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