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