_ Git - rust-lightning/blob - lightning-invoice/src/utils.rs

   1 //! Convenient utilities to create an invoice.
   2
   3 use {CreationError, Currency, DEFAULT_EXPIRY_TIME, Invoice, InvoiceBuilder, SignOrCreationError};
   4 use payment::{Payer, Router};
   5
   6 use bech32::ToBase32;
   7 use bitcoin_hashes::{Hash, sha256};
   8 use crate::prelude::*;
   9 use lightning::chain;
  10 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  11 use lightning::chain::keysinterface::{Recipient, KeysInterface, Sign};
  12 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  13 use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, PaymentId, PaymentSendFailure, MIN_FINAL_CLTV_EXPIRY};
  14 #[cfg(feature = "std")]
  15 use lightning::ln::channelmanager::{PhantomRouteHints, MIN_CLTV_EXPIRY_DELTA};
  16 use lightning::ln::msgs::LightningError;
  17 use lightning::routing::scoring::Score;
  18 use lightning::routing::network_graph::{NetworkGraph, RoutingFees};
  19 use lightning::routing::router::{Route, RouteHint, RouteHintHop, RouteParameters, find_route};
  20 use lightning::util::logger::Logger;
  21 use secp256k1::key::PublicKey;
  22 use core::convert::TryInto;
  23 use core::ops::Deref;
  24 use core::time::Duration;
  25 use sync::Mutex;
  26
  27 #[cfg(feature = "std")]
  28 /// Utility to create an invoice that can be paid to one of multiple nodes, or a "phantom invoice."
  29 /// See [`PhantomKeysManager`] for more information on phantom node payments.
  30 ///
  31 /// `phantom_route_hints` parameter:
  32 /// * Contains channel info for all nodes participating in the phantom invoice
  33 /// * Entries are retrieved from a call to [`ChannelManager::get_phantom_route_hints`] on each
  34 ///   participating node
  35 /// * It is fine to cache `phantom_route_hints` and reuse it across invoices, as long as the data is
  36 ///   updated when a channel becomes disabled or closes
  37 /// * Note that if too many channels are included in [`PhantomRouteHints::channels`], the invoice
  38 ///   may be too long for QR code scanning. To fix this, `PhantomRouteHints::channels` may be pared
  39 ///   down
  40 ///
  41 /// `payment_hash` and `payment_secret` come from [`ChannelManager::create_inbound_payment`] or
  42 /// [`ChannelManager::create_inbound_payment_for_hash`]. These values can be retrieved from any
  43 /// participating node.
  44 ///
  45 /// Note that the provided `keys_manager`'s `KeysInterface` implementation must support phantom
  46 /// invoices in its `sign_invoice` implementation ([`PhantomKeysManager`] satisfies this
  47 /// requirement).
  48 ///
  49 /// [`PhantomKeysManager`]: lightning::chain::keysinterface::PhantomKeysManager
  50 /// [`ChannelManager::get_phantom_route_hints`]: lightning::ln::channelmanager::ChannelManager::get_phantom_route_hints
  51 /// [`PhantomRouteHints::channels`]: lightning::ln::channelmanager::PhantomRouteHints::channels
  52 pub fn create_phantom_invoice<Signer: Sign, K: Deref>(
  53         amt_msat: Option<u64>, description: String, payment_hash: PaymentHash, payment_secret:
  54         PaymentSecret, phantom_route_hints: Vec<PhantomRouteHints>, keys_manager: K, network: Currency
  55 ) -> Result<Invoice, SignOrCreationError<()>> where K::Target: KeysInterface {
  56         if phantom_route_hints.len() == 0 {
  57                 return Err(SignOrCreationError::CreationError(CreationError::MissingRouteHints))
  58         }
  59         let mut invoice = InvoiceBuilder::new(network)
  60                 .description(description)
  61                 .current_timestamp()
  62                 .payment_hash(Hash::from_slice(&payment_hash.0).unwrap())
  63                 .payment_secret(payment_secret)
  64                 .min_final_cltv_expiry(MIN_FINAL_CLTV_EXPIRY.into());
  65         if let Some(amt) = amt_msat {
  66                 invoice = invoice.amount_milli_satoshis(amt);
  67         }
  68
  69         for hint in phantom_route_hints {
  70                 for channel in &hint.channels {
  71                         let short_channel_id = match channel.short_channel_id {
  72                                 Some(id) => id,
  73                                 None => continue,
  74                         };
  75                         let forwarding_info = match &channel.counterparty.forwarding_info {
  76                                 Some(info) => info.clone(),
  77                                 None => continue,
  78                         };
  79                         invoice = invoice.private_route(RouteHint(vec![
  80                                         RouteHintHop {
  81                                                 src_node_id: channel.counterparty.node_id,
  82                                                 short_channel_id,
  83                                                 fees: RoutingFees {
  84                                                         base_msat: forwarding_info.fee_base_msat,
  85                                                         proportional_millionths: forwarding_info.fee_proportional_millionths,
  86                                                 },
  87                                                 cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
  88                                                 htlc_minimum_msat: None,
  89                                                 htlc_maximum_msat: None,
  90                                         },
  91                                         RouteHintHop {
  92                                                 src_node_id: hint.real_node_pubkey,
  93                                                 short_channel_id: hint.phantom_scid,
  94                                                 fees: RoutingFees {
  95                                                         base_msat: 0,
  96                                                         proportional_millionths: 0,
  97                                                 },
  98                                                 cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
  99                                                 htlc_minimum_msat: None,
 100                                                 htlc_maximum_msat: None,
 101                                         }])
 102                         );
 103                 }
 104         }
 105
 106         let raw_invoice = match invoice.build_raw() {
 107                 Ok(inv) => inv,
 108                 Err(e) => return Err(SignOrCreationError::CreationError(e))
 109         };
 110         let hrp_str = raw_invoice.hrp.to_string();
 111         let hrp_bytes = hrp_str.as_bytes();
 112         let data_without_signature = raw_invoice.data.to_base32();
 113         let signed_raw_invoice = raw_invoice.sign(|_| keys_manager.sign_invoice(hrp_bytes, &data_without_signature, Recipient::PhantomNode));
 114         match signed_raw_invoice {
 115                 Ok(inv) => Ok(Invoice::from_signed(inv).unwrap()),
 116                 Err(e) => Err(SignOrCreationError::SignError(e))
 117         }
 118 }
 119
 120 #[cfg(feature = "std")]
 121 /// Utility to construct an invoice. Generally, unless you want to do something like a custom
 122 /// cltv_expiry, this is what you should be using to create an invoice. The reason being, this
 123 /// method stores the invoice's payment secret and preimage in `ChannelManager`, so (a) the user
 124 /// doesn't have to store preimage/payment secret information and (b) `ChannelManager` can verify
 125 /// that the payment secret is valid when the invoice is paid.
 126 pub fn create_invoice_from_channelmanager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>(
 127         channelmanager: &ChannelManager<Signer, M, T, K, F, L>, keys_manager: K, network: Currency,
 128         amt_msat: Option<u64>, description: String
 129 ) -> Result<Invoice, SignOrCreationError<()>>
 130 where
 131         M::Target: chain::Watch<Signer>,
 132         T::Target: BroadcasterInterface,
 133         K::Target: KeysInterface<Signer = Signer>,
 134         F::Target: FeeEstimator,
 135         L::Target: Logger,
 136 {
 137         use std::time::SystemTime;
 138         let duration = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)
 139                 .expect("for the foreseeable future this shouldn't happen");
 140         create_invoice_from_channelmanager_and_duration_since_epoch(
 141                 channelmanager,
 142                 keys_manager,
 143                 network,
 144                 amt_msat,
 145                 description,
 146                 duration
 147         )
 148 }
 149
 150 /// See [`create_invoice_from_channelmanager`]
 151 /// This version can be used in a `no_std` environment, where [`std::time::SystemTime`] is not
 152 /// available and the current time is supplied by the caller.
 153 pub fn create_invoice_from_channelmanager_and_duration_since_epoch<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>(
 154         channelmanager: &ChannelManager<Signer, M, T, K, F, L>, keys_manager: K, network: Currency,
 155         amt_msat: Option<u64>, description: String, duration_since_epoch: Duration,
 156 ) -> Result<Invoice, SignOrCreationError<()>>
 157 where
 158         M::Target: chain::Watch<Signer>,
 159         T::Target: BroadcasterInterface,
 160         K::Target: KeysInterface<Signer = Signer>,
 161         F::Target: FeeEstimator,
 162         L::Target: Logger,
 163 {
 164         // Marshall route hints.
 165         let our_channels = channelmanager.list_usable_channels();
 166         let mut route_hints = vec![];
 167         for channel in our_channels {
 168                 let short_channel_id = match channel.short_channel_id {
 169                         Some(id) => id,
 170                         None => continue,
 171                 };
 172                 let forwarding_info = match channel.counterparty.forwarding_info {
 173                         Some(info) => info,
 174                         None => continue,
 175                 };
 176                 route_hints.push(RouteHint(vec![RouteHintHop {
 177                         src_node_id: channel.counterparty.node_id,
 178                         short_channel_id,
 179                         fees: RoutingFees {
 180                                 base_msat: forwarding_info.fee_base_msat,
 181                                 proportional_millionths: forwarding_info.fee_proportional_millionths,
 182                         },
 183                         cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
 184                         htlc_minimum_msat: None,
 185                         htlc_maximum_msat: None,
 186                 }]));
 187         }
 188
 189         // `create_inbound_payment` only returns an error if the amount is greater than the total bitcoin
 190         // supply.
 191         let (payment_hash, payment_secret) = channelmanager.create_inbound_payment(
 192                 amt_msat, DEFAULT_EXPIRY_TIME.try_into().unwrap())
 193                 .map_err(|()| SignOrCreationError::CreationError(CreationError::InvalidAmount))?;
 194         let our_node_pubkey = channelmanager.get_our_node_id();
 195         let mut invoice = InvoiceBuilder::new(network)
 196                 .description(description)
 197                 .duration_since_epoch(duration_since_epoch)
 198                 .payee_pub_key(our_node_pubkey)
 199                 .payment_hash(Hash::from_slice(&payment_hash.0).unwrap())
 200                 .payment_secret(payment_secret)
 201                 .basic_mpp()
 202                 .min_final_cltv_expiry(MIN_FINAL_CLTV_EXPIRY.into());
 203         if let Some(amt) = amt_msat {
 204                 invoice = invoice.amount_milli_satoshis(amt);
 205         }
 206         for hint in route_hints {
 207                 invoice = invoice.private_route(hint);
 208         }
 209
 210         let raw_invoice = match invoice.build_raw() {
 211                 Ok(inv) => inv,
 212                 Err(e) => return Err(SignOrCreationError::CreationError(e))
 213         };
 214         let hrp_str = raw_invoice.hrp.to_string();
 215         let hrp_bytes = hrp_str.as_bytes();
 216         let data_without_signature = raw_invoice.data.to_base32();
 217         let signed_raw_invoice = raw_invoice.sign(|_| keys_manager.sign_invoice(hrp_bytes, &data_without_signature, Recipient::Node));
 218         match signed_raw_invoice {
 219                 Ok(inv) => Ok(Invoice::from_signed(inv).unwrap()),
 220                 Err(e) => Err(SignOrCreationError::SignError(e))
 221         }
 222 }
 223
 224 /// A [`Router`] implemented using [`find_route`].
 225 pub struct DefaultRouter<G: Deref<Target = NetworkGraph>, L: Deref> where L::Target: Logger {
 226         network_graph: G,
 227         logger: L,
 228         random_seed_bytes: Mutex<[u8; 32]>,
 229 }
 230
 231 impl<G: Deref<Target = NetworkGraph>, L: Deref> DefaultRouter<G, L> where L::Target: Logger {
 232         /// Creates a new router using the given [`NetworkGraph`], a [`Logger`], and a randomness source
 233         /// `random_seed_bytes`.
 234         pub fn new(network_graph: G, logger: L, random_seed_bytes: [u8; 32]) -> Self {
 235                 let random_seed_bytes = Mutex::new(random_seed_bytes);
 236                 Self { network_graph, logger, random_seed_bytes }
 237         }
 238 }
 239
 240 impl<G: Deref<Target = NetworkGraph>, L: Deref, S: Score> Router<S> for DefaultRouter<G, L>
 241 where L::Target: Logger {
 242         fn find_route(
 243                 &self, payer: &PublicKey, params: &RouteParameters, _payment_hash: &PaymentHash,
 244                 first_hops: Option<&[&ChannelDetails]>, scorer: &S
 245         ) -> Result<Route, LightningError> {
 246                 let random_seed_bytes = {
 247                         let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
 248                         *locked_random_seed_bytes = sha256::Hash::hash(&*locked_random_seed_bytes).into_inner();
 249                         *locked_random_seed_bytes
 250                 };
 251                 find_route(payer, params, &*self.network_graph, first_hops, &*self.logger, scorer, &random_seed_bytes)
 252         }
 253 }
 254
 255 impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Payer for ChannelManager<Signer, M, T, K, F, L>
 256 where
 257         M::Target: chain::Watch<Signer>,
 258         T::Target: BroadcasterInterface,
 259         K::Target: KeysInterface<Signer = Signer>,
 260         F::Target: FeeEstimator,
 261         L::Target: Logger,
 262 {
 263         fn node_id(&self) -> PublicKey {
 264                 self.get_our_node_id()
 265         }
 266
 267         fn first_hops(&self) -> Vec<ChannelDetails> {
 268                 self.list_usable_channels()
 269         }
 270
 271         fn send_payment(
 272                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>
 273         ) -> Result<PaymentId, PaymentSendFailure> {
 274                 self.send_payment(route, payment_hash, payment_secret)
 275         }
 276
 277         fn send_spontaneous_payment(
 278                 &self, route: &Route, payment_preimage: PaymentPreimage,
 279         ) -> Result<PaymentId, PaymentSendFailure> {
 280                 self.send_spontaneous_payment(route, Some(payment_preimage))
 281                         .map(|(_, payment_id)| payment_id)
 282         }
 283
 284         fn retry_payment(
 285                 &self, route: &Route, payment_id: PaymentId
 286         ) -> Result<(), PaymentSendFailure> {
 287                 self.retry_payment(route, payment_id)
 288         }
 289
 290         fn abandon_payment(&self, payment_id: PaymentId) {
 291                 self.abandon_payment(payment_id)
 292         }
 293 }
 294
 295 #[cfg(test)]
 296 mod test {
 297         use core::time::Duration;
 298         use {Currency, Description, InvoiceDescription};
 299         use bitcoin_hashes::Hash;
 300         use bitcoin_hashes::sha256::Hash as Sha256;
 301         use lightning::chain::keysinterface::PhantomKeysManager;
 302         use lightning::ln::{PaymentPreimage, PaymentHash};
 303         use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY;
 304         use lightning::ln::functional_test_utils::*;
 305         use lightning::ln::features::InitFeatures;
 306         use lightning::ln::msgs::ChannelMessageHandler;
 307         use lightning::routing::router::{PaymentParameters, RouteParameters, find_route};
 308         use lightning::util::enforcing_trait_impls::EnforcingSigner;
 309         use lightning::util::events::{MessageSendEvent, MessageSendEventsProvider, Event};
 310         use lightning::util::test_utils;
 311         use lightning::chain::keysinterface::KeysInterface;
 312         use utils::create_invoice_from_channelmanager_and_duration_since_epoch;
 313
 314         #[test]
 315         fn test_from_channelmanager() {
 316                 let chanmon_cfgs = create_chanmon_cfgs(2);
 317                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 318                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 319                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 320                 let _chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 321                 let invoice = create_invoice_from_channelmanager_and_duration_since_epoch(
 322                         &nodes[1].node, nodes[1].keys_manager, Currency::BitcoinTestnet, Some(10_000), "test".to_string(),
 323                         Duration::from_secs(1234567)).unwrap();
 324                 assert_eq!(invoice.amount_pico_btc(), Some(100_000));
 325                 assert_eq!(invoice.min_final_cltv_expiry(), MIN_FINAL_CLTV_EXPIRY as u64);
 326                 assert_eq!(invoice.description(), InvoiceDescription::Direct(&Description("test".to_string())));
 327
 328                 let payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
 329                         .with_features(invoice.features().unwrap().clone())
 330                         .with_route_hints(invoice.route_hints());
 331                 let route_params = RouteParameters {
 332                         payment_params,
 333                         final_value_msat: invoice.amount_milli_satoshis().unwrap(),
 334                         final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
 335                 };
 336                 let first_hops = nodes[0].node.list_usable_channels();
 337                 let network_graph = node_cfgs[0].network_graph;
 338                 let logger = test_utils::TestLogger::new();
 339                 let scorer = test_utils::TestScorer::with_penalty(0);
 340                 let random_seed_bytes = chanmon_cfgs[1].keys_manager.get_secure_random_bytes();
 341                 let route = find_route(
 342                         &nodes[0].node.get_our_node_id(), &route_params, network_graph,
 343                         Some(&first_hops.iter().collect::<Vec<_>>()), &logger, &scorer, &random_seed_bytes
 344                 ).unwrap();
 345
 346                 let payment_event = {
 347                         let mut payment_hash = PaymentHash([0; 32]);
 348                         payment_hash.0.copy_from_slice(&invoice.payment_hash().as_ref()[0..32]);
 349                         nodes[0].node.send_payment(&route, payment_hash, &Some(invoice.payment_secret().clone())).unwrap();
 350                         let mut added_monitors = nodes[0].chain_monitor.added_monitors.lock().unwrap();
 351                         assert_eq!(added_monitors.len(), 1);
 352                         added_monitors.clear();
 353
 354                         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 355                         assert_eq!(events.len(), 1);
 356                         SendEvent::from_event(events.remove(0))
 357
 358                 };
 359                 nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 360                 nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &payment_event.commitment_msg);
 361                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 362                 assert_eq!(added_monitors.len(), 1);
 363                 added_monitors.clear();
 364                 let events = nodes[1].node.get_and_clear_pending_msg_events();
 365                 assert_eq!(events.len(), 2);
 366         }
 367
 368         #[test]
 369         #[cfg(feature = "std")]
 370         fn test_multi_node_receive() {
 371                 do_test_multi_node_receive(true);
 372                 do_test_multi_node_receive(false);
 373         }
 374
 375         #[cfg(feature = "std")]
 376         fn do_test_multi_node_receive(user_generated_pmt_hash: bool) {
 377                 let mut chanmon_cfgs = create_chanmon_cfgs(3);
 378                 let seed_1 = [42 as u8; 32];
 379                 let seed_2 = [43 as u8; 32];
 380                 let cross_node_seed = [44 as u8; 32];
 381                 chanmon_cfgs[1].keys_manager.backing = PhantomKeysManager::new(&seed_1, 43, 44, &cross_node_seed);
 382                 chanmon_cfgs[2].keys_manager.backing = PhantomKeysManager::new(&seed_2, 43, 44, &cross_node_seed);
 383                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 384                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 385                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 386                 let chan_0_1 = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 10001, InitFeatures::known(), InitFeatures::known());
 387                 nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan_0_1.1);
 388                 nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &chan_0_1.0);
 389                 let chan_0_2 = create_announced_chan_between_nodes_with_value(&nodes, 0, 2, 100000, 10001, InitFeatures::known(), InitFeatures::known());
 390                 nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan_0_2.1);
 391                 nodes[2].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &chan_0_2.0);
 392
 393                 let payment_amt = 10_000;
 394                 let (payment_preimage, payment_hash, payment_secret) = {
 395                         if user_generated_pmt_hash {
 396                                 let payment_preimage = PaymentPreimage([1; 32]);
 397                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner());
 398                                 let payment_secret = nodes[1].node.create_inbound_payment_for_hash(payment_hash, Some(payment_amt), 3600).unwrap();
 399                                 (payment_preimage, payment_hash, payment_secret)
 400                         } else {
 401                                 let (payment_hash, payment_secret) = nodes[1].node.create_inbound_payment(Some(payment_amt), 3600).unwrap();
 402                                 let payment_preimage = nodes[1].node.get_payment_preimage(payment_hash, payment_secret).unwrap();
 403                                 (payment_preimage, payment_hash, payment_secret)
 404                         }
 405                 };
 406                 let route_hints = vec![
 407                         nodes[1].node.get_phantom_route_hints(),
 408                         nodes[2].node.get_phantom_route_hints(),
 409                 ];
 410                 let invoice = ::utils::create_phantom_invoice::<EnforcingSigner, &test_utils::TestKeysInterface>(Some(payment_amt), "test".to_string(), payment_hash, payment_secret, route_hints, &nodes[1].keys_manager, Currency::BitcoinTestnet).unwrap();
 411
 412                 assert_eq!(invoice.min_final_cltv_expiry(), MIN_FINAL_CLTV_EXPIRY as u64);
 413                 assert_eq!(invoice.description(), InvoiceDescription::Direct(&Description("test".to_string())));
 414                 assert_eq!(invoice.route_hints().len(), 2);
 415                 assert!(!invoice.features().unwrap().supports_basic_mpp());
 416
 417                 let payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
 418                         .with_features(invoice.features().unwrap().clone())
 419                         .with_route_hints(invoice.route_hints());
 420                 let params = RouteParameters {
 421                         payment_params,
 422                         final_value_msat: invoice.amount_milli_satoshis().unwrap(),
 423                         final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
 424                 };
 425                 let first_hops = nodes[0].node.list_usable_channels();
 426                 let network_graph = node_cfgs[0].network_graph;
 427                 let logger = test_utils::TestLogger::new();
 428                 let scorer = test_utils::TestScorer::with_penalty(0);
 429                 let random_seed_bytes = chanmon_cfgs[1].keys_manager.get_secure_random_bytes();
 430                 let route = find_route(
 431                         &nodes[0].node.get_our_node_id(), &params, network_graph,
 432                         Some(&first_hops.iter().collect::<Vec<_>>()), &logger, &scorer, &random_seed_bytes
 433                 ).unwrap();
 434                 let (payment_event, fwd_idx) = {
 435                         let mut payment_hash = PaymentHash([0; 32]);
 436                         payment_hash.0.copy_from_slice(&invoice.payment_hash().as_ref()[0..32]);
 437                         nodes[0].node.send_payment(&route, payment_hash, &Some(invoice.payment_secret().clone())).unwrap();
 438                         let mut added_monitors = nodes[0].chain_monitor.added_monitors.lock().unwrap();
 439                         assert_eq!(added_monitors.len(), 1);
 440                         added_monitors.clear();
 441
 442                         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 443                         assert_eq!(events.len(), 1);
 444                         let fwd_idx = match events[0] {
 445                                 MessageSendEvent::UpdateHTLCs { node_id, .. } => {
 446                                         if node_id == nodes[1].node.get_our_node_id() {
 447                                                 1
 448                                         } else { 2 }
 449                                 },
 450                                 _ => panic!("Unexpected event")
 451                         };
 452                         (SendEvent::from_event(events.remove(0)), fwd_idx)
 453                 };
 454                 nodes[fwd_idx].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 455                 commitment_signed_dance!(nodes[fwd_idx], nodes[0], &payment_event.commitment_msg, false, true);
 456
 457                 // Note that we have to "forward pending HTLCs" twice before we see the PaymentReceived as
 458                 // this "emulates" the payment taking two hops, providing some privacy to make phantom node
 459                 // payments "look real" by taking more time.
 460                 expect_pending_htlcs_forwardable_ignore!(nodes[fwd_idx]);
 461                 nodes[fwd_idx].node.process_pending_htlc_forwards();
 462                 expect_pending_htlcs_forwardable_ignore!(nodes[fwd_idx]);
 463                 nodes[fwd_idx].node.process_pending_htlc_forwards();
 464
 465                 let payment_preimage_opt = if user_generated_pmt_hash { None } else { Some(payment_preimage) };
 466                 expect_payment_received!(&nodes[fwd_idx], payment_hash, payment_secret, payment_amt, payment_preimage_opt);
 467                 do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[fwd_idx])[..]), false, payment_preimage);
 468                 let events = nodes[0].node.get_and_clear_pending_events();
 469                 assert_eq!(events.len(), 2);
 470                 match events[0] {
 471                         Event::PaymentSent { payment_preimage: ref ev_preimage, payment_hash: ref ev_hash, ref fee_paid_msat, .. } => {
 472                                 assert_eq!(payment_preimage, *ev_preimage);
 473                                 assert_eq!(payment_hash, *ev_hash);
 474                                 assert_eq!(fee_paid_msat, &Some(0));
 475                         },
 476                         _ => panic!("Unexpected event")
 477                 }
 478                 match events[1] {
 479                         Event::PaymentPathSuccessful { payment_hash: hash, .. } => {
 480                                 assert_eq!(hash, Some(payment_hash));
 481                         },
 482                         _ => panic!("Unexpected event")
 483                 }
 484         }
 485 }