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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! A module for paying Lightning invoices and sending spontaneous payments.
  11 //!
  12 //! Defines an [`InvoicePayer`] utility for sending payments, parameterized by [`Payer`] and
  13 //! [`Router`] traits. Implementations of [`Payer`] provide the payer's node id, channels, and means
  14 //! to send a payment over a [`Route`]. Implementations of [`Router`] find a [`Route`] between payer
  15 //! and payee using information provided by the payer and from the payee's [`Invoice`], when
  16 //! applicable.
  17 //!
  18 //! [`InvoicePayer`] is capable of retrying failed payments. It accomplishes this by implementing
  19 //! [`EventHandler`] which decorates a user-provided handler. It will intercept any
  20 //! [`Event::PaymentPathFailed`] events and retry the failed paths for a fixed number of total
  21 //! attempts or until retry is no longer possible. In such a situation, [`InvoicePayer`] will pass
  22 //! along the events to the user-provided handler.
  23 //!
  24 //! # Example
  25 //!
  26 //! ```
  27 //! # extern crate lightning;
  28 //! # extern crate lightning_invoice;
  29 //! # extern crate secp256k1;
  30 //! #
  31 //! # use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  32 //! # use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
  33 //! # use lightning::ln::msgs::LightningError;
  34 //! # use lightning::routing;
  35 //! # use lightning::routing::network_graph::NodeId;
  36 //! # use lightning::routing::router::{Route, RouteHop, RouteParameters};
  37 //! # use lightning::util::events::{Event, EventHandler, EventsProvider};
  38 //! # use lightning::util::logger::{Logger, Record};
  39 //! # use lightning_invoice::Invoice;
  40 //! # use lightning_invoice::payment::{InvoicePayer, Payer, RetryAttempts, Router};
  41 //! # use secp256k1::key::PublicKey;
  42 //! # use std::cell::RefCell;
  43 //! # use std::ops::Deref;
  44 //! #
  45 //! # struct FakeEventProvider {}
  46 //! # impl EventsProvider for FakeEventProvider {
  47 //! #     fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {}
  48 //! # }
  49 //! #
  50 //! # struct FakePayer {}
  51 //! # impl Payer for FakePayer {
  52 //! #     fn node_id(&self) -> PublicKey { unimplemented!() }
  53 //! #     fn first_hops(&self) -> Vec<ChannelDetails> { unimplemented!() }
  54 //! #     fn send_payment(
  55 //! #         &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>
  56 //! #     ) -> Result<PaymentId, PaymentSendFailure> { unimplemented!() }
  57 //! #     fn send_spontaneous_payment(
  58 //! #         &self, route: &Route, payment_preimage: PaymentPreimage
  59 //! #     ) -> Result<PaymentId, PaymentSendFailure> { unimplemented!() }
  60 //! #     fn retry_payment(
  61 //! #         &self, route: &Route, payment_id: PaymentId
  62 //! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
  63 //! # }
  64 //! #
  65 //! # struct FakeRouter {};
  66 //! # impl<S: routing::Score> Router<S> for FakeRouter {
  67 //! #     fn find_route(
  68 //! #         &self, payer: &PublicKey, params: &RouteParameters,
  69 //! #         first_hops: Option<&[&ChannelDetails]>, scorer: &S
  70 //! #     ) -> Result<Route, LightningError> { unimplemented!() }
  71 //! # }
  72 //! #
  73 //! # struct FakeScorer {};
  74 //! # impl routing::Score for FakeScorer {
  75 //! #     fn channel_penalty_msat(
  76 //! #         &self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId
  77 //! #     ) -> u64 { 0 }
  78 //! #     fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
  79 //! # }
  80 //! #
  81 //! # struct FakeLogger {};
  82 //! # impl Logger for FakeLogger {
  83 //! #     fn log(&self, record: &Record) { unimplemented!() }
  84 //! # }
  85 //! #
  86 //! # fn main() {
  87 //! let event_handler = |event: &Event| {
  88 //!     match event {
  89 //!         Event::PaymentPathFailed { .. } => println!("payment failed after retries"),
  90 //!         Event::PaymentSent { .. } => println!("payment successful"),
  91 //!         _ => {},
  92 //!     }
  93 //! };
  94 //! # let payer = FakePayer {};
  95 //! # let router = FakeRouter {};
  96 //! # let scorer = RefCell::new(FakeScorer {});
  97 //! # let logger = FakeLogger {};
  98 //! let invoice_payer = InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
  99 //!
 100 //! let invoice = "...";
 101 //! let invoice = invoice.parse::<Invoice>().unwrap();
 102 //! invoice_payer.pay_invoice(&invoice).unwrap();
 103 //!
 104 //! # let event_provider = FakeEventProvider {};
 105 //! loop {
 106 //!     event_provider.process_pending_events(&invoice_payer);
 107 //! }
 108 //! # }
 109 //! ```
 110 //!
 111 //! # Note
 112 //!
 113 //! The [`Route`] is computed before each payment attempt. Any updates affecting path finding such
 114 //! as updates to the network graph or changes to channel scores should be applied prior to
 115 //! retries, typically by way of composing [`EventHandler`]s accordingly.
 116
 117 use crate::Invoice;
 118
 119 use bitcoin_hashes::Hash;
 120 use bitcoin_hashes::sha256::Hash as Sha256;
 121
 122 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 123 use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
 124 use lightning::ln::msgs::LightningError;
 125 use lightning::routing;
 126 use lightning::routing::{LockableScore, Score};
 127 use lightning::routing::router::{Payee, Route, RouteParameters};
 128 use lightning::util::events::{Event, EventHandler};
 129 use lightning::util::logger::Logger;
 130
 131 use secp256k1::key::PublicKey;
 132
 133 use std::collections::hash_map::{self, HashMap};
 134 use std::ops::Deref;
 135 use std::sync::Mutex;
 136 use std::time::{Duration, SystemTime};
 137
 138 /// A utility for paying [`Invoice`]s and sending spontaneous payments.
 139 pub struct InvoicePayer<P: Deref, R, S: Deref, L: Deref, E>
 140 where
 141         P::Target: Payer,
 142         R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
 143         S::Target: for <'a> routing::LockableScore<'a>,
 144         L::Target: Logger,
 145         E: EventHandler,
 146 {
 147         payer: P,
 148         router: R,
 149         scorer: S,
 150         logger: L,
 151         event_handler: E,
 152         /// Caches the overall attempts at making a payment, which is updated prior to retrying.
 153         payment_cache: Mutex<HashMap<PaymentHash, usize>>,
 154         retry_attempts: RetryAttempts,
 155 }
 156
 157 /// A trait defining behavior of an [`Invoice`] payer.
 158 pub trait Payer {
 159         /// Returns the payer's node id.
 160         fn node_id(&self) -> PublicKey;
 161
 162         /// Returns the payer's channels.
 163         fn first_hops(&self) -> Vec<ChannelDetails>;
 164
 165         /// Sends a payment over the Lightning Network using the given [`Route`].
 166         fn send_payment(
 167                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>
 168         ) -> Result<PaymentId, PaymentSendFailure>;
 169
 170         /// Sends a spontaneous payment over the Lightning Network using the given [`Route`].
 171         fn send_spontaneous_payment(
 172                 &self, route: &Route, payment_preimage: PaymentPreimage
 173         ) -> Result<PaymentId, PaymentSendFailure>;
 174
 175         /// Retries a failed payment path for the [`PaymentId`] using the given [`Route`].
 176         fn retry_payment(&self, route: &Route, payment_id: PaymentId) -> Result<(), PaymentSendFailure>;
 177 }
 178
 179 /// A trait defining behavior for routing an [`Invoice`] payment.
 180 pub trait Router<S: routing::Score> {
 181         /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
 182         fn find_route(
 183                 &self, payer: &PublicKey, params: &RouteParameters, first_hops: Option<&[&ChannelDetails]>,
 184                 scorer: &S
 185         ) -> Result<Route, LightningError>;
 186 }
 187
 188 /// Number of attempts to retry payment path failures for an [`Invoice`].
 189 ///
 190 /// Note that this is the number of *path* failures, not full payment retries. For multi-path
 191 /// payments, if this is less than the total number of paths, we will never even retry all of the
 192 /// payment's paths.
 193 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 194 pub struct RetryAttempts(pub usize);
 195
 196 /// An error that may occur when making a payment.
 197 #[derive(Clone, Debug)]
 198 pub enum PaymentError {
 199         /// An error resulting from the provided [`Invoice`] or payment hash.
 200         Invoice(&'static str),
 201         /// An error occurring when finding a route.
 202         Routing(LightningError),
 203         /// An error occurring when sending a payment.
 204         Sending(PaymentSendFailure),
 205 }
 206
 207 impl<P: Deref, R, S: Deref, L: Deref, E> InvoicePayer<P, R, S, L, E>
 208 where
 209         P::Target: Payer,
 210         R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
 211         S::Target: for <'a> routing::LockableScore<'a>,
 212         L::Target: Logger,
 213         E: EventHandler,
 214 {
 215         /// Creates an invoice payer that retries failed payment paths.
 216         ///
 217         /// Will forward any [`Event::PaymentPathFailed`] events to the decorated `event_handler` once
 218         /// `retry_attempts` has been exceeded for a given [`Invoice`].
 219         pub fn new(
 220                 payer: P, router: R, scorer: S, logger: L, event_handler: E, retry_attempts: RetryAttempts
 221         ) -> Self {
 222                 Self {
 223                         payer,
 224                         router,
 225                         scorer,
 226                         logger,
 227                         event_handler,
 228                         payment_cache: Mutex::new(HashMap::new()),
 229                         retry_attempts,
 230                 }
 231         }
 232
 233         /// Pays the given [`Invoice`], caching it for later use in case a retry is needed.
 234         ///
 235         /// You should ensure that the `invoice.payment_hash()` is unique and the same payment_hash has
 236         /// never been paid before. Because [`InvoicePayer`] is stateless no effort is made to do so
 237         /// for you.
 238         pub fn pay_invoice(&self, invoice: &Invoice) -> Result<PaymentId, PaymentError> {
 239                 if invoice.amount_milli_satoshis().is_none() {
 240                         Err(PaymentError::Invoice("amount missing"))
 241                 } else {
 242                         self.pay_invoice_using_amount(invoice, None)
 243                 }
 244         }
 245
 246         /// Pays the given zero-value [`Invoice`] using the given amount, caching it for later use in
 247         /// case a retry is needed.
 248         ///
 249         /// You should ensure that the `invoice.payment_hash()` is unique and the same payment_hash has
 250         /// never been paid before. Because [`InvoicePayer`] is stateless no effort is made to do so
 251         /// for you.
 252         pub fn pay_zero_value_invoice(
 253                 &self, invoice: &Invoice, amount_msats: u64
 254         ) -> Result<PaymentId, PaymentError> {
 255                 if invoice.amount_milli_satoshis().is_some() {
 256                         Err(PaymentError::Invoice("amount unexpected"))
 257                 } else {
 258                         self.pay_invoice_using_amount(invoice, Some(amount_msats))
 259                 }
 260         }
 261
 262         fn pay_invoice_using_amount(
 263                 &self, invoice: &Invoice, amount_msats: Option<u64>
 264         ) -> Result<PaymentId, PaymentError> {
 265                 debug_assert!(invoice.amount_milli_satoshis().is_some() ^ amount_msats.is_some());
 266
 267                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 268                 match self.payment_cache.lock().unwrap().entry(payment_hash) {
 269                         hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
 270                         hash_map::Entry::Vacant(entry) => entry.insert(0),
 271                 };
 272
 273                 let payment_secret = Some(invoice.payment_secret().clone());
 274                 let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key())
 275                         .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs())
 276                         .with_route_hints(invoice.route_hints());
 277                 if let Some(features) = invoice.features() {
 278                         payee = payee.with_features(features.clone());
 279                 }
 280                 let params = RouteParameters {
 281                         payee,
 282                         final_value_msat: invoice.amount_milli_satoshis().or(amount_msats).unwrap(),
 283                         final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
 284                 };
 285
 286                 let send_payment = |route: &Route| {
 287                         self.payer.send_payment(route, payment_hash, &payment_secret)
 288                 };
 289                 self.pay_internal(&params, payment_hash, send_payment)
 290                         .map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
 291         }
 292
 293         /// Pays `pubkey` an amount using the hash of the given preimage, caching it for later use in
 294         /// case a retry is needed.
 295         ///
 296         /// You should ensure that `payment_preimage` is unique and that its `payment_hash` has never
 297         /// been paid before. Because [`InvoicePayer`] is stateless no effort is made to do so for you.
 298         pub fn pay_pubkey(
 299                 &self, pubkey: PublicKey, payment_preimage: PaymentPreimage, amount_msats: u64,
 300                 final_cltv_expiry_delta: u32
 301         ) -> Result<PaymentId, PaymentError> {
 302                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 303                 match self.payment_cache.lock().unwrap().entry(payment_hash) {
 304                         hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
 305                         hash_map::Entry::Vacant(entry) => entry.insert(0),
 306                 };
 307
 308                 let params = RouteParameters {
 309                         payee: Payee::for_keysend(pubkey),
 310                         final_value_msat: amount_msats,
 311                         final_cltv_expiry_delta,
 312                 };
 313
 314                 let send_payment = |route: &Route| {
 315                         self.payer.send_spontaneous_payment(route, payment_preimage)
 316                 };
 317                 self.pay_internal(&params, payment_hash, send_payment)
 318                         .map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
 319         }
 320
 321         fn pay_internal<F: FnOnce(&Route) -> Result<PaymentId, PaymentSendFailure> + Copy>(
 322                 &self, params: &RouteParameters, payment_hash: PaymentHash, send_payment: F,
 323         ) -> Result<PaymentId, PaymentError> {
 324                 if has_expired(params) {
 325                         log_trace!(self.logger, "Invoice expired prior to send for payment {}", log_bytes!(payment_hash.0));
 326                         return Err(PaymentError::Invoice("Invoice expired prior to send"));
 327                 }
 328
 329                 let payer = self.payer.node_id();
 330                 let first_hops = self.payer.first_hops();
 331                 let route = self.router.find_route(
 332                         &payer,
 333                         params,
 334                         Some(&first_hops.iter().collect::<Vec<_>>()),
 335                         &self.scorer.lock(),
 336                 ).map_err(|e| PaymentError::Routing(e))?;
 337
 338                 match send_payment(&route) {
 339                         Ok(payment_id) => Ok(payment_id),
 340                         Err(e) => match e {
 341                                 PaymentSendFailure::ParameterError(_) => Err(e),
 342                                 PaymentSendFailure::PathParameterError(_) => Err(e),
 343                                 PaymentSendFailure::AllFailedRetrySafe(_) => {
 344                                         let mut payment_cache = self.payment_cache.lock().unwrap();
 345                                         let retry_count = payment_cache.get_mut(&payment_hash).unwrap();
 346                                         if *retry_count >= self.retry_attempts.0 {
 347                                                 Err(e)
 348                                         } else {
 349                                                 *retry_count += 1;
 350                                                 std::mem::drop(payment_cache);
 351                                                 Ok(self.pay_internal(params, payment_hash, send_payment)?)
 352                                         }
 353                                 },
 354                                 PaymentSendFailure::PartialFailure { failed_paths_retry, payment_id, .. } => {
 355                                         if let Some(retry_data) = failed_paths_retry {
 356                                                 // Some paths were sent, even if we failed to send the full MPP value our
 357                                                 // recipient may misbehave and claim the funds, at which point we have to
 358                                                 // consider the payment sent, so return `Ok()` here, ignoring any retry
 359                                                 // errors.
 360                                                 let _ = self.retry_payment(payment_id, payment_hash, &retry_data);
 361                                                 Ok(payment_id)
 362                                         } else {
 363                                                 // This may happen if we send a payment and some paths fail, but
 364                                                 // only due to a temporary monitor failure or the like, implying
 365                                                 // they're really in-flight, but we haven't sent the initial
 366                                                 // HTLC-Add messages yet.
 367                                                 Ok(payment_id)
 368                                         }
 369                                 },
 370                         },
 371                 }.map_err(|e| PaymentError::Sending(e))
 372         }
 373
 374         fn retry_payment(
 375                 &self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters
 376         ) -> Result<(), ()> {
 377                 let max_payment_attempts = self.retry_attempts.0 + 1;
 378                 let attempts = *self.payment_cache.lock().unwrap()
 379                         .entry(payment_hash)
 380                         .and_modify(|attempts| *attempts += 1)
 381                         .or_insert(1);
 382
 383                 if attempts >= max_payment_attempts {
 384                         log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 385                         return Err(());
 386                 }
 387
 388                 if has_expired(params) {
 389                         log_trace!(self.logger, "Invoice expired for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 390                         return Err(());
 391                 }
 392
 393                 let payer = self.payer.node_id();
 394                 let first_hops = self.payer.first_hops();
 395                 let route = self.router.find_route(&payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), &self.scorer.lock());
 396                 if route.is_err() {
 397                         log_trace!(self.logger, "Failed to find a route for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 398                         return Err(());
 399                 }
 400
 401                 match self.payer.retry_payment(&route.unwrap(), payment_id) {
 402                         Ok(()) => Ok(()),
 403                         Err(PaymentSendFailure::ParameterError(_)) |
 404                         Err(PaymentSendFailure::PathParameterError(_)) => {
 405                                 log_trace!(self.logger, "Failed to retry for payment {} due to bogus route/payment data, not retrying.", log_bytes!(payment_hash.0));
 406                                 Err(())
 407                         },
 408                         Err(PaymentSendFailure::AllFailedRetrySafe(_)) => {
 409                                 self.retry_payment(payment_id, payment_hash, params)
 410                         },
 411                         Err(PaymentSendFailure::PartialFailure { failed_paths_retry, .. }) => {
 412                                 if let Some(retry) = failed_paths_retry {
 413                                         // Always return Ok for the same reason as noted in pay_internal.
 414                                         let _ = self.retry_payment(payment_id, payment_hash, &retry);
 415                                 }
 416                                 Ok(())
 417                         },
 418                 }
 419         }
 420
 421         /// Removes the payment cached by the given payment hash.
 422         ///
 423         /// Should be called once a payment has failed or succeeded if not using [`InvoicePayer`] as an
 424         /// [`EventHandler`]. Otherwise, calling this method is unnecessary.
 425         pub fn remove_cached_payment(&self, payment_hash: &PaymentHash) {
 426                 self.payment_cache.lock().unwrap().remove(payment_hash);
 427         }
 428 }
 429
 430 fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
 431         invoice.timestamp().duration_since(SystemTime::UNIX_EPOCH).unwrap() + invoice.expiry_time()
 432 }
 433
 434 fn has_expired(params: &RouteParameters) -> bool {
 435         if let Some(expiry_time) = params.payee.expiry_time {
 436                 Invoice::is_expired_from_epoch(&SystemTime::UNIX_EPOCH, Duration::from_secs(expiry_time))
 437         } else { false }
 438 }
 439
 440 impl<P: Deref, R, S: Deref, L: Deref, E> EventHandler for InvoicePayer<P, R, S, L, E>
 441 where
 442         P::Target: Payer,
 443         R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
 444         S::Target: for <'a> routing::LockableScore<'a>,
 445         L::Target: Logger,
 446         E: EventHandler,
 447 {
 448         fn handle_event(&self, event: &Event) {
 449                 match event {
 450                         Event::PaymentPathFailed {
 451                                 all_paths_failed, payment_id, payment_hash, rejected_by_dest, path,
 452                                 short_channel_id, retry, ..
 453                         } => {
 454                                 if let Some(short_channel_id) = short_channel_id {
 455                                         let path = path.iter().collect::<Vec<_>>();
 456                                         self.scorer.lock().payment_path_failed(&path, *short_channel_id);
 457                                 }
 458
 459                                 if *rejected_by_dest {
 460                                         log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0));
 461                                 } else if payment_id.is_none() {
 462                                         log_trace!(self.logger, "Payment {} has no id; not retrying", log_bytes!(payment_hash.0));
 463                                 } else if retry.is_none() {
 464                                         log_trace!(self.logger, "Payment {} missing retry params; not retrying", log_bytes!(payment_hash.0));
 465                                 } else if self.retry_payment(payment_id.unwrap(), *payment_hash, retry.as_ref().unwrap()).is_ok() {
 466                                         // We retried at least somewhat, don't provide the PaymentPathFailed event to the user.
 467                                         return;
 468                                 }
 469
 470                                 if *all_paths_failed { self.payment_cache.lock().unwrap().remove(payment_hash); }
 471                         },
 472                         Event::PaymentSent { payment_hash, .. } => {
 473                                 let mut payment_cache = self.payment_cache.lock().unwrap();
 474                                 let attempts = payment_cache
 475                                         .remove(payment_hash)
 476                                         .map_or(1, |attempts| attempts + 1);
 477                                 log_trace!(self.logger, "Payment {} succeeded (attempts: {})", log_bytes!(payment_hash.0), attempts);
 478                         },
 479                         _ => {},
 480                 }
 481
 482                 // Delegate to the decorated event handler unless the payment is retried.
 483                 self.event_handler.handle_event(event)
 484         }
 485 }
 486
 487 #[cfg(test)]
 488 mod tests {
 489         use super::*;
 490         use crate::{DEFAULT_EXPIRY_TIME, InvoiceBuilder, Currency};
 491         use utils::create_invoice_from_channelmanager;
 492         use bitcoin_hashes::sha256::Hash as Sha256;
 493         use lightning::ln::PaymentPreimage;
 494         use lightning::ln::features::{ChannelFeatures, NodeFeatures, InitFeatures};
 495         use lightning::ln::functional_test_utils::*;
 496         use lightning::ln::msgs::{ErrorAction, LightningError};
 497         use lightning::routing::network_graph::NodeId;
 498         use lightning::routing::router::{Payee, Route, RouteHop};
 499         use lightning::util::test_utils::TestLogger;
 500         use lightning::util::errors::APIError;
 501         use lightning::util::events::{Event, MessageSendEventsProvider};
 502         use secp256k1::{SecretKey, PublicKey, Secp256k1};
 503         use std::cell::RefCell;
 504         use std::collections::VecDeque;
 505         use std::time::{SystemTime, Duration};
 506
 507         fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
 508                 let payment_hash = Sha256::hash(&payment_preimage.0);
 509                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 510                 InvoiceBuilder::new(Currency::Bitcoin)
 511                         .description("test".into())
 512                         .payment_hash(payment_hash)
 513                         .payment_secret(PaymentSecret([0; 32]))
 514                         .current_timestamp()
 515                         .min_final_cltv_expiry(144)
 516                         .amount_milli_satoshis(128)
 517                         .build_signed(|hash| {
 518                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 519                         })
 520                         .unwrap()
 521         }
 522
 523         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 524                 let payment_hash = Sha256::hash(&payment_preimage.0);
 525                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 526                 InvoiceBuilder::new(Currency::Bitcoin)
 527                         .description("test".into())
 528                         .payment_hash(payment_hash)
 529                         .payment_secret(PaymentSecret([0; 32]))
 530                         .current_timestamp()
 531                         .min_final_cltv_expiry(144)
 532                         .build_signed(|hash| {
 533                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 534                         })
 535                         .unwrap()
 536         }
 537
 538         fn expired_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 539                 let payment_hash = Sha256::hash(&payment_preimage.0);
 540                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 541                 let timestamp = SystemTime::now()
 542                         .checked_sub(Duration::from_secs(DEFAULT_EXPIRY_TIME * 2))
 543                         .unwrap();
 544                 InvoiceBuilder::new(Currency::Bitcoin)
 545                         .description("test".into())
 546                         .payment_hash(payment_hash)
 547                         .payment_secret(PaymentSecret([0; 32]))
 548                         .timestamp(timestamp)
 549                         .min_final_cltv_expiry(144)
 550                         .amount_milli_satoshis(128)
 551                         .build_signed(|hash| {
 552                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 553                         })
 554                         .unwrap()
 555         }
 556
 557         fn pubkey() -> PublicKey {
 558                 PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap()
 559         }
 560
 561         #[test]
 562         fn pays_invoice_on_first_attempt() {
 563                 let event_handled = core::cell::RefCell::new(false);
 564                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 565
 566                 let payment_preimage = PaymentPreimage([1; 32]);
 567                 let invoice = invoice(payment_preimage);
 568                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 569                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 570
 571                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 572                 let router = TestRouter {};
 573                 let scorer = RefCell::new(TestScorer::new());
 574                 let logger = TestLogger::new();
 575                 let invoice_payer =
 576                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
 577
 578                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 579                 assert_eq!(*payer.attempts.borrow(), 1);
 580
 581                 invoice_payer.handle_event(&Event::PaymentSent {
 582                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 583                 });
 584                 assert_eq!(*event_handled.borrow(), true);
 585                 assert_eq!(*payer.attempts.borrow(), 1);
 586         }
 587
 588         #[test]
 589         fn pays_invoice_on_retry() {
 590                 let event_handled = core::cell::RefCell::new(false);
 591                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 592
 593                 let payment_preimage = PaymentPreimage([1; 32]);
 594                 let invoice = invoice(payment_preimage);
 595                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 596                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 597
 598                 let payer = TestPayer::new()
 599                         .expect_send(Amount::ForInvoice(final_value_msat))
 600                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 601                 let router = TestRouter {};
 602                 let scorer = RefCell::new(TestScorer::new());
 603                 let logger = TestLogger::new();
 604                 let invoice_payer =
 605                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 606
 607                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 608                 assert_eq!(*payer.attempts.borrow(), 1);
 609
 610                 let event = Event::PaymentPathFailed {
 611                         payment_id,
 612                         payment_hash,
 613                         network_update: None,
 614                         rejected_by_dest: false,
 615                         all_paths_failed: false,
 616                         path: TestRouter::path_for_value(final_value_msat),
 617                         short_channel_id: None,
 618                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 619                 };
 620                 invoice_payer.handle_event(&event);
 621                 assert_eq!(*event_handled.borrow(), false);
 622                 assert_eq!(*payer.attempts.borrow(), 2);
 623
 624                 invoice_payer.handle_event(&Event::PaymentSent {
 625                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 626                 });
 627                 assert_eq!(*event_handled.borrow(), true);
 628                 assert_eq!(*payer.attempts.borrow(), 2);
 629         }
 630
 631         #[test]
 632         fn retries_payment_path_for_unknown_payment() {
 633                 let event_handled = core::cell::RefCell::new(false);
 634                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 635
 636                 let payment_preimage = PaymentPreimage([1; 32]);
 637                 let invoice = invoice(payment_preimage);
 638                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 639                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 640
 641                 let payer = TestPayer::new()
 642                         .expect_send(Amount::OnRetry(final_value_msat / 2))
 643                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 644                 let router = TestRouter {};
 645                 let scorer = RefCell::new(TestScorer::new());
 646                 let logger = TestLogger::new();
 647                 let invoice_payer =
 648                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 649
 650                 let payment_id = Some(PaymentId([1; 32]));
 651                 let event = Event::PaymentPathFailed {
 652                         payment_id,
 653                         payment_hash,
 654                         network_update: None,
 655                         rejected_by_dest: false,
 656                         all_paths_failed: false,
 657                         path: TestRouter::path_for_value(final_value_msat),
 658                         short_channel_id: None,
 659                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 660                 };
 661                 invoice_payer.handle_event(&event);
 662                 assert_eq!(*event_handled.borrow(), false);
 663                 assert_eq!(*payer.attempts.borrow(), 1);
 664
 665                 invoice_payer.handle_event(&event);
 666                 assert_eq!(*event_handled.borrow(), false);
 667                 assert_eq!(*payer.attempts.borrow(), 2);
 668
 669                 invoice_payer.handle_event(&Event::PaymentSent {
 670                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 671                 });
 672                 assert_eq!(*event_handled.borrow(), true);
 673                 assert_eq!(*payer.attempts.borrow(), 2);
 674         }
 675
 676         #[test]
 677         fn fails_paying_invoice_after_max_retries() {
 678                 let event_handled = core::cell::RefCell::new(false);
 679                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 680
 681                 let payment_preimage = PaymentPreimage([1; 32]);
 682                 let invoice = invoice(payment_preimage);
 683                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 684
 685                 let payer = TestPayer::new()
 686                         .expect_send(Amount::ForInvoice(final_value_msat))
 687                         .expect_send(Amount::OnRetry(final_value_msat / 2))
 688                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 689                 let router = TestRouter {};
 690                 let scorer = RefCell::new(TestScorer::new());
 691                 let logger = TestLogger::new();
 692                 let invoice_payer =
 693                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 694
 695                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 696                 assert_eq!(*payer.attempts.borrow(), 1);
 697
 698                 let event = Event::PaymentPathFailed {
 699                         payment_id,
 700                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 701                         network_update: None,
 702                         rejected_by_dest: false,
 703                         all_paths_failed: true,
 704                         path: TestRouter::path_for_value(final_value_msat),
 705                         short_channel_id: None,
 706                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 707                 };
 708                 invoice_payer.handle_event(&event);
 709                 assert_eq!(*event_handled.borrow(), false);
 710                 assert_eq!(*payer.attempts.borrow(), 2);
 711
 712                 let event = Event::PaymentPathFailed {
 713                         payment_id,
 714                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 715                         network_update: None,
 716                         rejected_by_dest: false,
 717                         all_paths_failed: false,
 718                         path: TestRouter::path_for_value(final_value_msat / 2),
 719                         short_channel_id: None,
 720                         retry: Some(RouteParameters {
 721                                 final_value_msat: final_value_msat / 2, ..TestRouter::retry_for_invoice(&invoice)
 722                         }),
 723                 };
 724                 invoice_payer.handle_event(&event);
 725                 assert_eq!(*event_handled.borrow(), false);
 726                 assert_eq!(*payer.attempts.borrow(), 3);
 727
 728                 invoice_payer.handle_event(&event);
 729                 assert_eq!(*event_handled.borrow(), true);
 730                 assert_eq!(*payer.attempts.borrow(), 3);
 731         }
 732
 733         #[test]
 734         fn fails_paying_invoice_with_missing_retry_params() {
 735                 let event_handled = core::cell::RefCell::new(false);
 736                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 737
 738                 let payment_preimage = PaymentPreimage([1; 32]);
 739                 let invoice = invoice(payment_preimage);
 740                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 741
 742                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 743                 let router = TestRouter {};
 744                 let scorer = RefCell::new(TestScorer::new());
 745                 let logger = TestLogger::new();
 746                 let invoice_payer =
 747                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 748
 749                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 750                 assert_eq!(*payer.attempts.borrow(), 1);
 751
 752                 let event = Event::PaymentPathFailed {
 753                         payment_id,
 754                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 755                         network_update: None,
 756                         rejected_by_dest: false,
 757                         all_paths_failed: false,
 758                         path: vec![],
 759                         short_channel_id: None,
 760                         retry: None,
 761                 };
 762                 invoice_payer.handle_event(&event);
 763                 assert_eq!(*event_handled.borrow(), true);
 764                 assert_eq!(*payer.attempts.borrow(), 1);
 765         }
 766
 767         #[test]
 768         fn fails_paying_invoice_after_expiration() {
 769                 let event_handled = core::cell::RefCell::new(false);
 770                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 771
 772                 let payer = TestPayer::new();
 773                 let router = TestRouter {};
 774                 let scorer = RefCell::new(TestScorer::new());
 775                 let logger = TestLogger::new();
 776                 let invoice_payer =
 777                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 778
 779                 let payment_preimage = PaymentPreimage([1; 32]);
 780                 let invoice = expired_invoice(payment_preimage);
 781                 if let PaymentError::Invoice(msg) = invoice_payer.pay_invoice(&invoice).unwrap_err() {
 782                         assert_eq!(msg, "Invoice expired prior to send");
 783                 } else { panic!("Expected Invoice Error"); }
 784         }
 785
 786         #[test]
 787         fn fails_retrying_invoice_after_expiration() {
 788                 let event_handled = core::cell::RefCell::new(false);
 789                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 790
 791                 let payment_preimage = PaymentPreimage([1; 32]);
 792                 let invoice = invoice(payment_preimage);
 793                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 794
 795                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 796                 let router = TestRouter {};
 797                 let scorer = RefCell::new(TestScorer::new());
 798                 let logger = TestLogger::new();
 799                 let invoice_payer =
 800                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 801
 802                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 803                 assert_eq!(*payer.attempts.borrow(), 1);
 804
 805                 let mut retry_data = TestRouter::retry_for_invoice(&invoice);
 806                 retry_data.payee.expiry_time = Some(SystemTime::now()
 807                         .checked_sub(Duration::from_secs(2)).unwrap()
 808                         .duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs());
 809                 let event = Event::PaymentPathFailed {
 810                         payment_id,
 811                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 812                         network_update: None,
 813                         rejected_by_dest: false,
 814                         all_paths_failed: false,
 815                         path: vec![],
 816                         short_channel_id: None,
 817                         retry: Some(retry_data),
 818                 };
 819                 invoice_payer.handle_event(&event);
 820                 assert_eq!(*event_handled.borrow(), true);
 821                 assert_eq!(*payer.attempts.borrow(), 1);
 822         }
 823
 824         #[test]
 825         fn fails_paying_invoice_after_retry_error() {
 826                 let event_handled = core::cell::RefCell::new(false);
 827                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 828
 829                 let payment_preimage = PaymentPreimage([1; 32]);
 830                 let invoice = invoice(payment_preimage);
 831                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 832
 833                 let payer = TestPayer::new()
 834                         .fails_on_attempt(2)
 835                         .expect_send(Amount::ForInvoice(final_value_msat))
 836                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 837                 let router = TestRouter {};
 838                 let scorer = RefCell::new(TestScorer::new());
 839                 let logger = TestLogger::new();
 840                 let invoice_payer =
 841                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 842
 843                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 844                 assert_eq!(*payer.attempts.borrow(), 1);
 845
 846                 let event = Event::PaymentPathFailed {
 847                         payment_id,
 848                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 849                         network_update: None,
 850                         rejected_by_dest: false,
 851                         all_paths_failed: false,
 852                         path: TestRouter::path_for_value(final_value_msat / 2),
 853                         short_channel_id: None,
 854                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 855                 };
 856                 invoice_payer.handle_event(&event);
 857                 assert_eq!(*event_handled.borrow(), true);
 858                 assert_eq!(*payer.attempts.borrow(), 2);
 859         }
 860
 861         #[test]
 862         fn fails_paying_invoice_after_rejected_by_payee() {
 863                 let event_handled = core::cell::RefCell::new(false);
 864                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 865
 866                 let payment_preimage = PaymentPreimage([1; 32]);
 867                 let invoice = invoice(payment_preimage);
 868                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 869
 870                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 871                 let router = TestRouter {};
 872                 let scorer = RefCell::new(TestScorer::new());
 873                 let logger = TestLogger::new();
 874                 let invoice_payer =
 875                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 876
 877                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 878                 assert_eq!(*payer.attempts.borrow(), 1);
 879
 880                 let event = Event::PaymentPathFailed {
 881                         payment_id,
 882                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 883                         network_update: None,
 884                         rejected_by_dest: true,
 885                         all_paths_failed: false,
 886                         path: vec![],
 887                         short_channel_id: None,
 888                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 889                 };
 890                 invoice_payer.handle_event(&event);
 891                 assert_eq!(*event_handled.borrow(), true);
 892                 assert_eq!(*payer.attempts.borrow(), 1);
 893         }
 894
 895         #[test]
 896         fn fails_repaying_invoice_with_pending_payment() {
 897                 let event_handled = core::cell::RefCell::new(false);
 898                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 899
 900                 let payment_preimage = PaymentPreimage([1; 32]);
 901                 let invoice = invoice(payment_preimage);
 902                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 903
 904                 let payer = TestPayer::new()
 905                         .expect_send(Amount::ForInvoice(final_value_msat))
 906                         .expect_send(Amount::ForInvoice(final_value_msat));
 907                 let router = TestRouter {};
 908                 let scorer = RefCell::new(TestScorer::new());
 909                 let logger = TestLogger::new();
 910                 let invoice_payer =
 911                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
 912
 913                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 914
 915                 // Cannot repay an invoice pending payment.
 916                 match invoice_payer.pay_invoice(&invoice) {
 917                         Err(PaymentError::Invoice("payment pending")) => {},
 918                         Err(_) => panic!("unexpected error"),
 919                         Ok(_) => panic!("expected invoice error"),
 920                 }
 921
 922                 // Can repay an invoice once cleared from cache.
 923                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 924                 invoice_payer.remove_cached_payment(&payment_hash);
 925                 assert!(invoice_payer.pay_invoice(&invoice).is_ok());
 926
 927                 // Cannot retry paying an invoice if cleared from cache.
 928                 invoice_payer.remove_cached_payment(&payment_hash);
 929                 let event = Event::PaymentPathFailed {
 930                         payment_id,
 931                         payment_hash,
 932                         network_update: None,
 933                         rejected_by_dest: false,
 934                         all_paths_failed: false,
 935                         path: vec![],
 936                         short_channel_id: None,
 937                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 938                 };
 939                 invoice_payer.handle_event(&event);
 940                 assert_eq!(*event_handled.borrow(), true);
 941         }
 942
 943         #[test]
 944         fn fails_paying_invoice_with_routing_errors() {
 945                 let payer = TestPayer::new();
 946                 let router = FailingRouter {};
 947                 let scorer = RefCell::new(TestScorer::new());
 948                 let logger = TestLogger::new();
 949                 let invoice_payer =
 950                         InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
 951
 952                 let payment_preimage = PaymentPreimage([1; 32]);
 953                 let invoice = invoice(payment_preimage);
 954                 match invoice_payer.pay_invoice(&invoice) {
 955                         Err(PaymentError::Routing(_)) => {},
 956                         Err(_) => panic!("unexpected error"),
 957                         Ok(_) => panic!("expected routing error"),
 958                 }
 959         }
 960
 961         #[test]
 962         fn fails_paying_invoice_with_sending_errors() {
 963                 let payment_preimage = PaymentPreimage([1; 32]);
 964                 let invoice = invoice(payment_preimage);
 965                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 966
 967                 let payer = TestPayer::new()
 968                         .fails_on_attempt(1)
 969                         .expect_send(Amount::ForInvoice(final_value_msat));
 970                 let router = TestRouter {};
 971                 let scorer = RefCell::new(TestScorer::new());
 972                 let logger = TestLogger::new();
 973                 let invoice_payer =
 974                         InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
 975
 976                 match invoice_payer.pay_invoice(&invoice) {
 977                         Err(PaymentError::Sending(_)) => {},
 978                         Err(_) => panic!("unexpected error"),
 979                         Ok(_) => panic!("expected sending error"),
 980                 }
 981         }
 982
 983         #[test]
 984         fn pays_zero_value_invoice_using_amount() {
 985                 let event_handled = core::cell::RefCell::new(false);
 986                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 987
 988                 let payment_preimage = PaymentPreimage([1; 32]);
 989                 let invoice = zero_value_invoice(payment_preimage);
 990                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 991                 let final_value_msat = 100;
 992
 993                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 994                 let router = TestRouter {};
 995                 let scorer = RefCell::new(TestScorer::new());
 996                 let logger = TestLogger::new();
 997                 let invoice_payer =
 998                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
 999
1000                 let payment_id =
1001                         Some(invoice_payer.pay_zero_value_invoice(&invoice, final_value_msat).unwrap());
1002                 assert_eq!(*payer.attempts.borrow(), 1);
1003
1004                 invoice_payer.handle_event(&Event::PaymentSent {
1005                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
1006                 });
1007                 assert_eq!(*event_handled.borrow(), true);
1008                 assert_eq!(*payer.attempts.borrow(), 1);
1009         }
1010
1011         #[test]
1012         fn fails_paying_zero_value_invoice_with_amount() {
1013                 let event_handled = core::cell::RefCell::new(false);
1014                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1015
1016                 let payer = TestPayer::new();
1017                 let router = TestRouter {};
1018                 let scorer = RefCell::new(TestScorer::new());
1019                 let logger = TestLogger::new();
1020                 let invoice_payer =
1021                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
1022
1023                 let payment_preimage = PaymentPreimage([1; 32]);
1024                 let invoice = invoice(payment_preimage);
1025
1026                 // Cannot repay an invoice pending payment.
1027                 match invoice_payer.pay_zero_value_invoice(&invoice, 100) {
1028                         Err(PaymentError::Invoice("amount unexpected")) => {},
1029                         Err(_) => panic!("unexpected error"),
1030                         Ok(_) => panic!("expected invoice error"),
1031                 }
1032         }
1033
1034         #[test]
1035         fn pays_pubkey_with_amount() {
1036                 let event_handled = core::cell::RefCell::new(false);
1037                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1038
1039                 let pubkey = pubkey();
1040                 let payment_preimage = PaymentPreimage([1; 32]);
1041                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1042                 let final_value_msat = 100;
1043                 let final_cltv_expiry_delta = 42;
1044
1045                 let payer = TestPayer::new()
1046                         .expect_send(Amount::Spontaneous(final_value_msat))
1047                         .expect_send(Amount::OnRetry(final_value_msat));
1048                 let router = TestRouter {};
1049                 let scorer = RefCell::new(TestScorer::new());
1050                 let logger = TestLogger::new();
1051                 let invoice_payer =
1052                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
1053
1054                 let payment_id = Some(invoice_payer.pay_pubkey(
1055                                 pubkey, payment_preimage, final_value_msat, final_cltv_expiry_delta
1056                         ).unwrap());
1057                 assert_eq!(*payer.attempts.borrow(), 1);
1058
1059                 let retry = RouteParameters {
1060                         payee: Payee::for_keysend(pubkey),
1061                         final_value_msat,
1062                         final_cltv_expiry_delta,
1063                 };
1064                 let event = Event::PaymentPathFailed {
1065                         payment_id,
1066                         payment_hash,
1067                         network_update: None,
1068                         rejected_by_dest: false,
1069                         all_paths_failed: false,
1070                         path: vec![],
1071                         short_channel_id: None,
1072                         retry: Some(retry),
1073                 };
1074                 invoice_payer.handle_event(&event);
1075                 assert_eq!(*event_handled.borrow(), false);
1076                 assert_eq!(*payer.attempts.borrow(), 2);
1077
1078                 invoice_payer.handle_event(&Event::PaymentSent {
1079                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
1080                 });
1081                 assert_eq!(*event_handled.borrow(), true);
1082                 assert_eq!(*payer.attempts.borrow(), 2);
1083         }
1084
1085         #[test]
1086         fn scores_failed_channel() {
1087                 let event_handled = core::cell::RefCell::new(false);
1088                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1089
1090                 let payment_preimage = PaymentPreimage([1; 32]);
1091                 let invoice = invoice(payment_preimage);
1092                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
1093                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
1094                 let path = TestRouter::path_for_value(final_value_msat);
1095                 let short_channel_id = Some(path[0].short_channel_id);
1096
1097                 // Expect that scorer is given short_channel_id upon handling the event.
1098                 let payer = TestPayer::new()
1099                         .expect_send(Amount::ForInvoice(final_value_msat))
1100                         .expect_send(Amount::OnRetry(final_value_msat / 2));
1101                 let router = TestRouter {};
1102                 let scorer = RefCell::new(TestScorer::new().expect_channel_failure(short_channel_id.unwrap()));
1103                 let logger = TestLogger::new();
1104                 let invoice_payer =
1105                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
1106
1107                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
1108                 let event = Event::PaymentPathFailed {
1109                         payment_id,
1110                         payment_hash,
1111                         network_update: None,
1112                         rejected_by_dest: false,
1113                         all_paths_failed: false,
1114                         path,
1115                         short_channel_id,
1116                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
1117                 };
1118                 invoice_payer.handle_event(&event);
1119         }
1120
1121         struct TestRouter;
1122
1123         impl TestRouter {
1124                 fn route_for_value(final_value_msat: u64) -> Route {
1125                         Route {
1126                                 paths: vec![
1127                                         vec![RouteHop {
1128                                                 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
1129                                                 channel_features: ChannelFeatures::empty(),
1130                                                 node_features: NodeFeatures::empty(),
1131                                                 short_channel_id: 0, fee_msat: final_value_msat / 2, cltv_expiry_delta: 144
1132                                         }],
1133                                         vec![RouteHop {
1134                                                 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
1135                                                 channel_features: ChannelFeatures::empty(),
1136                                                 node_features: NodeFeatures::empty(),
1137                                                 short_channel_id: 1, fee_msat: final_value_msat / 2, cltv_expiry_delta: 144
1138                                         }],
1139                                 ],
1140                                 payee: None,
1141                         }
1142                 }
1143
1144                 fn path_for_value(final_value_msat: u64) -> Vec<RouteHop> {
1145                         TestRouter::route_for_value(final_value_msat).paths[0].clone()
1146                 }
1147
1148                 fn retry_for_invoice(invoice: &Invoice) -> RouteParameters {
1149                         let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key())
1150                                 .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
1151                                 .with_route_hints(invoice.route_hints());
1152                         if let Some(features) = invoice.features() {
1153                                 payee = payee.with_features(features.clone());
1154                         }
1155                         let final_value_msat = invoice.amount_milli_satoshis().unwrap() / 2;
1156                         RouteParameters {
1157                                 payee,
1158                                 final_value_msat,
1159                                 final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
1160                         }
1161                 }
1162         }
1163
1164         impl<S: routing::Score> Router<S> for TestRouter {
1165                 fn find_route(
1166                         &self,
1167                         _payer: &PublicKey,
1168                         params: &RouteParameters,
1169                         _first_hops: Option<&[&ChannelDetails]>,
1170                         _scorer: &S,
1171                 ) -> Result<Route, LightningError> {
1172                         Ok(Route {
1173                                 payee: Some(params.payee.clone()), ..Self::route_for_value(params.final_value_msat)
1174                         })
1175                 }
1176         }
1177
1178         struct FailingRouter;
1179
1180         impl<S: routing::Score> Router<S> for FailingRouter {
1181                 fn find_route(
1182                         &self,
1183                         _payer: &PublicKey,
1184                         _params: &RouteParameters,
1185                         _first_hops: Option<&[&ChannelDetails]>,
1186                         _scorer: &S,
1187                 ) -> Result<Route, LightningError> {
1188                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError })
1189                 }
1190         }
1191
1192         struct TestScorer {
1193                 expectations: VecDeque<u64>,
1194         }
1195
1196         impl TestScorer {
1197                 fn new() -> Self {
1198                         Self {
1199                                 expectations: VecDeque::new(),
1200                         }
1201                 }
1202
1203                 fn expect_channel_failure(mut self, short_channel_id: u64) -> Self {
1204                         self.expectations.push_back(short_channel_id);
1205                         self
1206                 }
1207         }
1208
1209         impl routing::Score for TestScorer {
1210                 fn channel_penalty_msat(
1211                         &self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId
1212                 ) -> u64 { 0 }
1213
1214                 fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
1215                         if let Some(expected_short_channel_id) = self.expectations.pop_front() {
1216                                 assert_eq!(short_channel_id, expected_short_channel_id);
1217                         }
1218                 }
1219         }
1220
1221         impl Drop for TestScorer {
1222                 fn drop(&mut self) {
1223                         if std::thread::panicking() {
1224                                 return;
1225                         }
1226
1227                         if !self.expectations.is_empty() {
1228                                 panic!("Unsatisfied channel failure expectations: {:?}", self.expectations);
1229                         }
1230                 }
1231         }
1232
1233         struct TestPayer {
1234                 expectations: core::cell::RefCell<VecDeque<Amount>>,
1235                 attempts: core::cell::RefCell<usize>,
1236                 failing_on_attempt: Option<usize>,
1237         }
1238
1239         #[derive(Clone, Debug, PartialEq, Eq)]
1240         enum Amount {
1241                 ForInvoice(u64),
1242                 Spontaneous(u64),
1243                 OnRetry(u64),
1244         }
1245
1246         impl TestPayer {
1247                 fn new() -> Self {
1248                         Self {
1249                                 expectations: core::cell::RefCell::new(VecDeque::new()),
1250                                 attempts: core::cell::RefCell::new(0),
1251                                 failing_on_attempt: None,
1252                         }
1253                 }
1254
1255                 fn expect_send(self, value_msat: Amount) -> Self {
1256                         self.expectations.borrow_mut().push_back(value_msat);
1257                         self
1258                 }
1259
1260                 fn fails_on_attempt(self, attempt: usize) -> Self {
1261                         Self {
1262                                 expectations: core::cell::RefCell::new(self.expectations.borrow().clone()),
1263                                 attempts: core::cell::RefCell::new(0),
1264                                 failing_on_attempt: Some(attempt),
1265                         }
1266                 }
1267
1268                 fn check_attempts(&self) -> Result<PaymentId, PaymentSendFailure> {
1269                         let mut attempts = self.attempts.borrow_mut();
1270                         *attempts += 1;
1271                         match self.failing_on_attempt {
1272                                 None => Ok(PaymentId([1; 32])),
1273                                 Some(attempt) if attempt != *attempts => Ok(PaymentId([1; 32])),
1274                                 Some(_) => Err(PaymentSendFailure::ParameterError(APIError::MonitorUpdateFailed)),
1275                         }
1276                 }
1277
1278                 fn check_value_msats(&self, actual_value_msats: Amount) {
1279                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
1280                         if let Some(expected_value_msats) = expected_value_msats {
1281                                 assert_eq!(actual_value_msats, expected_value_msats);
1282                         }
1283                 }
1284         }
1285
1286         impl Drop for TestPayer {
1287                 fn drop(&mut self) {
1288                         if std::thread::panicking() {
1289                                 return;
1290                         }
1291
1292                         if !self.expectations.borrow().is_empty() {
1293                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
1294                         }
1295                 }
1296         }
1297
1298         impl Payer for TestPayer {
1299                 fn node_id(&self) -> PublicKey {
1300                         let secp_ctx = Secp256k1::new();
1301                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
1302                 }
1303
1304                 fn first_hops(&self) -> Vec<ChannelDetails> {
1305                         Vec::new()
1306                 }
1307
1308                 fn send_payment(
1309                         &self, route: &Route, _payment_hash: PaymentHash,
1310                         _payment_secret: &Option<PaymentSecret>
1311                 ) -> Result<PaymentId, PaymentSendFailure> {
1312                         self.check_value_msats(Amount::ForInvoice(route.get_total_amount()));
1313                         self.check_attempts()
1314                 }
1315
1316                 fn send_spontaneous_payment(
1317                         &self, route: &Route, _payment_preimage: PaymentPreimage,
1318                 ) -> Result<PaymentId, PaymentSendFailure> {
1319                         self.check_value_msats(Amount::Spontaneous(route.get_total_amount()));
1320                         self.check_attempts()
1321                 }
1322
1323                 fn retry_payment(
1324                         &self, route: &Route, _payment_id: PaymentId
1325                 ) -> Result<(), PaymentSendFailure> {
1326                         self.check_value_msats(Amount::OnRetry(route.get_total_amount()));
1327                         self.check_attempts().map(|_| ())
1328                 }
1329         }
1330
1331         // *** Full Featured Functional Tests with a Real ChannelManager ***
1332         struct ManualRouter(RefCell<VecDeque<Result<Route, LightningError>>>);
1333
1334         impl<S: routing::Score> Router<S> for ManualRouter {
1335                 fn find_route(&self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>, _scorer: &S)
1336                 -> Result<Route, LightningError> {
1337                         self.0.borrow_mut().pop_front().unwrap()
1338                 }
1339         }
1340         impl ManualRouter {
1341                 fn expect_find_route(&self, result: Result<Route, LightningError>) {
1342                         self.0.borrow_mut().push_back(result);
1343                 }
1344         }
1345         impl Drop for ManualRouter {
1346                 fn drop(&mut self) {
1347                         if std::thread::panicking() {
1348                                 return;
1349                         }
1350                         assert!(self.0.borrow_mut().is_empty());
1351                 }
1352         }
1353
1354         #[test]
1355         fn retry_multi_path_single_failed_payment() {
1356                 // Tests that we can/will retry after a single path of an MPP payment failed immediately
1357                 let chanmon_cfgs = create_chanmon_cfgs(2);
1358                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1359                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
1360                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1361
1362                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1363                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1364                 let chans = nodes[0].node.list_usable_channels();
1365                 let mut route = Route {
1366                         paths: vec![
1367                                 vec![RouteHop {
1368                                         pubkey: nodes[1].node.get_our_node_id(),
1369                                         node_features: NodeFeatures::known(),
1370                                         short_channel_id: chans[0].short_channel_id.unwrap(),
1371                                         channel_features: ChannelFeatures::known(),
1372                                         fee_msat: 10_000,
1373                                         cltv_expiry_delta: 100,
1374                                 }],
1375                                 vec![RouteHop {
1376                                         pubkey: nodes[1].node.get_our_node_id(),
1377                                         node_features: NodeFeatures::known(),
1378                                         short_channel_id: chans[1].short_channel_id.unwrap(),
1379                                         channel_features: ChannelFeatures::known(),
1380                                         fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
1381                                         cltv_expiry_delta: 100,
1382                                 }],
1383                         ],
1384                         payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
1385                 };
1386                 let router = ManualRouter(RefCell::new(VecDeque::new()));
1387                 router.expect_find_route(Ok(route.clone()));
1388                 // On retry, split the payment across both channels.
1389                 route.paths[0][0].fee_msat = 50_000_001;
1390                 route.paths[1][0].fee_msat = 50_000_000;
1391                 router.expect_find_route(Ok(route.clone()));
1392
1393                 let event_handler = |_: &_| { panic!(); };
1394                 let scorer = RefCell::new(TestScorer::new());
1395                 let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
1396
1397                 assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
1398                         &nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
1399                         .is_ok());
1400                 let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
1401                 assert_eq!(htlc_msgs.len(), 2);
1402                 check_added_monitors!(nodes[0], 2);
1403         }
1404
1405         #[test]
1406         fn immediate_retry_on_failure() {
1407                 // Tests that we can/will retry immediately after a failure
1408                 let chanmon_cfgs = create_chanmon_cfgs(2);
1409                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1410                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
1411                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1412
1413                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1414                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1415                 let chans = nodes[0].node.list_usable_channels();
1416                 let mut route = Route {
1417                         paths: vec![
1418                                 vec![RouteHop {
1419                                         pubkey: nodes[1].node.get_our_node_id(),
1420                                         node_features: NodeFeatures::known(),
1421                                         short_channel_id: chans[0].short_channel_id.unwrap(),
1422                                         channel_features: ChannelFeatures::known(),
1423                                         fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
1424                                         cltv_expiry_delta: 100,
1425                                 }],
1426                         ],
1427                         payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
1428                 };
1429                 let router = ManualRouter(RefCell::new(VecDeque::new()));
1430                 router.expect_find_route(Ok(route.clone()));
1431                 // On retry, split the payment across both channels.
1432                 route.paths.push(route.paths[0].clone());
1433                 route.paths[0][0].short_channel_id = chans[1].short_channel_id.unwrap();
1434                 route.paths[0][0].fee_msat = 50_000_000;
1435                 route.paths[1][0].fee_msat = 50_000_001;
1436                 router.expect_find_route(Ok(route.clone()));
1437
1438                 let event_handler = |_: &_| { panic!(); };
1439                 let scorer = RefCell::new(TestScorer::new());
1440                 let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
1441
1442                 assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
1443                         &nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
1444                         .is_ok());
1445                 let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
1446                 assert_eq!(htlc_msgs.len(), 2);
1447                 check_added_monitors!(nodes[0], 2);
1448         }
1449 }