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