_ Git - rust-lightning/blob - lightning/src/ln/outbound_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 //! Utilities to send payments and manage outbound payment information.
  11
  12 use bitcoin::hashes::Hash;
  13 use bitcoin::hashes::sha256::Hash as Sha256;
  14 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
  15
  16 use crate::chain::keysinterface::{EntropySource, NodeSigner, Recipient};
  17 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  18 use crate::ln::channelmanager::{ChannelDetails, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
  19 use crate::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA as LDK_DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA;
  20 use crate::ln::msgs::DecodeError;
  21 use crate::ln::onion_utils::HTLCFailReason;
  22 use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters, RoutePath, Router};
  23 use crate::util::errors::APIError;
  24 use crate::util::events;
  25 use crate::util::logger::Logger;
  26 use crate::util::time::Time;
  27 #[cfg(all(not(feature = "no-std"), test))]
  28 use crate::util::time::tests::SinceEpoch;
  29
  30 use core::cmp;
  31 use core::fmt::{self, Display, Formatter};
  32 use core::ops::Deref;
  33
  34 use crate::prelude::*;
  35 use crate::sync::Mutex;
  36
  37 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  38 /// and later, also stores information for retrying the payment.
  39 pub(crate) enum PendingOutboundPayment {
  40         Legacy {
  41                 session_privs: HashSet<[u8; 32]>,
  42         },
  43         Retryable {
  44                 retry_strategy: Option<Retry>,
  45                 attempts: PaymentAttempts,
  46                 payment_params: Option<PaymentParameters>,
  47                 session_privs: HashSet<[u8; 32]>,
  48                 payment_hash: PaymentHash,
  49                 payment_secret: Option<PaymentSecret>,
  50                 keysend_preimage: Option<PaymentPreimage>,
  51                 pending_amt_msat: u64,
  52                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  53                 pending_fee_msat: Option<u64>,
  54                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  55                 total_msat: u64,
  56                 /// Our best known block height at the time this payment was initiated.
  57                 starting_block_height: u32,
  58         },
  59         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  60         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  61         /// and add a pending payment that was already fulfilled.
  62         Fulfilled {
  63                 session_privs: HashSet<[u8; 32]>,
  64                 payment_hash: Option<PaymentHash>,
  65                 timer_ticks_without_htlcs: u8,
  66         },
  67         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  68         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  69         Abandoned {
  70                 session_privs: HashSet<[u8; 32]>,
  71                 payment_hash: PaymentHash,
  72         },
  73 }
  74
  75 impl PendingOutboundPayment {
  76         fn increment_attempts(&mut self) {
  77                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  78                         attempts.count += 1;
  79                 }
  80         }
  81         fn is_auto_retryable_now(&self) -> bool {
  82                 match self {
  83                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  84                                 strategy.is_retryable_now(&attempts)
  85                         },
  86                         _ => false,
  87                 }
  88         }
  89         fn is_retryable_now(&self) -> bool {
  90                 match self {
  91                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
  92                                 // We're handling retries manually, we can always retry.
  93                                 true
  94                         },
  95                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  96                                 strategy.is_retryable_now(&attempts)
  97                         },
  98                         _ => false,
  99                 }
 100         }
 101         fn payment_parameters(&mut self) -> Option<&mut PaymentParameters> {
 102                 match self {
 103                         PendingOutboundPayment::Retryable { payment_params: Some(ref mut params), .. } => {
 104                                 Some(params)
 105                         },
 106                         _ => None,
 107                 }
 108         }
 109         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 110                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 111                         params.previously_failed_channels.push(scid);
 112                 }
 113         }
 114         pub(super) fn is_fulfilled(&self) -> bool {
 115                 match self {
 116                         PendingOutboundPayment::Fulfilled { .. } => true,
 117                         _ => false,
 118                 }
 119         }
 120         pub(super) fn abandoned(&self) -> bool {
 121                 match self {
 122                         PendingOutboundPayment::Abandoned { .. } => true,
 123                         _ => false,
 124                 }
 125         }
 126         fn get_pending_fee_msat(&self) -> Option<u64> {
 127                 match self {
 128                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 129                         _ => None,
 130                 }
 131         }
 132
 133         fn payment_hash(&self) -> Option<PaymentHash> {
 134                 match self {
 135                         PendingOutboundPayment::Legacy { .. } => None,
 136                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 137                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 138                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 139                 }
 140         }
 141
 142         fn mark_fulfilled(&mut self) {
 143                 let mut session_privs = HashSet::new();
 144                 core::mem::swap(&mut session_privs, match self {
 145                         PendingOutboundPayment::Legacy { session_privs } |
 146                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 147                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 148                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 149                         => session_privs,
 150                 });
 151                 let payment_hash = self.payment_hash();
 152                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 153         }
 154
 155         fn mark_abandoned(&mut self) -> Result<(), ()> {
 156                 let mut session_privs = HashSet::new();
 157                 let our_payment_hash;
 158                 core::mem::swap(&mut session_privs, match self {
 159                         PendingOutboundPayment::Legacy { .. } |
 160                         PendingOutboundPayment::Fulfilled { .. } =>
 161                                 return Err(()),
 162                         PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } |
 163                         PendingOutboundPayment::Abandoned { session_privs, payment_hash, .. } => {
 164                                 our_payment_hash = *payment_hash;
 165                                 session_privs
 166                         },
 167                 });
 168                 *self = PendingOutboundPayment::Abandoned { session_privs, payment_hash: our_payment_hash };
 169                 Ok(())
 170         }
 171
 172         /// panics if path is None and !self.is_fulfilled
 173         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Vec<RouteHop>>) -> bool {
 174                 let remove_res = match self {
 175                         PendingOutboundPayment::Legacy { session_privs } |
 176                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 177                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 178                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 179                                         session_privs.remove(session_priv)
 180                                 }
 181                 };
 182                 if remove_res {
 183                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 184                                 let path = path.expect("Fulfilling a payment should always come with a path");
 185                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 186                                 *pending_amt_msat -= path_last_hop.fee_msat;
 187                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 188                                         *fee_msat -= path.get_path_fees();
 189                                 }
 190                         }
 191                 }
 192                 remove_res
 193         }
 194
 195         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Vec<RouteHop>) -> bool {
 196                 let insert_res = match self {
 197                         PendingOutboundPayment::Legacy { session_privs } |
 198                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 199                                         session_privs.insert(session_priv)
 200                                 }
 201                         PendingOutboundPayment::Fulfilled { .. } => false,
 202                         PendingOutboundPayment::Abandoned { .. } => false,
 203                 };
 204                 if insert_res {
 205                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 206                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 207                                 *pending_amt_msat += path_last_hop.fee_msat;
 208                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 209                                         *fee_msat += path.get_path_fees();
 210                                 }
 211                         }
 212                 }
 213                 insert_res
 214         }
 215
 216         pub(super) fn remaining_parts(&self) -> usize {
 217                 match self {
 218                         PendingOutboundPayment::Legacy { session_privs } |
 219                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 220                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 221                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 222                                         session_privs.len()
 223                                 }
 224                 }
 225         }
 226 }
 227
 228 /// Strategies available to retry payment path failures.
 229 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 230 pub enum Retry {
 231         /// Max number of attempts to retry payment.
 232         ///
 233         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 234         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 235         /// were retried along a route from a single call to [`Router::find_route`].
 236         Attempts(usize),
 237         #[cfg(not(feature = "no-std"))]
 238         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 239         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 240         ///
 241         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 242         Timeout(core::time::Duration),
 243 }
 244
 245 impl Retry {
 246         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 247                 match (self, attempts) {
 248                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 249                                 max_retry_count > count
 250                         },
 251                         #[cfg(all(not(feature = "no-std"), not(test)))]
 252                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 253                                 *max_duration >= std::time::Instant::now().duration_since(*first_attempted_at),
 254                         #[cfg(all(not(feature = "no-std"), test))]
 255                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 256                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 257                 }
 258         }
 259 }
 260
 261 #[cfg(feature = "std")]
 262 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 263         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 264                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 265                         return elapsed > core::time::Duration::from_secs(expiry_time)
 266                 }
 267         }
 268         false
 269 }
 270
 271 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 272
 273 /// Storing minimal payment attempts information required for determining if a outbound payment can
 274 /// be retried.
 275 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 276         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 277         /// it means the result of the first attempt is not known yet.
 278         pub(crate) count: usize,
 279         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 280         first_attempted_at: T
 281 }
 282
 283 #[cfg(not(any(feature = "no-std", test)))]
 284 type ConfiguredTime = std::time::Instant;
 285 #[cfg(feature = "no-std")]
 286 type ConfiguredTime = crate::util::time::Eternity;
 287 #[cfg(all(not(feature = "no-std"), test))]
 288 type ConfiguredTime = SinceEpoch;
 289
 290 impl<T: Time> PaymentAttemptsUsingTime<T> {
 291         pub(crate) fn new() -> Self {
 292                 PaymentAttemptsUsingTime {
 293                         count: 0,
 294                         first_attempted_at: T::now()
 295                 }
 296         }
 297 }
 298
 299 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 300         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 301                 #[cfg(feature = "no-std")]
 302                 return write!(f, "attempts: {}", self.count);
 303                 #[cfg(not(feature = "no-std"))]
 304                 return write!(
 305                         f,
 306                         "attempts: {}, duration: {}s",
 307                         self.count,
 308                         T::now().duration_since(self.first_attempted_at).as_secs()
 309                 );
 310         }
 311 }
 312
 313 /// Indicates an immediate error on [`ChannelManager::send_payment_with_retry`]. Further errors
 314 /// may be surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 315 ///
 316 /// [`ChannelManager::send_payment_with_retry`]: crate::ln::channelmanager::ChannelManager::send_payment_with_retry
 317 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 318 /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 319 #[derive(Clone, Debug)]
 320 pub enum RetryableSendFailure {
 321         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 322         /// that this error is *not* caused by [`Retry::Timeout`].
 323         ///
 324         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 325         PaymentExpired,
 326         /// We were unable to find a route to the destination.
 327         RouteNotFound,
 328         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 329         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 330         ///
 331         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 332         /// [`Event::PaymentSent`]: crate::util::events::Event::PaymentSent
 333         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 334         DuplicatePayment,
 335 }
 336
 337 /// If a payment fails to send with [`ChannelManager::send_payment`], it can be in one of several
 338 /// states. This enum is returned as the Err() type describing which state the payment is in, see
 339 /// the description of individual enum states for more.
 340 ///
 341 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 342 #[derive(Clone, Debug)]
 343 pub enum PaymentSendFailure {
 344         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 345         /// send the payment at all.
 346         ///
 347         /// You can freely resend the payment in full (with the parameter error fixed).
 348         ///
 349         /// Because the payment failed outright, no payment tracking is done and no
 350         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 351         ///
 352         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 353         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 354         ParameterError(APIError),
 355         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 356         /// from attempting to send the payment at all.
 357         ///
 358         /// You can freely resend the payment in full (with the parameter error fixed).
 359         ///
 360         /// Because the payment failed outright, no payment tracking is done and no
 361         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 362         ///
 363         /// The results here are ordered the same as the paths in the route object which was passed to
 364         /// send_payment.
 365         ///
 366         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 367         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 368         PathParameterError(Vec<Result<(), APIError>>),
 369         /// All paths which were attempted failed to send, with no channel state change taking place.
 370         /// You can freely resend the payment in full (though you probably want to do so over different
 371         /// paths than the ones selected).
 372         ///
 373         /// Because the payment failed outright, no payment tracking is done and no
 374         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 375         ///
 376         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 377         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 378         AllFailedResendSafe(Vec<APIError>),
 379         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 380         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 381         ///
 382         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 383         /// [`Event::PaymentSent`]: crate::util::events::Event::PaymentSent
 384         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 385         DuplicatePayment,
 386         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 387         /// some paths have irrevocably committed to the HTLC.
 388         ///
 389         /// The results here are ordered the same as the paths in the route object that was passed to
 390         /// send_payment.
 391         ///
 392         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 393         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 394         ///
 395         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 396         PartialFailure {
 397                 /// The errors themselves, in the same order as the paths from the route.
 398                 results: Vec<Result<(), APIError>>,
 399                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 400                 /// contain a [`RouteParameters`] object for the failing paths.
 401                 failed_paths_retry: Option<RouteParameters>,
 402                 /// The payment id for the payment, which is now at least partially pending.
 403                 payment_id: PaymentId,
 404         },
 405 }
 406
 407 pub(super) struct OutboundPayments {
 408         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 409         pub(super) retry_lock: Mutex<()>,
 410 }
 411
 412 impl OutboundPayments {
 413         pub(super) fn new() -> Self {
 414                 Self {
 415                         pending_outbound_payments: Mutex::new(HashMap::new()),
 416                         retry_lock: Mutex::new(()),
 417                 }
 418         }
 419
 420         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 421                 &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId,
 422                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 423                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 424                 node_signer: &NS, best_block_height: u32, logger: &L,
 425                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 426         ) -> Result<(), RetryableSendFailure>
 427         where
 428                 R::Target: Router,
 429                 ES::Target: EntropySource,
 430                 NS::Target: NodeSigner,
 431                 L::Target: Logger,
 432                 IH: Fn() -> InFlightHtlcs,
 433                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 434                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 435         {
 436                 self.send_payment_internal(payment_id, payment_hash, payment_secret, None, retry_strategy,
 437                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 438                         best_block_height, logger, pending_events, &send_payment_along_path)
 439         }
 440
 441         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 442                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 443                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 444                 send_payment_along_path: F
 445         ) -> Result<(), PaymentSendFailure>
 446         where
 447                 ES::Target: EntropySource,
 448                 NS::Target: NodeSigner,
 449                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 450                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 451         {
 452                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, None, route, None, None, entropy_source, best_block_height)?;
 453                 self.pay_route_internal(route, payment_hash, payment_secret, None, payment_id, None,
 454                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 455                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 456         }
 457
 458         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 459                 &self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 460                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 461                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 462                 node_signer: &NS, best_block_height: u32, logger: &L,
 463                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
 464         ) -> Result<PaymentHash, RetryableSendFailure>
 465         where
 466                 R::Target: Router,
 467                 ES::Target: EntropySource,
 468                 NS::Target: NodeSigner,
 469                 L::Target: Logger,
 470                 IH: Fn() -> InFlightHtlcs,
 471                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 472                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 473         {
 474                 let preimage = payment_preimage
 475                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 476                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 477                 self.send_payment_internal(payment_id, payment_hash, &None, Some(preimage), retry_strategy,
 478                         route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer,
 479                         best_block_height, logger, pending_events, send_payment_along_path)
 480                         .map(|()| payment_hash)
 481         }
 482
 483         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 484                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 485                 entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 486         ) -> Result<PaymentHash, PaymentSendFailure>
 487         where
 488                 ES::Target: EntropySource,
 489                 NS::Target: NodeSigner,
 490                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 491                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 492         {
 493                 let preimage = payment_preimage
 494                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 495                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 496                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 497
 498                 match self.pay_route_internal(route, payment_hash, &None, Some(preimage), payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path) {
 499                         Ok(()) => Ok(payment_hash),
 500                         Err(e) => {
 501                                 self.remove_outbound_if_all_failed(payment_id, &e);
 502                                 Err(e)
 503                         }
 504                 }
 505         }
 506
 507         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 508                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 509                 best_block_height: u32, pending_events: &Mutex<Vec<events::Event>>, logger: &L,
 510                 send_payment_along_path: SP,
 511         )
 512         where
 513                 R::Target: Router,
 514                 ES::Target: EntropySource,
 515                 NS::Target: NodeSigner,
 516                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 517                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 518                 IH: Fn() -> InFlightHtlcs,
 519                 FH: Fn() -> Vec<ChannelDetails>,
 520                 L::Target: Logger,
 521         {
 522                 let _single_thread = self.retry_lock.lock().unwrap();
 523                 loop {
 524                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 525                         let mut retry_id_route_params = None;
 526                         for (pmt_id, pmt) in outbounds.iter_mut() {
 527                                 if pmt.is_auto_retryable_now() {
 528                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), .. } = pmt {
 529                                                 if pending_amt_msat < total_msat {
 530                                                         retry_id_route_params = Some((*pmt_id, RouteParameters {
 531                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 532                                                                 final_cltv_expiry_delta:
 533                                                                         if let Some(delta) = params.final_cltv_expiry_delta { delta }
 534                                                                         else {
 535                                                                                 debug_assert!(false, "We always set the final_cltv_expiry_delta when a path fails");
 536                                                                                 LDK_DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA.into()
 537                                                                         },
 538                                                                 payment_params: params.clone(),
 539                                                         }));
 540                                                         break
 541                                                 }
 542                                         }
 543                                 }
 544                         }
 545                         core::mem::drop(outbounds);
 546                         if let Some((payment_id, route_params)) = retry_id_route_params {
 547                                 self.retry_payment_internal(payment_id, route_params, router, first_hops(), &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path)
 548                         } else { break }
 549                 }
 550
 551                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 552                 outbounds.retain(|pmt_id, pmt| {
 553                         let mut retain = true;
 554                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 555                                 if pmt.mark_abandoned().is_ok() {
 556                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 557                                                 payment_id: *pmt_id,
 558                                                 payment_hash: pmt.payment_hash().expect("PendingOutboundPayments::Retryable always has a payment hash set"),
 559                                         });
 560                                         retain = false;
 561                                 }
 562                         }
 563                         retain
 564                 });
 565         }
 566
 567         pub(super) fn needs_abandon(&self) -> bool {
 568                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 569                 outbounds.iter().any(|(_, pmt)|
 570                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 571         }
 572
 573         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 574         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 575         ///
 576         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 577         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 578         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 579                 &self, payment_id: PaymentId, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 580                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 581                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 582                 node_signer: &NS, best_block_height: u32, logger: &L,
 583                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 584         ) -> Result<(), RetryableSendFailure>
 585         where
 586                 R::Target: Router,
 587                 ES::Target: EntropySource,
 588                 NS::Target: NodeSigner,
 589                 L::Target: Logger,
 590                 IH: Fn() -> InFlightHtlcs,
 591                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 592                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 593         {
 594                 #[cfg(feature = "std")] {
 595                         if has_expired(&route_params) {
 596                                 return Err(RetryableSendFailure::PaymentExpired)
 597                         }
 598                 }
 599
 600                 let route = router.find_route(
 601                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 602                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs()
 603                 ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 604
 605                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret,
 606                         payment_id, keysend_preimage, &route, Some(retry_strategy),
 607                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 608                         .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 609
 610                 let res = self.pay_route_internal(&route, payment_hash, payment_secret, None, payment_id, None,
 611                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 612                 log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
 613                 if let Err(e) = res {
 614                         self.handle_pay_route_err(e, payment_id, payment_hash, route, route_params, router, first_hops, &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path);
 615                 }
 616                 Ok(())
 617         }
 618
 619         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 620                 &self, payment_id: PaymentId, route_params: RouteParameters, router: &R,
 621                 first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS,
 622                 best_block_height: u32, logger: &L, pending_events: &Mutex<Vec<events::Event>>,
 623                 send_payment_along_path: &SP,
 624         )
 625         where
 626                 R::Target: Router,
 627                 ES::Target: EntropySource,
 628                 NS::Target: NodeSigner,
 629                 L::Target: Logger,
 630                 IH: Fn() -> InFlightHtlcs,
 631                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 632                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 633         {
 634                 #[cfg(feature = "std")] {
 635                         if has_expired(&route_params) {
 636                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
 637                                 self.abandon_payment(payment_id, pending_events);
 638                                 return
 639                         }
 640                 }
 641
 642                 let route = match router.find_route(
 643                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 644                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs()
 645                 ) {
 646                         Ok(route) => route,
 647                         Err(e) => {
 648                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
 649                                 self.abandon_payment(payment_id, pending_events);
 650                                 return
 651                         }
 652                 };
 653                 for path in route.paths.iter() {
 654                         if path.len() == 0 {
 655                                 log_error!(logger, "length-0 path in route");
 656                                 self.abandon_payment(payment_id, pending_events);
 657                                 return
 658                         }
 659                 }
 660
 661                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 662                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 663                 for _ in 0..route.paths.len() {
 664                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 665                 }
 666
 667                 macro_rules! abandon_with_entry {
 668                         ($payment_id: expr, $payment_hash: expr, $payment: expr, $pending_events: expr) => {
 669                                 if $payment.get_mut().mark_abandoned().is_ok() && $payment.get().remaining_parts() == 0 {
 670                                         $pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 671                                                 payment_id: $payment_id,
 672                                                 payment_hash: $payment_hash,
 673                                         });
 674                                         $payment.remove();
 675                                 }
 676                         }
 677                 }
 678                 let (total_msat, payment_hash, payment_secret, keysend_preimage) = {
 679                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 680                         match outbounds.entry(payment_id) {
 681                                 hash_map::Entry::Occupied(mut payment) => {
 682                                         let res = match payment.get() {
 683                                                 PendingOutboundPayment::Retryable {
 684                                                         total_msat, payment_hash, keysend_preimage, payment_secret, pending_amt_msat, ..
 685                                                 } => {
 686                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 687                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 688                                                                 log_error!(logger, "retry_amt_msat of {} will put pending_amt_msat (currently: {}) more than 10% over total_payment_amt_msat of {}", retry_amt_msat, pending_amt_msat, total_msat);
 689                                                                 let payment_hash = *payment_hash;
 690                                                                 abandon_with_entry!(payment_id, payment_hash, payment, pending_events);
 691                                                                 return
 692                                                         }
 693                                                         (*total_msat, *payment_hash, *payment_secret, *keysend_preimage)
 694                                                 },
 695                                                 PendingOutboundPayment::Legacy { .. } => {
 696                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 697                                                         return
 698                                                 },
 699                                                 PendingOutboundPayment::Fulfilled { .. } => {
 700                                                         log_error!(logger, "Payment already completed");
 701                                                         return
 702                                                 },
 703                                                 PendingOutboundPayment::Abandoned { .. } => {
 704                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 705                                                         return
 706                                                 },
 707                                         };
 708                                         if !payment.get().is_retryable_now() {
 709                                                 log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
 710                                                 abandon_with_entry!(payment_id, res.1, payment, pending_events);
 711                                                 return
 712                                         }
 713                                         payment.get_mut().increment_attempts();
 714                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 715                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 716                                         }
 717                                         res
 718                                 },
 719                                 hash_map::Entry::Vacant(_) => {
 720                                         log_error!(logger, "Payment with ID {} not found", log_bytes!(payment_id.0));
 721                                         return
 722                                 }
 723                         }
 724                 };
 725                 let res = self.pay_route_internal(&route, payment_hash, &payment_secret, keysend_preimage,
 726                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 727                         &send_payment_along_path);
 728                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
 729                 if let Err(e) = res {
 730                         self.handle_pay_route_err(e, payment_id, payment_hash, route, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 731                 }
 732         }
 733
 734         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 735                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 736                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 737                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 738                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 739         )
 740         where
 741                 R::Target: Router,
 742                 ES::Target: EntropySource,
 743                 NS::Target: NodeSigner,
 744                 L::Target: Logger,
 745                 IH: Fn() -> InFlightHtlcs,
 746                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 747                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 748         {
 749                 match err {
 750                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 751                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, errs.into_iter().map(|e| Err(e)), pending_events);
 752                                 self.retry_payment_internal(payment_id, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 753                         },
 754                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 755                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), pending_events);
 756                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 757                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 758                                 // return `Ok()` here, ignoring any retry errors.
 759                                 self.retry_payment_internal(payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 760                         },
 761                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 762                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 763                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 764                                 // initial HTLC-Add messages yet.
 765                         },
 766                         PaymentSendFailure::PathParameterError(results) => {
 767                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), pending_events);
 768                                 self.abandon_payment(payment_id, pending_events);
 769                         },
 770                         PaymentSendFailure::ParameterError(e) => {
 771                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 772                                 self.abandon_payment(payment_id, pending_events);
 773                         },
 774                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 775                 }
 776         }
 777
 778         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>>(
 779                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 780                 paths: Vec<Vec<RouteHop>>, path_results: I, pending_events: &Mutex<Vec<events::Event>>
 781         ) {
 782                 let mut events = pending_events.lock().unwrap();
 783                 debug_assert_eq!(paths.len(), path_results.len());
 784                 for (path, path_res) in paths.into_iter().zip(path_results) {
 785                         if let Err(e) = path_res {
 786                                 let failed_scid = if let APIError::InvalidRoute { .. } = e {
 787                                         None
 788                                 } else {
 789                                         let scid = path[0].short_channel_id;
 790                                         route_params.payment_params.previously_failed_channels.push(scid);
 791                                         Some(scid)
 792                                 };
 793                                 events.push(events::Event::PaymentPathFailed {
 794                                         payment_id: Some(payment_id),
 795                                         payment_hash,
 796                                         payment_failed_permanently: false,
 797                                         network_update: None,
 798                                         all_paths_failed: false,
 799                                         path,
 800                                         short_channel_id: failed_scid,
 801                                         retry: None,
 802                                         #[cfg(test)]
 803                                         error_code: None,
 804                                         #[cfg(test)]
 805                                         error_data: None,
 806                                 });
 807                         }
 808                 }
 809         }
 810
 811         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 812                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 813                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 814         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 815         where
 816                 ES::Target: EntropySource,
 817                 NS::Target: NodeSigner,
 818                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 819                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 820         {
 821                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 822
 823                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 824
 825                 if hops.len() < 2 {
 826                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 827                                 err: "No need probing a path with less than two hops".to_string()
 828                         }))
 829                 }
 830
 831                 let route = Route { paths: vec![hops], payment_params: None };
 832                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, None, &route, None, None, entropy_source, best_block_height)?;
 833
 834                 match self.pay_route_internal(&route, payment_hash, &None, None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path) {
 835                         Ok(()) => Ok((payment_hash, payment_id)),
 836                         Err(e) => {
 837                                 self.remove_outbound_if_all_failed(payment_id, &e);
 838                                 Err(e)
 839                         }
 840                 }
 841         }
 842
 843         #[cfg(test)]
 844         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 845                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 846                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 847         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 848                 self.add_new_pending_payment(payment_hash, payment_secret, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 849         }
 850
 851         pub(super) fn add_new_pending_payment<ES: Deref>(
 852                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 853                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 854                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 855         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 856                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 857                 for _ in 0..route.paths.len() {
 858                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 859                 }
 860
 861                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 862                 match pending_outbounds.entry(payment_id) {
 863                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 864                         hash_map::Entry::Vacant(entry) => {
 865                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 866                                         retry_strategy,
 867                                         attempts: PaymentAttempts::new(),
 868                                         payment_params,
 869                                         session_privs: HashSet::new(),
 870                                         pending_amt_msat: 0,
 871                                         pending_fee_msat: Some(0),
 872                                         payment_hash,
 873                                         payment_secret,
 874                                         keysend_preimage,
 875                                         starting_block_height: best_block_height,
 876                                         total_msat: route.get_total_amount(),
 877                                 });
 878
 879                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 880                                         assert!(payment.insert(*session_priv_bytes, path));
 881                                 }
 882
 883                                 Ok(onion_session_privs)
 884                         },
 885                 }
 886         }
 887
 888         fn pay_route_internal<NS: Deref, F>(
 889                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 890                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 891                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 892                 send_payment_along_path: &F
 893         ) -> Result<(), PaymentSendFailure>
 894         where
 895                 NS::Target: NodeSigner,
 896                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 897                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 898         {
 899                 if route.paths.len() < 1 {
 900                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over"}));
 901                 }
 902                 if payment_secret.is_none() && route.paths.len() > 1 {
 903                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_string()}));
 904                 }
 905                 let mut total_value = 0;
 906                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 907                 let mut path_errs = Vec::with_capacity(route.paths.len());
 908                 'path_check: for path in route.paths.iter() {
 909                         if path.len() < 1 || path.len() > 20 {
 910                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size"}));
 911                                 continue 'path_check;
 912                         }
 913                         for (idx, hop) in path.iter().enumerate() {
 914                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 915                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us"}));
 916                                         continue 'path_check;
 917                                 }
 918                         }
 919                         total_value += path.last().unwrap().fee_msat;
 920                         path_errs.push(Ok(()));
 921                 }
 922                 if path_errs.iter().any(|e| e.is_err()) {
 923                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 924                 }
 925                 if let Some(amt_msat) = recv_value_msat {
 926                         debug_assert!(amt_msat >= total_value);
 927                         total_value = amt_msat;
 928                 }
 929
 930                 let cur_height = best_block_height + 1;
 931                 let mut results = Vec::new();
 932                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 933                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 934                         let mut path_res = send_payment_along_path(&path, &route.payment_params, &payment_hash, payment_secret, total_value, cur_height, payment_id, &keysend_preimage, session_priv);
 935                         match path_res {
 936                                 Ok(_) => {},
 937                                 Err(APIError::MonitorUpdateInProgress) => {
 938                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 939                                         // considered "in flight" and we shouldn't remove it from the
 940                                         // PendingOutboundPayment set.
 941                                 },
 942                                 Err(_) => {
 943                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 944                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
 945                                                 let removed = payment.remove(&session_priv, Some(path));
 946                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
 947                                         } else {
 948                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
 949                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
 950                                         }
 951                                 }
 952                         }
 953                         results.push(path_res);
 954                 }
 955                 let mut has_ok = false;
 956                 let mut has_err = false;
 957                 let mut pending_amt_unsent = 0;
 958                 let mut max_unsent_cltv_delta = 0;
 959                 for (res, path) in results.iter().zip(route.paths.iter()) {
 960                         if res.is_ok() { has_ok = true; }
 961                         if res.is_err() { has_err = true; }
 962                         if let &Err(APIError::MonitorUpdateInProgress) = res {
 963                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
 964                                 // PartialFailure.
 965                                 has_err = true;
 966                                 has_ok = true;
 967                         } else if res.is_err() {
 968                                 pending_amt_unsent += path.last().unwrap().fee_msat;
 969                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
 970                         }
 971                 }
 972                 if has_err && has_ok {
 973                         Err(PaymentSendFailure::PartialFailure {
 974                                 results,
 975                                 payment_id,
 976                                 failed_paths_retry: if pending_amt_unsent != 0 {
 977                                         if let Some(payment_params) = &route.payment_params {
 978                                                 Some(RouteParameters {
 979                                                         payment_params: payment_params.clone(),
 980                                                         final_value_msat: pending_amt_unsent,
 981                                                         final_cltv_expiry_delta:
 982                                                                 if let Some(delta) = payment_params.final_cltv_expiry_delta { delta }
 983                                                                 else { max_unsent_cltv_delta },
 984                                                 })
 985                                         } else { None }
 986                                 } else { None },
 987                         })
 988                 } else if has_err {
 989                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
 990                 } else {
 991                         Ok(())
 992                 }
 993         }
 994
 995         #[cfg(test)]
 996         pub(super) fn test_send_payment_internal<NS: Deref, F>(
 997                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 998                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 999                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1000                 send_payment_along_path: F
1001         ) -> Result<(), PaymentSendFailure>
1002         where
1003                 NS::Target: NodeSigner,
1004                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
1005                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
1006         {
1007                 self.pay_route_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
1008                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1009                         &send_payment_along_path)
1010                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1011         }
1012
1013         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1014         // map as the payment is free to be resent.
1015         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1016                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1017                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1018                         debug_assert!(removed, "We should always have a pending payment to remove here");
1019                 }
1020         }
1021
1022         pub(super) fn claim_htlc<L: Deref>(
1023                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1024                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1025         ) where L::Target: Logger {
1026                 let mut session_priv_bytes = [0; 32];
1027                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1028                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1029                 let mut pending_events = pending_events.lock().unwrap();
1030                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1031                         if !payment.get().is_fulfilled() {
1032                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1033                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1034                                 pending_events.push(
1035                                         events::Event::PaymentSent {
1036                                                 payment_id: Some(payment_id),
1037                                                 payment_preimage,
1038                                                 payment_hash,
1039                                                 fee_paid_msat,
1040                                         }
1041                                 );
1042                                 payment.get_mut().mark_fulfilled();
1043                         }
1044
1045                         if from_onchain {
1046                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1047                                 // This could potentially lead to removing a pending payment too early,
1048                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1049                                 // restart.
1050                                 // TODO: We should have a second monitor event that informs us of payments
1051                                 // irrevocably fulfilled.
1052                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1053                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1054                                         pending_events.push(
1055                                                 events::Event::PaymentPathSuccessful {
1056                                                         payment_id,
1057                                                         payment_hash,
1058                                                         path,
1059                                                 }
1060                                         );
1061                                 }
1062                         }
1063                 } else {
1064                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
1065                 }
1066         }
1067
1068         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
1069                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1070                 let mut pending_events = pending_events.lock().unwrap();
1071                 for source in sources {
1072                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1073                                 let mut session_priv_bytes = [0; 32];
1074                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1075                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1076                                         assert!(payment.get().is_fulfilled());
1077                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1078                                                 pending_events.push(
1079                                                         events::Event::PaymentPathSuccessful {
1080                                                                 payment_id,
1081                                                                 payment_hash: payment.get().payment_hash(),
1082                                                                 path,
1083                                                         }
1084                                                 );
1085                                         }
1086                                 }
1087                         }
1088                 }
1089         }
1090
1091         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
1092                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1093                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1094                 // this could race the user making a duplicate send_payment call and our idempotency
1095                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1096                 // removal. This should be more than sufficient to ensure the idempotency of any
1097                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1098                 // processed.
1099                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1100                 let pending_events = pending_events.lock().unwrap();
1101                 pending_outbound_payments.retain(|payment_id, payment| {
1102                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1103                                 let mut no_remaining_entries = session_privs.is_empty();
1104                                 if no_remaining_entries {
1105                                         for ev in pending_events.iter() {
1106                                                 match ev {
1107                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1108                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1109                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1110                                                                         if payment_id == ev_payment_id {
1111                                                                                 no_remaining_entries = false;
1112                                                                                 break;
1113                                                                         }
1114                                                                 },
1115                                                         _ => {},
1116                                                 }
1117                                         }
1118                                 }
1119                                 if no_remaining_entries {
1120                                         *timer_ticks_without_htlcs += 1;
1121                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1122                                 } else {
1123                                         *timer_ticks_without_htlcs = 0;
1124                                         true
1125                                 }
1126                         } else { true }
1127                 });
1128         }
1129
1130         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1131         pub(super) fn fail_htlc<L: Deref>(
1132                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1133                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
1134                 payment_params: &Option<PaymentParameters>, probing_cookie_secret: [u8; 32],
1135                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1136         ) -> bool where L::Target: Logger {
1137                 #[cfg(test)]
1138                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1139                 #[cfg(not(test))]
1140                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1141
1142                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1143                 let mut session_priv_bytes = [0; 32];
1144                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1145                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1146
1147                 // If any payments already need retry, there's no need to generate a redundant
1148                 // `PendingHTLCsForwardable`.
1149                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1150                         let mut awaiting_retry = false;
1151                         if pmt.is_auto_retryable_now() {
1152                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1153                                         if pending_amt_msat < total_msat {
1154                                                 awaiting_retry = true;
1155                                         }
1156                                 }
1157                         }
1158                         awaiting_retry
1159                 });
1160
1161                 let mut all_paths_failed = false;
1162                 let mut full_failure_ev = None;
1163                 let mut pending_retry_ev = false;
1164                 let mut retry = None;
1165                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1166                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1167                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1168                                 return false
1169                         }
1170                         if payment.get().is_fulfilled() {
1171                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1172                                 return false
1173                         }
1174                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1175                         if let Some(scid) = short_channel_id {
1176                                 payment.get_mut().insert_previously_failed_scid(scid);
1177                         }
1178
1179                         // We want to move towards only using the `PaymentParameters` in the outbound payments
1180                         // map. However, for backwards-compatibility, we still need to support passing the
1181                         // `PaymentParameters` data that was shoved in the HTLC (and given to us via
1182                         // `payment_params`) back to the user.
1183                         let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
1184                         if let Some(params) = payment.get_mut().payment_parameters() {
1185                                 if params.final_cltv_expiry_delta.is_none() {
1186                                         // This should be rare, but a user could provide None for the payment data, and
1187                                         // we need it when we go to retry the payment, so fill it in.
1188                                         params.final_cltv_expiry_delta = Some(path_last_hop.cltv_expiry_delta);
1189                                 }
1190                                 retry = Some(RouteParameters {
1191                                         payment_params: params.clone(),
1192                                         final_value_msat: path_last_hop.fee_msat,
1193                                         final_cltv_expiry_delta: params.final_cltv_expiry_delta.unwrap(),
1194                                 });
1195                         } else if let Some(params) = payment_params {
1196                                 retry = Some(RouteParameters {
1197                                         payment_params: params.clone(),
1198                                         final_value_msat: path_last_hop.fee_msat,
1199                                         final_cltv_expiry_delta:
1200                                                 if let Some(delta) = params.final_cltv_expiry_delta { delta }
1201                                                 else { path_last_hop.cltv_expiry_delta },
1202                                 });
1203                         }
1204
1205                         if payment_is_probe || !is_retryable_now || !payment_retryable || retry.is_none() {
1206                                 let _ = payment.get_mut().mark_abandoned(); // we'll only Err if it's a legacy payment
1207                                 is_retryable_now = false;
1208                         }
1209                         if payment.get().remaining_parts() == 0 {
1210                                 all_paths_failed = true;
1211                                 if payment.get().abandoned() {
1212                                         if !payment_is_probe {
1213                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1214                                                         payment_id: *payment_id,
1215                                                         payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1216                                                 });
1217                                         }
1218                                         payment.remove();
1219                                 }
1220                         }
1221                         is_retryable_now
1222                 } else {
1223                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1224                         return false
1225                 };
1226                 core::mem::drop(outbounds);
1227                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1228
1229                 let path_failure = {
1230                         if payment_is_probe {
1231                                 if !payment_retryable {
1232                                         events::Event::ProbeSuccessful {
1233                                                 payment_id: *payment_id,
1234                                                 payment_hash: payment_hash.clone(),
1235                                                 path: path.clone(),
1236                                         }
1237                                 } else {
1238                                         events::Event::ProbeFailed {
1239                                                 payment_id: *payment_id,
1240                                                 payment_hash: payment_hash.clone(),
1241                                                 path: path.clone(),
1242                                                 short_channel_id,
1243                                         }
1244                                 }
1245                         } else {
1246                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1247                                 // process_onion_failure we should close that channel as it implies our
1248                                 // next-hop is needlessly blaming us!
1249                                 if let Some(scid) = short_channel_id {
1250                                         retry.as_mut().map(|r| r.payment_params.previously_failed_channels.push(scid));
1251                                 }
1252                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1253                                 // payment will sit in our outbounds forever.
1254                                 if attempts_remaining && !already_awaiting_retry {
1255                                         debug_assert!(full_failure_ev.is_none());
1256                                         pending_retry_ev = true;
1257                                 }
1258                                 events::Event::PaymentPathFailed {
1259                                         payment_id: Some(*payment_id),
1260                                         payment_hash: payment_hash.clone(),
1261                                         payment_failed_permanently: !payment_retryable,
1262                                         network_update,
1263                                         all_paths_failed,
1264                                         path: path.clone(),
1265                                         short_channel_id,
1266                                         retry,
1267                                         #[cfg(test)]
1268                                         error_code: onion_error_code,
1269                                         #[cfg(test)]
1270                                         error_data: onion_error_data
1271                                 }
1272                         }
1273                 };
1274                 let mut pending_events = pending_events.lock().unwrap();
1275                 pending_events.push(path_failure);
1276                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
1277                 pending_retry_ev
1278         }
1279
1280         pub(super) fn abandon_payment(
1281                 &self, payment_id: PaymentId, pending_events: &Mutex<Vec<events::Event>>
1282         ) {
1283                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1284                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1285                         if let Ok(()) = payment.get_mut().mark_abandoned() {
1286                                 if payment.get().remaining_parts() == 0 {
1287                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
1288                                                 payment_id,
1289                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1290                                         });
1291                                         payment.remove();
1292                                 }
1293                         }
1294                 }
1295         }
1296
1297         #[cfg(test)]
1298         pub fn has_pending_payments(&self) -> bool {
1299                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1300         }
1301
1302         #[cfg(test)]
1303         pub fn clear_pending_payments(&self) {
1304                 self.pending_outbound_payments.lock().unwrap().clear()
1305         }
1306 }
1307
1308 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1309 /// payment probe.
1310 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1311         probing_cookie_secret: [u8; 32]) -> bool
1312 {
1313         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1314         target_payment_hash == *payment_hash
1315 }
1316
1317 /// Returns the 'probing cookie' for the given [`PaymentId`].
1318 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1319         let mut preimage = [0u8; 64];
1320         preimage[..32].copy_from_slice(&probing_cookie_secret);
1321         preimage[32..].copy_from_slice(&payment_id.0);
1322         PaymentHash(Sha256::hash(&preimage).into_inner())
1323 }
1324
1325 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1326         (0, Legacy) => {
1327                 (0, session_privs, required),
1328         },
1329         (1, Fulfilled) => {
1330                 (0, session_privs, required),
1331                 (1, payment_hash, option),
1332                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1333         },
1334         (2, Retryable) => {
1335                 (0, session_privs, required),
1336                 (1, pending_fee_msat, option),
1337                 (2, payment_hash, required),
1338                 (3, payment_params, option),
1339                 (4, payment_secret, option),
1340                 (5, keysend_preimage, option),
1341                 (6, total_msat, required),
1342                 (8, pending_amt_msat, required),
1343                 (10, starting_block_height, required),
1344                 (not_written, retry_strategy, (static_value, None)),
1345                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1346         },
1347         (3, Abandoned) => {
1348                 (0, session_privs, required),
1349                 (2, payment_hash, required),
1350         },
1351 );
1352
1353 #[cfg(test)]
1354 mod tests {
1355         use bitcoin::network::constants::Network;
1356         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1357
1358         use crate::ln::PaymentHash;
1359         use crate::ln::channelmanager::PaymentId;
1360         use crate::ln::msgs::{ErrorAction, LightningError};
1361         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1362         use crate::routing::gossip::NetworkGraph;
1363         use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteParameters};
1364         use crate::sync::{Arc, Mutex};
1365         use crate::util::events::Event;
1366         use crate::util::test_utils;
1367
1368         #[test]
1369         #[cfg(feature = "std")]
1370         fn fails_paying_after_expiration() {
1371                 do_fails_paying_after_expiration(false);
1372                 do_fails_paying_after_expiration(true);
1373         }
1374         #[cfg(feature = "std")]
1375         fn do_fails_paying_after_expiration(on_retry: bool) {
1376                 let outbound_payments = OutboundPayments::new();
1377                 let logger = test_utils::TestLogger::new();
1378                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1379                 let scorer = Mutex::new(test_utils::TestScorer::new());
1380                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1381                 let secp_ctx = Secp256k1::new();
1382                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1383
1384                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1385                 let payment_params = PaymentParameters::from_node_id(
1386                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1387                                 0
1388                         ).with_expiry_time(past_expiry_time);
1389                 let expired_route_params = RouteParameters {
1390                         payment_params,
1391                         final_value_msat: 0,
1392                         final_cltv_expiry_delta: 0,
1393                 };
1394                 let pending_events = Mutex::new(Vec::new());
1395                 if on_retry {
1396                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
1397                         &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
1398                         Some(expired_route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
1399                         outbound_payments.retry_payment_internal(
1400                                 PaymentId([0; 32]), expired_route_params, &&router, vec![], &|| InFlightHtlcs::new(),
1401                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1402                                 &|_, _, _, _, _, _, _, _, _| Ok(()));
1403                         let events = pending_events.lock().unwrap();
1404                         assert_eq!(events.len(), 1);
1405                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1406                 } else {
1407                         let err = outbound_payments.send_payment(
1408                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), expired_route_params,
1409                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1410                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1411                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1412                 }
1413         }
1414
1415         #[test]
1416         fn find_route_error() {
1417                 do_find_route_error(false);
1418                 do_find_route_error(true);
1419         }
1420         fn do_find_route_error(on_retry: bool) {
1421                 let outbound_payments = OutboundPayments::new();
1422                 let logger = test_utils::TestLogger::new();
1423                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1424                 let scorer = Mutex::new(test_utils::TestScorer::new());
1425                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1426                 let secp_ctx = Secp256k1::new();
1427                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1428
1429                 let payment_params = PaymentParameters::from_node_id(
1430                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1431                 let route_params = RouteParameters {
1432                         payment_params,
1433                         final_value_msat: 0,
1434                         final_cltv_expiry_delta: 0,
1435                 };
1436                 router.expect_find_route(route_params.clone(),
1437                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1438
1439                 let pending_events = Mutex::new(Vec::new());
1440                 if on_retry {
1441                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
1442                                 &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
1443                                 Some(route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
1444                         outbound_payments.retry_payment_internal(
1445                                 PaymentId([0; 32]), route_params, &&router, vec![], &|| InFlightHtlcs::new(),
1446                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1447                                 &|_, _, _, _, _, _, _, _, _| Ok(()));
1448                         let events = pending_events.lock().unwrap();
1449                         assert_eq!(events.len(), 1);
1450                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1451                 } else {
1452                         let err = outbound_payments.send_payment(
1453                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params,
1454                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1455                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1456                         if let RetryableSendFailure::RouteNotFound = err {
1457                         } else { panic!("Unexpected error"); }
1458                 }
1459         }
1460 }