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

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