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