_ 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::{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", msg: 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", msg: None}),
 126                         Some(node) => {
 127                                 if node.last_update >= msg.contents.timestamp {
 128                                         return Err(HandleError{err: "Update older than last processed update", msg: None});
 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", msg: 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", msg: None})
 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_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<(), HandleError> {
 218                 let mut network = self.network_map.write().unwrap();
 219                 let dest_node_id;
 220                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 221                 let chan_was_enabled;
 222
 223                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 224                         None => return Err(HandleError{err: "Couldn't find channel for update", msg: None}),
 225                         Some(channel) => {
 226                                 macro_rules! maybe_update_channel_info {
 227                                         ( $target: expr) => {
 228                                                 if $target.last_update >= msg.contents.timestamp {
 229                                                         return Err(HandleError{err: "Update older than last processed update", msg: None});
 230                                                 }
 231                                                 chan_was_enabled = $target.enabled;
 232                                                 $target.last_update = msg.contents.timestamp;
 233                                                 $target.enabled = chan_enabled;
 234                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 235                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 236                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 237                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 238                                         }
 239                                 }
 240
 241                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 242                                 if msg.contents.flags & 1 == 1 {
 243                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 244                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 245                                         maybe_update_channel_info!(channel.two_to_one);
 246                                 } else {
 247                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 248                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 249                                         maybe_update_channel_info!(channel.one_to_two);
 250                                 }
 251                         }
 252                 }
 253
 254                 if chan_enabled {
 255                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 256                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 257                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 258                 } else if chan_was_enabled {
 259                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 260                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 261
 262                         {
 263                                 let node = network.nodes.get(&dest_node_id).unwrap();
 264
 265                                 for chan_id in node.channels.iter() {
 266                                         let chan = network.channels.get(chan_id).unwrap();
 267                                         if chan.one_to_two.src_node_id == dest_node_id {
 268                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 269                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 270                                         } else {
 271                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 272                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 273                                         }
 274                                 }
 275                         }
 276
 277                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 278                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 279                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 280                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 281                 }
 282
 283                 Ok(())
 284         }
 285 }
 286
 287 #[derive(Eq, PartialEq)]
 288 struct RouteGraphNode {
 289         pubkey: PublicKey,
 290         lowest_fee_to_peer_through_node: u64,
 291 }
 292
 293 impl cmp::Ord for RouteGraphNode {
 294         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 295                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 296                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 297         }
 298 }
 299
 300 impl cmp::PartialOrd for RouteGraphNode {
 301         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 302                 Some(self.cmp(other))
 303         }
 304 }
 305
 306 impl Router {
 307         pub fn new(our_pubkey: PublicKey) -> Router {
 308                 let mut nodes = HashMap::new();
 309                 nodes.insert(our_pubkey.clone(), NodeInfo {
 310                         channels: Vec::new(),
 311                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 312                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 313                         features: GlobalFeatures::new(),
 314                         last_update: 0,
 315                         rgb: [0; 3],
 316                         alias: [0; 32],
 317                         addresses: Vec::new(),
 318                 });
 319                 Router {
 320                         secp_ctx: Secp256k1::new(),
 321                         network_map: RwLock::new(NetworkMap {
 322                                 channels: HashMap::new(),
 323                                 our_node_id: our_pubkey,
 324                                 nodes: nodes,
 325                         }),
 326                 }
 327         }
 328
 329         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 330         /// with an expotnential decay in node "badness". Note that there is deliberately no
 331         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 332         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 333         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 334         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 335         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 336                 unimplemented!();
 337         }
 338
 339         /// Gets a route from us to the given target node.
 340         /// Extra routing hops between known nodes and the target will be used if they are included in
 341         /// last_hops.
 342         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 343         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 344         /// *is* checked as they may change based on the receiving node.
 345         pub fn get_route(&self, target: &PublicKey, last_hops: &Vec<RouteHint>, final_value_msat: u64, final_cltv: u32) -> Result<Route, HandleError> {
 346                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 347                 // uptime/success in using a node in the past.
 348                 let network = self.network_map.read().unwrap();
 349
 350                 if *target == network.our_node_id {
 351                         return Err(HandleError{err: "Cannot generate a route to ourselves", msg: None});
 352                 }
 353
 354                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 355                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 356                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 357                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 358                 // one.
 359
 360                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 361                 let mut dist = HashMap::with_capacity(network.nodes.len());
 362                 for (key, node) in network.nodes.iter() {
 363                         dist.insert(key.clone(), (u64::max_value(),
 364                                 node.lowest_inbound_channel_fee_base_msat as u64,
 365                                 node.lowest_inbound_channel_fee_proportional_millionths as u64,
 366                                 RouteHop {
 367                                         pubkey: PublicKey::new(),
 368                                         short_channel_id: 0,
 369                                         fee_msat: 0,
 370                                         cltv_expiry_delta: 0,
 371                         }));
 372                 }
 373
 374                 macro_rules! add_entry {
 375                         // Adds entry which goes from the node pointed to by $directional_info to
 376                         // $dest_node_id over the channel with id $chan_id with fees described in
 377                         // $directional_info.
 378                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 379                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 380                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 381                                         let new_fee = $directional_info.fee_base_msat as u64 + ($starting_fee_msat + final_value_msat) * ($directional_info.fee_proportional_millionths as u64) / 1000000;
 382                                         let mut total_fee = $starting_fee_msat as u64;
 383                                         let old_entry = dist.get_mut(&$directional_info.src_node_id).unwrap();
 384                                         if $directional_info.src_node_id != network.our_node_id {
 385                                                 // Ignore new_fee for channel-from-us as we assume all channels-from-us
 386                                                 // will have the same effective-fee
 387                                                 total_fee += new_fee;
 388                                                 total_fee += old_entry.2 * (final_value_msat + total_fee) / 1000000 + old_entry.1;
 389                                         }
 390                                         let new_graph_node = RouteGraphNode {
 391                                                 pubkey: $directional_info.src_node_id,
 392                                                 lowest_fee_to_peer_through_node: total_fee,
 393                                         };
 394                                         if old_entry.0 > total_fee {
 395                                                 targets.push(new_graph_node);
 396                                                 old_entry.0 = total_fee;
 397                                                 old_entry.3 = RouteHop {
 398                                                         pubkey: $dest_node_id.clone(),
 399                                                         short_channel_id: $chan_id.clone(),
 400                                                         fee_msat: new_fee, // This field is ignored on the last-hop anyway
 401                                                         cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 402                                                 }
 403                                         }
 404                                 }
 405                         };
 406                 }
 407
 408                 macro_rules! add_entries_to_cheapest_to_target_node {
 409                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 410                                 for chan_id in $node.channels.iter() {
 411                                         let chan = network.channels.get(chan_id).unwrap();
 412                                         if chan.one_to_two.src_node_id == *$node_id {
 413                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 414                                                 if chan.two_to_one.enabled {
 415                                                         add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 416                                                 }
 417                                         } else {
 418                                                 if chan.one_to_two.enabled {
 419                                                         add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 420                                                 }
 421                                         }
 422                                 }
 423                         };
 424                 }
 425
 426                 match network.nodes.get(target) {
 427                         None => {},
 428                         Some(node) => {
 429                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 430                         },
 431                 }
 432
 433                 for hop in last_hops.iter() {
 434                         if network.nodes.get(&hop.src_node_id).is_some() {
 435                                 add_entry!(hop.short_channel_id, target, hop, 0);
 436                         }
 437                 }
 438
 439                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_peer_through_node }) = targets.pop() {
 440                         if pubkey == network.our_node_id {
 441                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 442                                 while res.last().unwrap().pubkey != *target {
 443                                         let new_entry = dist.remove(&res.last().unwrap().pubkey).unwrap().3;
 444                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 445                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 446                                         res.push(new_entry);
 447                                 }
 448                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 449                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 450                                 return Ok(Route {
 451                                         hops: res
 452                                 });
 453                         }
 454
 455                         match network.nodes.get(&pubkey) {
 456                                 None => {},
 457                                 Some(node) => {
 458                                         let mut fee = lowest_fee_to_peer_through_node - node.lowest_inbound_channel_fee_base_msat as u64;
 459                                         fee -= node.lowest_inbound_channel_fee_proportional_millionths as u64 * (fee + final_value_msat) / 1000000;
 460                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, fee);
 461                                 },
 462                         }
 463                 }
 464
 465                 Err(HandleError{err: "Failed to find a path to the given destination", msg: None})
 466         }
 467 }
 468
 469 #[cfg(test)]
 470 mod tests {
 471         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 472         use ln::msgs::GlobalFeatures;
 473
 474         use bitcoin::util::misc::hex_bytes;
 475         use bitcoin::util::hash::Sha256dHash;
 476
 477         use secp256k1::key::{PublicKey,SecretKey};
 478         use secp256k1::Secp256k1;
 479
 480         #[test]
 481         fn route_test() {
 482                 let secp_ctx = Secp256k1::new();
 483                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap()).unwrap();
 484                 let router = Router::new(our_id);
 485
 486                 // Build network from our_id to node8:
 487                 //
 488                 //        -1(1)2- node1 -1(3)2-
 489                 //       /                     \
 490                 // our_id                       - node3
 491                 //       \                     /
 492                 //        -1(2)2- node2 -1(4)2-
 493                 //
 494                 //
 495                 // chan1 1-to-2: disabled
 496                 // chan1 2-to-1: enabled, 0 fee
 497                 //
 498                 // chan2 1-to-2: enabled, ignored fee
 499                 // chan2 2-to-1: enabled, 0 fee
 500                 //
 501                 // chan3 1-to-2: enabled, 0 fee
 502                 // chan3 2-to-1: enabled, 100 msat fee
 503                 //
 504                 // chan4 1-to-2: enabled, 100% fee
 505                 // chan4 2-to-1: enabled, 0 fee
 506                 //
 507                 //
 508                 //
 509                 //       -1(5)2- node4 -1(8)2--
 510                 //       |         2          |
 511                 //       |       (11)         |
 512                 //      /          1           \
 513                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 514                 //      \                      /
 515                 //       -1(7)2- node6 -1(10)2-
 516                 //
 517                 // chan5  1-to-2: enabled, 100 msat fee
 518                 // chan5  2-to-1: enabled, 0 fee
 519                 //
 520                 // chan6  1-to-2: enabled, 0 fee
 521                 // chan6  2-to-1: enabled, 0 fee
 522                 //
 523                 // chan7  1-to-2: enabled, 100% fee
 524                 // chan7  2-to-1: enabled, 0 fee
 525                 //
 526                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 527                 // chan8  2-to-1: enabled, 0 fee
 528                 //
 529                 // chan9  1-to-2: enabled, 1001 msat fee
 530                 // chan9  2-to-1: enabled, 0 fee
 531                 //
 532                 // chan10 1-to-2: enabled, 0 fee
 533                 // chan10 2-to-1: enabled, 0 fee
 534                 //
 535                 // chan11 1-to-2: enabled, 0 fee
 536                 // chan11 2-to-1: enabled, 0 fee
 537
 538                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap()).unwrap();
 539                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap()).unwrap();
 540                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap()).unwrap();
 541                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap()).unwrap();
 542                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap()).unwrap();
 543                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap()).unwrap();
 544                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap()).unwrap();
 545
 546                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 547
 548                 {
 549                         let mut network = router.network_map.write().unwrap();
 550
 551                         network.nodes.insert(node1.clone(), NodeInfo {
 552                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 553                                 lowest_inbound_channel_fee_base_msat: 100,
 554                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 555                                 features: GlobalFeatures::new(),
 556                                 last_update: 1,
 557                                 rgb: [0; 3],
 558                                 alias: [0; 32],
 559                                 addresses: Vec::new(),
 560                         });
 561                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 562                                 features: GlobalFeatures::new(),
 563                                 one_to_two: DirectionalChannelInfo {
 564                                         src_node_id: our_id.clone(),
 565                                         last_update: 0,
 566                                         enabled: false,
 567                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 568                                         htlc_minimum_msat: 0,
 569                                         fee_base_msat: u32::max_value(), // This value should be ignored
 570                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 571                                 }, two_to_one: DirectionalChannelInfo {
 572                                         src_node_id: node1.clone(),
 573                                         last_update: 0,
 574                                         enabled: true,
 575                                         cltv_expiry_delta: 0,
 576                                         htlc_minimum_msat: 0,
 577                                         fee_base_msat: 0,
 578                                         fee_proportional_millionths: 0,
 579                                 },
 580                         });
 581                         network.nodes.insert(node2.clone(), NodeInfo {
 582                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 583                                 lowest_inbound_channel_fee_base_msat: 0,
 584                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 585                                 features: GlobalFeatures::new(),
 586                                 last_update: 1,
 587                                 rgb: [0; 3],
 588                                 alias: [0; 32],
 589                                 addresses: Vec::new(),
 590                         });
 591                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 592                                 features: GlobalFeatures::new(),
 593                                 one_to_two: DirectionalChannelInfo {
 594                                         src_node_id: our_id.clone(),
 595                                         last_update: 0,
 596                                         enabled: true,
 597                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 598                                         htlc_minimum_msat: 0,
 599                                         fee_base_msat: u32::max_value(), // This value should be ignored
 600                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 601                                 }, two_to_one: DirectionalChannelInfo {
 602                                         src_node_id: node2.clone(),
 603                                         last_update: 0,
 604                                         enabled: true,
 605                                         cltv_expiry_delta: 0,
 606                                         htlc_minimum_msat: 0,
 607                                         fee_base_msat: 0,
 608                                         fee_proportional_millionths: 0,
 609                                 },
 610                         });
 611                         network.nodes.insert(node3.clone(), NodeInfo {
 612                                 channels: vec!(
 613                                         NetworkMap::get_key(3, zero_hash.clone()),
 614                                         NetworkMap::get_key(4, zero_hash.clone()),
 615                                         NetworkMap::get_key(5, zero_hash.clone()),
 616                                         NetworkMap::get_key(6, zero_hash.clone()),
 617                                         NetworkMap::get_key(7, zero_hash.clone())),
 618                                 lowest_inbound_channel_fee_base_msat: 0,
 619                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 620                                 features: GlobalFeatures::new(),
 621                                 last_update: 1,
 622                                 rgb: [0; 3],
 623                                 alias: [0; 32],
 624                                 addresses: Vec::new(),
 625                         });
 626                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 627                                 features: GlobalFeatures::new(),
 628                                 one_to_two: DirectionalChannelInfo {
 629                                         src_node_id: node1.clone(),
 630                                         last_update: 0,
 631                                         enabled: true,
 632                                         cltv_expiry_delta: (3 << 8) | 1,
 633                                         htlc_minimum_msat: 0,
 634                                         fee_base_msat: 0,
 635                                         fee_proportional_millionths: 0,
 636                                 }, two_to_one: DirectionalChannelInfo {
 637                                         src_node_id: node3.clone(),
 638                                         last_update: 0,
 639                                         enabled: true,
 640                                         cltv_expiry_delta: (3 << 8) | 2,
 641                                         htlc_minimum_msat: 0,
 642                                         fee_base_msat: 100,
 643                                         fee_proportional_millionths: 0,
 644                                 },
 645                         });
 646                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 647                                 features: GlobalFeatures::new(),
 648                                 one_to_two: DirectionalChannelInfo {
 649                                         src_node_id: node2.clone(),
 650                                         last_update: 0,
 651                                         enabled: true,
 652                                         cltv_expiry_delta: (4 << 8) | 1,
 653                                         htlc_minimum_msat: 0,
 654                                         fee_base_msat: 0,
 655                                         fee_proportional_millionths: 1000000,
 656                                 }, two_to_one: DirectionalChannelInfo {
 657                                         src_node_id: node3.clone(),
 658                                         last_update: 0,
 659                                         enabled: true,
 660                                         cltv_expiry_delta: (4 << 8) | 2,
 661                                         htlc_minimum_msat: 0,
 662                                         fee_base_msat: 0,
 663                                         fee_proportional_millionths: 0,
 664                                 },
 665                         });
 666                         network.nodes.insert(node4.clone(), NodeInfo {
 667                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 668                                 lowest_inbound_channel_fee_base_msat: 0,
 669                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 670                                 features: GlobalFeatures::new(),
 671                                 last_update: 1,
 672                                 rgb: [0; 3],
 673                                 alias: [0; 32],
 674                                 addresses: Vec::new(),
 675                         });
 676                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
 677                                 features: GlobalFeatures::new(),
 678                                 one_to_two: DirectionalChannelInfo {
 679                                         src_node_id: node3.clone(),
 680                                         last_update: 0,
 681                                         enabled: true,
 682                                         cltv_expiry_delta: (5 << 8) | 1,
 683                                         htlc_minimum_msat: 0,
 684                                         fee_base_msat: 100,
 685                                         fee_proportional_millionths: 0,
 686                                 }, two_to_one: DirectionalChannelInfo {
 687                                         src_node_id: node4.clone(),
 688                                         last_update: 0,
 689                                         enabled: true,
 690                                         cltv_expiry_delta: (5 << 8) | 2,
 691                                         htlc_minimum_msat: 0,
 692                                         fee_base_msat: 0,
 693                                         fee_proportional_millionths: 0,
 694                                 },
 695                         });
 696                         network.nodes.insert(node5.clone(), NodeInfo {
 697                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 698                                 lowest_inbound_channel_fee_base_msat: 0,
 699                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 700                                 features: GlobalFeatures::new(),
 701                                 last_update: 1,
 702                                 rgb: [0; 3],
 703                                 alias: [0; 32],
 704                                 addresses: Vec::new(),
 705                         });
 706                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
 707                                 features: GlobalFeatures::new(),
 708                                 one_to_two: DirectionalChannelInfo {
 709                                         src_node_id: node3.clone(),
 710                                         last_update: 0,
 711                                         enabled: true,
 712                                         cltv_expiry_delta: (6 << 8) | 1,
 713                                         htlc_minimum_msat: 0,
 714                                         fee_base_msat: 0,
 715                                         fee_proportional_millionths: 0,
 716                                 }, two_to_one: DirectionalChannelInfo {
 717                                         src_node_id: node5.clone(),
 718                                         last_update: 0,
 719                                         enabled: true,
 720                                         cltv_expiry_delta: (6 << 8) | 2,
 721                                         htlc_minimum_msat: 0,
 722                                         fee_base_msat: 0,
 723                                         fee_proportional_millionths: 0,
 724                                 },
 725                         });
 726                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
 727                                 features: GlobalFeatures::new(),
 728                                 one_to_two: DirectionalChannelInfo {
 729                                         src_node_id: node5.clone(),
 730                                         last_update: 0,
 731                                         enabled: true,
 732                                         cltv_expiry_delta: (11 << 8) | 1,
 733                                         htlc_minimum_msat: 0,
 734                                         fee_base_msat: 0,
 735                                         fee_proportional_millionths: 0,
 736                                 }, two_to_one: DirectionalChannelInfo {
 737                                         src_node_id: node4.clone(),
 738                                         last_update: 0,
 739                                         enabled: true,
 740                                         cltv_expiry_delta: (11 << 8) | 2,
 741                                         htlc_minimum_msat: 0,
 742                                         fee_base_msat: 0,
 743                                         fee_proportional_millionths: 0,
 744                                 },
 745                         });
 746                         network.nodes.insert(node6.clone(), NodeInfo {
 747                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
 748                                 lowest_inbound_channel_fee_base_msat: 0,
 749                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 750                                 features: GlobalFeatures::new(),
 751                                 last_update: 1,
 752                                 rgb: [0; 3],
 753                                 alias: [0; 32],
 754                                 addresses: Vec::new(),
 755                         });
 756                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
 757                                 features: GlobalFeatures::new(),
 758                                 one_to_two: DirectionalChannelInfo {
 759                                         src_node_id: node3.clone(),
 760                                         last_update: 0,
 761                                         enabled: true,
 762                                         cltv_expiry_delta: (7 << 8) | 1,
 763                                         htlc_minimum_msat: 0,
 764                                         fee_base_msat: 0,
 765                                         fee_proportional_millionths: 1000000,
 766                                 }, two_to_one: DirectionalChannelInfo {
 767                                         src_node_id: node6.clone(),
 768                                         last_update: 0,
 769                                         enabled: true,
 770                                         cltv_expiry_delta: (7 << 8) | 2,
 771                                         htlc_minimum_msat: 0,
 772                                         fee_base_msat: 0,
 773                                         fee_proportional_millionths: 0,
 774                                 },
 775                         });
 776                 }
 777
 778                 { // Simple route to 3 via 2
 779                         let route = router.get_route(&node3, &Vec::new(), 100, 42).unwrap();
 780                         assert_eq!(route.hops.len(), 2);
 781
 782                         assert_eq!(route.hops[0].pubkey, node2);
 783                         assert_eq!(route.hops[0].short_channel_id, 2);
 784                         assert_eq!(route.hops[0].fee_msat, 100);
 785                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
 786
 787                         assert_eq!(route.hops[1].pubkey, node3);
 788                         assert_eq!(route.hops[1].short_channel_id, 4);
 789                         assert_eq!(route.hops[1].fee_msat, 100);
 790                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
 791                 }
 792
 793                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
 794                         let route = router.get_route(&node1, &Vec::new(), 100, 42).unwrap();
 795                         assert_eq!(route.hops.len(), 3);
 796
 797                         assert_eq!(route.hops[0].pubkey, node2);
 798                         assert_eq!(route.hops[0].short_channel_id, 2);
 799                         assert_eq!(route.hops[0].fee_msat, 200);
 800                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
 801
 802                         assert_eq!(route.hops[1].pubkey, node3);
 803                         assert_eq!(route.hops[1].short_channel_id, 4);
 804                         assert_eq!(route.hops[1].fee_msat, 100);
 805                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
 806
 807                         assert_eq!(route.hops[2].pubkey, node1);
 808                         assert_eq!(route.hops[2].short_channel_id, 3);
 809                         assert_eq!(route.hops[2].fee_msat, 100);
 810                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
 811                 }
 812
 813                 let mut last_hops = vec!(RouteHint {
 814                                 src_node_id: node4.clone(),
 815                                 short_channel_id: 8,
 816                                 fee_base_msat: 0,
 817                                 fee_proportional_millionths: 0,
 818                                 cltv_expiry_delta: (8 << 8) | 1,
 819                                 htlc_minimum_msat: 0,
 820                         }, RouteHint {
 821                                 src_node_id: node5.clone(),
 822                                 short_channel_id: 9,
 823                                 fee_base_msat: 1001,
 824                                 fee_proportional_millionths: 0,
 825                                 cltv_expiry_delta: (9 << 8) | 1,
 826                                 htlc_minimum_msat: 0,
 827                         }, RouteHint {
 828                                 src_node_id: node6.clone(),
 829                                 short_channel_id: 10,
 830                                 fee_base_msat: 0,
 831                                 fee_proportional_millionths: 0,
 832                                 cltv_expiry_delta: (10 << 8) | 1,
 833                                 htlc_minimum_msat: 0,
 834                         });
 835
 836                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
 837                         let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
 838                         assert_eq!(route.hops.len(), 5);
 839
 840                         assert_eq!(route.hops[0].pubkey, node2);
 841                         assert_eq!(route.hops[0].short_channel_id, 2);
 842                         assert_eq!(route.hops[0].fee_msat, 100);
 843                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
 844
 845                         assert_eq!(route.hops[1].pubkey, node3);
 846                         assert_eq!(route.hops[1].short_channel_id, 4);
 847                         assert_eq!(route.hops[1].fee_msat, 0);
 848                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
 849
 850                         assert_eq!(route.hops[2].pubkey, node5);
 851                         assert_eq!(route.hops[2].short_channel_id, 6);
 852                         assert_eq!(route.hops[2].fee_msat, 0);
 853                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
 854
 855                         assert_eq!(route.hops[3].pubkey, node4);
 856                         assert_eq!(route.hops[3].short_channel_id, 11);
 857                         assert_eq!(route.hops[3].fee_msat, 0);
 858                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
 859
 860                         assert_eq!(route.hops[4].pubkey, node7);
 861                         assert_eq!(route.hops[4].short_channel_id, 8);
 862                         assert_eq!(route.hops[4].fee_msat, 100);
 863                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
 864                 }
 865
 866                 last_hops[0].fee_base_msat = 1000;
 867
 868                 { // Revert to via 6 as the fee on 8 goes up
 869                         let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
 870                         assert_eq!(route.hops.len(), 4);
 871
 872                         assert_eq!(route.hops[0].pubkey, node2);
 873                         assert_eq!(route.hops[0].short_channel_id, 2);
 874                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
 875                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
 876
 877                         assert_eq!(route.hops[1].pubkey, node3);
 878                         assert_eq!(route.hops[1].short_channel_id, 4);
 879                         assert_eq!(route.hops[1].fee_msat, 100);
 880                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
 881
 882                         assert_eq!(route.hops[2].pubkey, node6);
 883                         assert_eq!(route.hops[2].short_channel_id, 7);
 884                         assert_eq!(route.hops[2].fee_msat, 0);
 885                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
 886
 887                         assert_eq!(route.hops[3].pubkey, node7);
 888                         assert_eq!(route.hops[3].short_channel_id, 10);
 889                         assert_eq!(route.hops[3].fee_msat, 100);
 890                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
 891                 }
 892
 893                 { // ...but still use 8 for larger payments as 6 has a variable feerate
 894                         let route = router.get_route(&node7, &last_hops, 2000, 42).unwrap();
 895                         assert_eq!(route.hops.len(), 5);
 896
 897                         assert_eq!(route.hops[0].pubkey, node2);
 898                         assert_eq!(route.hops[0].short_channel_id, 2);
 899                         assert_eq!(route.hops[0].fee_msat, 3000);
 900                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
 901
 902                         assert_eq!(route.hops[1].pubkey, node3);
 903                         assert_eq!(route.hops[1].short_channel_id, 4);
 904                         assert_eq!(route.hops[1].fee_msat, 0);
 905                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
 906
 907                         assert_eq!(route.hops[2].pubkey, node5);
 908                         assert_eq!(route.hops[2].short_channel_id, 6);
 909                         assert_eq!(route.hops[2].fee_msat, 0);
 910                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
 911
 912                         assert_eq!(route.hops[3].pubkey, node4);
 913                         assert_eq!(route.hops[3].short_channel_id, 11);
 914                         assert_eq!(route.hops[3].fee_msat, 1000);
 915                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
 916
 917                         assert_eq!(route.hops[4].pubkey, node7);
 918                         assert_eq!(route.hops[4].short_channel_id, 8);
 919                         assert_eq!(route.hops[4].fee_msat, 2000);
 920                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
 921                 }
 922         }
 923 }