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