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