_ 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::onion_utils::HTLCFailReason;
  21 use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters, RoutePath, Router};
  22 use crate::util::errors::APIError;
  23 use crate::util::events;
  24 use crate::util::logger::Logger;
  25 use crate::util::time::Time;
  26 #[cfg(all(not(feature = "no-std"), test))]
  27 use crate::util::time::tests::SinceEpoch;
  28
  29 use core::cmp;
  30 use core::fmt::{self, Display, Formatter};
  31 use core::ops::Deref;
  32
  33 use crate::prelude::*;
  34 use crate::sync::Mutex;
  35
  36 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  37 /// and later, also stores information for retrying the payment.
  38 pub(crate) enum PendingOutboundPayment {
  39         Legacy {
  40                 session_privs: HashSet<[u8; 32]>,
  41         },
  42         Retryable {
  43                 retry_strategy: Option<Retry>,
  44                 attempts: PaymentAttempts,
  45                 payment_params: Option<PaymentParameters>,
  46                 session_privs: HashSet<[u8; 32]>,
  47                 payment_hash: PaymentHash,
  48                 payment_secret: Option<PaymentSecret>,
  49                 keysend_preimage: Option<PaymentPreimage>,
  50                 pending_amt_msat: u64,
  51                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  52                 pending_fee_msat: Option<u64>,
  53                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  54                 total_msat: u64,
  55                 /// Our best known block height at the time this payment was initiated.
  56                 starting_block_height: u32,
  57         },
  58         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  59         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  60         /// and add a pending payment that was already fulfilled.
  61         Fulfilled {
  62                 session_privs: HashSet<[u8; 32]>,
  63                 payment_hash: Option<PaymentHash>,
  64                 timer_ticks_without_htlcs: u8,
  65         },
  66         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  67         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  68         Abandoned {
  69                 session_privs: HashSet<[u8; 32]>,
  70                 payment_hash: PaymentHash,
  71         },
  72 }
  73
  74 impl PendingOutboundPayment {
  75         fn increment_attempts(&mut self) {
  76                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  77                         attempts.count += 1;
  78                 }
  79         }
  80         fn is_auto_retryable_now(&self) -> bool {
  81                 match self {
  82                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  83                                 strategy.is_retryable_now(&attempts)
  84                         },
  85                         _ => false,
  86                 }
  87         }
  88         fn is_retryable_now(&self) -> bool {
  89                 match self {
  90                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
  91                                 // We're handling retries manually, we can always retry.
  92                                 true
  93                         },
  94                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  95                                 strategy.is_retryable_now(&attempts)
  96                         },
  97                         _ => false,
  98                 }
  99         }
 100         fn payment_parameters(&mut self) -> Option<&mut PaymentParameters> {
 101                 match self {
 102                         PendingOutboundPayment::Retryable { payment_params: Some(ref mut params), .. } => {
 103                                 Some(params)
 104                         },
 105                         _ => None,
 106                 }
 107         }
 108         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 109                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 110                         params.previously_failed_channels.push(scid);
 111                 }
 112         }
 113         pub(super) fn is_fulfilled(&self) -> bool {
 114                 match self {
 115                         PendingOutboundPayment::Fulfilled { .. } => true,
 116                         _ => false,
 117                 }
 118         }
 119         pub(super) fn abandoned(&self) -> bool {
 120                 match self {
 121                         PendingOutboundPayment::Abandoned { .. } => true,
 122                         _ => false,
 123                 }
 124         }
 125         fn get_pending_fee_msat(&self) -> Option<u64> {
 126                 match self {
 127                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 128                         _ => None,
 129                 }
 130         }
 131
 132         fn payment_hash(&self) -> Option<PaymentHash> {
 133                 match self {
 134                         PendingOutboundPayment::Legacy { .. } => None,
 135                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 136                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 137                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 138                 }
 139         }
 140
 141         fn mark_fulfilled(&mut self) {
 142                 let mut session_privs = HashSet::new();
 143                 core::mem::swap(&mut session_privs, match self {
 144                         PendingOutboundPayment::Legacy { session_privs } |
 145                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 146                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 147                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 148                         => session_privs,
 149                 });
 150                 let payment_hash = self.payment_hash();
 151                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 152         }
 153
 154         fn mark_abandoned(&mut self) -> Result<(), ()> {
 155                 let mut session_privs = HashSet::new();
 156                 let our_payment_hash;
 157                 core::mem::swap(&mut session_privs, match self {
 158                         PendingOutboundPayment::Legacy { .. } |
 159                         PendingOutboundPayment::Fulfilled { .. } =>
 160                                 return Err(()),
 161                         PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } |
 162                         PendingOutboundPayment::Abandoned { session_privs, payment_hash, .. } => {
 163                                 our_payment_hash = *payment_hash;
 164                                 session_privs
 165                         },
 166                 });
 167                 *self = PendingOutboundPayment::Abandoned { session_privs, payment_hash: our_payment_hash };
 168                 Ok(())
 169         }
 170
 171         /// panics if path is None and !self.is_fulfilled
 172         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Vec<RouteHop>>) -> bool {
 173                 let remove_res = match self {
 174                         PendingOutboundPayment::Legacy { session_privs } |
 175                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 176                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 177                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 178                                         session_privs.remove(session_priv)
 179                                 }
 180                 };
 181                 if remove_res {
 182                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 183                                 let path = path.expect("Fulfilling a payment should always come with a path");
 184                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 185                                 *pending_amt_msat -= path_last_hop.fee_msat;
 186                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 187                                         *fee_msat -= path.get_path_fees();
 188                                 }
 189                         }
 190                 }
 191                 remove_res
 192         }
 193
 194         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Vec<RouteHop>) -> bool {
 195                 let insert_res = match self {
 196                         PendingOutboundPayment::Legacy { session_privs } |
 197                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 198                                         session_privs.insert(session_priv)
 199                                 }
 200                         PendingOutboundPayment::Fulfilled { .. } => false,
 201                         PendingOutboundPayment::Abandoned { .. } => false,
 202                 };
 203                 if insert_res {
 204                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 205                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 206                                 *pending_amt_msat += path_last_hop.fee_msat;
 207                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 208                                         *fee_msat += path.get_path_fees();
 209                                 }
 210                         }
 211                 }
 212                 insert_res
 213         }
 214
 215         pub(super) fn remaining_parts(&self) -> usize {
 216                 match self {
 217                         PendingOutboundPayment::Legacy { session_privs } |
 218                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 219                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 220                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 221                                         session_privs.len()
 222                                 }
 223                 }
 224         }
 225 }
 226
 227 /// Strategies available to retry payment path failures.
 228 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 229 pub enum Retry {
 230         /// Max number of attempts to retry payment.
 231         ///
 232         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 233         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 234         /// were retried along a route from a single call to [`Router::find_route`].
 235         Attempts(usize),
 236         #[cfg(not(feature = "no-std"))]
 237         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 238         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 239         ///
 240         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 241         Timeout(core::time::Duration),
 242 }
 243
 244 impl Retry {
 245         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 246                 match (self, attempts) {
 247                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 248                                 max_retry_count > count
 249                         },
 250                         #[cfg(all(not(feature = "no-std"), not(test)))]
 251                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 252                                 *max_duration >= std::time::Instant::now().duration_since(*first_attempted_at),
 253                         #[cfg(all(not(feature = "no-std"), test))]
 254                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 255                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 256                 }
 257         }
 258 }
 259
 260 #[cfg(feature = "std")]
 261 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 262         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 263                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 264                         return elapsed > core::time::Duration::from_secs(expiry_time)
 265                 }
 266         }
 267         false
 268 }
 269
 270 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 271
 272 /// Storing minimal payment attempts information required for determining if a outbound payment can
 273 /// be retried.
 274 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 275         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 276         /// it means the result of the first attempt is not known yet.
 277         pub(crate) count: usize,
 278         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 279         first_attempted_at: T
 280 }
 281
 282 #[cfg(not(any(feature = "no-std", test)))]
 283 type ConfiguredTime = std::time::Instant;
 284 #[cfg(feature = "no-std")]
 285 type ConfiguredTime = crate::util::time::Eternity;
 286 #[cfg(all(not(feature = "no-std"), test))]
 287 type ConfiguredTime = SinceEpoch;
 288
 289 impl<T: Time> PaymentAttemptsUsingTime<T> {
 290         pub(crate) fn new() -> Self {
 291                 PaymentAttemptsUsingTime {
 292                         count: 0,
 293                         first_attempted_at: T::now()
 294                 }
 295         }
 296 }
 297
 298 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 299         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 300                 #[cfg(feature = "no-std")]
 301                 return write!(f, "attempts: {}", self.count);
 302                 #[cfg(not(feature = "no-std"))]
 303                 return write!(
 304                         f,
 305                         "attempts: {}, duration: {}s",
 306                         self.count,
 307                         T::now().duration_since(self.first_attempted_at).as_secs()
 308                 );
 309         }
 310 }
 311
 312 /// Indicates an immediate error on [`ChannelManager::send_payment_with_retry`]. Further errors
 313 /// may be surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 314 ///
 315 /// [`ChannelManager::send_payment_with_retry`]: crate::ln::channelmanager::ChannelManager::send_payment_with_retry
 316 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 317 /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 318 #[derive(Clone, Debug)]
 319 pub enum RetryableSendFailure {
 320         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 321         /// that this error is *not* caused by [`Retry::Timeout`].
 322         ///
 323         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 324         PaymentExpired,
 325         /// We were unable to find a route to the destination.
 326         RouteNotFound,
 327         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 328         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 329         ///
 330         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 331         /// [`Event::PaymentSent`]: crate::util::events::Event::PaymentSent
 332         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 333         DuplicatePayment,
 334 }
 335
 336 /// If a payment fails to send with [`ChannelManager::send_payment`], it can be in one of several
 337 /// states. This enum is returned as the Err() type describing which state the payment is in, see
 338 /// the description of individual enum states for more.
 339 ///
 340 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 341 #[derive(Clone, Debug)]
 342 pub enum PaymentSendFailure {
 343         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 344         /// send the payment at all.
 345         ///
 346         /// You can freely resend the payment in full (with the parameter error fixed).
 347         ///
 348         /// Because the payment failed outright, no payment tracking is done and no
 349         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 350         ///
 351         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 352         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 353         ParameterError(APIError),
 354         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 355         /// from attempting to send the payment at all.
 356         ///
 357         /// You can freely resend the payment in full (with the parameter error fixed).
 358         ///
 359         /// Because the payment failed outright, no payment tracking is done and no
 360         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 361         ///
 362         /// The results here are ordered the same as the paths in the route object which was passed to
 363         /// send_payment.
 364         ///
 365         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 366         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 367         PathParameterError(Vec<Result<(), APIError>>),
 368         /// All paths which were attempted failed to send, with no channel state change taking place.
 369         /// You can freely resend the payment in full (though you probably want to do so over different
 370         /// paths than the ones selected).
 371         ///
 372         /// Because the payment failed outright, no payment tracking is done and no
 373         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 374         ///
 375         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 376         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 377         AllFailedResendSafe(Vec<APIError>),
 378         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 379         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 380         ///
 381         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 382         /// [`Event::PaymentSent`]: crate::util::events::Event::PaymentSent
 383         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 384         DuplicatePayment,
 385         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 386         /// some paths have irrevocably committed to the HTLC.
 387         ///
 388         /// The results here are ordered the same as the paths in the route object that was passed to
 389         /// send_payment.
 390         ///
 391         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 392         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 393         ///
 394         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 395         PartialFailure {
 396                 /// The errors themselves, in the same order as the paths from the route.
 397                 results: Vec<Result<(), APIError>>,
 398                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 399                 /// contain a [`RouteParameters`] object for the failing paths.
 400                 failed_paths_retry: Option<RouteParameters>,
 401                 /// The payment id for the payment, which is now at least partially pending.
 402                 payment_id: PaymentId,
 403         },
 404 }
 405
 406 pub(super) struct OutboundPayments {
 407         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 408         pub(super) retry_lock: Mutex<()>,
 409 }
 410
 411 impl OutboundPayments {
 412         pub(super) fn new() -> Self {
 413                 Self {
 414                         pending_outbound_payments: Mutex::new(HashMap::new()),
 415                         retry_lock: Mutex::new(()),
 416                 }
 417         }
 418
 419         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 420                 &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId,
 421                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 422                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 423                 node_signer: &NS, best_block_height: u32, logger: &L,
 424                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 425         ) -> Result<(), RetryableSendFailure>
 426         where
 427                 R::Target: Router,
 428                 ES::Target: EntropySource,
 429                 NS::Target: NodeSigner,
 430                 L::Target: Logger,
 431                 IH: Fn() -> InFlightHtlcs,
 432                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 433                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 434         {
 435                 self.send_payment_internal(payment_id, payment_hash, payment_secret, None, retry_strategy,
 436                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 437                         best_block_height, logger, pending_events, &send_payment_along_path)
 438         }
 439
 440         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 441                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 442                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 443                 send_payment_along_path: F
 444         ) -> Result<(), PaymentSendFailure>
 445         where
 446                 ES::Target: EntropySource,
 447                 NS::Target: NodeSigner,
 448                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 449                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 450         {
 451                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, None, route, None, None, entropy_source, best_block_height)?;
 452                 self.pay_route_internal(route, payment_hash, payment_secret, None, payment_id, None,
 453                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 454                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 455         }
 456
 457         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 458                 &self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 459                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 460                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 461                 node_signer: &NS, best_block_height: u32, logger: &L,
 462                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
 463         ) -> Result<PaymentHash, RetryableSendFailure>
 464         where
 465                 R::Target: Router,
 466                 ES::Target: EntropySource,
 467                 NS::Target: NodeSigner,
 468                 L::Target: Logger,
 469                 IH: Fn() -> InFlightHtlcs,
 470                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 471                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 472         {
 473                 let preimage = payment_preimage
 474                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 475                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 476                 self.send_payment_internal(payment_id, payment_hash, &None, Some(preimage), retry_strategy,
 477                         route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer,
 478                         best_block_height, logger, pending_events, send_payment_along_path)
 479                         .map(|()| payment_hash)
 480         }
 481
 482         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 483                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 484                 entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 485         ) -> Result<PaymentHash, PaymentSendFailure>
 486         where
 487                 ES::Target: EntropySource,
 488                 NS::Target: NodeSigner,
 489                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 490                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 491         {
 492                 let preimage = payment_preimage
 493                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 494                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 495                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 496
 497                 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) {
 498                         Ok(()) => Ok(payment_hash),
 499                         Err(e) => {
 500                                 self.remove_outbound_if_all_failed(payment_id, &e);
 501                                 Err(e)
 502                         }
 503                 }
 504         }
 505
 506         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 507                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 508                 best_block_height: u32, pending_events: &Mutex<Vec<events::Event>>, logger: &L,
 509                 send_payment_along_path: SP,
 510         )
 511         where
 512                 R::Target: Router,
 513                 ES::Target: EntropySource,
 514                 NS::Target: NodeSigner,
 515                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 516                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 517                 IH: Fn() -> InFlightHtlcs,
 518                 FH: Fn() -> Vec<ChannelDetails>,
 519                 L::Target: Logger,
 520         {
 521                 let _single_thread = self.retry_lock.lock().unwrap();
 522                 loop {
 523                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 524                         let mut retry_id_route_params = None;
 525                         for (pmt_id, pmt) in outbounds.iter_mut() {
 526                                 if pmt.is_auto_retryable_now() {
 527                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), .. } = pmt {
 528                                                 if pending_amt_msat < total_msat {
 529                                                         retry_id_route_params = Some((*pmt_id, RouteParameters {
 530                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 531                                                                 final_cltv_expiry_delta:
 532                                                                         if let Some(delta) = params.final_cltv_expiry_delta { delta }
 533                                                                         else {
 534                                                                                 debug_assert!(false, "We always set the final_cltv_expiry_delta when a path fails");
 535                                                                                 LDK_DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA.into()
 536                                                                         },
 537                                                                 payment_params: params.clone(),
 538                                                         }));
 539                                                         break
 540                                                 }
 541                                         }
 542                                 }
 543                         }
 544                         core::mem::drop(outbounds);
 545                         if let Some((payment_id, route_params)) = retry_id_route_params {
 546                                 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)
 547                         } else { break }
 548                 }
 549
 550                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 551                 outbounds.retain(|pmt_id, pmt| {
 552                         let mut retain = true;
 553                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 554                                 if pmt.mark_abandoned().is_ok() {
 555                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 556                                                 payment_id: *pmt_id,
 557                                                 payment_hash: pmt.payment_hash().expect("PendingOutboundPayments::Retryable always has a payment hash set"),
 558                                         });
 559                                         retain = false;
 560                                 }
 561                         }
 562                         retain
 563                 });
 564         }
 565
 566         pub(super) fn needs_abandon(&self) -> bool {
 567                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 568                 outbounds.iter().any(|(_, pmt)|
 569                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 570         }
 571
 572         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 573         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 574         ///
 575         /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
 576         /// [`Event::PaymentFailed`]: crate::util::events::Event::PaymentFailed
 577         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 578                 &self, payment_id: PaymentId, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 579                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 580                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 581                 node_signer: &NS, best_block_height: u32, logger: &L,
 582                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 583         ) -> Result<(), RetryableSendFailure>
 584         where
 585                 R::Target: Router,
 586                 ES::Target: EntropySource,
 587                 NS::Target: NodeSigner,
 588                 L::Target: Logger,
 589                 IH: Fn() -> InFlightHtlcs,
 590                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 591                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 592         {
 593                 #[cfg(feature = "std")] {
 594                         if has_expired(&route_params) {
 595                                 return Err(RetryableSendFailure::PaymentExpired)
 596                         }
 597                 }
 598
 599                 let route = router.find_route(
 600                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 601                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs()
 602                 ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 603
 604                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret,
 605                         payment_id, keysend_preimage, &route, Some(retry_strategy),
 606                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 607                         .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 608
 609                 let res = self.pay_route_internal(&route, payment_hash, payment_secret, None, payment_id, None,
 610                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 611                 log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
 612                 if let Err(e) = res {
 613                         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);
 614                 }
 615                 Ok(())
 616         }
 617
 618         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 619                 &self, payment_id: PaymentId, route_params: RouteParameters, router: &R,
 620                 first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS,
 621                 best_block_height: u32, logger: &L, pending_events: &Mutex<Vec<events::Event>>,
 622                 send_payment_along_path: &SP,
 623         )
 624         where
 625                 R::Target: Router,
 626                 ES::Target: EntropySource,
 627                 NS::Target: NodeSigner,
 628                 L::Target: Logger,
 629                 IH: Fn() -> InFlightHtlcs,
 630                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 631                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 632         {
 633                 #[cfg(feature = "std")] {
 634                         if has_expired(&route_params) {
 635                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
 636                                 self.abandon_payment(payment_id, pending_events);
 637                                 return
 638                         }
 639                 }
 640
 641                 let route = match router.find_route(
 642                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 643                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs()
 644                 ) {
 645                         Ok(route) => route,
 646                         Err(e) => {
 647                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
 648                                 self.abandon_payment(payment_id, pending_events);
 649                                 return
 650                         }
 651                 };
 652                 for path in route.paths.iter() {
 653                         if path.len() == 0 {
 654                                 log_error!(logger, "length-0 path in route");
 655                                 self.abandon_payment(payment_id, pending_events);
 656                                 return
 657                         }
 658                 }
 659
 660                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 661                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 662                 for _ in 0..route.paths.len() {
 663                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 664                 }
 665
 666                 macro_rules! abandon_with_entry {
 667                         ($payment_id: expr, $payment_hash: expr, $payment: expr, $pending_events: expr) => {
 668                                 if $payment.get_mut().mark_abandoned().is_ok() && $payment.get().remaining_parts() == 0 {
 669                                         $pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 670                                                 payment_id: $payment_id,
 671                                                 payment_hash: $payment_hash,
 672                                         });
 673                                         $payment.remove();
 674                                 }
 675                         }
 676                 }
 677                 let (total_msat, payment_hash, payment_secret, keysend_preimage) = {
 678                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 679                         match outbounds.entry(payment_id) {
 680                                 hash_map::Entry::Occupied(mut payment) => {
 681                                         let res = match payment.get() {
 682                                                 PendingOutboundPayment::Retryable {
 683                                                         total_msat, payment_hash, keysend_preimage, payment_secret, pending_amt_msat, ..
 684                                                 } => {
 685                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 686                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 687                                                                 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);
 688                                                                 let payment_hash = *payment_hash;
 689                                                                 abandon_with_entry!(payment_id, payment_hash, payment, pending_events);
 690                                                                 return
 691                                                         }
 692                                                         (*total_msat, *payment_hash, *payment_secret, *keysend_preimage)
 693                                                 },
 694                                                 PendingOutboundPayment::Legacy { .. } => {
 695                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 696                                                         return
 697                                                 },
 698                                                 PendingOutboundPayment::Fulfilled { .. } => {
 699                                                         log_error!(logger, "Payment already completed");
 700                                                         return
 701                                                 },
 702                                                 PendingOutboundPayment::Abandoned { .. } => {
 703                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 704                                                         return
 705                                                 },
 706                                         };
 707                                         if !payment.get().is_retryable_now() {
 708                                                 log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
 709                                                 abandon_with_entry!(payment_id, res.1, payment, pending_events);
 710                                                 return
 711                                         }
 712                                         payment.get_mut().increment_attempts();
 713                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 714                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 715                                         }
 716                                         res
 717                                 },
 718                                 hash_map::Entry::Vacant(_) => {
 719                                         log_error!(logger, "Payment with ID {} not found", log_bytes!(payment_id.0));
 720                                         return
 721                                 }
 722                         }
 723                 };
 724                 let res = self.pay_route_internal(&route, payment_hash, &payment_secret, keysend_preimage,
 725                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 726                         &send_payment_along_path);
 727                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
 728                 if let Err(e) = res {
 729                         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);
 730                 }
 731         }
 732
 733         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 734                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 735                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 736                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 737                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 738         )
 739         where
 740                 R::Target: Router,
 741                 ES::Target: EntropySource,
 742                 NS::Target: NodeSigner,
 743                 L::Target: Logger,
 744                 IH: Fn() -> InFlightHtlcs,
 745                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 746                     u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 747         {
 748                 match err {
 749                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 750                                 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);
 751                                 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);
 752                         },
 753                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 754                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), pending_events);
 755                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 756                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 757                                 // return `Ok()` here, ignoring any retry errors.
 758                                 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);
 759                         },
 760                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 761                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 762                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 763                                 // initial HTLC-Add messages yet.
 764                         },
 765                         PaymentSendFailure::PathParameterError(results) => {
 766                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), pending_events);
 767                                 self.abandon_payment(payment_id, pending_events);
 768                         },
 769                         PaymentSendFailure::ParameterError(e) => {
 770                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 771                                 self.abandon_payment(payment_id, pending_events);
 772                         },
 773                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 774                 }
 775         }
 776
 777         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>>(
 778                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 779                 paths: Vec<Vec<RouteHop>>, path_results: I, pending_events: &Mutex<Vec<events::Event>>
 780         ) {
 781                 let mut events = pending_events.lock().unwrap();
 782                 debug_assert_eq!(paths.len(), path_results.len());
 783                 for (path, path_res) in paths.into_iter().zip(path_results) {
 784                         if let Err(e) = path_res {
 785                                 if let APIError::MonitorUpdateInProgress = e { continue }
 786                                 let mut failed_scid = None;
 787                                 if let APIError::ChannelUnavailable { .. } = e {
 788                                         let scid = path[0].short_channel_id;
 789                                         failed_scid = Some(scid);
 790                                         route_params.payment_params.previously_failed_channels.push(scid);
 791                                 }
 792                                 events.push(events::Event::PaymentPathFailed {
 793                                         payment_id: Some(payment_id),
 794                                         payment_hash,
 795                                         payment_failed_permanently: false,
 796                                         failure: events::PathFailure::InitialSend { err: e },
 797                                         path,
 798                                         short_channel_id: failed_scid,
 799                                         retry: None,
 800                                         #[cfg(test)]
 801                                         error_code: None,
 802                                         #[cfg(test)]
 803                                         error_data: None,
 804                                 });
 805                         }
 806                 }
 807         }
 808
 809         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 810                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 811                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 812         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 813         where
 814                 ES::Target: EntropySource,
 815                 NS::Target: NodeSigner,
 816                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 817                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 818         {
 819                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 820
 821                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 822
 823                 if hops.len() < 2 {
 824                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 825                                 err: "No need probing a path with less than two hops".to_string()
 826                         }))
 827                 }
 828
 829                 let route = Route { paths: vec![hops], payment_params: None };
 830                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, None, &route, None, None, entropy_source, best_block_height)?;
 831
 832                 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) {
 833                         Ok(()) => Ok((payment_hash, payment_id)),
 834                         Err(e) => {
 835                                 self.remove_outbound_if_all_failed(payment_id, &e);
 836                                 Err(e)
 837                         }
 838                 }
 839         }
 840
 841         #[cfg(test)]
 842         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 843                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 844                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 845         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 846                 self.add_new_pending_payment(payment_hash, payment_secret, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 847         }
 848
 849         pub(super) fn add_new_pending_payment<ES: Deref>(
 850                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 851                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 852                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 853         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 854                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 855                 for _ in 0..route.paths.len() {
 856                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 857                 }
 858
 859                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 860                 match pending_outbounds.entry(payment_id) {
 861                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 862                         hash_map::Entry::Vacant(entry) => {
 863                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 864                                         retry_strategy,
 865                                         attempts: PaymentAttempts::new(),
 866                                         payment_params,
 867                                         session_privs: HashSet::new(),
 868                                         pending_amt_msat: 0,
 869                                         pending_fee_msat: Some(0),
 870                                         payment_hash,
 871                                         payment_secret,
 872                                         keysend_preimage,
 873                                         starting_block_height: best_block_height,
 874                                         total_msat: route.get_total_amount(),
 875                                 });
 876
 877                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 878                                         assert!(payment.insert(*session_priv_bytes, path));
 879                                 }
 880
 881                                 Ok(onion_session_privs)
 882                         },
 883                 }
 884         }
 885
 886         fn pay_route_internal<NS: Deref, F>(
 887                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 888                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 889                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 890                 send_payment_along_path: &F
 891         ) -> Result<(), PaymentSendFailure>
 892         where
 893                 NS::Target: NodeSigner,
 894                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 895                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 896         {
 897                 if route.paths.len() < 1 {
 898                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
 899                 }
 900                 if payment_secret.is_none() && route.paths.len() > 1 {
 901                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
 902                 }
 903                 let mut total_value = 0;
 904                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 905                 let mut path_errs = Vec::with_capacity(route.paths.len());
 906                 'path_check: for path in route.paths.iter() {
 907                         if path.len() < 1 || path.len() > 20 {
 908                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
 909                                 continue 'path_check;
 910                         }
 911                         for (idx, hop) in path.iter().enumerate() {
 912                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 913                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
 914                                         continue 'path_check;
 915                                 }
 916                         }
 917                         total_value += path.last().unwrap().fee_msat;
 918                         path_errs.push(Ok(()));
 919                 }
 920                 if path_errs.iter().any(|e| e.is_err()) {
 921                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 922                 }
 923                 if let Some(amt_msat) = recv_value_msat {
 924                         debug_assert!(amt_msat >= total_value);
 925                         total_value = amt_msat;
 926                 }
 927
 928                 let cur_height = best_block_height + 1;
 929                 let mut results = Vec::new();
 930                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 931                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 932                         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);
 933                         match path_res {
 934                                 Ok(_) => {},
 935                                 Err(APIError::MonitorUpdateInProgress) => {
 936                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 937                                         // considered "in flight" and we shouldn't remove it from the
 938                                         // PendingOutboundPayment set.
 939                                 },
 940                                 Err(_) => {
 941                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 942                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
 943                                                 let removed = payment.remove(&session_priv, Some(path));
 944                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
 945                                         } else {
 946                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
 947                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
 948                                         }
 949                                 }
 950                         }
 951                         results.push(path_res);
 952                 }
 953                 let mut has_ok = false;
 954                 let mut has_err = false;
 955                 let mut pending_amt_unsent = 0;
 956                 let mut max_unsent_cltv_delta = 0;
 957                 for (res, path) in results.iter().zip(route.paths.iter()) {
 958                         if res.is_ok() { has_ok = true; }
 959                         if res.is_err() { has_err = true; }
 960                         if let &Err(APIError::MonitorUpdateInProgress) = res {
 961                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
 962                                 // PartialFailure.
 963                                 has_err = true;
 964                                 has_ok = true;
 965                         } else if res.is_err() {
 966                                 pending_amt_unsent += path.last().unwrap().fee_msat;
 967                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
 968                         }
 969                 }
 970                 if has_err && has_ok {
 971                         Err(PaymentSendFailure::PartialFailure {
 972                                 results,
 973                                 payment_id,
 974                                 failed_paths_retry: if pending_amt_unsent != 0 {
 975                                         if let Some(payment_params) = &route.payment_params {
 976                                                 Some(RouteParameters {
 977                                                         payment_params: payment_params.clone(),
 978                                                         final_value_msat: pending_amt_unsent,
 979                                                         final_cltv_expiry_delta:
 980                                                                 if let Some(delta) = payment_params.final_cltv_expiry_delta { delta }
 981                                                                 else { max_unsent_cltv_delta },
 982                                                 })
 983                                         } else { None }
 984                                 } else { None },
 985                         })
 986                 } else if has_err {
 987                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
 988                 } else {
 989                         Ok(())
 990                 }
 991         }
 992
 993         #[cfg(test)]
 994         pub(super) fn test_send_payment_internal<NS: Deref, F>(
 995                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 996                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 997                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 998                 send_payment_along_path: F
 999         ) -> Result<(), PaymentSendFailure>
1000         where
1001                 NS::Target: NodeSigner,
1002                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
1003                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
1004         {
1005                 self.pay_route_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
1006                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1007                         &send_payment_along_path)
1008                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1009         }
1010
1011         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1012         // map as the payment is free to be resent.
1013         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1014                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1015                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1016                         debug_assert!(removed, "We should always have a pending payment to remove here");
1017                 }
1018         }
1019
1020         pub(super) fn claim_htlc<L: Deref>(
1021                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1022                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1023         ) where L::Target: Logger {
1024                 let mut session_priv_bytes = [0; 32];
1025                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1026                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1027                 let mut pending_events = pending_events.lock().unwrap();
1028                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1029                         if !payment.get().is_fulfilled() {
1030                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1031                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1032                                 pending_events.push(
1033                                         events::Event::PaymentSent {
1034                                                 payment_id: Some(payment_id),
1035                                                 payment_preimage,
1036                                                 payment_hash,
1037                                                 fee_paid_msat,
1038                                         }
1039                                 );
1040                                 payment.get_mut().mark_fulfilled();
1041                         }
1042
1043                         if from_onchain {
1044                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1045                                 // This could potentially lead to removing a pending payment too early,
1046                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1047                                 // restart.
1048                                 // TODO: We should have a second monitor event that informs us of payments
1049                                 // irrevocably fulfilled.
1050                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1051                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1052                                         pending_events.push(
1053                                                 events::Event::PaymentPathSuccessful {
1054                                                         payment_id,
1055                                                         payment_hash,
1056                                                         path,
1057                                                 }
1058                                         );
1059                                 }
1060                         }
1061                 } else {
1062                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
1063                 }
1064         }
1065
1066         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
1067                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1068                 let mut pending_events = pending_events.lock().unwrap();
1069                 for source in sources {
1070                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1071                                 let mut session_priv_bytes = [0; 32];
1072                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1073                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1074                                         assert!(payment.get().is_fulfilled());
1075                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1076                                                 pending_events.push(
1077                                                         events::Event::PaymentPathSuccessful {
1078                                                                 payment_id,
1079                                                                 payment_hash: payment.get().payment_hash(),
1080                                                                 path,
1081                                                         }
1082                                                 );
1083                                         }
1084                                 }
1085                         }
1086                 }
1087         }
1088
1089         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
1090                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1091                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1092                 // this could race the user making a duplicate send_payment call and our idempotency
1093                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1094                 // removal. This should be more than sufficient to ensure the idempotency of any
1095                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1096                 // processed.
1097                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1098                 let pending_events = pending_events.lock().unwrap();
1099                 pending_outbound_payments.retain(|payment_id, payment| {
1100                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1101                                 let mut no_remaining_entries = session_privs.is_empty();
1102                                 if no_remaining_entries {
1103                                         for ev in pending_events.iter() {
1104                                                 match ev {
1105                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1106                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1107                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1108                                                                         if payment_id == ev_payment_id {
1109                                                                                 no_remaining_entries = false;
1110                                                                                 break;
1111                                                                         }
1112                                                                 },
1113                                                         _ => {},
1114                                                 }
1115                                         }
1116                                 }
1117                                 if no_remaining_entries {
1118                                         *timer_ticks_without_htlcs += 1;
1119                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1120                                 } else {
1121                                         *timer_ticks_without_htlcs = 0;
1122                                         true
1123                                 }
1124                         } else { true }
1125                 });
1126         }
1127
1128         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1129         pub(super) fn fail_htlc<L: Deref>(
1130                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1131                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
1132                 payment_params: &Option<PaymentParameters>, probing_cookie_secret: [u8; 32],
1133                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1134         ) -> bool where L::Target: Logger {
1135                 #[cfg(test)]
1136                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1137                 #[cfg(not(test))]
1138                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1139
1140                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1141                 let mut session_priv_bytes = [0; 32];
1142                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1143                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1144
1145                 // If any payments already need retry, there's no need to generate a redundant
1146                 // `PendingHTLCsForwardable`.
1147                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1148                         let mut awaiting_retry = false;
1149                         if pmt.is_auto_retryable_now() {
1150                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1151                                         if pending_amt_msat < total_msat {
1152                                                 awaiting_retry = true;
1153                                         }
1154                                 }
1155                         }
1156                         awaiting_retry
1157                 });
1158
1159                 let mut full_failure_ev = None;
1160                 let mut pending_retry_ev = false;
1161                 let mut retry = None;
1162                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1163                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1164                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1165                                 return false
1166                         }
1167                         if payment.get().is_fulfilled() {
1168                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1169                                 return false
1170                         }
1171                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1172                         if let Some(scid) = short_channel_id {
1173                                 payment.get_mut().insert_previously_failed_scid(scid);
1174                         }
1175
1176                         // We want to move towards only using the `PaymentParameters` in the outbound payments
1177                         // map. However, for backwards-compatibility, we still need to support passing the
1178                         // `PaymentParameters` data that was shoved in the HTLC (and given to us via
1179                         // `payment_params`) back to the user.
1180                         let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
1181                         if let Some(params) = payment.get_mut().payment_parameters() {
1182                                 if params.final_cltv_expiry_delta.is_none() {
1183                                         // This should be rare, but a user could provide None for the payment data, and
1184                                         // we need it when we go to retry the payment, so fill it in.
1185                                         params.final_cltv_expiry_delta = Some(path_last_hop.cltv_expiry_delta);
1186                                 }
1187                                 retry = Some(RouteParameters {
1188                                         payment_params: params.clone(),
1189                                         final_value_msat: path_last_hop.fee_msat,
1190                                         final_cltv_expiry_delta: params.final_cltv_expiry_delta.unwrap(),
1191                                 });
1192                         } else if let Some(params) = payment_params {
1193                                 retry = Some(RouteParameters {
1194                                         payment_params: params.clone(),
1195                                         final_value_msat: path_last_hop.fee_msat,
1196                                         final_cltv_expiry_delta:
1197                                                 if let Some(delta) = params.final_cltv_expiry_delta { delta }
1198                                                 else { path_last_hop.cltv_expiry_delta },
1199                                 });
1200                         }
1201
1202                         if payment_is_probe || !is_retryable_now || !payment_retryable || retry.is_none() {
1203                                 let _ = payment.get_mut().mark_abandoned(); // we'll only Err if it's a legacy payment
1204                                 is_retryable_now = false;
1205                         }
1206                         if payment.get().remaining_parts() == 0 {
1207                                 if payment.get().abandoned() {
1208                                         if !payment_is_probe {
1209                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1210                                                         payment_id: *payment_id,
1211                                                         payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1212                                                 });
1213                                         }
1214                                         payment.remove();
1215                                 }
1216                         }
1217                         is_retryable_now
1218                 } else {
1219                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1220                         return false
1221                 };
1222                 core::mem::drop(outbounds);
1223                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1224
1225                 let path_failure = {
1226                         if payment_is_probe {
1227                                 if !payment_retryable {
1228                                         events::Event::ProbeSuccessful {
1229                                                 payment_id: *payment_id,
1230                                                 payment_hash: payment_hash.clone(),
1231                                                 path: path.clone(),
1232                                         }
1233                                 } else {
1234                                         events::Event::ProbeFailed {
1235                                                 payment_id: *payment_id,
1236                                                 payment_hash: payment_hash.clone(),
1237                                                 path: path.clone(),
1238                                                 short_channel_id,
1239                                         }
1240                                 }
1241                         } else {
1242                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1243                                 // process_onion_failure we should close that channel as it implies our
1244                                 // next-hop is needlessly blaming us!
1245                                 if let Some(scid) = short_channel_id {
1246                                         retry.as_mut().map(|r| r.payment_params.previously_failed_channels.push(scid));
1247                                 }
1248                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1249                                 // payment will sit in our outbounds forever.
1250                                 if attempts_remaining && !already_awaiting_retry {
1251                                         debug_assert!(full_failure_ev.is_none());
1252                                         pending_retry_ev = true;
1253                                 }
1254                                 events::Event::PaymentPathFailed {
1255                                         payment_id: Some(*payment_id),
1256                                         payment_hash: payment_hash.clone(),
1257                                         payment_failed_permanently: !payment_retryable,
1258                                         failure: events::PathFailure::OnPath { network_update },
1259                                         path: path.clone(),
1260                                         short_channel_id,
1261                                         retry,
1262                                         #[cfg(test)]
1263                                         error_code: onion_error_code,
1264                                         #[cfg(test)]
1265                                         error_data: onion_error_data
1266                                 }
1267                         }
1268                 };
1269                 let mut pending_events = pending_events.lock().unwrap();
1270                 pending_events.push(path_failure);
1271                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
1272                 pending_retry_ev
1273         }
1274
1275         pub(super) fn abandon_payment(
1276                 &self, payment_id: PaymentId, pending_events: &Mutex<Vec<events::Event>>
1277         ) {
1278                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1279                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1280                         if let Ok(()) = payment.get_mut().mark_abandoned() {
1281                                 if payment.get().remaining_parts() == 0 {
1282                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
1283                                                 payment_id,
1284                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1285                                         });
1286                                         payment.remove();
1287                                 }
1288                         }
1289                 }
1290         }
1291
1292         #[cfg(test)]
1293         pub fn has_pending_payments(&self) -> bool {
1294                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1295         }
1296
1297         #[cfg(test)]
1298         pub fn clear_pending_payments(&self) {
1299                 self.pending_outbound_payments.lock().unwrap().clear()
1300         }
1301 }
1302
1303 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1304 /// payment probe.
1305 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1306         probing_cookie_secret: [u8; 32]) -> bool
1307 {
1308         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1309         target_payment_hash == *payment_hash
1310 }
1311
1312 /// Returns the 'probing cookie' for the given [`PaymentId`].
1313 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1314         let mut preimage = [0u8; 64];
1315         preimage[..32].copy_from_slice(&probing_cookie_secret);
1316         preimage[32..].copy_from_slice(&payment_id.0);
1317         PaymentHash(Sha256::hash(&preimage).into_inner())
1318 }
1319
1320 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1321         (0, Legacy) => {
1322                 (0, session_privs, required),
1323         },
1324         (1, Fulfilled) => {
1325                 (0, session_privs, required),
1326                 (1, payment_hash, option),
1327                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1328         },
1329         (2, Retryable) => {
1330                 (0, session_privs, required),
1331                 (1, pending_fee_msat, option),
1332                 (2, payment_hash, required),
1333                 (3, payment_params, option),
1334                 (4, payment_secret, option),
1335                 (5, keysend_preimage, option),
1336                 (6, total_msat, required),
1337                 (8, pending_amt_msat, required),
1338                 (10, starting_block_height, required),
1339                 (not_written, retry_strategy, (static_value, None)),
1340                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1341         },
1342         (3, Abandoned) => {
1343                 (0, session_privs, required),
1344                 (2, payment_hash, required),
1345         },
1346 );
1347
1348 #[cfg(test)]
1349 mod tests {
1350         use bitcoin::network::constants::Network;
1351         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1352
1353         use crate::ln::PaymentHash;
1354         use crate::ln::channelmanager::PaymentId;
1355         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1356         use crate::ln::msgs::{ErrorAction, LightningError};
1357         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1358         use crate::routing::gossip::NetworkGraph;
1359         use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters};
1360         use crate::sync::{Arc, Mutex};
1361         use crate::util::errors::APIError;
1362         use crate::util::events::{Event, PathFailure};
1363         use crate::util::test_utils;
1364
1365         #[test]
1366         #[cfg(feature = "std")]
1367         fn fails_paying_after_expiration() {
1368                 do_fails_paying_after_expiration(false);
1369                 do_fails_paying_after_expiration(true);
1370         }
1371         #[cfg(feature = "std")]
1372         fn do_fails_paying_after_expiration(on_retry: bool) {
1373                 let outbound_payments = OutboundPayments::new();
1374                 let logger = test_utils::TestLogger::new();
1375                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1376                 let scorer = Mutex::new(test_utils::TestScorer::new());
1377                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1378                 let secp_ctx = Secp256k1::new();
1379                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1380
1381                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1382                 let payment_params = PaymentParameters::from_node_id(
1383                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1384                                 0
1385                         ).with_expiry_time(past_expiry_time);
1386                 let expired_route_params = RouteParameters {
1387                         payment_params,
1388                         final_value_msat: 0,
1389                         final_cltv_expiry_delta: 0,
1390                 };
1391                 let pending_events = Mutex::new(Vec::new());
1392                 if on_retry {
1393                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
1394                         &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
1395                         Some(expired_route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
1396                         outbound_payments.retry_payment_internal(
1397                                 PaymentId([0; 32]), expired_route_params, &&router, vec![], &|| InFlightHtlcs::new(),
1398                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1399                                 &|_, _, _, _, _, _, _, _, _| Ok(()));
1400                         let events = pending_events.lock().unwrap();
1401                         assert_eq!(events.len(), 1);
1402                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1403                 } else {
1404                         let err = outbound_payments.send_payment(
1405                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), expired_route_params,
1406                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1407                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1408                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1409                 }
1410         }
1411
1412         #[test]
1413         fn find_route_error() {
1414                 do_find_route_error(false);
1415                 do_find_route_error(true);
1416         }
1417         fn do_find_route_error(on_retry: bool) {
1418                 let outbound_payments = OutboundPayments::new();
1419                 let logger = test_utils::TestLogger::new();
1420                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1421                 let scorer = Mutex::new(test_utils::TestScorer::new());
1422                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1423                 let secp_ctx = Secp256k1::new();
1424                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1425
1426                 let payment_params = PaymentParameters::from_node_id(
1427                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1428                 let route_params = RouteParameters {
1429                         payment_params,
1430                         final_value_msat: 0,
1431                         final_cltv_expiry_delta: 0,
1432                 };
1433                 router.expect_find_route(route_params.clone(),
1434                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1435
1436                 let pending_events = Mutex::new(Vec::new());
1437                 if on_retry {
1438                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
1439                                 &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
1440                                 Some(route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
1441                         outbound_payments.retry_payment_internal(
1442                                 PaymentId([0; 32]), route_params, &&router, vec![], &|| InFlightHtlcs::new(),
1443                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1444                                 &|_, _, _, _, _, _, _, _, _| Ok(()));
1445                         let events = pending_events.lock().unwrap();
1446                         assert_eq!(events.len(), 1);
1447                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1448                 } else {
1449                         let err = outbound_payments.send_payment(
1450                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params,
1451                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1452                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1453                         if let RetryableSendFailure::RouteNotFound = err {
1454                         } else { panic!("Unexpected error"); }
1455                 }
1456         }
1457
1458         #[test]
1459         fn initial_send_payment_path_failed_evs() {
1460                 let outbound_payments = OutboundPayments::new();
1461                 let logger = test_utils::TestLogger::new();
1462                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1463                 let scorer = Mutex::new(test_utils::TestScorer::new());
1464                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1465                 let secp_ctx = Secp256k1::new();
1466                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1467
1468                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1469                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1470                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1471                 let route_params = RouteParameters {
1472                         payment_params: payment_params.clone(),
1473                         final_value_msat: 0,
1474                         final_cltv_expiry_delta: 0,
1475                 };
1476                 let failed_scid = 42;
1477                 let route = Route {
1478                         paths: vec![vec![RouteHop {
1479                                 pubkey: receiver_pk,
1480                                 node_features: NodeFeatures::empty(),
1481                                 short_channel_id: failed_scid,
1482                                 channel_features: ChannelFeatures::empty(),
1483                                 fee_msat: 0,
1484                                 cltv_expiry_delta: 0,
1485                         }]],
1486                         payment_params: Some(payment_params),
1487                 };
1488                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1489                 let mut route_params_w_failed_scid = route_params.clone();
1490                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1491                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1492                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1493                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1494
1495                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1496                 // PaymentPathFailed event.
1497                 let pending_events = Mutex::new(Vec::new());
1498                 outbound_payments.send_payment(
1499                         PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params.clone(),
1500                         &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1501                         &pending_events,
1502                         |_, _, _, _, _, _, _, _, _| Err(APIError::ChannelUnavailable { err: "test".to_owned() }))
1503                         .unwrap();
1504                 let mut events = pending_events.lock().unwrap();
1505                 assert_eq!(events.len(), 2);
1506                 if let Event::PaymentPathFailed {
1507                         short_channel_id,
1508                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0]
1509                 {
1510                         assert_eq!(short_channel_id, Some(failed_scid));
1511                 } else { panic!("Unexpected event"); }
1512                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1513                 events.clear();
1514                 core::mem::drop(events);
1515
1516                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1517                 outbound_payments.send_payment(
1518                         PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params.clone(),
1519                         &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1520                         &pending_events, |_, _, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress))
1521                         .unwrap();
1522                 {
1523                         let events = pending_events.lock().unwrap();
1524                         assert_eq!(events.len(), 0);
1525                 }
1526
1527                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1528                 outbound_payments.send_payment(
1529                         PaymentHash([0; 32]), &None, PaymentId([1; 32]), Retry::Attempts(0), route_params.clone(),
1530                         &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1531                         &pending_events,
1532                         |_, _, _, _, _, _, _, _, _| Err(APIError::APIMisuseError { err: "test".to_owned() }))
1533                         .unwrap();
1534                 let events = pending_events.lock().unwrap();
1535                 assert_eq!(events.len(), 2);
1536                 if let Event::PaymentPathFailed {
1537                         short_channel_id,
1538                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0]
1539                 {
1540                         assert_eq!(short_channel_id, None);
1541                 } else { panic!("Unexpected event"); }
1542                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1543         }
1544 }