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

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