493         }
 494 }
 495
 496 struct DummyDirectionalChannelInfo {
 497         src_node_id: PublicKey,
 498         cltv_expiry_delta: u32,
 499         htlc_minimum_msat: u64,
 500         fee_base_msat: u32,
 501         fee_proportional_millionths: u32,
 502 }
 503
 504 impl Router {
 505         /// Creates a new router with the given node_id to be used as the source for get_route()
 506         pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
 507                 let mut nodes = HashMap::new();
 508                 nodes.insert(our_pubkey.clone(), NodeInfo {
 509                         channels: Vec::new(),
 510                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 511                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 512                         features: GlobalFeatures::new(),
 513                         last_update: 0,
 514                         rgb: [0; 3],
 515                         alias: [0; 32],
 516                         addresses: Vec::new(),
 517                 });
 518                 Router {
 519                         secp_ctx: Secp256k1::verification_only(),
 520                         network_map: RwLock::new(NetworkMap {
 521                                 channels: HashMap::new(),
 522                                 our_node_id: our_pubkey,
 523                                 nodes: nodes,
 524                         }),
 525                         chain_monitor,
 526                         logger,
 527                 }
 528         }
 529
 530         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 531         /// level Trace
 532         pub fn trace_state(&self) {
 533                 log_trace!(self, "{}", self.network_map.read().unwrap());
 534         }
 535
 536         /// Get network addresses by node id
 537         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 538                 let network = self.network_map.read().unwrap();
 539                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 540         }
 541
 542         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 543         /// with an expotnential decay in node "badness". Note that there is deliberately no
 544         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 545         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 546         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 547         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 548         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 549                 unimplemented!();
 550         }
 551
 552         fn remove_channel_in_nodes(nodes: &mut HashMap<PublicKey, NodeInfo>, chan: &ChannelInfo, short_channel_id: u64) {
 553                 macro_rules! remove_from_node {
 554                         ($node_id: expr) => {
 555                                 if let Entry::Occupied(mut entry) = nodes.entry($node_id) {
 556                                         entry.get_mut().channels.retain(|chan_id| {
 557                                                 short_channel_id != *NetworkMap::get_short_id(chan_id)
 558                                         });
 559                                         if entry.get().channels.is_empty() {
 560                                                 entry.remove_entry();
 561                                         }
 562                                 } else {
 563                                         panic!("Had channel that pointed to unknown node (ie inconsistent network map)!");
 564                                 }
 565                         }
 566                 }
 567                 remove_from_node!(chan.one_to_two.src_node_id);
 568                 remove_from_node!(chan.two_to_one.src_node_id);
 569         }
 570
 571         /// Gets a route from us to the given target node.
 572         ///
 573         /// Extra routing hops between known nodes and the target will be used if they are included in
 574         /// last_hops.
 575         ///
 576         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 577         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 578         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 579         /// will be used.
 580         ///
 581         /// Panics if first_hops contains channels without short_channel_ids
 582         /// (ChannelManager::list_usable_channels will never include such channels).
 583         ///
 584         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 585         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 586         /// *is* checked as they may change based on the receiving node.
 587         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> {
 588                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 589                 // uptime/success in using a node in the past.
 590                 let network = self.network_map.read().unwrap();
 591
 592                 if *target == network.our_node_id {
 593                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 594                 }
 595
 596                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 597                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 598                 }
 599
 600                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 601                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 602                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 603                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 604                 // one.
 605
 606                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 607                         src_node_id: network.our_node_id.clone(),
 608                         cltv_expiry_delta: 0,
 609                         htlc_minimum_msat: 0,
 610                         fee_base_msat: 0,
 611                         fee_proportional_millionths: 0,
 612                 };
 613
 614                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 615                 let mut dist = HashMap::with_capacity(network.nodes.len());
 616
 617                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 618                 if let Some(hops) = first_hops {
 619                         for chan in hops {
 620                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 621                                 if chan.remote_network_id == *target {
 622                                         return Ok(Route {
 623                                                 hops: vec![RouteHop {
 624                                                         pubkey: chan.remote_network_id,
 625                                                         short_channel_id,
 626                                                         fee_msat: final_value_msat,
 627                                                         cltv_expiry_delta: final_cltv,
 628                                                 }],
 629                                         });
 630                                 }
 631                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 632                         }
 633                         if first_hop_targets.is_empty() {
 634                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 635                         }
 636                 }
 637
 638                 macro_rules! add_entry {
 639                         // Adds entry which goes from the node pointed to by $directional_info to
 640                         // $dest_node_id over the channel with id $chan_id with fees described in
 641                         // $directional_info.
 642                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 643                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 644                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 645                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 646                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 647                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 648                                         {
 649                                                 let mut total_fee = $starting_fee_msat as u64;
 650                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 651                                                 let old_entry = hm_entry.or_insert_with(|| {
 652                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 653                                                         (u64::max_value(),
 654                                                                 node.lowest_inbound_channel_fee_base_msat,
 655                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 656                                                                 RouteHop {
 657                                                                         pubkey: $dest_node_id.clone(),
 658                                                                         short_channel_id: 0,
 659                                                                         fee_msat: 0,
 660                                                                         cltv_expiry_delta: 0,
 661                                                         })
 662                                                 });
 663                                                 if $directional_info.src_node_id != network.our_node_id {
 664                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 665                                                         // will have the same effective-fee
 666                                                         total_fee += new_fee;
 667                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 668                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 669                                                         } else {
 670                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 671                                                                 total_fee = u64::max_value();
 672                                                         }
 673                                                 }
 674                                                 let new_graph_node = RouteGraphNode {
 675                                                         pubkey: $directional_info.src_node_id,
 676                                                         lowest_fee_to_peer_through_node: total_fee,
 677                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 678                                                 };
 679                                                 if old_entry.0 > total_fee {
 680                                                         targets.push(new_graph_node);
 681                                                         old_entry.0 = total_fee;
 682                                                         old_entry.3 = RouteHop {
 683                                                                 pubkey: $dest_node_id.clone(),
 684                                                                 short_channel_id: $chan_id.clone(),
 685                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 686                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 687                                                         }
 688                                                 }
 689                                         }
 690                                 }
 691                         };
 692                 }
 693
 694                 macro_rules! add_entries_to_cheapest_to_target_node {
 695                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 696                                 if first_hops.is_some() {
 697                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 698                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 699                                         }
 700                                 }
 701
 702                                 for chan_id in $node.channels.iter() {
 703                                         let chan = network.channels.get(chan_id).unwrap();
 704                                         if chan.one_to_two.src_node_id == *$node_id {
 705                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 706                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 707                                                         if chan.two_to_one.enabled {
 708                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 709                                                         }
 710                                                 }
 711                                         } else {
 712                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 713                                                         if chan.one_to_two.enabled {
 714                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 715                                                         }
 716                                                 }
 717                                         }
 718                                 }
 719                         };
 720                 }
 721
 722                 match network.nodes.get(target) {
 723                         None => {},
 724                         Some(node) => {
 725                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 726                         },
 727                 }
 728
 729                 for hop in last_hops.iter() {
 730                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 731                                 if network.nodes.get(&hop.src_node_id).is_some() {
 732                                         if first_hops.is_some() {
 733                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 734                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 735                                                 }
 736                                         }
 737                                         add_entry!(hop.short_channel_id, target, hop, 0);
 738                                 }
 739                         }
 740                 }
 741
 742                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 743                         if pubkey == network.our_node_id {
 744                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 745                                 while res.last().unwrap().pubkey != *target {
 746                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 747                                                 Some(hop) => hop.3,
 748                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 749                                         };
 750                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 751                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 752                                         res.push(new_entry);
 753                                 }
 754                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 755                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 756                                 let route = Route { hops: res };
 757                                 log_trace!(self, "Got route: {}", log_route!(route));
 758                                 return Ok(route);
 759                         }
 760
 761                         match network.nodes.get(&pubkey) {
 762                                 None => {},
 763                                 Some(node) => {
 764                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 765                                 },
 766                         }
 767                 }
 768
 769                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 770         }
 771 }
 772
 773 #[cfg(test)]
 774 mod tests {
 775         use chain::chaininterface;
 776         use ln::channelmanager;
 777         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 778         use ln::msgs::GlobalFeatures;
 779         use util::test_utils;
 780         use util::logger::Logger;
 781
 782         use bitcoin::util::hash::Sha256dHash;
 783         use bitcoin::network::constants::Network;
 784
 785         use hex;
 786
 787         use secp256k1::key::{PublicKey,SecretKey};
 788         use secp256k1::Secp256k1;
 789
 790         use std::sync::Arc;
 791
 792         #[test]
 793         fn route_test() {
 794                 let secp_ctx = Secp256k1::new();
 795                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 796                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 797                 let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
 798                 let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 799
 800                 // Build network from our_id to node8:
 801                 //
 802                 //        -1(1)2-  node1  -1(3)2-
 803                 //       /                       \
 804                 // our_id -1(12)2- node8 -1(13)2--- node3
 805                 //       \                       /
 806                 //        -1(2)2-  node2  -1(4)2-
 807                 //
 808                 //
 809                 // chan1  1-to-2: disabled
 810                 // chan1  2-to-1: enabled, 0 fee
 811                 //
 812                 // chan2  1-to-2: enabled, ignored fee
 813                 // chan2  2-to-1: enabled, 0 fee
 814                 //
 815                 // chan3  1-to-2: enabled, 0 fee
 816                 // chan3  2-to-1: enabled, 100 msat fee
 817                 //
 818                 // chan4  1-to-2: enabled, 100% fee
 819                 // chan4  2-to-1: enabled, 0 fee
 820                 //
 821                 // chan12 1-to-2: enabled, ignored fee
 822                 // chan12 2-to-1: enabled, 0 fee
 823                 //
 824                 // chan13 1-to-2: enabled, 200% fee
 825                 // chan13 2-to-1: enabled, 0 fee
 826                 //
 827                 //
 828                 //       -1(5)2- node4 -1(8)2--
 829                 //       |         2          |
 830                 //       |       (11)         |
 831                 //      /          1           \
 832                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 833                 //      \                      /
 834                 //       -1(7)2- node6 -1(10)2-
 835                 //
 836                 // chan5  1-to-2: enabled, 100 msat fee
 837                 // chan5  2-to-1: enabled, 0 fee
 838                 //
 839                 // chan6  1-to-2: enabled, 0 fee
 840                 // chan6  2-to-1: enabled, 0 fee
 841                 //
 842                 // chan7  1-to-2: enabled, 100% fee
 843                 // chan7  2-to-1: enabled, 0 fee
 844                 //
 845                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 846                 // chan8  2-to-1: enabled, 0 fee
 847                 //
 848                 // chan9  1-to-2: enabled, 1001 msat fee
 849                 // chan9  2-to-1: enabled, 0 fee
 850                 //
 851                 // chan10 1-to-2: enabled, 0 fee
 852                 // chan10 2-to-1: enabled, 0 fee
 853                 //
 854                 // chan11 1-to-2: enabled, 0 fee
 855                 // chan11 2-to-1: enabled, 0 fee
 856
 857                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 858                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 859                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 860                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 861                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 862                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 863                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 864                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 865
 866                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 867
 868                 {
 869                         let mut network = router.network_map.write().unwrap();
 870
 871                         network.nodes.insert(node1.clone(), NodeInfo {
 872                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 873                                 lowest_inbound_channel_fee_base_msat: 100,
 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(1, 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: false,
 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: node1.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(node2.clone(), NodeInfo {
 902                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, 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(2, 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: node2.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(node8.clone(), NodeInfo {
 932                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 933                                 lowest_inbound_channel_fee_base_msat: 0,
 934                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 935                                 features: GlobalFeatures::new(),
 936                                 last_update: 1,
 937                                 rgb: [0; 3],
 938                                 alias: [0; 32],
 939                                 addresses: Vec::new(),
 940                         });
 941                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 942                                 features: GlobalFeatures::new(),
 943                                 one_to_two: DirectionalChannelInfo {
 944                                         src_node_id: our_id.clone(),
 945                                         last_update: 0,
 946                                         enabled: true,
 947                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 948                                         htlc_minimum_msat: 0,
 949                                         fee_base_msat: u32::max_value(), // This value should be ignored
 950                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 951                                 }, two_to_one: DirectionalChannelInfo {
 952                                         src_node_id: node8.clone(),
 953                                         last_update: 0,
 954                                         enabled: true,
 955                                         cltv_expiry_delta: 0,
 956                                         htlc_minimum_msat: 0,
 957                                         fee_base_msat: 0,
 958                                         fee_proportional_millionths: 0,
 959                                 },
 960                         });
 961                         network.nodes.insert(node3.clone(), NodeInfo {
 962                                 channels: vec!(
 963                                         NetworkMap::get_key(3, zero_hash.clone()),
 964                                         NetworkMap::get_key(4, zero_hash.clone()),
 965                                         NetworkMap::get_key(13, zero_hash.clone()),
 966                                         NetworkMap::get_key(5, zero_hash.clone()),
 967                                         NetworkMap::get_key(6, zero_hash.clone()),
 968                                         NetworkMap::get_key(7, zero_hash.clone())),
 969                                 lowest_inbound_channel_fee_base_msat: 0,
 970                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 971                                 features: GlobalFeatures::new(),
 972                                 last_update: 1,
 973                                 rgb: [0; 3],
 974                                 alias: [0; 32],
 975                                 addresses: Vec::new(),
 976                         });
 977                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 978                                 features: GlobalFeatures::new(),
 979                                 one_to_two: DirectionalChannelInfo {
 980                                         src_node_id: node1.clone(),
 981                                         last_update: 0,
 982                                         enabled: true,
 983                                         cltv_expiry_delta: (3 << 8) | 1,
 984                                         htlc_minimum_msat: 0,
 985                                         fee_base_msat: 0,
 986                                         fee_proportional_millionths: 0,
 987                                 }, two_to_one: DirectionalChannelInfo {
 988                                         src_node_id: node3.clone(),
 989                                         last_update: 0,
 990                                         enabled: true,
 991                                         cltv_expiry_delta: (3 << 8) | 2,
 992                                         htlc_minimum_msat: 0,
 993                                         fee_base_msat: 100,
 994                                         fee_proportional_millionths: 0,
 995                                 },
 996                         });
 997                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 998                                 features: GlobalFeatures::new(),
 999                                 one_to_two: DirectionalChannelInfo {
1000                                         src_node_id: node2.clone(),
1001                                         last_update: 0,
1002                                         enabled: true,
1003                                         cltv_expiry_delta: (4 << 8) | 1,
1004                                         htlc_minimum_msat: 0,
1005                                         fee_base_msat: 0,
1006                                         fee_proportional_millionths: 1000000,
1007                                 }, two_to_one: DirectionalChannelInfo {
1008                                         src_node_id: node3.clone(),
1009                                         last_update: 0,
1010                                         enabled: true,
1011                                         cltv_expiry_delta: (4 << 8) | 2,
1012                                         htlc_minimum_msat: 0,
1013                                         fee_base_msat: 0,
1014                                         fee_proportional_millionths: 0,
1015                                 },
1016                         });
1017                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
1018                                 features: GlobalFeatures::new(),
1019                                 one_to_two: DirectionalChannelInfo {
1020                                         src_node_id: node8.clone(),
1021                                         last_update: 0,
1022                                         enabled: true,
1023                                         cltv_expiry_delta: (13 << 8) | 1,
1024                                         htlc_minimum_msat: 0,
1025                                         fee_base_msat: 0,
1026                                         fee_proportional_millionths: 2000000,
1027                                 }, two_to_one: DirectionalChannelInfo {
1028                                         src_node_id: node3.clone(),
1029                                         last_update: 0,
1030                                         enabled: true,
1031                                         cltv_expiry_delta: (13 << 8) | 2,
1032                                         htlc_minimum_msat: 0,
1033                                         fee_base_msat: 0,
1034                                         fee_proportional_millionths: 0,
1035                                 },
1036                         });
1037                         network.nodes.insert(node4.clone(), NodeInfo {
1038                                 channels: vec!(NetworkMap::get_key(5, 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(5, 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: (5 << 8) | 1,
1054                                         htlc_minimum_msat: 0,
1055                                         fee_base_msat: 100,
1056                                         fee_proportional_millionths: 0,
1057                                 }, two_to_one: DirectionalChannelInfo {
1058                                         src_node_id: node4.clone(),
1059                                         last_update: 0,
1060                                         enabled: true,
1061                                         cltv_expiry_delta: (5 << 8) | 2,
1062                                         htlc_minimum_msat: 0,
1063                                         fee_base_msat: 0,
1064                                         fee_proportional_millionths: 0,
1065                                 },
1066                         });
1067                         network.nodes.insert(node5.clone(), NodeInfo {
1068                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
1069                                 lowest_inbound_channel_fee_base_msat: 0,
1070                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1071                                 features: GlobalFeatures::new(),
1072                                 last_update: 1,
1073                                 rgb: [0; 3],
1074                                 alias: [0; 32],
1075                                 addresses: Vec::new(),
1076                         });
1077                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
1078                                 features: GlobalFeatures::new(),
1079                                 one_to_two: DirectionalChannelInfo {
1080                                         src_node_id: node3.clone(),
1081                                         last_update: 0,
1082                                         enabled: true,
1083                                         cltv_expiry_delta: (6 << 8) | 1,
1084                                         htlc_minimum_msat: 0,
1085                                         fee_base_msat: 0,
1086                                         fee_proportional_millionths: 0,
1087                                 }, two_to_one: DirectionalChannelInfo {
1088                                         src_node_id: node5.clone(),
1089                                         last_update: 0,
1090                                         enabled: true,
1091                                         cltv_expiry_delta: (6 << 8) | 2,
1092                                         htlc_minimum_msat: 0,
1093                                         fee_base_msat: 0,
1094                                         fee_proportional_millionths: 0,
1095                                 },
1096                         });
1097                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
1098                                 features: GlobalFeatures::new(),
1099                                 one_to_two: DirectionalChannelInfo {
1100                                         src_node_id: node5.clone(),
1101                                         last_update: 0,
1102                                         enabled: true,
1103                                         cltv_expiry_delta: (11 << 8) | 1,
1104                                         htlc_minimum_msat: 0,
1105                                         fee_base_msat: 0,
1106                                         fee_proportional_millionths: 0,
1107                                 }, two_to_one: DirectionalChannelInfo {
1108                                         src_node_id: node4.clone(),
1109                                         last_update: 0,
1110                                         enabled: true,
1111                                         cltv_expiry_delta: (11 << 8) | 2,
1112                                         htlc_minimum_msat: 0,
1113                                         fee_base_msat: 0,
1114                                         fee_proportional_millionths: 0,
1115                                 },
1116                         });
1117                         network.nodes.insert(node6.clone(), NodeInfo {
1118                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
1119                                 lowest_inbound_channel_fee_base_msat: 0,
1120                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1121                                 features: GlobalFeatures::new(),
1122                                 last_update: 1,
1123                                 rgb: [0; 3],
1124                                 alias: [0; 32],
1125                                 addresses: Vec::new(),
1126                         });
1127                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
1128                                 features: GlobalFeatures::new(),
1129                                 one_to_two: DirectionalChannelInfo {
1130                                         src_node_id: node3.clone(),
1131                                         last_update: 0,
1132                                         enabled: true,
1133                                         cltv_expiry_delta: (7 << 8) | 1,
1134                                         htlc_minimum_msat: 0,
1135                                         fee_base_msat: 0,
1136                                         fee_proportional_millionths: 1000000,
1137                                 }, two_to_one: DirectionalChannelInfo {
1138                                         src_node_id: node6.clone(),
1139                                         last_update: 0,
1140                                         enabled: true,
1141                                         cltv_expiry_delta: (7 << 8) | 2,
1142                                         htlc_minimum_msat: 0,
1143                                         fee_base_msat: 0,
1144                                         fee_proportional_millionths: 0,
1145                                 },
1146                         });
1147                 }
1148
1149                 { // Simple route to 3 via 2
1150                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1151                         assert_eq!(route.hops.len(), 2);
1152
1153                         assert_eq!(route.hops[0].pubkey, node2);
1154                         assert_eq!(route.hops[0].short_channel_id, 2);
1155                         assert_eq!(route.hops[0].fee_msat, 100);
1156                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1157
1158                         assert_eq!(route.hops[1].pubkey, node3);
1159                         assert_eq!(route.hops[1].short_channel_id, 4);
1160                         assert_eq!(route.hops[1].fee_msat, 100);
1161                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1162                 }
1163
1164                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1165                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1166                         assert_eq!(route.hops.len(), 3);
1167
1168                         assert_eq!(route.hops[0].pubkey, node2);
1169                         assert_eq!(route.hops[0].short_channel_id, 2);
1170                         assert_eq!(route.hops[0].fee_msat, 200);
1171                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1172
1173                         assert_eq!(route.hops[1].pubkey, node3);
1174                         assert_eq!(route.hops[1].short_channel_id, 4);
1175                         assert_eq!(route.hops[1].fee_msat, 100);
1176                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1177
1178                         assert_eq!(route.hops[2].pubkey, node1);
1179                         assert_eq!(route.hops[2].short_channel_id, 3);
1180                         assert_eq!(route.hops[2].fee_msat, 100);
1181                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1182                 }
1183
1184                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1185                         let our_chans = vec![channelmanager::ChannelDetails {
1186                                 channel_id: [0; 32],
1187                                 short_channel_id: Some(42),
1188                                 remote_network_id: node8.clone(),
1189                                 channel_value_satoshis: 0,
1190                                 user_id: 0,
1191                         }];
1192                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1193                         assert_eq!(route.hops.len(), 2);
1194
1195                         assert_eq!(route.hops[0].pubkey, node8);
1196                         assert_eq!(route.hops[0].short_channel_id, 42);
1197                         assert_eq!(route.hops[0].fee_msat, 200);
1198                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1199
1200                         assert_eq!(route.hops[1].pubkey, node3);
1201                         assert_eq!(route.hops[1].short_channel_id, 13);
1202                         assert_eq!(route.hops[1].fee_msat, 100);
1203                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1204                 }
1205
1206                 let mut last_hops = vec!(RouteHint {
1207                                 src_node_id: node4.clone(),
1208                                 short_channel_id: 8,
1209                                 fee_base_msat: 0,
1210                                 fee_proportional_millionths: 0,
1211                                 cltv_expiry_delta: (8 << 8) | 1,
1212                                 htlc_minimum_msat: 0,
1213                         }, RouteHint {
1214                                 src_node_id: node5.clone(),
1215                                 short_channel_id: 9,
1216                                 fee_base_msat: 1001,
1217                                 fee_proportional_millionths: 0,
1218                                 cltv_expiry_delta: (9 << 8) | 1,
1219                                 htlc_minimum_msat: 0,
1220                         }, RouteHint {
1221                                 src_node_id: node6.clone(),
1222                                 short_channel_id: 10,
1223                                 fee_base_msat: 0,
1224                                 fee_proportional_millionths: 0,
1225                                 cltv_expiry_delta: (10 << 8) | 1,
1226                                 htlc_minimum_msat: 0,
1227                         });
1228
1229                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1230                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1231                         assert_eq!(route.hops.len(), 5);
1232
1233                         assert_eq!(route.hops[0].pubkey, node2);
1234                         assert_eq!(route.hops[0].short_channel_id, 2);
1235                         assert_eq!(route.hops[0].fee_msat, 100);
1236                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1237
1238                         assert_eq!(route.hops[1].pubkey, node3);
1239                         assert_eq!(route.hops[1].short_channel_id, 4);
1240                         assert_eq!(route.hops[1].fee_msat, 0);
1241                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1242
1243                         assert_eq!(route.hops[2].pubkey, node5);
1244                         assert_eq!(route.hops[2].short_channel_id, 6);
1245                         assert_eq!(route.hops[2].fee_msat, 0);
1246                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1247
1248                         assert_eq!(route.hops[3].pubkey, node4);
1249                         assert_eq!(route.hops[3].short_channel_id, 11);
1250                         assert_eq!(route.hops[3].fee_msat, 0);
1251                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1252
1253                         assert_eq!(route.hops[4].pubkey, node7);
1254                         assert_eq!(route.hops[4].short_channel_id, 8);
1255                         assert_eq!(route.hops[4].fee_msat, 100);
1256                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1257                 }
1258
1259                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1260                         let our_chans = vec![channelmanager::ChannelDetails {
1261                                 channel_id: [0; 32],
1262                                 short_channel_id: Some(42),
1263                                 remote_network_id: node4.clone(),
1264                                 channel_value_satoshis: 0,
1265                                 user_id: 0,
1266                         }];
1267                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1268                         assert_eq!(route.hops.len(), 2);
1269
1270                         assert_eq!(route.hops[0].pubkey, node4);
1271                         assert_eq!(route.hops[0].short_channel_id, 42);
1272                         assert_eq!(route.hops[0].fee_msat, 0);
1273                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1274
1275                         assert_eq!(route.hops[1].pubkey, node7);
1276                         assert_eq!(route.hops[1].short_channel_id, 8);
1277                         assert_eq!(route.hops[1].fee_msat, 100);
1278                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1279                 }
1280
1281                 last_hops[0].fee_base_msat = 1000;
1282
1283                 { // Revert to via 6 as the fee on 8 goes up
1284                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1285                         assert_eq!(route.hops.len(), 4);
1286
1287                         assert_eq!(route.hops[0].pubkey, node2);
1288                         assert_eq!(route.hops[0].short_channel_id, 2);
1289                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1290                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1291
1292                         assert_eq!(route.hops[1].pubkey, node3);
1293                         assert_eq!(route.hops[1].short_channel_id, 4);
1294                         assert_eq!(route.hops[1].fee_msat, 100);
1295                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1296
1297                         assert_eq!(route.hops[2].pubkey, node6);
1298                         assert_eq!(route.hops[2].short_channel_id, 7);
1299                         assert_eq!(route.hops[2].fee_msat, 0);
1300                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1301
1302                         assert_eq!(route.hops[3].pubkey, node7);
1303                         assert_eq!(route.hops[3].short_channel_id, 10);
1304                         assert_eq!(route.hops[3].fee_msat, 100);
1305                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1306                 }
1307
1308                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1309                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1310                         assert_eq!(route.hops.len(), 5);
1311
1312                         assert_eq!(route.hops[0].pubkey, node2);
1313                         assert_eq!(route.hops[0].short_channel_id, 2);
1314                         assert_eq!(route.hops[0].fee_msat, 3000);
1315                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1316
1317                         assert_eq!(route.hops[1].pubkey, node3);
1318                         assert_eq!(route.hops[1].short_channel_id, 4);
1319                         assert_eq!(route.hops[1].fee_msat, 0);
1320                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1321
1322                         assert_eq!(route.hops[2].pubkey, node5);
1323                         assert_eq!(route.hops[2].short_channel_id, 6);
1324                         assert_eq!(route.hops[2].fee_msat, 0);
1325                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1326
1327                         assert_eq!(route.hops[3].pubkey, node4);
1328                         assert_eq!(route.hops[3].short_channel_id, 11);
1329                         assert_eq!(route.hops[3].fee_msat, 1000);
1330                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1331
1332                         assert_eq!(route.hops[4].pubkey, node7);
1333                         assert_eq!(route.hops[4].short_channel_id, 8);
1334                         assert_eq!(route.hops[4].fee_msat, 2000);
1335                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1336                 }
1337         }
1338 }