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

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