_ 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                                         network.nodes.get_mut(&chan.one_to_two.src_node_id).unwrap().channels.retain(|chan_id| {
 310                                                 chan_id != NetworkMap::get_short_id(chan_id)
 311                                         });
 312                                         network.nodes.get_mut(&chan.two_to_one.src_node_id).unwrap().channels.retain(|chan_id| {
 313                                                 chan_id != NetworkMap::get_short_id(chan_id)
 314                                         });
 315                                 }
 316                         },
 317                 }
 318         }
 319
 320         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
 321                 let mut network = self.network_map.write().unwrap();
 322                 let dest_node_id;
 323                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 324                 let chan_was_enabled;
 325
 326                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 327                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 328                         Some(channel) => {
 329                                 macro_rules! maybe_update_channel_info {
 330                                         ( $target: expr) => {
 331                                                 if $target.last_update >= msg.contents.timestamp {
 332                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 333                                                 }
 334                                                 chan_was_enabled = $target.enabled;
 335                                                 $target.last_update = msg.contents.timestamp;
 336                                                 $target.enabled = chan_enabled;
 337                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 338                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 339                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 340                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 341                                         }
 342                                 }
 343
 344                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 345                                 if msg.contents.flags & 1 == 1 {
 346                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 347                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 348                                         maybe_update_channel_info!(channel.two_to_one);
 349                                 } else {
 350                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 351                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 352                                         maybe_update_channel_info!(channel.one_to_two);
 353                                 }
 354                         }
 355                 }
 356
 357                 if chan_enabled {
 358                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 359                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 360                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 361                 } else if chan_was_enabled {
 362                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 363                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 364
 365                         {
 366                                 let node = network.nodes.get(&dest_node_id).unwrap();
 367
 368                                 for chan_id in node.channels.iter() {
 369                                         let chan = network.channels.get(chan_id).unwrap();
 370                                         if chan.one_to_two.src_node_id == dest_node_id {
 371                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 372                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 373                                         } else {
 374                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 375                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 376                                         }
 377                                 }
 378                         }
 379
 380                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 381                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 382                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 383                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 384                 }
 385
 386                 Ok(msg.contents.excess_data.is_empty())
 387         }
 388 }
 389
 390 #[derive(Eq, PartialEq)]
 391 struct RouteGraphNode {
 392         pubkey: PublicKey,
 393         lowest_fee_to_peer_through_node: u64,
 394         lowest_fee_to_node: u64,
 395 }
 396
 397 impl cmp::Ord for RouteGraphNode {
 398         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 399                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 400                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 401         }
 402 }
 403
 404 impl cmp::PartialOrd for RouteGraphNode {
 405         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 406                 Some(self.cmp(other))
 407         }
 408 }
 409
 410 struct DummyDirectionalChannelInfo {
 411         src_node_id: PublicKey,
 412         cltv_expiry_delta: u32,
 413         htlc_minimum_msat: u64,
 414         fee_base_msat: u32,
 415         fee_proportional_millionths: u32,
 416 }
 417
 418 impl Router {
 419         pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
 420                 let mut nodes = HashMap::new();
 421                 nodes.insert(our_pubkey.clone(), NodeInfo {
 422                         channels: Vec::new(),
 423                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 424                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 425                         features: GlobalFeatures::new(),
 426                         last_update: 0,
 427                         rgb: [0; 3],
 428                         alias: [0; 32],
 429                         addresses: Vec::new(),
 430                 });
 431                 Router {
 432                         secp_ctx: Secp256k1::verification_only(),
 433                         network_map: RwLock::new(NetworkMap {
 434                                 channels: HashMap::new(),
 435                                 our_node_id: our_pubkey,
 436                                 nodes: nodes,
 437                         }),
 438                         chain_monitor,
 439                         logger,
 440                 }
 441         }
 442
 443         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 444         /// level Trace
 445         pub fn trace_state(&self) {
 446                 log_trace!(self, "{}", self.network_map.read().unwrap());
 447         }
 448
 449         /// Get network addresses by node id
 450         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 451                 let network = self.network_map.read().unwrap();
 452                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 453         }
 454
 455         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 456         /// with an expotnential decay in node "badness". Note that there is deliberately no
 457         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 458         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 459         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 460         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 461         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 462                 unimplemented!();
 463         }
 464
 465         /// Gets a route from us to the given target node.
 466         /// Extra routing hops between known nodes and the target will be used if they are included in
 467         /// last_hops.
 468         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 469         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 470         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 471         /// will be used. Panics if first_hops contains channels without short_channel_ids
 472         /// (ChannelManager::list_usable_channels will never include such channels).
 473         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 474         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 475         /// *is* checked as they may change based on the receiving node.
 476         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> {
 477                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 478                 // uptime/success in using a node in the past.
 479                 let network = self.network_map.read().unwrap();
 480
 481                 if *target == network.our_node_id {
 482                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 483                 }
 484
 485                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 486                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 487                 }
 488
 489                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 490                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 491                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 492                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 493                 // one.
 494
 495                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 496                         src_node_id: network.our_node_id.clone(),
 497                         cltv_expiry_delta: 0,
 498                         htlc_minimum_msat: 0,
 499                         fee_base_msat: 0,
 500                         fee_proportional_millionths: 0,
 501                 };
 502
 503                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 504                 let mut dist = HashMap::with_capacity(network.nodes.len());
 505
 506                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 507                 if let Some(hops) = first_hops {
 508                         for chan in hops {
 509                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 510                                 if chan.remote_network_id == *target {
 511                                         return Ok(Route {
 512                                                 hops: vec![RouteHop {
 513                                                         pubkey: chan.remote_network_id,
 514                                                         short_channel_id,
 515                                                         fee_msat: final_value_msat,
 516                                                         cltv_expiry_delta: final_cltv,
 517                                                 }],
 518                                         });
 519                                 }
 520                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 521                         }
 522                         if first_hop_targets.is_empty() {
 523                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 524                         }
 525                 }
 526
 527                 macro_rules! add_entry {
 528                         // Adds entry which goes from the node pointed to by $directional_info to
 529                         // $dest_node_id over the channel with id $chan_id with fees described in
 530                         // $directional_info.
 531                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 532                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 533                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 534                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 535                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 536                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 537                                         {
 538                                                 let mut total_fee = $starting_fee_msat as u64;
 539                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 540                                                 let old_entry = hm_entry.or_insert_with(|| {
 541                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 542                                                         (u64::max_value(),
 543                                                                 node.lowest_inbound_channel_fee_base_msat,
 544                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 545                                                                 RouteHop {
 546                                                                         pubkey: $dest_node_id.clone(),
 547                                                                         short_channel_id: 0,
 548                                                                         fee_msat: 0,
 549                                                                         cltv_expiry_delta: 0,
 550                                                         })
 551                                                 });
 552                                                 if $directional_info.src_node_id != network.our_node_id {
 553                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 554                                                         // will have the same effective-fee
 555                                                         total_fee += new_fee;
 556                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 557                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 558                                                         } else {
 559                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 560                                                                 total_fee = u64::max_value();
 561                                                         }
 562                                                 }
 563                                                 let new_graph_node = RouteGraphNode {
 564                                                         pubkey: $directional_info.src_node_id,
 565                                                         lowest_fee_to_peer_through_node: total_fee,
 566                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 567                                                 };
 568                                                 if old_entry.0 > total_fee {
 569                                                         targets.push(new_graph_node);
 570                                                         old_entry.0 = total_fee;
 571                                                         old_entry.3 = RouteHop {
 572                                                                 pubkey: $dest_node_id.clone(),
 573                                                                 short_channel_id: $chan_id.clone(),
 574                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 575                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 576                                                         }
 577                                                 }
 578                                         }
 579                                 }
 580                         };
 581                 }
 582
 583                 macro_rules! add_entries_to_cheapest_to_target_node {
 584                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 585                                 if first_hops.is_some() {
 586                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 587                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 588                                         }
 589                                 }
 590
 591                                 for chan_id in $node.channels.iter() {
 592                                         let chan = network.channels.get(chan_id).unwrap();
 593                                         if chan.one_to_two.src_node_id == *$node_id {
 594                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 595                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 596                                                         if chan.two_to_one.enabled {
 597                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 598                                                         }
 599                                                 }
 600                                         } else {
 601                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 602                                                         if chan.one_to_two.enabled {
 603                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 604                                                         }
 605                                                 }
 606                                         }
 607                                 }
 608                         };
 609                 }
 610
 611                 match network.nodes.get(target) {
 612                         None => {},
 613                         Some(node) => {
 614                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 615                         },
 616                 }
 617
 618                 for hop in last_hops.iter() {
 619                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 620                                 if network.nodes.get(&hop.src_node_id).is_some() {
 621                                         if first_hops.is_some() {
 622                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 623                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 624                                                 }
 625                                         }
 626                                         add_entry!(hop.short_channel_id, target, hop, 0);
 627                                 }
 628                         }
 629                 }
 630
 631                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 632                         if pubkey == network.our_node_id {
 633                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 634                                 while res.last().unwrap().pubkey != *target {
 635                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 636                                                 Some(hop) => hop.3,
 637                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 638                                         };
 639                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 640                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 641                                         res.push(new_entry);
 642                                 }
 643                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 644                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 645                                 let route = Route { hops: res };
 646                                 log_trace!(self, "Got route: {}", log_route!(route));
 647                                 return Ok(route);
 648                         }
 649
 650                         match network.nodes.get(&pubkey) {
 651                                 None => {},
 652                                 Some(node) => {
 653                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 654                                 },
 655                         }
 656                 }
 657
 658                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 659         }
 660 }
 661
 662 #[cfg(test)]
 663 mod tests {
 664         use chain::chaininterface;
 665         use ln::channelmanager;
 666         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 667         use ln::msgs::GlobalFeatures;
 668         use util::test_utils;
 669         use util::logger::Logger;
 670
 671         use bitcoin::util::hash::Sha256dHash;
 672         use bitcoin::network::constants::Network;
 673
 674         use hex;
 675
 676         use secp256k1::key::{PublicKey,SecretKey};
 677         use secp256k1::Secp256k1;
 678
 679         use std::sync::Arc;
 680
 681         #[test]
 682         fn route_test() {
 683                 let secp_ctx = Secp256k1::new();
 684                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 685                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 686                 let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
 687                 let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 688
 689                 // Build network from our_id to node8:
 690                 //
 691                 //        -1(1)2-  node1  -1(3)2-
 692                 //       /                       \
 693                 // our_id -1(12)2- node8 -1(13)2--- node3
 694                 //       \                       /
 695                 //        -1(2)2-  node2  -1(4)2-
 696                 //
 697                 //
 698                 // chan1  1-to-2: disabled
 699                 // chan1  2-to-1: enabled, 0 fee
 700                 //
 701                 // chan2  1-to-2: enabled, ignored fee
 702                 // chan2  2-to-1: enabled, 0 fee
 703                 //
 704                 // chan3  1-to-2: enabled, 0 fee
 705                 // chan3  2-to-1: enabled, 100 msat fee
 706                 //
 707                 // chan4  1-to-2: enabled, 100% fee
 708                 // chan4  2-to-1: enabled, 0 fee
 709                 //
 710                 // chan12 1-to-2: enabled, ignored fee
 711                 // chan12 2-to-1: enabled, 0 fee
 712                 //
 713                 // chan13 1-to-2: enabled, 200% fee
 714                 // chan13 2-to-1: enabled, 0 fee
 715                 //
 716                 //
 717                 //       -1(5)2- node4 -1(8)2--
 718                 //       |         2          |
 719                 //       |       (11)         |
 720                 //      /          1           \
 721                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 722                 //      \                      /
 723                 //       -1(7)2- node6 -1(10)2-
 724                 //
 725                 // chan5  1-to-2: enabled, 100 msat fee
 726                 // chan5  2-to-1: enabled, 0 fee
 727                 //
 728                 // chan6  1-to-2: enabled, 0 fee
 729                 // chan6  2-to-1: enabled, 0 fee
 730                 //
 731                 // chan7  1-to-2: enabled, 100% fee
 732                 // chan7  2-to-1: enabled, 0 fee
 733                 //
 734                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 735                 // chan8  2-to-1: enabled, 0 fee
 736                 //
 737                 // chan9  1-to-2: enabled, 1001 msat fee
 738                 // chan9  2-to-1: enabled, 0 fee
 739                 //
 740                 // chan10 1-to-2: enabled, 0 fee
 741                 // chan10 2-to-1: enabled, 0 fee
 742                 //
 743                 // chan11 1-to-2: enabled, 0 fee
 744                 // chan11 2-to-1: enabled, 0 fee
 745
 746                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 747                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 748                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 749                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 750                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 751                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 752                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 753                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 754
 755                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 756
 757                 {
 758                         let mut network = router.network_map.write().unwrap();
 759
 760                         network.nodes.insert(node1.clone(), NodeInfo {
 761                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 762                                 lowest_inbound_channel_fee_base_msat: 100,
 763                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 764                                 features: GlobalFeatures::new(),
 765                                 last_update: 1,
 766                                 rgb: [0; 3],
 767                                 alias: [0; 32],
 768                                 addresses: Vec::new(),
 769                         });
 770                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 771                                 features: GlobalFeatures::new(),
 772                                 one_to_two: DirectionalChannelInfo {
 773                                         src_node_id: our_id.clone(),
 774                                         last_update: 0,
 775                                         enabled: false,
 776                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 777                                         htlc_minimum_msat: 0,
 778                                         fee_base_msat: u32::max_value(), // This value should be ignored
 779                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 780                                 }, two_to_one: DirectionalChannelInfo {
 781                                         src_node_id: node1.clone(),
 782                                         last_update: 0,
 783                                         enabled: true,
 784                                         cltv_expiry_delta: 0,
 785                                         htlc_minimum_msat: 0,
 786                                         fee_base_msat: 0,
 787                                         fee_proportional_millionths: 0,
 788                                 },
 789                         });
 790                         network.nodes.insert(node2.clone(), NodeInfo {
 791                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 792                                 lowest_inbound_channel_fee_base_msat: 0,
 793                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 794                                 features: GlobalFeatures::new(),
 795                                 last_update: 1,
 796                                 rgb: [0; 3],
 797                                 alias: [0; 32],
 798                                 addresses: Vec::new(),
 799                         });
 800                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 801                                 features: GlobalFeatures::new(),
 802                                 one_to_two: DirectionalChannelInfo {
 803                                         src_node_id: our_id.clone(),
 804                                         last_update: 0,
 805                                         enabled: true,
 806                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 807                                         htlc_minimum_msat: 0,
 808                                         fee_base_msat: u32::max_value(), // This value should be ignored
 809                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 810                                 }, two_to_one: DirectionalChannelInfo {
 811                                         src_node_id: node2.clone(),
 812                                         last_update: 0,
 813                                         enabled: true,
 814                                         cltv_expiry_delta: 0,
 815                                         htlc_minimum_msat: 0,
 816                                         fee_base_msat: 0,
 817                                         fee_proportional_millionths: 0,
 818                                 },
 819                         });
 820                         network.nodes.insert(node8.clone(), NodeInfo {
 821                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 822                                 lowest_inbound_channel_fee_base_msat: 0,
 823                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 824                                 features: GlobalFeatures::new(),
 825                                 last_update: 1,
 826                                 rgb: [0; 3],
 827                                 alias: [0; 32],
 828                                 addresses: Vec::new(),
 829                         });
 830                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 831                                 features: GlobalFeatures::new(),
 832                                 one_to_two: DirectionalChannelInfo {
 833                                         src_node_id: our_id.clone(),
 834                                         last_update: 0,
 835                                         enabled: true,
 836                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 837                                         htlc_minimum_msat: 0,
 838                                         fee_base_msat: u32::max_value(), // This value should be ignored
 839                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 840                                 }, two_to_one: DirectionalChannelInfo {
 841                                         src_node_id: node8.clone(),
 842                                         last_update: 0,
 843                                         enabled: true,
 844                                         cltv_expiry_delta: 0,
 845                                         htlc_minimum_msat: 0,
 846                                         fee_base_msat: 0,
 847                                         fee_proportional_millionths: 0,
 848                                 },
 849                         });
 850                         network.nodes.insert(node3.clone(), NodeInfo {
 851                                 channels: vec!(
 852                                         NetworkMap::get_key(3, zero_hash.clone()),
 853                                         NetworkMap::get_key(4, zero_hash.clone()),
 854                                         NetworkMap::get_key(13, zero_hash.clone()),
 855                                         NetworkMap::get_key(5, zero_hash.clone()),
 856                                         NetworkMap::get_key(6, zero_hash.clone()),
 857                                         NetworkMap::get_key(7, zero_hash.clone())),
 858                                 lowest_inbound_channel_fee_base_msat: 0,
 859                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 860                                 features: GlobalFeatures::new(),
 861                                 last_update: 1,
 862                                 rgb: [0; 3],
 863                                 alias: [0; 32],
 864                                 addresses: Vec::new(),
 865                         });
 866                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 867                                 features: GlobalFeatures::new(),
 868                                 one_to_two: DirectionalChannelInfo {
 869                                         src_node_id: node1.clone(),
 870                                         last_update: 0,
 871                                         enabled: true,
 872                                         cltv_expiry_delta: (3 << 8) | 1,
 873                                         htlc_minimum_msat: 0,
 874                                         fee_base_msat: 0,
 875                                         fee_proportional_millionths: 0,
 876                                 }, two_to_one: DirectionalChannelInfo {
 877                                         src_node_id: node3.clone(),
 878                                         last_update: 0,
 879                                         enabled: true,
 880                                         cltv_expiry_delta: (3 << 8) | 2,
 881                                         htlc_minimum_msat: 0,
 882                                         fee_base_msat: 100,
 883                                         fee_proportional_millionths: 0,
 884                                 },
 885                         });
 886                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 887                                 features: GlobalFeatures::new(),
 888                                 one_to_two: DirectionalChannelInfo {
 889                                         src_node_id: node2.clone(),
 890                                         last_update: 0,
 891                                         enabled: true,
 892                                         cltv_expiry_delta: (4 << 8) | 1,
 893                                         htlc_minimum_msat: 0,
 894                                         fee_base_msat: 0,
 895                                         fee_proportional_millionths: 1000000,
 896                                 }, two_to_one: DirectionalChannelInfo {
 897                                         src_node_id: node3.clone(),
 898                                         last_update: 0,
 899                                         enabled: true,
 900                                         cltv_expiry_delta: (4 << 8) | 2,
 901                                         htlc_minimum_msat: 0,
 902                                         fee_base_msat: 0,
 903                                         fee_proportional_millionths: 0,
 904                                 },
 905                         });
 906                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
 907                                 features: GlobalFeatures::new(),
 908                                 one_to_two: DirectionalChannelInfo {
 909                                         src_node_id: node8.clone(),
 910                                         last_update: 0,
 911                                         enabled: true,
 912                                         cltv_expiry_delta: (13 << 8) | 1,
 913                                         htlc_minimum_msat: 0,
 914                                         fee_base_msat: 0,
 915                                         fee_proportional_millionths: 2000000,
 916                                 }, two_to_one: DirectionalChannelInfo {
 917                                         src_node_id: node3.clone(),
 918                                         last_update: 0,
 919                                         enabled: true,
 920                                         cltv_expiry_delta: (13 << 8) | 2,
 921                                         htlc_minimum_msat: 0,
 922                                         fee_base_msat: 0,
 923                                         fee_proportional_millionths: 0,
 924                                 },
 925                         });
 926                         network.nodes.insert(node4.clone(), NodeInfo {
 927                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 928                                 lowest_inbound_channel_fee_base_msat: 0,
 929                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 930                                 features: GlobalFeatures::new(),
 931                                 last_update: 1,
 932                                 rgb: [0; 3],
 933                                 alias: [0; 32],
 934                                 addresses: Vec::new(),
 935                         });
 936                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
 937                                 features: GlobalFeatures::new(),
 938                                 one_to_two: DirectionalChannelInfo {
 939                                         src_node_id: node3.clone(),
 940                                         last_update: 0,
 941                                         enabled: true,
 942                                         cltv_expiry_delta: (5 << 8) | 1,
 943                                         htlc_minimum_msat: 0,
 944                                         fee_base_msat: 100,
 945                                         fee_proportional_millionths: 0,
 946                                 }, two_to_one: DirectionalChannelInfo {
 947                                         src_node_id: node4.clone(),
 948                                         last_update: 0,
 949                                         enabled: true,
 950                                         cltv_expiry_delta: (5 << 8) | 2,
 951                                         htlc_minimum_msat: 0,
 952                                         fee_base_msat: 0,
 953                                         fee_proportional_millionths: 0,
 954                                 },
 955                         });
 956                         network.nodes.insert(node5.clone(), NodeInfo {
 957                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 958                                 lowest_inbound_channel_fee_base_msat: 0,
 959                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 960                                 features: GlobalFeatures::new(),
 961                                 last_update: 1,
 962                                 rgb: [0; 3],
 963                                 alias: [0; 32],
 964                                 addresses: Vec::new(),
 965                         });
 966                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
 967                                 features: GlobalFeatures::new(),
 968                                 one_to_two: DirectionalChannelInfo {
 969                                         src_node_id: node3.clone(),
 970                                         last_update: 0,
 971                                         enabled: true,
 972                                         cltv_expiry_delta: (6 << 8) | 1,
 973                                         htlc_minimum_msat: 0,
 974                                         fee_base_msat: 0,
 975                                         fee_proportional_millionths: 0,
 976                                 }, two_to_one: DirectionalChannelInfo {
 977                                         src_node_id: node5.clone(),
 978                                         last_update: 0,
 979                                         enabled: true,
 980                                         cltv_expiry_delta: (6 << 8) | 2,
 981                                         htlc_minimum_msat: 0,
 982                                         fee_base_msat: 0,
 983                                         fee_proportional_millionths: 0,
 984                                 },
 985                         });
 986                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
 987                                 features: GlobalFeatures::new(),
 988                                 one_to_two: DirectionalChannelInfo {
 989                                         src_node_id: node5.clone(),
 990                                         last_update: 0,
 991                                         enabled: true,
 992                                         cltv_expiry_delta: (11 << 8) | 1,
 993                                         htlc_minimum_msat: 0,
 994                                         fee_base_msat: 0,
 995                                         fee_proportional_millionths: 0,
 996                                 }, two_to_one: DirectionalChannelInfo {
 997                                         src_node_id: node4.clone(),
 998                                         last_update: 0,
 999                                         enabled: true,
1000                                         cltv_expiry_delta: (11 << 8) | 2,
1001                                         htlc_minimum_msat: 0,
1002                                         fee_base_msat: 0,
1003                                         fee_proportional_millionths: 0,
1004                                 },
1005                         });
1006                         network.nodes.insert(node6.clone(), NodeInfo {
1007                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
1008                                 lowest_inbound_channel_fee_base_msat: 0,
1009                                 lowest_inbound_channel_fee_proportional_millionths: 0,
1010                                 features: GlobalFeatures::new(),
1011                                 last_update: 1,
1012                                 rgb: [0; 3],
1013                                 alias: [0; 32],
1014                                 addresses: Vec::new(),
1015                         });
1016                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
1017                                 features: GlobalFeatures::new(),
1018                                 one_to_two: DirectionalChannelInfo {
1019                                         src_node_id: node3.clone(),
1020                                         last_update: 0,
1021                                         enabled: true,
1022                                         cltv_expiry_delta: (7 << 8) | 1,
1023                                         htlc_minimum_msat: 0,
1024                                         fee_base_msat: 0,
1025                                         fee_proportional_millionths: 1000000,
1026                                 }, two_to_one: DirectionalChannelInfo {
1027                                         src_node_id: node6.clone(),
1028                                         last_update: 0,
1029                                         enabled: true,
1030                                         cltv_expiry_delta: (7 << 8) | 2,
1031                                         htlc_minimum_msat: 0,
1032                                         fee_base_msat: 0,
1033                                         fee_proportional_millionths: 0,
1034                                 },
1035                         });
1036                 }
1037
1038                 { // Simple route to 3 via 2
1039                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1040                         assert_eq!(route.hops.len(), 2);
1041
1042                         assert_eq!(route.hops[0].pubkey, node2);
1043                         assert_eq!(route.hops[0].short_channel_id, 2);
1044                         assert_eq!(route.hops[0].fee_msat, 100);
1045                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1046
1047                         assert_eq!(route.hops[1].pubkey, node3);
1048                         assert_eq!(route.hops[1].short_channel_id, 4);
1049                         assert_eq!(route.hops[1].fee_msat, 100);
1050                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1051                 }
1052
1053                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1054                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1055                         assert_eq!(route.hops.len(), 3);
1056
1057                         assert_eq!(route.hops[0].pubkey, node2);
1058                         assert_eq!(route.hops[0].short_channel_id, 2);
1059                         assert_eq!(route.hops[0].fee_msat, 200);
1060                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1061
1062                         assert_eq!(route.hops[1].pubkey, node3);
1063                         assert_eq!(route.hops[1].short_channel_id, 4);
1064                         assert_eq!(route.hops[1].fee_msat, 100);
1065                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1066
1067                         assert_eq!(route.hops[2].pubkey, node1);
1068                         assert_eq!(route.hops[2].short_channel_id, 3);
1069                         assert_eq!(route.hops[2].fee_msat, 100);
1070                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1071                 }
1072
1073                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1074                         let our_chans = vec![channelmanager::ChannelDetails {
1075                                 channel_id: [0; 32],
1076                                 short_channel_id: Some(42),
1077                                 remote_network_id: node8.clone(),
1078                                 channel_value_satoshis: 0,
1079                                 user_id: 0,
1080                         }];
1081                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1082                         assert_eq!(route.hops.len(), 2);
1083
1084                         assert_eq!(route.hops[0].pubkey, node8);
1085                         assert_eq!(route.hops[0].short_channel_id, 42);
1086                         assert_eq!(route.hops[0].fee_msat, 200);
1087                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1088
1089                         assert_eq!(route.hops[1].pubkey, node3);
1090                         assert_eq!(route.hops[1].short_channel_id, 13);
1091                         assert_eq!(route.hops[1].fee_msat, 100);
1092                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1093                 }
1094
1095                 let mut last_hops = vec!(RouteHint {
1096                                 src_node_id: node4.clone(),
1097                                 short_channel_id: 8,
1098                                 fee_base_msat: 0,
1099                                 fee_proportional_millionths: 0,
1100                                 cltv_expiry_delta: (8 << 8) | 1,
1101                                 htlc_minimum_msat: 0,
1102                         }, RouteHint {
1103                                 src_node_id: node5.clone(),
1104                                 short_channel_id: 9,
1105                                 fee_base_msat: 1001,
1106                                 fee_proportional_millionths: 0,
1107                                 cltv_expiry_delta: (9 << 8) | 1,
1108                                 htlc_minimum_msat: 0,
1109                         }, RouteHint {
1110                                 src_node_id: node6.clone(),
1111                                 short_channel_id: 10,
1112                                 fee_base_msat: 0,
1113                                 fee_proportional_millionths: 0,
1114                                 cltv_expiry_delta: (10 << 8) | 1,
1115                                 htlc_minimum_msat: 0,
1116                         });
1117
1118                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1119                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1120                         assert_eq!(route.hops.len(), 5);
1121
1122                         assert_eq!(route.hops[0].pubkey, node2);
1123                         assert_eq!(route.hops[0].short_channel_id, 2);
1124                         assert_eq!(route.hops[0].fee_msat, 100);
1125                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1126
1127                         assert_eq!(route.hops[1].pubkey, node3);
1128                         assert_eq!(route.hops[1].short_channel_id, 4);
1129                         assert_eq!(route.hops[1].fee_msat, 0);
1130                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1131
1132                         assert_eq!(route.hops[2].pubkey, node5);
1133                         assert_eq!(route.hops[2].short_channel_id, 6);
1134                         assert_eq!(route.hops[2].fee_msat, 0);
1135                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1136
1137                         assert_eq!(route.hops[3].pubkey, node4);
1138                         assert_eq!(route.hops[3].short_channel_id, 11);
1139                         assert_eq!(route.hops[3].fee_msat, 0);
1140                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1141
1142                         assert_eq!(route.hops[4].pubkey, node7);
1143                         assert_eq!(route.hops[4].short_channel_id, 8);
1144                         assert_eq!(route.hops[4].fee_msat, 100);
1145                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1146                 }
1147
1148                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1149                         let our_chans = vec![channelmanager::ChannelDetails {
1150                                 channel_id: [0; 32],
1151                                 short_channel_id: Some(42),
1152                                 remote_network_id: node4.clone(),
1153                                 channel_value_satoshis: 0,
1154                                 user_id: 0,
1155                         }];
1156                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1157                         assert_eq!(route.hops.len(), 2);
1158
1159                         assert_eq!(route.hops[0].pubkey, node4);
1160                         assert_eq!(route.hops[0].short_channel_id, 42);
1161                         assert_eq!(route.hops[0].fee_msat, 0);
1162                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1163
1164                         assert_eq!(route.hops[1].pubkey, node7);
1165                         assert_eq!(route.hops[1].short_channel_id, 8);
1166                         assert_eq!(route.hops[1].fee_msat, 100);
1167                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1168                 }
1169
1170                 last_hops[0].fee_base_msat = 1000;
1171
1172                 { // Revert to via 6 as the fee on 8 goes up
1173                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1174                         assert_eq!(route.hops.len(), 4);
1175
1176                         assert_eq!(route.hops[0].pubkey, node2);
1177                         assert_eq!(route.hops[0].short_channel_id, 2);
1178                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1179                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1180
1181                         assert_eq!(route.hops[1].pubkey, node3);
1182                         assert_eq!(route.hops[1].short_channel_id, 4);
1183                         assert_eq!(route.hops[1].fee_msat, 100);
1184                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1185
1186                         assert_eq!(route.hops[2].pubkey, node6);
1187                         assert_eq!(route.hops[2].short_channel_id, 7);
1188                         assert_eq!(route.hops[2].fee_msat, 0);
1189                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1190
1191                         assert_eq!(route.hops[3].pubkey, node7);
1192                         assert_eq!(route.hops[3].short_channel_id, 10);
1193                         assert_eq!(route.hops[3].fee_msat, 100);
1194                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1195                 }
1196
1197                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1198                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1199                         assert_eq!(route.hops.len(), 5);
1200
1201                         assert_eq!(route.hops[0].pubkey, node2);
1202                         assert_eq!(route.hops[0].short_channel_id, 2);
1203                         assert_eq!(route.hops[0].fee_msat, 3000);
1204                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1205
1206                         assert_eq!(route.hops[1].pubkey, node3);
1207                         assert_eq!(route.hops[1].short_channel_id, 4);
1208                         assert_eq!(route.hops[1].fee_msat, 0);
1209                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1210
1211                         assert_eq!(route.hops[2].pubkey, node5);
1212                         assert_eq!(route.hops[2].short_channel_id, 6);
1213                         assert_eq!(route.hops[2].fee_msat, 0);
1214                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1215
1216                         assert_eq!(route.hops[3].pubkey, node4);
1217                         assert_eq!(route.hops[3].short_channel_id, 11);
1218                         assert_eq!(route.hops[3].fee_msat, 1000);
1219                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1220
1221                         assert_eq!(route.hops[4].pubkey, node7);
1222                         assert_eq!(route.hops[4].short_channel_id, 8);
1223                         assert_eq!(route.hops[4].fee_msat, 2000);
1224                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1225                 }
1226         }
1227 }