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

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