Merge pull request #67 from yuntai/issue_56
[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                 for (key, node) in network.nodes.iter() {
381                         dist.insert(key.clone(), (u64::max_value(),
382                                 node.lowest_inbound_channel_fee_base_msat as u64,
383                                 node.lowest_inbound_channel_fee_proportional_millionths as u64,
384                                 RouteHop {
385                                         pubkey: PublicKey::new(),
386                                         short_channel_id: 0,
387                                         fee_msat: 0,
388                                         cltv_expiry_delta: 0,
389                         }));
390                 }
391
392                 macro_rules! add_entry {
393                         // Adds entry which goes from the node pointed to by $directional_info to
394                         // $dest_node_id over the channel with id $chan_id with fees described in
395                         // $directional_info.
396                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
397                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
398                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
399                                         let new_fee = $directional_info.fee_base_msat as u64 + ($starting_fee_msat + final_value_msat) * ($directional_info.fee_proportional_millionths as u64) / 1000000;
400                                         let mut total_fee = $starting_fee_msat as u64;
401                                         let old_entry = dist.get_mut(&$directional_info.src_node_id).unwrap();
402                                         if $directional_info.src_node_id != network.our_node_id {
403                                                 // Ignore new_fee for channel-from-us as we assume all channels-from-us
404                                                 // will have the same effective-fee
405                                                 total_fee += new_fee;
406                                                 total_fee += old_entry.2 * (final_value_msat + total_fee) / 1000000 + old_entry.1;
407                                         }
408                                         let new_graph_node = RouteGraphNode {
409                                                 pubkey: $directional_info.src_node_id,
410                                                 lowest_fee_to_peer_through_node: total_fee,
411                                         };
412                                         if old_entry.0 > total_fee {
413                                                 targets.push(new_graph_node);
414                                                 old_entry.0 = total_fee;
415                                                 old_entry.3 = RouteHop {
416                                                         pubkey: $dest_node_id.clone(),
417                                                         short_channel_id: $chan_id.clone(),
418                                                         fee_msat: new_fee, // This field is ignored on the last-hop anyway
419                                                         cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
420                                                 }
421                                         }
422                                 }
423                         };
424                 }
425
426                 macro_rules! add_entries_to_cheapest_to_target_node {
427                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
428                                 for chan_id in $node.channels.iter() {
429                                         let chan = network.channels.get(chan_id).unwrap();
430                                         if chan.one_to_two.src_node_id == *$node_id {
431                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
432                                                 if chan.two_to_one.enabled {
433                                                         add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
434                                                 }
435                                         } else {
436                                                 if chan.one_to_two.enabled {
437                                                         add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
438                                                 }
439                                         }
440                                 }
441                         };
442                 }
443
444                 match network.nodes.get(target) {
445                         None => {},
446                         Some(node) => {
447                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
448                         },
449                 }
450
451                 for hop in last_hops.iter() {
452                         if network.nodes.get(&hop.src_node_id).is_some() {
453                                 add_entry!(hop.short_channel_id, target, hop, 0);
454                         }
455                 }
456
457                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_peer_through_node }) = targets.pop() {
458                         if pubkey == network.our_node_id {
459                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
460                                 while res.last().unwrap().pubkey != *target {
461                                         let new_entry = dist.remove(&res.last().unwrap().pubkey).unwrap().3;
462                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
463                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
464                                         res.push(new_entry);
465                                 }
466                                 res.last_mut().unwrap().fee_msat = final_value_msat;
467                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
468                                 return Ok(Route {
469                                         hops: res
470                                 });
471                         }
472
473                         match network.nodes.get(&pubkey) {
474                                 None => {},
475                                 Some(node) => {
476                                         let mut fee = lowest_fee_to_peer_through_node - node.lowest_inbound_channel_fee_base_msat as u64;
477                                         fee -= node.lowest_inbound_channel_fee_proportional_millionths as u64 * (fee + final_value_msat) / 1000000;
478                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, fee);
479                                 },
480                         }
481                 }
482
483                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
484         }
485 }
486
487 #[cfg(test)]
488 mod tests {
489         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
490         use ln::msgs::GlobalFeatures;
491
492         use bitcoin::util::misc::hex_bytes;
493         use bitcoin::util::hash::Sha256dHash;
494
495         use secp256k1::key::{PublicKey,SecretKey};
496         use secp256k1::Secp256k1;
497
498         #[test]
499         fn route_test() {
500                 let secp_ctx = Secp256k1::new();
501                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap()).unwrap();
502                 let router = Router::new(our_id);
503
504                 // Build network from our_id to node8:
505                 //
506                 //        -1(1)2- node1 -1(3)2-
507                 //       /                     \
508                 // our_id                       - node3
509                 //       \                     /
510                 //        -1(2)2- node2 -1(4)2-
511                 //
512                 //
513                 // chan1 1-to-2: disabled
514                 // chan1 2-to-1: enabled, 0 fee
515                 //
516                 // chan2 1-to-2: enabled, ignored fee
517                 // chan2 2-to-1: enabled, 0 fee
518                 //
519                 // chan3 1-to-2: enabled, 0 fee
520                 // chan3 2-to-1: enabled, 100 msat fee
521                 //
522                 // chan4 1-to-2: enabled, 100% fee
523                 // chan4 2-to-1: enabled, 0 fee
524                 //
525                 //
526                 //
527                 //       -1(5)2- node4 -1(8)2--
528                 //       |         2          |
529                 //       |       (11)         |
530                 //      /          1           \
531                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
532                 //      \                      /
533                 //       -1(7)2- node6 -1(10)2-
534                 //
535                 // chan5  1-to-2: enabled, 100 msat fee
536                 // chan5  2-to-1: enabled, 0 fee
537                 //
538                 // chan6  1-to-2: enabled, 0 fee
539                 // chan6  2-to-1: enabled, 0 fee
540                 //
541                 // chan7  1-to-2: enabled, 100% fee
542                 // chan7  2-to-1: enabled, 0 fee
543                 //
544                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
545                 // chan8  2-to-1: enabled, 0 fee
546                 //
547                 // chan9  1-to-2: enabled, 1001 msat fee
548                 // chan9  2-to-1: enabled, 0 fee
549                 //
550                 // chan10 1-to-2: enabled, 0 fee
551                 // chan10 2-to-1: enabled, 0 fee
552                 //
553                 // chan11 1-to-2: enabled, 0 fee
554                 // chan11 2-to-1: enabled, 0 fee
555
556                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap()).unwrap();
557                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap()).unwrap();
558                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap()).unwrap();
559                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap()).unwrap();
560                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap()).unwrap();
561                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap()).unwrap();
562                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex_bytes("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap()).unwrap();
563
564                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
565
566                 {
567                         let mut network = router.network_map.write().unwrap();
568
569                         network.nodes.insert(node1.clone(), NodeInfo {
570                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
571                                 lowest_inbound_channel_fee_base_msat: 100,
572                                 lowest_inbound_channel_fee_proportional_millionths: 0,
573                                 features: GlobalFeatures::new(),
574                                 last_update: 1,
575                                 rgb: [0; 3],
576                                 alias: [0; 32],
577                                 addresses: Vec::new(),
578                         });
579                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
580                                 features: GlobalFeatures::new(),
581                                 one_to_two: DirectionalChannelInfo {
582                                         src_node_id: our_id.clone(),
583                                         last_update: 0,
584                                         enabled: false,
585                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
586                                         htlc_minimum_msat: 0,
587                                         fee_base_msat: u32::max_value(), // This value should be ignored
588                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
589                                 }, two_to_one: DirectionalChannelInfo {
590                                         src_node_id: node1.clone(),
591                                         last_update: 0,
592                                         enabled: true,
593                                         cltv_expiry_delta: 0,
594                                         htlc_minimum_msat: 0,
595                                         fee_base_msat: 0,
596                                         fee_proportional_millionths: 0,
597                                 },
598                         });
599                         network.nodes.insert(node2.clone(), NodeInfo {
600                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
601                                 lowest_inbound_channel_fee_base_msat: 0,
602                                 lowest_inbound_channel_fee_proportional_millionths: 0,
603                                 features: GlobalFeatures::new(),
604                                 last_update: 1,
605                                 rgb: [0; 3],
606                                 alias: [0; 32],
607                                 addresses: Vec::new(),
608                         });
609                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
610                                 features: GlobalFeatures::new(),
611                                 one_to_two: DirectionalChannelInfo {
612                                         src_node_id: our_id.clone(),
613                                         last_update: 0,
614                                         enabled: true,
615                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
616                                         htlc_minimum_msat: 0,
617                                         fee_base_msat: u32::max_value(), // This value should be ignored
618                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
619                                 }, two_to_one: DirectionalChannelInfo {
620                                         src_node_id: node2.clone(),
621                                         last_update: 0,
622                                         enabled: true,
623                                         cltv_expiry_delta: 0,
624                                         htlc_minimum_msat: 0,
625                                         fee_base_msat: 0,
626                                         fee_proportional_millionths: 0,
627                                 },
628                         });
629                         network.nodes.insert(node3.clone(), NodeInfo {
630                                 channels: vec!(
631                                         NetworkMap::get_key(3, zero_hash.clone()),
632                                         NetworkMap::get_key(4, zero_hash.clone()),
633                                         NetworkMap::get_key(5, zero_hash.clone()),
634                                         NetworkMap::get_key(6, zero_hash.clone()),
635                                         NetworkMap::get_key(7, zero_hash.clone())),
636                                 lowest_inbound_channel_fee_base_msat: 0,
637                                 lowest_inbound_channel_fee_proportional_millionths: 0,
638                                 features: GlobalFeatures::new(),
639                                 last_update: 1,
640                                 rgb: [0; 3],
641                                 alias: [0; 32],
642                                 addresses: Vec::new(),
643                         });
644                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
645                                 features: GlobalFeatures::new(),
646                                 one_to_two: DirectionalChannelInfo {
647                                         src_node_id: node1.clone(),
648                                         last_update: 0,
649                                         enabled: true,
650                                         cltv_expiry_delta: (3 << 8) | 1,
651                                         htlc_minimum_msat: 0,
652                                         fee_base_msat: 0,
653                                         fee_proportional_millionths: 0,
654                                 }, two_to_one: DirectionalChannelInfo {
655                                         src_node_id: node3.clone(),
656                                         last_update: 0,
657                                         enabled: true,
658                                         cltv_expiry_delta: (3 << 8) | 2,
659                                         htlc_minimum_msat: 0,
660                                         fee_base_msat: 100,
661                                         fee_proportional_millionths: 0,
662                                 },
663                         });
664                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
665                                 features: GlobalFeatures::new(),
666                                 one_to_two: DirectionalChannelInfo {
667                                         src_node_id: node2.clone(),
668                                         last_update: 0,
669                                         enabled: true,
670                                         cltv_expiry_delta: (4 << 8) | 1,
671                                         htlc_minimum_msat: 0,
672                                         fee_base_msat: 0,
673                                         fee_proportional_millionths: 1000000,
674                                 }, two_to_one: DirectionalChannelInfo {
675                                         src_node_id: node3.clone(),
676                                         last_update: 0,
677                                         enabled: true,
678                                         cltv_expiry_delta: (4 << 8) | 2,
679                                         htlc_minimum_msat: 0,
680                                         fee_base_msat: 0,
681                                         fee_proportional_millionths: 0,
682                                 },
683                         });
684                         network.nodes.insert(node4.clone(), NodeInfo {
685                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
686                                 lowest_inbound_channel_fee_base_msat: 0,
687                                 lowest_inbound_channel_fee_proportional_millionths: 0,
688                                 features: GlobalFeatures::new(),
689                                 last_update: 1,
690                                 rgb: [0; 3],
691                                 alias: [0; 32],
692                                 addresses: Vec::new(),
693                         });
694                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
695                                 features: GlobalFeatures::new(),
696                                 one_to_two: DirectionalChannelInfo {
697                                         src_node_id: node3.clone(),
698                                         last_update: 0,
699                                         enabled: true,
700                                         cltv_expiry_delta: (5 << 8) | 1,
701                                         htlc_minimum_msat: 0,
702                                         fee_base_msat: 100,
703                                         fee_proportional_millionths: 0,
704                                 }, two_to_one: DirectionalChannelInfo {
705                                         src_node_id: node4.clone(),
706                                         last_update: 0,
707                                         enabled: true,
708                                         cltv_expiry_delta: (5 << 8) | 2,
709                                         htlc_minimum_msat: 0,
710                                         fee_base_msat: 0,
711                                         fee_proportional_millionths: 0,
712                                 },
713                         });
714                         network.nodes.insert(node5.clone(), NodeInfo {
715                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
716                                 lowest_inbound_channel_fee_base_msat: 0,
717                                 lowest_inbound_channel_fee_proportional_millionths: 0,
718                                 features: GlobalFeatures::new(),
719                                 last_update: 1,
720                                 rgb: [0; 3],
721                                 alias: [0; 32],
722                                 addresses: Vec::new(),
723                         });
724                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
725                                 features: GlobalFeatures::new(),
726                                 one_to_two: DirectionalChannelInfo {
727                                         src_node_id: node3.clone(),
728                                         last_update: 0,
729                                         enabled: true,
730                                         cltv_expiry_delta: (6 << 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: node5.clone(),
736                                         last_update: 0,
737                                         enabled: true,
738                                         cltv_expiry_delta: (6 << 8) | 2,
739                                         htlc_minimum_msat: 0,
740                                         fee_base_msat: 0,
741                                         fee_proportional_millionths: 0,
742                                 },
743                         });
744                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
745                                 features: GlobalFeatures::new(),
746                                 one_to_two: DirectionalChannelInfo {
747                                         src_node_id: node5.clone(),
748                                         last_update: 0,
749                                         enabled: true,
750                                         cltv_expiry_delta: (11 << 8) | 1,
751                                         htlc_minimum_msat: 0,
752                                         fee_base_msat: 0,
753                                         fee_proportional_millionths: 0,
754                                 }, two_to_one: DirectionalChannelInfo {
755                                         src_node_id: node4.clone(),
756                                         last_update: 0,
757                                         enabled: true,
758                                         cltv_expiry_delta: (11 << 8) | 2,
759                                         htlc_minimum_msat: 0,
760                                         fee_base_msat: 0,
761                                         fee_proportional_millionths: 0,
762                                 },
763                         });
764                         network.nodes.insert(node6.clone(), NodeInfo {
765                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
766                                 lowest_inbound_channel_fee_base_msat: 0,
767                                 lowest_inbound_channel_fee_proportional_millionths: 0,
768                                 features: GlobalFeatures::new(),
769                                 last_update: 1,
770                                 rgb: [0; 3],
771                                 alias: [0; 32],
772                                 addresses: Vec::new(),
773                         });
774                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
775                                 features: GlobalFeatures::new(),
776                                 one_to_two: DirectionalChannelInfo {
777                                         src_node_id: node3.clone(),
778                                         last_update: 0,
779                                         enabled: true,
780                                         cltv_expiry_delta: (7 << 8) | 1,
781                                         htlc_minimum_msat: 0,
782                                         fee_base_msat: 0,
783                                         fee_proportional_millionths: 1000000,
784                                 }, two_to_one: DirectionalChannelInfo {
785                                         src_node_id: node6.clone(),
786                                         last_update: 0,
787                                         enabled: true,
788                                         cltv_expiry_delta: (7 << 8) | 2,
789                                         htlc_minimum_msat: 0,
790                                         fee_base_msat: 0,
791                                         fee_proportional_millionths: 0,
792                                 },
793                         });
794                 }
795
796                 { // Simple route to 3 via 2
797                         let route = router.get_route(&node3, &Vec::new(), 100, 42).unwrap();
798                         assert_eq!(route.hops.len(), 2);
799
800                         assert_eq!(route.hops[0].pubkey, node2);
801                         assert_eq!(route.hops[0].short_channel_id, 2);
802                         assert_eq!(route.hops[0].fee_msat, 100);
803                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
804
805                         assert_eq!(route.hops[1].pubkey, node3);
806                         assert_eq!(route.hops[1].short_channel_id, 4);
807                         assert_eq!(route.hops[1].fee_msat, 100);
808                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
809                 }
810
811                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
812                         let route = router.get_route(&node1, &Vec::new(), 100, 42).unwrap();
813                         assert_eq!(route.hops.len(), 3);
814
815                         assert_eq!(route.hops[0].pubkey, node2);
816                         assert_eq!(route.hops[0].short_channel_id, 2);
817                         assert_eq!(route.hops[0].fee_msat, 200);
818                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
819
820                         assert_eq!(route.hops[1].pubkey, node3);
821                         assert_eq!(route.hops[1].short_channel_id, 4);
822                         assert_eq!(route.hops[1].fee_msat, 100);
823                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
824
825                         assert_eq!(route.hops[2].pubkey, node1);
826                         assert_eq!(route.hops[2].short_channel_id, 3);
827                         assert_eq!(route.hops[2].fee_msat, 100);
828                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
829                 }
830
831                 let mut last_hops = vec!(RouteHint {
832                                 src_node_id: node4.clone(),
833                                 short_channel_id: 8,
834                                 fee_base_msat: 0,
835                                 fee_proportional_millionths: 0,
836                                 cltv_expiry_delta: (8 << 8) | 1,
837                                 htlc_minimum_msat: 0,
838                         }, RouteHint {
839                                 src_node_id: node5.clone(),
840                                 short_channel_id: 9,
841                                 fee_base_msat: 1001,
842                                 fee_proportional_millionths: 0,
843                                 cltv_expiry_delta: (9 << 8) | 1,
844                                 htlc_minimum_msat: 0,
845                         }, RouteHint {
846                                 src_node_id: node6.clone(),
847                                 short_channel_id: 10,
848                                 fee_base_msat: 0,
849                                 fee_proportional_millionths: 0,
850                                 cltv_expiry_delta: (10 << 8) | 1,
851                                 htlc_minimum_msat: 0,
852                         });
853
854                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
855                         let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
856                         assert_eq!(route.hops.len(), 5);
857
858                         assert_eq!(route.hops[0].pubkey, node2);
859                         assert_eq!(route.hops[0].short_channel_id, 2);
860                         assert_eq!(route.hops[0].fee_msat, 100);
861                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
862
863                         assert_eq!(route.hops[1].pubkey, node3);
864                         assert_eq!(route.hops[1].short_channel_id, 4);
865                         assert_eq!(route.hops[1].fee_msat, 0);
866                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
867
868                         assert_eq!(route.hops[2].pubkey, node5);
869                         assert_eq!(route.hops[2].short_channel_id, 6);
870                         assert_eq!(route.hops[2].fee_msat, 0);
871                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
872
873                         assert_eq!(route.hops[3].pubkey, node4);
874                         assert_eq!(route.hops[3].short_channel_id, 11);
875                         assert_eq!(route.hops[3].fee_msat, 0);
876                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
877
878                         assert_eq!(route.hops[4].pubkey, node7);
879                         assert_eq!(route.hops[4].short_channel_id, 8);
880                         assert_eq!(route.hops[4].fee_msat, 100);
881                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
882                 }
883
884                 last_hops[0].fee_base_msat = 1000;
885
886                 { // Revert to via 6 as the fee on 8 goes up
887                         let route = router.get_route(&node7, &last_hops, 100, 42).unwrap();
888                         assert_eq!(route.hops.len(), 4);
889
890                         assert_eq!(route.hops[0].pubkey, node2);
891                         assert_eq!(route.hops[0].short_channel_id, 2);
892                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
893                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
894
895                         assert_eq!(route.hops[1].pubkey, node3);
896                         assert_eq!(route.hops[1].short_channel_id, 4);
897                         assert_eq!(route.hops[1].fee_msat, 100);
898                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
899
900                         assert_eq!(route.hops[2].pubkey, node6);
901                         assert_eq!(route.hops[2].short_channel_id, 7);
902                         assert_eq!(route.hops[2].fee_msat, 0);
903                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
904
905                         assert_eq!(route.hops[3].pubkey, node7);
906                         assert_eq!(route.hops[3].short_channel_id, 10);
907                         assert_eq!(route.hops[3].fee_msat, 100);
908                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
909                 }
910
911                 { // ...but still use 8 for larger payments as 6 has a variable feerate
912                         let route = router.get_route(&node7, &last_hops, 2000, 42).unwrap();
913                         assert_eq!(route.hops.len(), 5);
914
915                         assert_eq!(route.hops[0].pubkey, node2);
916                         assert_eq!(route.hops[0].short_channel_id, 2);
917                         assert_eq!(route.hops[0].fee_msat, 3000);
918                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
919
920                         assert_eq!(route.hops[1].pubkey, node3);
921                         assert_eq!(route.hops[1].short_channel_id, 4);
922                         assert_eq!(route.hops[1].fee_msat, 0);
923                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
924
925                         assert_eq!(route.hops[2].pubkey, node5);
926                         assert_eq!(route.hops[2].short_channel_id, 6);
927                         assert_eq!(route.hops[2].fee_msat, 0);
928                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
929
930                         assert_eq!(route.hops[3].pubkey, node4);
931                         assert_eq!(route.hops[3].short_channel_id, 11);
932                         assert_eq!(route.hops[3].fee_msat, 1000);
933                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
934
935                         assert_eq!(route.hops[4].pubkey, node7);
936                         assert_eq!(route.hops[4].short_channel_id, 8);
937                         assert_eq!(route.hops[4].fee_msat, 2000);
938                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
939                 }
940         }
941 }