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