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