git.bitcoin.ninja 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, payment_hash: &PaymentHash,
  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, _send_amt: u64, _chan_amt: Option<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, payment_hash: &PaymentHash,
 184                 first_hops: Option<&[&ChannelDetails]>, 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, params, &payment_hash, Some(&first_hops.iter().collect::<Vec<_>>()),
 333                         &self.scorer.lock()
 334                 ).map_err(|e| PaymentError::Routing(e))?;
 335
 336                 match send_payment(&route) {
 337                         Ok(payment_id) => Ok(payment_id),
 338                         Err(e) => match e {
 339                                 PaymentSendFailure::ParameterError(_) => Err(e),
 340                                 PaymentSendFailure::PathParameterError(_) => Err(e),
 341                                 PaymentSendFailure::AllFailedRetrySafe(_) => {
 342                                         let mut payment_cache = self.payment_cache.lock().unwrap();
 343                                         let retry_count = payment_cache.get_mut(&payment_hash).unwrap();
 344                                         if *retry_count >= self.retry_attempts.0 {
 345                                                 Err(e)
 346                                         } else {
 347                                                 *retry_count += 1;
 348                                                 std::mem::drop(payment_cache);
 349                                                 Ok(self.pay_internal(params, payment_hash, send_payment)?)
 350                                         }
 351                                 },
 352                                 PaymentSendFailure::PartialFailure { failed_paths_retry, payment_id, .. } => {
 353                                         if let Some(retry_data) = failed_paths_retry {
 354                                                 // Some paths were sent, even if we failed to send the full MPP value our
 355                                                 // recipient may misbehave and claim the funds, at which point we have to
 356                                                 // consider the payment sent, so return `Ok()` here, ignoring any retry
 357                                                 // errors.
 358                                                 let _ = self.retry_payment(payment_id, payment_hash, &retry_data);
 359                                                 Ok(payment_id)
 360                                         } else {
 361                                                 // This may happen if we send a payment and some paths fail, but
 362                                                 // only due to a temporary monitor failure or the like, implying
 363                                                 // they're really in-flight, but we haven't sent the initial
 364                                                 // HTLC-Add messages yet.
 365                                                 Ok(payment_id)
 366                                         }
 367                                 },
 368                         },
 369                 }.map_err(|e| PaymentError::Sending(e))
 370         }
 371
 372         fn retry_payment(
 373                 &self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters
 374         ) -> Result<(), ()> {
 375                 let max_payment_attempts = self.retry_attempts.0 + 1;
 376                 let attempts = *self.payment_cache.lock().unwrap()
 377                         .entry(payment_hash)
 378                         .and_modify(|attempts| *attempts += 1)
 379                         .or_insert(1);
 380
 381                 if attempts >= max_payment_attempts {
 382                         log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 383                         return Err(());
 384                 }
 385
 386                 if has_expired(params) {
 387                         log_trace!(self.logger, "Invoice expired for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 388                         return Err(());
 389                 }
 390
 391                 let payer = self.payer.node_id();
 392                 let first_hops = self.payer.first_hops();
 393                 let route = self.router.find_route(
 394                         &payer, &params, &payment_hash, Some(&first_hops.iter().collect::<Vec<_>>()),
 395                         &self.scorer.lock()
 396                 );
 397                 if route.is_err() {
 398                         log_trace!(self.logger, "Failed to find a route for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
 399                         return Err(());
 400                 }
 401
 402                 match self.payer.retry_payment(&route.unwrap(), payment_id) {
 403                         Ok(()) => Ok(()),
 404                         Err(PaymentSendFailure::ParameterError(_)) |
 405                         Err(PaymentSendFailure::PathParameterError(_)) => {
 406                                 log_trace!(self.logger, "Failed to retry for payment {} due to bogus route/payment data, not retrying.", log_bytes!(payment_hash.0));
 407                                 Err(())
 408                         },
 409                         Err(PaymentSendFailure::AllFailedRetrySafe(_)) => {
 410                                 self.retry_payment(payment_id, payment_hash, params)
 411                         },
 412                         Err(PaymentSendFailure::PartialFailure { failed_paths_retry, .. }) => {
 413                                 if let Some(retry) = failed_paths_retry {
 414                                         // Always return Ok for the same reason as noted in pay_internal.
 415                                         let _ = self.retry_payment(payment_id, payment_hash, &retry);
 416                                 }
 417                                 Ok(())
 418                         },
 419                 }
 420         }
 421
 422         /// Removes the payment cached by the given payment hash.
 423         ///
 424         /// Should be called once a payment has failed or succeeded if not using [`InvoicePayer`] as an
 425         /// [`EventHandler`]. Otherwise, calling this method is unnecessary.
 426         pub fn remove_cached_payment(&self, payment_hash: &PaymentHash) {
 427                 self.payment_cache.lock().unwrap().remove(payment_hash);
 428         }
 429 }
 430
 431 fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
 432         invoice.timestamp().duration_since(SystemTime::UNIX_EPOCH).unwrap() + invoice.expiry_time()
 433 }
 434
 435 fn has_expired(params: &RouteParameters) -> bool {
 436         if let Some(expiry_time) = params.payee.expiry_time {
 437                 Invoice::is_expired_from_epoch(&SystemTime::UNIX_EPOCH, Duration::from_secs(expiry_time))
 438         } else { false }
 439 }
 440
 441 impl<P: Deref, R, S: Deref, L: Deref, E> EventHandler for InvoicePayer<P, R, S, L, E>
 442 where
 443         P::Target: Payer,
 444         R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
 445         S::Target: for <'a> routing::LockableScore<'a>,
 446         L::Target: Logger,
 447         E: EventHandler,
 448 {
 449         fn handle_event(&self, event: &Event) {
 450                 match event {
 451                         Event::PaymentPathFailed {
 452                                 all_paths_failed, payment_id, payment_hash, rejected_by_dest, path,
 453                                 short_channel_id, retry, ..
 454                         } => {
 455                                 if let Some(short_channel_id) = short_channel_id {
 456                                         let path = path.iter().collect::<Vec<_>>();
 457                                         self.scorer.lock().payment_path_failed(&path, *short_channel_id);
 458                                 }
 459
 460                                 if *rejected_by_dest {
 461                                         log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0));
 462                                 } else if payment_id.is_none() {
 463                                         log_trace!(self.logger, "Payment {} has no id; not retrying", log_bytes!(payment_hash.0));
 464                                 } else if retry.is_none() {
 465                                         log_trace!(self.logger, "Payment {} missing retry params; not retrying", log_bytes!(payment_hash.0));
 466                                 } else if self.retry_payment(payment_id.unwrap(), *payment_hash, retry.as_ref().unwrap()).is_ok() {
 467                                         // We retried at least somewhat, don't provide the PaymentPathFailed event to the user.
 468                                         return;
 469                                 }
 470
 471                                 if *all_paths_failed { self.payment_cache.lock().unwrap().remove(payment_hash); }
 472                         },
 473                         Event::PaymentSent { payment_hash, .. } => {
 474                                 let mut payment_cache = self.payment_cache.lock().unwrap();
 475                                 let attempts = payment_cache
 476                                         .remove(payment_hash)
 477                                         .map_or(1, |attempts| attempts + 1);
 478                                 log_trace!(self.logger, "Payment {} succeeded (attempts: {})", log_bytes!(payment_hash.0), attempts);
 479                         },
 480                         _ => {},
 481                 }
 482
 483                 // Delegate to the decorated event handler unless the payment is retried.
 484                 self.event_handler.handle_event(event)
 485         }
 486 }
 487
 488 #[cfg(test)]
 489 mod tests {
 490         use super::*;
 491         use crate::{DEFAULT_EXPIRY_TIME, InvoiceBuilder, Currency};
 492         use utils::create_invoice_from_channelmanager;
 493         use bitcoin_hashes::sha256::Hash as Sha256;
 494         use lightning::ln::PaymentPreimage;
 495         use lightning::ln::features::{ChannelFeatures, NodeFeatures, InitFeatures};
 496         use lightning::ln::functional_test_utils::*;
 497         use lightning::ln::msgs::{ErrorAction, LightningError};
 498         use lightning::routing::network_graph::NodeId;
 499         use lightning::routing::router::{Payee, Route, RouteHop};
 500         use lightning::util::test_utils::TestLogger;
 501         use lightning::util::errors::APIError;
 502         use lightning::util::events::{Event, MessageSendEventsProvider};
 503         use secp256k1::{SecretKey, PublicKey, Secp256k1};
 504         use std::cell::RefCell;
 505         use std::collections::VecDeque;
 506         use std::time::{SystemTime, Duration};
 507
 508         fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
 509                 let payment_hash = Sha256::hash(&payment_preimage.0);
 510                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 511                 InvoiceBuilder::new(Currency::Bitcoin)
 512                         .description("test".into())
 513                         .payment_hash(payment_hash)
 514                         .payment_secret(PaymentSecret([0; 32]))
 515                         .current_timestamp()
 516                         .min_final_cltv_expiry(144)
 517                         .amount_milli_satoshis(128)
 518                         .build_signed(|hash| {
 519                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 520                         })
 521                         .unwrap()
 522         }
 523
 524         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 525                 let payment_hash = Sha256::hash(&payment_preimage.0);
 526                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 527                 InvoiceBuilder::new(Currency::Bitcoin)
 528                         .description("test".into())
 529                         .payment_hash(payment_hash)
 530                         .payment_secret(PaymentSecret([0; 32]))
 531                         .current_timestamp()
 532                         .min_final_cltv_expiry(144)
 533                         .build_signed(|hash| {
 534                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 535                         })
 536                         .unwrap()
 537         }
 538
 539         fn expired_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 540                 let payment_hash = Sha256::hash(&payment_preimage.0);
 541                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 542                 let timestamp = SystemTime::now()
 543                         .checked_sub(Duration::from_secs(DEFAULT_EXPIRY_TIME * 2))
 544                         .unwrap();
 545                 InvoiceBuilder::new(Currency::Bitcoin)
 546                         .description("test".into())
 547                         .payment_hash(payment_hash)
 548                         .payment_secret(PaymentSecret([0; 32]))
 549                         .timestamp(timestamp)
 550                         .min_final_cltv_expiry(144)
 551                         .amount_milli_satoshis(128)
 552                         .build_signed(|hash| {
 553                                 Secp256k1::new().sign_recoverable(hash, &private_key)
 554                         })
 555                         .unwrap()
 556         }
 557
 558         fn pubkey() -> PublicKey {
 559                 PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap()
 560         }
 561
 562         #[test]
 563         fn pays_invoice_on_first_attempt() {
 564                 let event_handled = core::cell::RefCell::new(false);
 565                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 566
 567                 let payment_preimage = PaymentPreimage([1; 32]);
 568                 let invoice = invoice(payment_preimage);
 569                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 570                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 571
 572                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 573                 let router = TestRouter {};
 574                 let scorer = RefCell::new(TestScorer::new());
 575                 let logger = TestLogger::new();
 576                 let invoice_payer =
 577                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
 578
 579                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 580                 assert_eq!(*payer.attempts.borrow(), 1);
 581
 582                 invoice_payer.handle_event(&Event::PaymentSent {
 583                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 584                 });
 585                 assert_eq!(*event_handled.borrow(), true);
 586                 assert_eq!(*payer.attempts.borrow(), 1);
 587         }
 588
 589         #[test]
 590         fn pays_invoice_on_retry() {
 591                 let event_handled = core::cell::RefCell::new(false);
 592                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 593
 594                 let payment_preimage = PaymentPreimage([1; 32]);
 595                 let invoice = invoice(payment_preimage);
 596                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 597                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 598
 599                 let payer = TestPayer::new()
 600                         .expect_send(Amount::ForInvoice(final_value_msat))
 601                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 602                 let router = TestRouter {};
 603                 let scorer = RefCell::new(TestScorer::new());
 604                 let logger = TestLogger::new();
 605                 let invoice_payer =
 606                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 607
 608                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 609                 assert_eq!(*payer.attempts.borrow(), 1);
 610
 611                 let event = Event::PaymentPathFailed {
 612                         payment_id,
 613                         payment_hash,
 614                         network_update: None,
 615                         rejected_by_dest: false,
 616                         all_paths_failed: false,
 617                         path: TestRouter::path_for_value(final_value_msat),
 618                         short_channel_id: None,
 619                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 620                 };
 621                 invoice_payer.handle_event(&event);
 622                 assert_eq!(*event_handled.borrow(), false);
 623                 assert_eq!(*payer.attempts.borrow(), 2);
 624
 625                 invoice_payer.handle_event(&Event::PaymentSent {
 626                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 627                 });
 628                 assert_eq!(*event_handled.borrow(), true);
 629                 assert_eq!(*payer.attempts.borrow(), 2);
 630         }
 631
 632         #[test]
 633         fn pays_invoice_on_partial_failure() {
 634                 let event_handler = |_: &_| { panic!() };
 635
 636                 let payment_preimage = PaymentPreimage([1; 32]);
 637                 let invoice = invoice(payment_preimage);
 638                 let retry = TestRouter::retry_for_invoice(&invoice);
 639                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 640
 641                 let payer = TestPayer::new()
 642                         .fails_with_partial_failure(retry.clone(), OnAttempt(1))
 643                         .fails_with_partial_failure(retry, OnAttempt(2))
 644                         .expect_send(Amount::ForInvoice(final_value_msat))
 645                         .expect_send(Amount::OnRetry(final_value_msat / 2))
 646                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 647                 let router = TestRouter {};
 648                 let scorer = RefCell::new(TestScorer::new());
 649                 let logger = TestLogger::new();
 650                 let invoice_payer =
 651                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 652
 653                 assert!(invoice_payer.pay_invoice(&invoice).is_ok());
 654         }
 655
 656         #[test]
 657         fn retries_payment_path_for_unknown_payment() {
 658                 let event_handled = core::cell::RefCell::new(false);
 659                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 660
 661                 let payment_preimage = PaymentPreimage([1; 32]);
 662                 let invoice = invoice(payment_preimage);
 663                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 664                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 665
 666                 let payer = TestPayer::new()
 667                         .expect_send(Amount::OnRetry(final_value_msat / 2))
 668                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 669                 let router = TestRouter {};
 670                 let scorer = RefCell::new(TestScorer::new());
 671                 let logger = TestLogger::new();
 672                 let invoice_payer =
 673                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 674
 675                 let payment_id = Some(PaymentId([1; 32]));
 676                 let event = Event::PaymentPathFailed {
 677                         payment_id,
 678                         payment_hash,
 679                         network_update: None,
 680                         rejected_by_dest: false,
 681                         all_paths_failed: false,
 682                         path: TestRouter::path_for_value(final_value_msat),
 683                         short_channel_id: None,
 684                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 685                 };
 686                 invoice_payer.handle_event(&event);
 687                 assert_eq!(*event_handled.borrow(), false);
 688                 assert_eq!(*payer.attempts.borrow(), 1);
 689
 690                 invoice_payer.handle_event(&event);
 691                 assert_eq!(*event_handled.borrow(), false);
 692                 assert_eq!(*payer.attempts.borrow(), 2);
 693
 694                 invoice_payer.handle_event(&Event::PaymentSent {
 695                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
 696                 });
 697                 assert_eq!(*event_handled.borrow(), true);
 698                 assert_eq!(*payer.attempts.borrow(), 2);
 699         }
 700
 701         #[test]
 702         fn fails_paying_invoice_after_max_retries() {
 703                 let event_handled = core::cell::RefCell::new(false);
 704                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 705
 706                 let payment_preimage = PaymentPreimage([1; 32]);
 707                 let invoice = invoice(payment_preimage);
 708                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 709
 710                 let payer = TestPayer::new()
 711                         .expect_send(Amount::ForInvoice(final_value_msat))
 712                         .expect_send(Amount::OnRetry(final_value_msat / 2))
 713                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 714                 let router = TestRouter {};
 715                 let scorer = RefCell::new(TestScorer::new());
 716                 let logger = TestLogger::new();
 717                 let invoice_payer =
 718                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 719
 720                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 721                 assert_eq!(*payer.attempts.borrow(), 1);
 722
 723                 let event = Event::PaymentPathFailed {
 724                         payment_id,
 725                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 726                         network_update: None,
 727                         rejected_by_dest: false,
 728                         all_paths_failed: true,
 729                         path: TestRouter::path_for_value(final_value_msat),
 730                         short_channel_id: None,
 731                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 732                 };
 733                 invoice_payer.handle_event(&event);
 734                 assert_eq!(*event_handled.borrow(), false);
 735                 assert_eq!(*payer.attempts.borrow(), 2);
 736
 737                 let event = Event::PaymentPathFailed {
 738                         payment_id,
 739                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 740                         network_update: None,
 741                         rejected_by_dest: false,
 742                         all_paths_failed: false,
 743                         path: TestRouter::path_for_value(final_value_msat / 2),
 744                         short_channel_id: None,
 745                         retry: Some(RouteParameters {
 746                                 final_value_msat: final_value_msat / 2, ..TestRouter::retry_for_invoice(&invoice)
 747                         }),
 748                 };
 749                 invoice_payer.handle_event(&event);
 750                 assert_eq!(*event_handled.borrow(), false);
 751                 assert_eq!(*payer.attempts.borrow(), 3);
 752
 753                 invoice_payer.handle_event(&event);
 754                 assert_eq!(*event_handled.borrow(), true);
 755                 assert_eq!(*payer.attempts.borrow(), 3);
 756         }
 757
 758         #[test]
 759         fn fails_paying_invoice_with_missing_retry_params() {
 760                 let event_handled = core::cell::RefCell::new(false);
 761                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 762
 763                 let payment_preimage = PaymentPreimage([1; 32]);
 764                 let invoice = invoice(payment_preimage);
 765                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 766
 767                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 768                 let router = TestRouter {};
 769                 let scorer = RefCell::new(TestScorer::new());
 770                 let logger = TestLogger::new();
 771                 let invoice_payer =
 772                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 773
 774                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 775                 assert_eq!(*payer.attempts.borrow(), 1);
 776
 777                 let event = Event::PaymentPathFailed {
 778                         payment_id,
 779                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 780                         network_update: None,
 781                         rejected_by_dest: false,
 782                         all_paths_failed: false,
 783                         path: vec![],
 784                         short_channel_id: None,
 785                         retry: None,
 786                 };
 787                 invoice_payer.handle_event(&event);
 788                 assert_eq!(*event_handled.borrow(), true);
 789                 assert_eq!(*payer.attempts.borrow(), 1);
 790         }
 791
 792         #[test]
 793         fn fails_paying_invoice_after_expiration() {
 794                 let event_handled = core::cell::RefCell::new(false);
 795                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 796
 797                 let payer = TestPayer::new();
 798                 let router = TestRouter {};
 799                 let scorer = RefCell::new(TestScorer::new());
 800                 let logger = TestLogger::new();
 801                 let invoice_payer =
 802                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 803
 804                 let payment_preimage = PaymentPreimage([1; 32]);
 805                 let invoice = expired_invoice(payment_preimage);
 806                 if let PaymentError::Invoice(msg) = invoice_payer.pay_invoice(&invoice).unwrap_err() {
 807                         assert_eq!(msg, "Invoice expired prior to send");
 808                 } else { panic!("Expected Invoice Error"); }
 809         }
 810
 811         #[test]
 812         fn fails_retrying_invoice_after_expiration() {
 813                 let event_handled = core::cell::RefCell::new(false);
 814                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 815
 816                 let payment_preimage = PaymentPreimage([1; 32]);
 817                 let invoice = invoice(payment_preimage);
 818                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 819
 820                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 821                 let router = TestRouter {};
 822                 let scorer = RefCell::new(TestScorer::new());
 823                 let logger = TestLogger::new();
 824                 let invoice_payer =
 825                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 826
 827                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 828                 assert_eq!(*payer.attempts.borrow(), 1);
 829
 830                 let mut retry_data = TestRouter::retry_for_invoice(&invoice);
 831                 retry_data.payee.expiry_time = Some(SystemTime::now()
 832                         .checked_sub(Duration::from_secs(2)).unwrap()
 833                         .duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs());
 834                 let event = Event::PaymentPathFailed {
 835                         payment_id,
 836                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 837                         network_update: None,
 838                         rejected_by_dest: false,
 839                         all_paths_failed: false,
 840                         path: vec![],
 841                         short_channel_id: None,
 842                         retry: Some(retry_data),
 843                 };
 844                 invoice_payer.handle_event(&event);
 845                 assert_eq!(*event_handled.borrow(), true);
 846                 assert_eq!(*payer.attempts.borrow(), 1);
 847         }
 848
 849         #[test]
 850         fn fails_paying_invoice_after_retry_error() {
 851                 let event_handled = core::cell::RefCell::new(false);
 852                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 853
 854                 let payment_preimage = PaymentPreimage([1; 32]);
 855                 let invoice = invoice(payment_preimage);
 856                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 857
 858                 let payer = TestPayer::new()
 859                         .fails_on_attempt(2)
 860                         .expect_send(Amount::ForInvoice(final_value_msat))
 861                         .expect_send(Amount::OnRetry(final_value_msat / 2));
 862                 let router = TestRouter {};
 863                 let scorer = RefCell::new(TestScorer::new());
 864                 let logger = TestLogger::new();
 865                 let invoice_payer =
 866                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 867
 868                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 869                 assert_eq!(*payer.attempts.borrow(), 1);
 870
 871                 let event = Event::PaymentPathFailed {
 872                         payment_id,
 873                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 874                         network_update: None,
 875                         rejected_by_dest: false,
 876                         all_paths_failed: false,
 877                         path: TestRouter::path_for_value(final_value_msat / 2),
 878                         short_channel_id: None,
 879                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 880                 };
 881                 invoice_payer.handle_event(&event);
 882                 assert_eq!(*event_handled.borrow(), true);
 883                 assert_eq!(*payer.attempts.borrow(), 2);
 884         }
 885
 886         #[test]
 887         fn fails_paying_invoice_after_rejected_by_payee() {
 888                 let event_handled = core::cell::RefCell::new(false);
 889                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 890
 891                 let payment_preimage = PaymentPreimage([1; 32]);
 892                 let invoice = invoice(payment_preimage);
 893                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 894
 895                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
 896                 let router = TestRouter {};
 897                 let scorer = RefCell::new(TestScorer::new());
 898                 let logger = TestLogger::new();
 899                 let invoice_payer =
 900                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 901
 902                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 903                 assert_eq!(*payer.attempts.borrow(), 1);
 904
 905                 let event = Event::PaymentPathFailed {
 906                         payment_id,
 907                         payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
 908                         network_update: None,
 909                         rejected_by_dest: true,
 910                         all_paths_failed: false,
 911                         path: vec![],
 912                         short_channel_id: None,
 913                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 914                 };
 915                 invoice_payer.handle_event(&event);
 916                 assert_eq!(*event_handled.borrow(), true);
 917                 assert_eq!(*payer.attempts.borrow(), 1);
 918         }
 919
 920         #[test]
 921         fn fails_repaying_invoice_with_pending_payment() {
 922                 let event_handled = core::cell::RefCell::new(false);
 923                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 924
 925                 let payment_preimage = PaymentPreimage([1; 32]);
 926                 let invoice = invoice(payment_preimage);
 927                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 928
 929                 let payer = TestPayer::new()
 930                         .expect_send(Amount::ForInvoice(final_value_msat))
 931                         .expect_send(Amount::ForInvoice(final_value_msat));
 932                 let router = TestRouter {};
 933                 let scorer = RefCell::new(TestScorer::new());
 934                 let logger = TestLogger::new();
 935                 let invoice_payer =
 936                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
 937
 938                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 939
 940                 // Cannot repay an invoice pending payment.
 941                 match invoice_payer.pay_invoice(&invoice) {
 942                         Err(PaymentError::Invoice("payment pending")) => {},
 943                         Err(_) => panic!("unexpected error"),
 944                         Ok(_) => panic!("expected invoice error"),
 945                 }
 946
 947                 // Can repay an invoice once cleared from cache.
 948                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 949                 invoice_payer.remove_cached_payment(&payment_hash);
 950                 assert!(invoice_payer.pay_invoice(&invoice).is_ok());
 951
 952                 // Cannot retry paying an invoice if cleared from cache.
 953                 invoice_payer.remove_cached_payment(&payment_hash);
 954                 let event = Event::PaymentPathFailed {
 955                         payment_id,
 956                         payment_hash,
 957                         network_update: None,
 958                         rejected_by_dest: false,
 959                         all_paths_failed: false,
 960                         path: vec![],
 961                         short_channel_id: None,
 962                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
 963                 };
 964                 invoice_payer.handle_event(&event);
 965                 assert_eq!(*event_handled.borrow(), true);
 966         }
 967
 968         #[test]
 969         fn fails_paying_invoice_with_routing_errors() {
 970                 let payer = TestPayer::new();
 971                 let router = FailingRouter {};
 972                 let scorer = RefCell::new(TestScorer::new());
 973                 let logger = TestLogger::new();
 974                 let invoice_payer =
 975                         InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
 976
 977                 let payment_preimage = PaymentPreimage([1; 32]);
 978                 let invoice = invoice(payment_preimage);
 979                 match invoice_payer.pay_invoice(&invoice) {
 980                         Err(PaymentError::Routing(_)) => {},
 981                         Err(_) => panic!("unexpected error"),
 982                         Ok(_) => panic!("expected routing error"),
 983                 }
 984         }
 985
 986         #[test]
 987         fn fails_paying_invoice_with_sending_errors() {
 988                 let payment_preimage = PaymentPreimage([1; 32]);
 989                 let invoice = invoice(payment_preimage);
 990                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 991
 992                 let payer = TestPayer::new()
 993                         .fails_on_attempt(1)
 994                         .expect_send(Amount::ForInvoice(final_value_msat));
 995                 let router = TestRouter {};
 996                 let scorer = RefCell::new(TestScorer::new());
 997                 let logger = TestLogger::new();
 998                 let invoice_payer =
 999                         InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
1000
1001                 match invoice_payer.pay_invoice(&invoice) {
1002                         Err(PaymentError::Sending(_)) => {},
1003                         Err(_) => panic!("unexpected error"),
1004                         Ok(_) => panic!("expected sending error"),
1005                 }
1006         }
1007
1008         #[test]
1009         fn pays_zero_value_invoice_using_amount() {
1010                 let event_handled = core::cell::RefCell::new(false);
1011                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1012
1013                 let payment_preimage = PaymentPreimage([1; 32]);
1014                 let invoice = zero_value_invoice(payment_preimage);
1015                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
1016                 let final_value_msat = 100;
1017
1018                 let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
1019                 let router = TestRouter {};
1020                 let scorer = RefCell::new(TestScorer::new());
1021                 let logger = TestLogger::new();
1022                 let invoice_payer =
1023                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
1024
1025                 let payment_id =
1026                         Some(invoice_payer.pay_zero_value_invoice(&invoice, final_value_msat).unwrap());
1027                 assert_eq!(*payer.attempts.borrow(), 1);
1028
1029                 invoice_payer.handle_event(&Event::PaymentSent {
1030                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
1031                 });
1032                 assert_eq!(*event_handled.borrow(), true);
1033                 assert_eq!(*payer.attempts.borrow(), 1);
1034         }
1035
1036         #[test]
1037         fn fails_paying_zero_value_invoice_with_amount() {
1038                 let event_handled = core::cell::RefCell::new(false);
1039                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1040
1041                 let payer = TestPayer::new();
1042                 let router = TestRouter {};
1043                 let scorer = RefCell::new(TestScorer::new());
1044                 let logger = TestLogger::new();
1045                 let invoice_payer =
1046                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
1047
1048                 let payment_preimage = PaymentPreimage([1; 32]);
1049                 let invoice = invoice(payment_preimage);
1050
1051                 // Cannot repay an invoice pending payment.
1052                 match invoice_payer.pay_zero_value_invoice(&invoice, 100) {
1053                         Err(PaymentError::Invoice("amount unexpected")) => {},
1054                         Err(_) => panic!("unexpected error"),
1055                         Ok(_) => panic!("expected invoice error"),
1056                 }
1057         }
1058
1059         #[test]
1060         fn pays_pubkey_with_amount() {
1061                 let event_handled = core::cell::RefCell::new(false);
1062                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1063
1064                 let pubkey = pubkey();
1065                 let payment_preimage = PaymentPreimage([1; 32]);
1066                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1067                 let final_value_msat = 100;
1068                 let final_cltv_expiry_delta = 42;
1069
1070                 let payer = TestPayer::new()
1071                         .expect_send(Amount::Spontaneous(final_value_msat))
1072                         .expect_send(Amount::OnRetry(final_value_msat));
1073                 let router = TestRouter {};
1074                 let scorer = RefCell::new(TestScorer::new());
1075                 let logger = TestLogger::new();
1076                 let invoice_payer =
1077                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
1078
1079                 let payment_id = Some(invoice_payer.pay_pubkey(
1080                                 pubkey, payment_preimage, final_value_msat, final_cltv_expiry_delta
1081                         ).unwrap());
1082                 assert_eq!(*payer.attempts.borrow(), 1);
1083
1084                 let retry = RouteParameters {
1085                         payee: Payee::for_keysend(pubkey),
1086                         final_value_msat,
1087                         final_cltv_expiry_delta,
1088                 };
1089                 let event = Event::PaymentPathFailed {
1090                         payment_id,
1091                         payment_hash,
1092                         network_update: None,
1093                         rejected_by_dest: false,
1094                         all_paths_failed: false,
1095                         path: vec![],
1096                         short_channel_id: None,
1097                         retry: Some(retry),
1098                 };
1099                 invoice_payer.handle_event(&event);
1100                 assert_eq!(*event_handled.borrow(), false);
1101                 assert_eq!(*payer.attempts.borrow(), 2);
1102
1103                 invoice_payer.handle_event(&Event::PaymentSent {
1104                         payment_id, payment_preimage, payment_hash, fee_paid_msat: None
1105                 });
1106                 assert_eq!(*event_handled.borrow(), true);
1107                 assert_eq!(*payer.attempts.borrow(), 2);
1108         }
1109
1110         #[test]
1111         fn scores_failed_channel() {
1112                 let event_handled = core::cell::RefCell::new(false);
1113                 let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
1114
1115                 let payment_preimage = PaymentPreimage([1; 32]);
1116                 let invoice = invoice(payment_preimage);
1117                 let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
1118                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
1119                 let path = TestRouter::path_for_value(final_value_msat);
1120                 let short_channel_id = Some(path[0].short_channel_id);
1121
1122                 // Expect that scorer is given short_channel_id upon handling the event.
1123                 let payer = TestPayer::new()
1124                         .expect_send(Amount::ForInvoice(final_value_msat))
1125                         .expect_send(Amount::OnRetry(final_value_msat / 2));
1126                 let router = TestRouter {};
1127                 let scorer = RefCell::new(TestScorer::new().expect_channel_failure(short_channel_id.unwrap()));
1128                 let logger = TestLogger::new();
1129                 let invoice_payer =
1130                         InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
1131
1132                 let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
1133                 let event = Event::PaymentPathFailed {
1134                         payment_id,
1135                         payment_hash,
1136                         network_update: None,
1137                         rejected_by_dest: false,
1138                         all_paths_failed: false,
1139                         path,
1140                         short_channel_id,
1141                         retry: Some(TestRouter::retry_for_invoice(&invoice)),
1142                 };
1143                 invoice_payer.handle_event(&event);
1144         }
1145
1146         struct TestRouter;
1147
1148         impl TestRouter {
1149                 fn route_for_value(final_value_msat: u64) -> Route {
1150                         Route {
1151                                 paths: vec![
1152                                         vec![RouteHop {
1153                                                 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
1154                                                 channel_features: ChannelFeatures::empty(),
1155                                                 node_features: NodeFeatures::empty(),
1156                                                 short_channel_id: 0, fee_msat: final_value_msat / 2, cltv_expiry_delta: 144
1157                                         }],
1158                                         vec![RouteHop {
1159                                                 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
1160                                                 channel_features: ChannelFeatures::empty(),
1161                                                 node_features: NodeFeatures::empty(),
1162                                                 short_channel_id: 1, fee_msat: final_value_msat / 2, cltv_expiry_delta: 144
1163                                         }],
1164                                 ],
1165                                 payee: None,
1166                         }
1167                 }
1168
1169                 fn path_for_value(final_value_msat: u64) -> Vec<RouteHop> {
1170                         TestRouter::route_for_value(final_value_msat).paths[0].clone()
1171                 }
1172
1173                 fn retry_for_invoice(invoice: &Invoice) -> RouteParameters {
1174                         let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key())
1175                                 .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
1176                                 .with_route_hints(invoice.route_hints());
1177                         if let Some(features) = invoice.features() {
1178                                 payee = payee.with_features(features.clone());
1179                         }
1180                         let final_value_msat = invoice.amount_milli_satoshis().unwrap() / 2;
1181                         RouteParameters {
1182                                 payee,
1183                                 final_value_msat,
1184                                 final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
1185                         }
1186                 }
1187         }
1188
1189         impl<S: routing::Score> Router<S> for TestRouter {
1190                 fn find_route(
1191                         &self, _payer: &PublicKey, params: &RouteParameters, _payment_hash: &PaymentHash,
1192                         _first_hops: Option<&[&ChannelDetails]>, _scorer: &S
1193                 ) -> Result<Route, LightningError> {
1194                         Ok(Route {
1195                                 payee: Some(params.payee.clone()), ..Self::route_for_value(params.final_value_msat)
1196                         })
1197                 }
1198         }
1199
1200         struct FailingRouter;
1201
1202         impl<S: routing::Score> Router<S> for FailingRouter {
1203                 fn find_route(
1204                         &self, _payer: &PublicKey, _params: &RouteParameters, _payment_hash: &PaymentHash,
1205                         _first_hops: Option<&[&ChannelDetails]>, _scorer: &S
1206                 ) -> Result<Route, LightningError> {
1207                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError })
1208                 }
1209         }
1210
1211         struct TestScorer {
1212                 expectations: VecDeque<u64>,
1213         }
1214
1215         impl TestScorer {
1216                 fn new() -> Self {
1217                         Self {
1218                                 expectations: VecDeque::new(),
1219                         }
1220                 }
1221
1222                 fn expect_channel_failure(mut self, short_channel_id: u64) -> Self {
1223                         self.expectations.push_back(short_channel_id);
1224                         self
1225                 }
1226         }
1227
1228         impl routing::Score for TestScorer {
1229                 fn channel_penalty_msat(
1230                         &self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId
1231                 ) -> u64 { 0 }
1232
1233                 fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
1234                         if let Some(expected_short_channel_id) = self.expectations.pop_front() {
1235                                 assert_eq!(short_channel_id, expected_short_channel_id);
1236                         }
1237                 }
1238         }
1239
1240         impl Drop for TestScorer {
1241                 fn drop(&mut self) {
1242                         if std::thread::panicking() {
1243                                 return;
1244                         }
1245
1246                         if !self.expectations.is_empty() {
1247                                 panic!("Unsatisfied channel failure expectations: {:?}", self.expectations);
1248                         }
1249                 }
1250         }
1251
1252         struct TestPayer {
1253                 expectations: core::cell::RefCell<VecDeque<Amount>>,
1254                 attempts: core::cell::RefCell<usize>,
1255                 failing_on_attempt: core::cell::RefCell<HashMap<usize, PaymentSendFailure>>,
1256         }
1257
1258         #[derive(Clone, Debug, PartialEq, Eq)]
1259         enum Amount {
1260                 ForInvoice(u64),
1261                 Spontaneous(u64),
1262                 OnRetry(u64),
1263         }
1264
1265         struct OnAttempt(usize);
1266
1267         impl TestPayer {
1268                 fn new() -> Self {
1269                         Self {
1270                                 expectations: core::cell::RefCell::new(VecDeque::new()),
1271                                 attempts: core::cell::RefCell::new(0),
1272                                 failing_on_attempt: core::cell::RefCell::new(HashMap::new()),
1273                         }
1274                 }
1275
1276                 fn expect_send(self, value_msat: Amount) -> Self {
1277                         self.expectations.borrow_mut().push_back(value_msat);
1278                         self
1279                 }
1280
1281                 fn fails_on_attempt(self, attempt: usize) -> Self {
1282                         let failure = PaymentSendFailure::ParameterError(APIError::MonitorUpdateFailed);
1283                         self.fails_with(failure, OnAttempt(attempt))
1284                 }
1285
1286                 fn fails_with_partial_failure(self, retry: RouteParameters, attempt: OnAttempt) -> Self {
1287                         self.fails_with(PaymentSendFailure::PartialFailure {
1288                                 results: vec![],
1289                                 failed_paths_retry: Some(retry),
1290                                 payment_id: PaymentId([1; 32]),
1291                         }, attempt)
1292                 }
1293
1294                 fn fails_with(self, failure: PaymentSendFailure, attempt: OnAttempt) -> Self {
1295                         self.failing_on_attempt.borrow_mut().insert(attempt.0, failure);
1296                         self
1297                 }
1298
1299                 fn check_attempts(&self) -> Result<PaymentId, PaymentSendFailure> {
1300                         let mut attempts = self.attempts.borrow_mut();
1301                         *attempts += 1;
1302
1303                         match self.failing_on_attempt.borrow_mut().remove(&*attempts) {
1304                                 Some(failure) => Err(failure),
1305                                 None => Ok(PaymentId([1; 32])),
1306                         }
1307                 }
1308
1309                 fn check_value_msats(&self, actual_value_msats: Amount) {
1310                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
1311                         if let Some(expected_value_msats) = expected_value_msats {
1312                                 assert_eq!(actual_value_msats, expected_value_msats);
1313                         } else {
1314                                 panic!("Unexpected amount: {:?}", actual_value_msats);
1315                         }
1316                 }
1317         }
1318
1319         impl Drop for TestPayer {
1320                 fn drop(&mut self) {
1321                         if std::thread::panicking() {
1322                                 return;
1323                         }
1324
1325                         if !self.expectations.borrow().is_empty() {
1326                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
1327                         }
1328                 }
1329         }
1330
1331         impl Payer for TestPayer {
1332                 fn node_id(&self) -> PublicKey {
1333                         let secp_ctx = Secp256k1::new();
1334                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
1335                 }
1336
1337                 fn first_hops(&self) -> Vec<ChannelDetails> {
1338                         Vec::new()
1339                 }
1340
1341                 fn send_payment(
1342                         &self, route: &Route, _payment_hash: PaymentHash,
1343                         _payment_secret: &Option<PaymentSecret>
1344                 ) -> Result<PaymentId, PaymentSendFailure> {
1345                         self.check_value_msats(Amount::ForInvoice(route.get_total_amount()));
1346                         self.check_attempts()
1347                 }
1348
1349                 fn send_spontaneous_payment(
1350                         &self, route: &Route, _payment_preimage: PaymentPreimage,
1351                 ) -> Result<PaymentId, PaymentSendFailure> {
1352                         self.check_value_msats(Amount::Spontaneous(route.get_total_amount()));
1353                         self.check_attempts()
1354                 }
1355
1356                 fn retry_payment(
1357                         &self, route: &Route, _payment_id: PaymentId
1358                 ) -> Result<(), PaymentSendFailure> {
1359                         self.check_value_msats(Amount::OnRetry(route.get_total_amount()));
1360                         self.check_attempts().map(|_| ())
1361                 }
1362         }
1363
1364         // *** Full Featured Functional Tests with a Real ChannelManager ***
1365         struct ManualRouter(RefCell<VecDeque<Result<Route, LightningError>>>);
1366
1367         impl<S: routing::Score> Router<S> for ManualRouter {
1368                 fn find_route(
1369                         &self, _payer: &PublicKey, _params: &RouteParameters, _payment_hash: &PaymentHash,
1370                         _first_hops: Option<&[&ChannelDetails]>, _scorer: &S
1371                 ) -> Result<Route, LightningError> {
1372                         self.0.borrow_mut().pop_front().unwrap()
1373                 }
1374         }
1375         impl ManualRouter {
1376                 fn expect_find_route(&self, result: Result<Route, LightningError>) {
1377                         self.0.borrow_mut().push_back(result);
1378                 }
1379         }
1380         impl Drop for ManualRouter {
1381                 fn drop(&mut self) {
1382                         if std::thread::panicking() {
1383                                 return;
1384                         }
1385                         assert!(self.0.borrow_mut().is_empty());
1386                 }
1387         }
1388
1389         #[test]
1390         fn retry_multi_path_single_failed_payment() {
1391                 // Tests that we can/will retry after a single path of an MPP payment failed immediately
1392                 let chanmon_cfgs = create_chanmon_cfgs(2);
1393                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1394                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
1395                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1396
1397                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1398                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1399                 let chans = nodes[0].node.list_usable_channels();
1400                 let mut route = Route {
1401                         paths: vec![
1402                                 vec![RouteHop {
1403                                         pubkey: nodes[1].node.get_our_node_id(),
1404                                         node_features: NodeFeatures::known(),
1405                                         short_channel_id: chans[0].short_channel_id.unwrap(),
1406                                         channel_features: ChannelFeatures::known(),
1407                                         fee_msat: 10_000,
1408                                         cltv_expiry_delta: 100,
1409                                 }],
1410                                 vec![RouteHop {
1411                                         pubkey: nodes[1].node.get_our_node_id(),
1412                                         node_features: NodeFeatures::known(),
1413                                         short_channel_id: chans[1].short_channel_id.unwrap(),
1414                                         channel_features: ChannelFeatures::known(),
1415                                         fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
1416                                         cltv_expiry_delta: 100,
1417                                 }],
1418                         ],
1419                         payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
1420                 };
1421                 let router = ManualRouter(RefCell::new(VecDeque::new()));
1422                 router.expect_find_route(Ok(route.clone()));
1423                 // On retry, split the payment across both channels.
1424                 route.paths[0][0].fee_msat = 50_000_001;
1425                 route.paths[1][0].fee_msat = 50_000_000;
1426                 router.expect_find_route(Ok(route.clone()));
1427
1428                 let event_handler = |_: &_| { panic!(); };
1429                 let scorer = RefCell::new(TestScorer::new());
1430                 let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
1431
1432                 assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
1433                         &nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
1434                         .is_ok());
1435                 let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
1436                 assert_eq!(htlc_msgs.len(), 2);
1437                 check_added_monitors!(nodes[0], 2);
1438         }
1439
1440         #[test]
1441         fn immediate_retry_on_failure() {
1442                 // Tests that we can/will retry immediately after a failure
1443                 let chanmon_cfgs = create_chanmon_cfgs(2);
1444                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1445                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
1446                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1447
1448                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1449                 create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0, InitFeatures::known(), InitFeatures::known());
1450                 let chans = nodes[0].node.list_usable_channels();
1451                 let mut route = Route {
1452                         paths: vec![
1453                                 vec![RouteHop {
1454                                         pubkey: nodes[1].node.get_our_node_id(),
1455                                         node_features: NodeFeatures::known(),
1456                                         short_channel_id: chans[0].short_channel_id.unwrap(),
1457                                         channel_features: ChannelFeatures::known(),
1458                                         fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
1459                                         cltv_expiry_delta: 100,
1460                                 }],
1461                         ],
1462                         payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
1463                 };
1464                 let router = ManualRouter(RefCell::new(VecDeque::new()));
1465                 router.expect_find_route(Ok(route.clone()));
1466                 // On retry, split the payment across both channels.
1467                 route.paths.push(route.paths[0].clone());
1468                 route.paths[0][0].short_channel_id = chans[1].short_channel_id.unwrap();
1469                 route.paths[0][0].fee_msat = 50_000_000;
1470                 route.paths[1][0].fee_msat = 50_000_001;
1471                 router.expect_find_route(Ok(route.clone()));
1472
1473                 let event_handler = |_: &_| { panic!(); };
1474                 let scorer = RefCell::new(TestScorer::new());
1475                 let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
1476
1477                 assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
1478                         &nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
1479                         .is_ok());
1480                 let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
1481                 assert_eq!(htlc_msgs.len(), 2);
1482                 check_added_monitors!(nodes[0], 2);
1483         }
1484 }