_ 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::events;
  18 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  19 use crate::ln::channelmanager::{ChannelDetails, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
  20 use crate::ln::onion_utils::HTLCFailReason;
  21 use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters, RoutePath, Router};
  22 use crate::util::errors::APIError;
  23 use crate::util::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                 payment_metadata: Option<Vec<u8>>,
  50                 keysend_preimage: Option<PaymentPreimage>,
  51                 pending_amt_msat: u64,
  52                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  53                 pending_fee_msat: Option<u64>,
  54                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  55                 total_msat: u64,
  56                 /// Our best known block height at the time this payment was initiated.
  57                 starting_block_height: u32,
  58         },
  59         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  60         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  61         /// and add a pending payment that was already fulfilled.
  62         Fulfilled {
  63                 session_privs: HashSet<[u8; 32]>,
  64                 payment_hash: Option<PaymentHash>,
  65                 timer_ticks_without_htlcs: u8,
  66         },
  67         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  68         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  69         Abandoned {
  70                 session_privs: HashSet<[u8; 32]>,
  71                 payment_hash: PaymentHash,
  72         },
  73 }
  74
  75 impl PendingOutboundPayment {
  76         fn increment_attempts(&mut self) {
  77                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  78                         attempts.count += 1;
  79                 }
  80         }
  81         fn is_auto_retryable_now(&self) -> bool {
  82                 match self {
  83                         PendingOutboundPayment::Retryable {
  84                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
  85                         } => {
  86                                 strategy.is_retryable_now(&attempts)
  87                         },
  88                         _ => false,
  89                 }
  90         }
  91         fn is_retryable_now(&self) -> bool {
  92                 match self {
  93                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
  94                                 // We're handling retries manually, we can always retry.
  95                                 true
  96                         },
  97                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  98                                 strategy.is_retryable_now(&attempts)
  99                         },
 100                         _ => false,
 101                 }
 102         }
 103         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 104                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 105                         params.previously_failed_channels.push(scid);
 106                 }
 107         }
 108         pub(super) fn is_fulfilled(&self) -> bool {
 109                 match self {
 110                         PendingOutboundPayment::Fulfilled { .. } => true,
 111                         _ => false,
 112                 }
 113         }
 114         pub(super) fn abandoned(&self) -> bool {
 115                 match self {
 116                         PendingOutboundPayment::Abandoned { .. } => true,
 117                         _ => false,
 118                 }
 119         }
 120         fn get_pending_fee_msat(&self) -> Option<u64> {
 121                 match self {
 122                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 123                         _ => None,
 124                 }
 125         }
 126
 127         fn payment_hash(&self) -> Option<PaymentHash> {
 128                 match self {
 129                         PendingOutboundPayment::Legacy { .. } => None,
 130                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 131                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 132                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 133                 }
 134         }
 135
 136         fn mark_fulfilled(&mut self) {
 137                 let mut session_privs = HashSet::new();
 138                 core::mem::swap(&mut session_privs, match self {
 139                         PendingOutboundPayment::Legacy { session_privs } |
 140                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 141                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 142                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 143                         => session_privs,
 144                 });
 145                 let payment_hash = self.payment_hash();
 146                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 147         }
 148
 149         fn mark_abandoned(&mut self) -> Result<(), ()> {
 150                 let mut session_privs = HashSet::new();
 151                 let our_payment_hash;
 152                 core::mem::swap(&mut session_privs, match self {
 153                         PendingOutboundPayment::Legacy { .. } |
 154                         PendingOutboundPayment::Fulfilled { .. } =>
 155                                 return Err(()),
 156                         PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } |
 157                         PendingOutboundPayment::Abandoned { session_privs, payment_hash, .. } => {
 158                                 our_payment_hash = *payment_hash;
 159                                 session_privs
 160                         },
 161                 });
 162                 *self = PendingOutboundPayment::Abandoned { session_privs, payment_hash: our_payment_hash };
 163                 Ok(())
 164         }
 165
 166         /// panics if path is None and !self.is_fulfilled
 167         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Vec<RouteHop>>) -> bool {
 168                 let remove_res = match self {
 169                         PendingOutboundPayment::Legacy { session_privs } |
 170                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 171                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 172                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 173                                         session_privs.remove(session_priv)
 174                                 }
 175                 };
 176                 if remove_res {
 177                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 178                                 let path = path.expect("Fulfilling a payment should always come with a path");
 179                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 180                                 *pending_amt_msat -= path_last_hop.fee_msat;
 181                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 182                                         *fee_msat -= path.get_path_fees();
 183                                 }
 184                         }
 185                 }
 186                 remove_res
 187         }
 188
 189         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Vec<RouteHop>) -> bool {
 190                 let insert_res = match self {
 191                         PendingOutboundPayment::Legacy { session_privs } |
 192                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 193                                         session_privs.insert(session_priv)
 194                                 }
 195                         PendingOutboundPayment::Fulfilled { .. } => false,
 196                         PendingOutboundPayment::Abandoned { .. } => false,
 197                 };
 198                 if insert_res {
 199                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 200                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 201                                 *pending_amt_msat += path_last_hop.fee_msat;
 202                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 203                                         *fee_msat += path.get_path_fees();
 204                                 }
 205                         }
 206                 }
 207                 insert_res
 208         }
 209
 210         pub(super) fn remaining_parts(&self) -> usize {
 211                 match self {
 212                         PendingOutboundPayment::Legacy { session_privs } |
 213                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 214                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 215                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 216                                         session_privs.len()
 217                                 }
 218                 }
 219         }
 220 }
 221
 222 /// Strategies available to retry payment path failures.
 223 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 224 pub enum Retry {
 225         /// Max number of attempts to retry payment.
 226         ///
 227         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 228         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 229         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 230         Attempts(usize),
 231         #[cfg(not(feature = "no-std"))]
 232         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 233         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 234         ///
 235         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 236         Timeout(core::time::Duration),
 237 }
 238
 239 impl Retry {
 240         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 241                 match (self, attempts) {
 242                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 243                                 max_retry_count > count
 244                         },
 245                         #[cfg(all(not(feature = "no-std"), not(test)))]
 246                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 247                                 *max_duration >= std::time::Instant::now().duration_since(*first_attempted_at),
 248                         #[cfg(all(not(feature = "no-std"), test))]
 249                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 250                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 251                 }
 252         }
 253 }
 254
 255 #[cfg(feature = "std")]
 256 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 257         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 258                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 259                         return elapsed > core::time::Duration::from_secs(expiry_time)
 260                 }
 261         }
 262         false
 263 }
 264
 265 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 266
 267 /// Storing minimal payment attempts information required for determining if a outbound payment can
 268 /// be retried.
 269 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 270         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 271         /// it means the result of the first attempt is not known yet.
 272         pub(crate) count: usize,
 273         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 274         #[cfg(not(feature = "no-std"))]
 275         first_attempted_at: T,
 276         #[cfg(feature = "no-std")]
 277         phantom: core::marker::PhantomData<T>,
 278
 279 }
 280
 281 #[cfg(not(any(feature = "no-std", test)))]
 282 type ConfiguredTime = std::time::Instant;
 283 #[cfg(feature = "no-std")]
 284 type ConfiguredTime = crate::util::time::Eternity;
 285 #[cfg(all(not(feature = "no-std"), test))]
 286 type ConfiguredTime = SinceEpoch;
 287
 288 impl<T: Time> PaymentAttemptsUsingTime<T> {
 289         pub(crate) fn new() -> Self {
 290                 PaymentAttemptsUsingTime {
 291                         count: 0,
 292                         #[cfg(not(feature = "no-std"))]
 293                         first_attempted_at: T::now(),
 294                         #[cfg(feature = "no-std")]
 295                         phantom: core::marker::PhantomData,
 296                 }
 297         }
 298 }
 299
 300 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 301         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 302                 #[cfg(feature = "no-std")]
 303                 return write!(f, "attempts: {}", self.count);
 304                 #[cfg(not(feature = "no-std"))]
 305                 return write!(
 306                         f,
 307                         "attempts: {}, duration: {}s",
 308                         self.count,
 309                         T::now().duration_since(self.first_attempted_at).as_secs()
 310                 );
 311         }
 312 }
 313
 314 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 315 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 316 ///
 317 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 318 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 319 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 320 #[derive(Clone, Debug)]
 321 pub enum RetryableSendFailure {
 322         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 323         /// that this error is *not* caused by [`Retry::Timeout`].
 324         ///
 325         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 326         PaymentExpired,
 327         /// We were unable to find a route to the destination.
 328         RouteNotFound,
 329         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 330         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 331         ///
 332         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 333         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 334         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 335         DuplicatePayment,
 336 }
 337
 338 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 339 /// of several states. This enum is returned as the Err() type describing which state the payment
 340 /// is in, see the description of individual enum states for more.
 341 ///
 342 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 343 #[derive(Clone, Debug)]
 344 pub enum PaymentSendFailure {
 345         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 346         /// send the payment at all.
 347         ///
 348         /// You can freely resend the payment in full (with the parameter error fixed).
 349         ///
 350         /// Because the payment failed outright, no payment tracking is done and no
 351         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 352         ///
 353         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 354         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 355         ParameterError(APIError),
 356         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 357         /// from attempting to send the payment at all.
 358         ///
 359         /// You can freely resend the payment in full (with the parameter error fixed).
 360         ///
 361         /// Because the payment failed outright, no payment tracking is done and no
 362         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 363         ///
 364         /// The results here are ordered the same as the paths in the route object which was passed to
 365         /// send_payment.
 366         ///
 367         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 368         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 369         PathParameterError(Vec<Result<(), APIError>>),
 370         /// All paths which were attempted failed to send, with no channel state change taking place.
 371         /// You can freely resend the payment in full (though you probably want to do so over different
 372         /// paths than the ones selected).
 373         ///
 374         /// Because the payment failed outright, no payment tracking is done and no
 375         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 376         ///
 377         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 378         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 379         AllFailedResendSafe(Vec<APIError>),
 380         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 381         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 382         ///
 383         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 384         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 385         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 386         DuplicatePayment,
 387         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 388         /// some paths have irrevocably committed to the HTLC.
 389         ///
 390         /// The results here are ordered the same as the paths in the route object that was passed to
 391         /// send_payment.
 392         ///
 393         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 394         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 395         ///
 396         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 397         PartialFailure {
 398                 /// The errors themselves, in the same order as the paths from the route.
 399                 results: Vec<Result<(), APIError>>,
 400                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 401                 /// contain a [`RouteParameters`] object for the failing paths.
 402                 failed_paths_retry: Option<RouteParameters>,
 403                 /// The payment id for the payment, which is now at least partially pending.
 404                 payment_id: PaymentId,
 405         },
 406 }
 407
 408 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 409 ///
 410 /// This should generally be constructed with data communicated to us from the recipient (via a
 411 /// BOLT11 or BOLT12 invoice).
 412 #[derive(Clone)]
 413 pub struct RecipientOnionFields {
 414         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 415         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 416         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 417         /// attacks.
 418         ///
 419         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 420         /// multi-path payments require a recipient-provided secret.
 421         ///
 422         /// Note that for spontaneous payments most lightning nodes do not currently support MPP
 423         /// receives, thus you should generally never be providing a secret here for spontaneous
 424         /// payments.
 425         pub payment_secret: Option<PaymentSecret>,
 426         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 427         /// arbitrary length. This gives recipients substantially more flexibility to receive
 428         /// additional data.
 429         ///
 430         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 431         /// scheme to authenticate received payments against expected payments and invoices, this field
 432         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 433         /// invoices which will be received with the payment.
 434         ///
 435         /// Note that this field was added to the lightning specification more recently than
 436         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 437         /// may not be supported as universally.
 438         pub payment_metadata: Option<Vec<u8>>,
 439 }
 440
 441 impl RecipientOnionFields {
 442         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 443         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 444         /// but do not require or provide any further data.
 445         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 446                 Self { payment_secret: Some(payment_secret), payment_metadata: None }
 447         }
 448
 449         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 450         /// payable HTLCs except for spontaneous payments, i.e. this should generally only be used for
 451         /// calls to [`ChannelManager::send_spontaneous_payment`].
 452         ///
 453         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 454         pub fn spontaneous_empty() -> Self {
 455                 Self { payment_secret: None, payment_metadata: None }
 456         }
 457 }
 458
 459 pub(super) struct OutboundPayments {
 460         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 461         pub(super) retry_lock: Mutex<()>,
 462 }
 463
 464 impl OutboundPayments {
 465         pub(super) fn new() -> Self {
 466                 Self {
 467                         pending_outbound_payments: Mutex::new(HashMap::new()),
 468                         retry_lock: Mutex::new(()),
 469                 }
 470         }
 471
 472         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 473                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 474                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 475                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 476                 node_signer: &NS, best_block_height: u32, logger: &L,
 477                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 478         ) -> Result<(), RetryableSendFailure>
 479         where
 480                 R::Target: Router,
 481                 ES::Target: EntropySource,
 482                 NS::Target: NodeSigner,
 483                 L::Target: Logger,
 484                 IH: Fn() -> InFlightHtlcs,
 485                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 486                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 487         {
 488                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 489                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 490                         best_block_height, logger, pending_events, &send_payment_along_path)
 491         }
 492
 493         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 494                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 495                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 496                 send_payment_along_path: F
 497         ) -> Result<(), PaymentSendFailure>
 498         where
 499                 ES::Target: EntropySource,
 500                 NS::Target: NodeSigner,
 501                 F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 502                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 503         {
 504                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(), payment_id, None, route, None, None, entropy_source, best_block_height)?;
 505                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 506                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 507                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 508         }
 509
 510         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 511                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 512                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 513                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 514                 node_signer: &NS, best_block_height: u32, logger: &L,
 515                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
 516         ) -> Result<PaymentHash, RetryableSendFailure>
 517         where
 518                 R::Target: Router,
 519                 ES::Target: EntropySource,
 520                 NS::Target: NodeSigner,
 521                 L::Target: Logger,
 522                 IH: Fn() -> InFlightHtlcs,
 523                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 524                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 525         {
 526                 let preimage = payment_preimage
 527                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 528                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 529                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 530                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 531                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 532                         .map(|()| payment_hash)
 533         }
 534
 535         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 536                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 537                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 538                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 539         ) -> Result<PaymentHash, PaymentSendFailure>
 540         where
 541                 ES::Target: EntropySource,
 542                 NS::Target: NodeSigner,
 543                 F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 544                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 545         {
 546                 let preimage = payment_preimage
 547                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 548                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 549                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 550                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 551
 552                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 553                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 554                 ) {
 555                         Ok(()) => Ok(payment_hash),
 556                         Err(e) => {
 557                                 self.remove_outbound_if_all_failed(payment_id, &e);
 558                                 Err(e)
 559                         }
 560                 }
 561         }
 562
 563         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 564                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 565                 best_block_height: u32, pending_events: &Mutex<Vec<events::Event>>, logger: &L,
 566                 send_payment_along_path: SP,
 567         )
 568         where
 569                 R::Target: Router,
 570                 ES::Target: EntropySource,
 571                 NS::Target: NodeSigner,
 572                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 573                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 574                 IH: Fn() -> InFlightHtlcs,
 575                 FH: Fn() -> Vec<ChannelDetails>,
 576                 L::Target: Logger,
 577         {
 578                 let _single_thread = self.retry_lock.lock().unwrap();
 579                 loop {
 580                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 581                         let mut retry_id_route_params = None;
 582                         for (pmt_id, pmt) in outbounds.iter_mut() {
 583                                 if pmt.is_auto_retryable_now() {
 584                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 585                                                 if pending_amt_msat < total_msat {
 586                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 587                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 588                                                                 payment_params: params.clone(),
 589                                                         }));
 590                                                         break
 591                                                 }
 592                                         } else { debug_assert!(false); }
 593                                 }
 594                         }
 595                         core::mem::drop(outbounds);
 596                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 597                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops(), &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path)
 598                         } else { break }
 599                 }
 600
 601                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 602                 outbounds.retain(|pmt_id, pmt| {
 603                         let mut retain = true;
 604                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 605                                 if pmt.mark_abandoned().is_ok() {
 606                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 607                                                 payment_id: *pmt_id,
 608                                                 payment_hash: pmt.payment_hash().expect("PendingOutboundPayments::Retryable always has a payment hash set"),
 609                                         });
 610                                         retain = false;
 611                                 }
 612                         }
 613                         retain
 614                 });
 615         }
 616
 617         pub(super) fn needs_abandon(&self) -> bool {
 618                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 619                 outbounds.iter().any(|(_, pmt)|
 620                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 621         }
 622
 623         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 624         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 625         ///
 626         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 627         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 628         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 629                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 630                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 631                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 632                 node_signer: &NS, best_block_height: u32, logger: &L,
 633                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 634         ) -> Result<(), RetryableSendFailure>
 635         where
 636                 R::Target: Router,
 637                 ES::Target: EntropySource,
 638                 NS::Target: NodeSigner,
 639                 L::Target: Logger,
 640                 IH: Fn() -> InFlightHtlcs,
 641                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 642                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 643         {
 644                 #[cfg(feature = "std")] {
 645                         if has_expired(&route_params) {
 646                                 return Err(RetryableSendFailure::PaymentExpired)
 647                         }
 648                 }
 649
 650                 let route = router.find_route_with_id(
 651                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 652                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs(),
 653                         payment_hash, payment_id,
 654                 ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 655
 656                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 657                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 658                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 659                         .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 660
 661                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, None, payment_id, None,
 662                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 663                 log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
 664                 if let Err(e) = res {
 665                         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);
 666                 }
 667                 Ok(())
 668         }
 669
 670         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 671                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 672                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 673                 node_signer: &NS, best_block_height: u32, logger: &L,
 674                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 675         )
 676         where
 677                 R::Target: Router,
 678                 ES::Target: EntropySource,
 679                 NS::Target: NodeSigner,
 680                 L::Target: Logger,
 681                 IH: Fn() -> InFlightHtlcs,
 682                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 683                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 684         {
 685                 #[cfg(feature = "std")] {
 686                         if has_expired(&route_params) {
 687                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
 688                                 self.abandon_payment(payment_id, pending_events);
 689                                 return
 690                         }
 691                 }
 692
 693                 let route = match router.find_route_with_id(
 694                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 695                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs(),
 696                         payment_hash, payment_id,
 697                 ) {
 698                         Ok(route) => route,
 699                         Err(e) => {
 700                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
 701                                 self.abandon_payment(payment_id, pending_events);
 702                                 return
 703                         }
 704                 };
 705                 for path in route.paths.iter() {
 706                         if path.len() == 0 {
 707                                 log_error!(logger, "length-0 path in route");
 708                                 self.abandon_payment(payment_id, pending_events);
 709                                 return
 710                         }
 711                 }
 712
 713                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 714                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 715                 for _ in 0..route.paths.len() {
 716                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 717                 }
 718
 719                 macro_rules! abandon_with_entry {
 720                         ($payment: expr) => {
 721                                 if $payment.get_mut().mark_abandoned().is_ok() && $payment.get().remaining_parts() == 0 {
 722                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 723                                                 payment_id,
 724                                                 payment_hash,
 725                                         });
 726                                         $payment.remove();
 727                                 }
 728                         }
 729                 }
 730                 let (total_msat, recipient_onion, keysend_preimage) = {
 731                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 732                         match outbounds.entry(payment_id) {
 733                                 hash_map::Entry::Occupied(mut payment) => {
 734                                         let res = match payment.get() {
 735                                                 PendingOutboundPayment::Retryable {
 736                                                         total_msat, keysend_preimage, payment_secret, payment_metadata, pending_amt_msat, ..
 737                                                 } => {
 738                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 739                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 740                                                                 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);
 741                                                                 abandon_with_entry!(payment);
 742                                                                 return
 743                                                         }
 744                                                         (*total_msat, RecipientOnionFields {
 745                                                                         payment_secret: *payment_secret,
 746                                                                         payment_metadata: payment_metadata.clone(),
 747                                                                 }, *keysend_preimage)
 748                                                 },
 749                                                 PendingOutboundPayment::Legacy { .. } => {
 750                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 751                                                         return
 752                                                 },
 753                                                 PendingOutboundPayment::Fulfilled { .. } => {
 754                                                         log_error!(logger, "Payment already completed");
 755                                                         return
 756                                                 },
 757                                                 PendingOutboundPayment::Abandoned { .. } => {
 758                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 759                                                         return
 760                                                 },
 761                                         };
 762                                         if !payment.get().is_retryable_now() {
 763                                                 log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
 764                                                 abandon_with_entry!(payment);
 765                                                 return
 766                                         }
 767                                         payment.get_mut().increment_attempts();
 768                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 769                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 770                                         }
 771                                         res
 772                                 },
 773                                 hash_map::Entry::Vacant(_) => {
 774                                         log_error!(logger, "Payment with ID {} not found", log_bytes!(payment_id.0));
 775                                         return
 776                                 }
 777                         }
 778                 };
 779                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
 780                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 781                         &send_payment_along_path);
 782                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
 783                 if let Err(e) = res {
 784                         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);
 785                 }
 786         }
 787
 788         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 789                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 790                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 791                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 792                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 793         )
 794         where
 795                 R::Target: Router,
 796                 ES::Target: EntropySource,
 797                 NS::Target: NodeSigner,
 798                 L::Target: Logger,
 799                 IH: Fn() -> InFlightHtlcs,
 800                 SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 801                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 802         {
 803                 match err {
 804                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 805                                 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);
 806                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 807                         },
 808                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 809                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), pending_events);
 810                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 811                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 812                                 // return `Ok()` here, ignoring any retry errors.
 813                                 self.retry_payment_internal(payment_hash, payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 814                         },
 815                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 816                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 817                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 818                                 // initial HTLC-Add messages yet.
 819                         },
 820                         PaymentSendFailure::PathParameterError(results) => {
 821                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), pending_events);
 822                                 self.abandon_payment(payment_id, pending_events);
 823                         },
 824                         PaymentSendFailure::ParameterError(e) => {
 825                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 826                                 self.abandon_payment(payment_id, pending_events);
 827                         },
 828                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 829                 }
 830         }
 831
 832         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>>(
 833                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 834                 paths: Vec<Vec<RouteHop>>, path_results: I, pending_events: &Mutex<Vec<events::Event>>
 835         ) {
 836                 let mut events = pending_events.lock().unwrap();
 837                 debug_assert_eq!(paths.len(), path_results.len());
 838                 for (path, path_res) in paths.into_iter().zip(path_results) {
 839                         if let Err(e) = path_res {
 840                                 if let APIError::MonitorUpdateInProgress = e { continue }
 841                                 let mut failed_scid = None;
 842                                 if let APIError::ChannelUnavailable { .. } = e {
 843                                         let scid = path[0].short_channel_id;
 844                                         failed_scid = Some(scid);
 845                                         route_params.payment_params.previously_failed_channels.push(scid);
 846                                 }
 847                                 events.push(events::Event::PaymentPathFailed {
 848                                         payment_id: Some(payment_id),
 849                                         payment_hash,
 850                                         payment_failed_permanently: false,
 851                                         failure: events::PathFailure::InitialSend { err: e },
 852                                         path,
 853                                         short_channel_id: failed_scid,
 854                                         #[cfg(test)]
 855                                         error_code: None,
 856                                         #[cfg(test)]
 857                                         error_data: None,
 858                                 });
 859                         }
 860                 }
 861         }
 862
 863         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 864                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 865                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 866         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 867         where
 868                 ES::Target: EntropySource,
 869                 NS::Target: NodeSigner,
 870                 F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 871                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 872         {
 873                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 874
 875                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 876
 877                 if hops.len() < 2 {
 878                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 879                                 err: "No need probing a path with less than two hops".to_string()
 880                         }))
 881                 }
 882
 883                 let route = Route { paths: vec![hops], payment_params: None };
 884                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 885                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
 886                         entropy_source, best_block_height)?;
 887
 888                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
 889                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 890                 ) {
 891                         Ok(()) => Ok((payment_hash, payment_id)),
 892                         Err(e) => {
 893                                 self.remove_outbound_if_all_failed(payment_id, &e);
 894                                 Err(e)
 895                         }
 896                 }
 897         }
 898
 899         #[cfg(test)]
 900         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 901                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 902                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 903         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 904                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 905         }
 906
 907         pub(super) fn add_new_pending_payment<ES: Deref>(
 908                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 909                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 910                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 911         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 912                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 913                 for _ in 0..route.paths.len() {
 914                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 915                 }
 916
 917                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 918                 match pending_outbounds.entry(payment_id) {
 919                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 920                         hash_map::Entry::Vacant(entry) => {
 921                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 922                                         retry_strategy,
 923                                         attempts: PaymentAttempts::new(),
 924                                         payment_params,
 925                                         session_privs: HashSet::new(),
 926                                         pending_amt_msat: 0,
 927                                         pending_fee_msat: Some(0),
 928                                         payment_hash,
 929                                         payment_secret: recipient_onion.payment_secret,
 930                                         payment_metadata: recipient_onion.payment_metadata,
 931                                         keysend_preimage,
 932                                         starting_block_height: best_block_height,
 933                                         total_msat: route.get_total_amount(),
 934                                 });
 935
 936                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 937                                         assert!(payment.insert(*session_priv_bytes, path));
 938                                 }
 939
 940                                 Ok(onion_session_privs)
 941                         },
 942                 }
 943         }
 944
 945         fn pay_route_internal<NS: Deref, F>(
 946                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 947                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 948                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 949                 send_payment_along_path: &F
 950         ) -> Result<(), PaymentSendFailure>
 951         where
 952                 NS::Target: NodeSigner,
 953                 F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 954                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 955         {
 956                 if route.paths.len() < 1 {
 957                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
 958                 }
 959                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
 960                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
 961                 }
 962                 let mut total_value = 0;
 963                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 964                 let mut path_errs = Vec::with_capacity(route.paths.len());
 965                 'path_check: for path in route.paths.iter() {
 966                         if path.len() < 1 || path.len() > 20 {
 967                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
 968                                 continue 'path_check;
 969                         }
 970                         for (idx, hop) in path.iter().enumerate() {
 971                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 972                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
 973                                         continue 'path_check;
 974                                 }
 975                         }
 976                         total_value += path.last().unwrap().fee_msat;
 977                         path_errs.push(Ok(()));
 978                 }
 979                 if path_errs.iter().any(|e| e.is_err()) {
 980                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 981                 }
 982                 if let Some(amt_msat) = recv_value_msat {
 983                         total_value = amt_msat;
 984                 }
 985
 986                 let cur_height = best_block_height + 1;
 987                 let mut results = Vec::new();
 988                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 989                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 990                         let mut path_res = send_payment_along_path(&path, &payment_hash, recipient_onion.clone(),
 991                                 total_value, cur_height, payment_id, &keysend_preimage, session_priv);
 992                         match path_res {
 993                                 Ok(_) => {},
 994                                 Err(APIError::MonitorUpdateInProgress) => {
 995                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 996                                         // considered "in flight" and we shouldn't remove it from the
 997                                         // PendingOutboundPayment set.
 998                                 },
 999                                 Err(_) => {
1000                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1001                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1002                                                 let removed = payment.remove(&session_priv, Some(path));
1003                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1004                                         } else {
1005                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1006                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1007                                         }
1008                                 }
1009                         }
1010                         results.push(path_res);
1011                 }
1012                 let mut has_ok = false;
1013                 let mut has_err = false;
1014                 let mut pending_amt_unsent = 0;
1015                 let mut max_unsent_cltv_delta = 0;
1016                 for (res, path) in results.iter().zip(route.paths.iter()) {
1017                         if res.is_ok() { has_ok = true; }
1018                         if res.is_err() { has_err = true; }
1019                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1020                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1021                                 // PartialFailure.
1022                                 has_err = true;
1023                                 has_ok = true;
1024                         } else if res.is_err() {
1025                                 pending_amt_unsent += path.last().unwrap().fee_msat;
1026                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
1027                         }
1028                 }
1029                 if has_err && has_ok {
1030                         Err(PaymentSendFailure::PartialFailure {
1031                                 results,
1032                                 payment_id,
1033                                 failed_paths_retry: if pending_amt_unsent != 0 {
1034                                         if let Some(payment_params) = &route.payment_params {
1035                                                 Some(RouteParameters {
1036                                                         payment_params: payment_params.clone(),
1037                                                         final_value_msat: pending_amt_unsent,
1038                                                 })
1039                                         } else { None }
1040                                 } else { None },
1041                         })
1042                 } else if has_err {
1043                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1044                 } else {
1045                         Ok(())
1046                 }
1047         }
1048
1049         #[cfg(test)]
1050         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1051                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1052                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1053                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1054                 send_payment_along_path: F
1055         ) -> Result<(), PaymentSendFailure>
1056         where
1057                 NS::Target: NodeSigner,
1058                 F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
1059                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
1060         {
1061                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1062                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1063                         &send_payment_along_path)
1064                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1065         }
1066
1067         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1068         // map as the payment is free to be resent.
1069         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1070                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1071                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1072                         debug_assert!(removed, "We should always have a pending payment to remove here");
1073                 }
1074         }
1075
1076         pub(super) fn claim_htlc<L: Deref>(
1077                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1078                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1079         ) where L::Target: Logger {
1080                 let mut session_priv_bytes = [0; 32];
1081                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1082                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1083                 let mut pending_events = pending_events.lock().unwrap();
1084                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1085                         if !payment.get().is_fulfilled() {
1086                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1087                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1088                                 pending_events.push(
1089                                         events::Event::PaymentSent {
1090                                                 payment_id: Some(payment_id),
1091                                                 payment_preimage,
1092                                                 payment_hash,
1093                                                 fee_paid_msat,
1094                                         }
1095                                 );
1096                                 payment.get_mut().mark_fulfilled();
1097                         }
1098
1099                         if from_onchain {
1100                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1101                                 // This could potentially lead to removing a pending payment too early,
1102                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1103                                 // restart.
1104                                 // TODO: We should have a second monitor event that informs us of payments
1105                                 // irrevocably fulfilled.
1106                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1107                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1108                                         pending_events.push(
1109                                                 events::Event::PaymentPathSuccessful {
1110                                                         payment_id,
1111                                                         payment_hash,
1112                                                         path,
1113                                                 }
1114                                         );
1115                                 }
1116                         }
1117                 } else {
1118                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
1119                 }
1120         }
1121
1122         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
1123                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1124                 let mut pending_events = pending_events.lock().unwrap();
1125                 for source in sources {
1126                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1127                                 let mut session_priv_bytes = [0; 32];
1128                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1129                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1130                                         assert!(payment.get().is_fulfilled());
1131                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1132                                                 pending_events.push(
1133                                                         events::Event::PaymentPathSuccessful {
1134                                                                 payment_id,
1135                                                                 payment_hash: payment.get().payment_hash(),
1136                                                                 path,
1137                                                         }
1138                                                 );
1139                                         }
1140                                 }
1141                         }
1142                 }
1143         }
1144
1145         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
1146                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1147                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1148                 // this could race the user making a duplicate send_payment call and our idempotency
1149                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1150                 // removal. This should be more than sufficient to ensure the idempotency of any
1151                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1152                 // processed.
1153                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1154                 let pending_events = pending_events.lock().unwrap();
1155                 pending_outbound_payments.retain(|payment_id, payment| {
1156                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1157                                 let mut no_remaining_entries = session_privs.is_empty();
1158                                 if no_remaining_entries {
1159                                         for ev in pending_events.iter() {
1160                                                 match ev {
1161                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1162                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1163                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1164                                                                         if payment_id == ev_payment_id {
1165                                                                                 no_remaining_entries = false;
1166                                                                                 break;
1167                                                                         }
1168                                                                 },
1169                                                         _ => {},
1170                                                 }
1171                                         }
1172                                 }
1173                                 if no_remaining_entries {
1174                                         *timer_ticks_without_htlcs += 1;
1175                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1176                                 } else {
1177                                         *timer_ticks_without_htlcs = 0;
1178                                         true
1179                                 }
1180                         } else { true }
1181                 });
1182         }
1183
1184         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1185         pub(super) fn fail_htlc<L: Deref>(
1186                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1187                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
1188                 probing_cookie_secret: [u8; 32], secp_ctx: &Secp256k1<secp256k1::All>,
1189                 pending_events: &Mutex<Vec<events::Event>>, logger: &L
1190         ) -> bool where L::Target: Logger {
1191                 #[cfg(test)]
1192                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1193                 #[cfg(not(test))]
1194                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1195
1196                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1197                 let mut session_priv_bytes = [0; 32];
1198                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1199                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1200
1201                 // If any payments already need retry, there's no need to generate a redundant
1202                 // `PendingHTLCsForwardable`.
1203                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1204                         let mut awaiting_retry = false;
1205                         if pmt.is_auto_retryable_now() {
1206                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1207                                         if pending_amt_msat < total_msat {
1208                                                 awaiting_retry = true;
1209                                         }
1210                                 }
1211                         }
1212                         awaiting_retry
1213                 });
1214
1215                 let mut full_failure_ev = None;
1216                 let mut pending_retry_ev = false;
1217                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1218                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1219                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1220                                 return false
1221                         }
1222                         if payment.get().is_fulfilled() {
1223                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1224                                 return false
1225                         }
1226                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1227                         if let Some(scid) = short_channel_id {
1228                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1229                                 // process_onion_failure we should close that channel as it implies our
1230                                 // next-hop is needlessly blaming us!
1231                                 payment.get_mut().insert_previously_failed_scid(scid);
1232                         }
1233
1234                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1235                                 let _ = payment.get_mut().mark_abandoned(); // we'll only Err if it's a legacy payment
1236                                 is_retryable_now = false;
1237                         }
1238                         if payment.get().remaining_parts() == 0 {
1239                                 if payment.get().abandoned() {
1240                                         if !payment_is_probe {
1241                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1242                                                         payment_id: *payment_id,
1243                                                         payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1244                                                 });
1245                                         }
1246                                         payment.remove();
1247                                 }
1248                         }
1249                         is_retryable_now
1250                 } else {
1251                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1252                         return false
1253                 };
1254                 core::mem::drop(outbounds);
1255                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1256
1257                 let path_failure = {
1258                         if payment_is_probe {
1259                                 if !payment_retryable {
1260                                         events::Event::ProbeSuccessful {
1261                                                 payment_id: *payment_id,
1262                                                 payment_hash: payment_hash.clone(),
1263                                                 path: path.clone(),
1264                                         }
1265                                 } else {
1266                                         events::Event::ProbeFailed {
1267                                                 payment_id: *payment_id,
1268                                                 payment_hash: payment_hash.clone(),
1269                                                 path: path.clone(),
1270                                                 short_channel_id,
1271                                         }
1272                                 }
1273                         } else {
1274                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1275                                 // payment will sit in our outbounds forever.
1276                                 if attempts_remaining && !already_awaiting_retry {
1277                                         debug_assert!(full_failure_ev.is_none());
1278                                         pending_retry_ev = true;
1279                                 }
1280                                 events::Event::PaymentPathFailed {
1281                                         payment_id: Some(*payment_id),
1282                                         payment_hash: payment_hash.clone(),
1283                                         payment_failed_permanently: !payment_retryable,
1284                                         failure: events::PathFailure::OnPath { network_update },
1285                                         path: path.clone(),
1286                                         short_channel_id,
1287                                         #[cfg(test)]
1288                                         error_code: onion_error_code,
1289                                         #[cfg(test)]
1290                                         error_data: onion_error_data
1291                                 }
1292                         }
1293                 };
1294                 let mut pending_events = pending_events.lock().unwrap();
1295                 pending_events.push(path_failure);
1296                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
1297                 pending_retry_ev
1298         }
1299
1300         pub(super) fn abandon_payment(
1301                 &self, payment_id: PaymentId, pending_events: &Mutex<Vec<events::Event>>
1302         ) {
1303                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1304                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1305                         if let Ok(()) = payment.get_mut().mark_abandoned() {
1306                                 if payment.get().remaining_parts() == 0 {
1307                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
1308                                                 payment_id,
1309                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1310                                         });
1311                                         payment.remove();
1312                                 }
1313                         }
1314                 }
1315         }
1316
1317         #[cfg(test)]
1318         pub fn has_pending_payments(&self) -> bool {
1319                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1320         }
1321
1322         #[cfg(test)]
1323         pub fn clear_pending_payments(&self) {
1324                 self.pending_outbound_payments.lock().unwrap().clear()
1325         }
1326 }
1327
1328 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1329 /// payment probe.
1330 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1331         probing_cookie_secret: [u8; 32]) -> bool
1332 {
1333         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1334         target_payment_hash == *payment_hash
1335 }
1336
1337 /// Returns the 'probing cookie' for the given [`PaymentId`].
1338 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1339         let mut preimage = [0u8; 64];
1340         preimage[..32].copy_from_slice(&probing_cookie_secret);
1341         preimage[32..].copy_from_slice(&payment_id.0);
1342         PaymentHash(Sha256::hash(&preimage).into_inner())
1343 }
1344
1345 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1346         (0, Legacy) => {
1347                 (0, session_privs, required),
1348         },
1349         (1, Fulfilled) => {
1350                 (0, session_privs, required),
1351                 (1, payment_hash, option),
1352                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1353         },
1354         (2, Retryable) => {
1355                 (0, session_privs, required),
1356                 (1, pending_fee_msat, option),
1357                 (2, payment_hash, required),
1358                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1359                 // never see it - `payment_params` was added here after the field was added/required.
1360                 (3, payment_params, (option: ReadableArgs, 0)),
1361                 (4, payment_secret, option),
1362                 (5, keysend_preimage, option),
1363                 (6, total_msat, required),
1364                 (7, payment_metadata, option),
1365                 (8, pending_amt_msat, required),
1366                 (10, starting_block_height, required),
1367                 (not_written, retry_strategy, (static_value, None)),
1368                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1369         },
1370         (3, Abandoned) => {
1371                 (0, session_privs, required),
1372                 (2, payment_hash, required),
1373         },
1374 );
1375
1376 #[cfg(test)]
1377 mod tests {
1378         use bitcoin::network::constants::Network;
1379         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1380
1381         use crate::events::{Event, PathFailure};
1382         use crate::ln::PaymentHash;
1383         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1384         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1385         use crate::ln::msgs::{ErrorAction, LightningError};
1386         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1387         use crate::routing::gossip::NetworkGraph;
1388         use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters};
1389         use crate::sync::{Arc, Mutex};
1390         use crate::util::errors::APIError;
1391         use crate::util::test_utils;
1392
1393         #[test]
1394         #[cfg(feature = "std")]
1395         fn fails_paying_after_expiration() {
1396                 do_fails_paying_after_expiration(false);
1397                 do_fails_paying_after_expiration(true);
1398         }
1399         #[cfg(feature = "std")]
1400         fn do_fails_paying_after_expiration(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 past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1410                 let payment_params = PaymentParameters::from_node_id(
1411                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1412                                 0
1413                         ).with_expiry_time(past_expiry_time);
1414                 let expired_route_params = RouteParameters {
1415                         payment_params,
1416                         final_value_msat: 0,
1417                 };
1418                 let pending_events = Mutex::new(Vec::new());
1419                 if on_retry {
1420                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1421                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1422                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1423                                 &&keys_manager, 0).unwrap();
1424                         outbound_payments.retry_payment_internal(
1425                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1426                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1427                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1428                         let events = pending_events.lock().unwrap();
1429                         assert_eq!(events.len(), 1);
1430                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1431                 } else {
1432                         let err = outbound_payments.send_payment(
1433                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1434                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1435                                 &&keys_manager, &&keys_manager, 0, &&logger,
1436                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1437                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1438                 }
1439         }
1440
1441         #[test]
1442         fn find_route_error() {
1443                 do_find_route_error(false);
1444                 do_find_route_error(true);
1445         }
1446         fn do_find_route_error(on_retry: bool) {
1447                 let outbound_payments = OutboundPayments::new();
1448                 let logger = test_utils::TestLogger::new();
1449                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1450                 let scorer = Mutex::new(test_utils::TestScorer::new());
1451                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1452                 let secp_ctx = Secp256k1::new();
1453                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1454
1455                 let payment_params = PaymentParameters::from_node_id(
1456                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1457                 let route_params = RouteParameters {
1458                         payment_params,
1459                         final_value_msat: 0,
1460                 };
1461                 router.expect_find_route(route_params.clone(),
1462                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1463
1464                 let pending_events = Mutex::new(Vec::new());
1465                 if on_retry {
1466                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1467                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1468                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1469                                 &&keys_manager, 0).unwrap();
1470                         outbound_payments.retry_payment_internal(
1471                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1472                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1473                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1474                         let events = pending_events.lock().unwrap();
1475                         assert_eq!(events.len(), 1);
1476                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1477                 } else {
1478                         let err = outbound_payments.send_payment(
1479                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1480                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1481                                 &&keys_manager, &&keys_manager, 0, &&logger,
1482                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1483                         if let RetryableSendFailure::RouteNotFound = err {
1484                         } else { panic!("Unexpected error"); }
1485                 }
1486         }
1487
1488         #[test]
1489         fn initial_send_payment_path_failed_evs() {
1490                 let outbound_payments = OutboundPayments::new();
1491                 let logger = test_utils::TestLogger::new();
1492                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1493                 let scorer = Mutex::new(test_utils::TestScorer::new());
1494                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1495                 let secp_ctx = Secp256k1::new();
1496                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1497
1498                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1499                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1500                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1501                 let route_params = RouteParameters {
1502                         payment_params: payment_params.clone(),
1503                         final_value_msat: 0,
1504                 };
1505                 let failed_scid = 42;
1506                 let route = Route {
1507                         paths: vec![vec![RouteHop {
1508                                 pubkey: receiver_pk,
1509                                 node_features: NodeFeatures::empty(),
1510                                 short_channel_id: failed_scid,
1511                                 channel_features: ChannelFeatures::empty(),
1512                                 fee_msat: 0,
1513                                 cltv_expiry_delta: 0,
1514                         }]],
1515                         payment_params: Some(payment_params),
1516                 };
1517                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1518                 let mut route_params_w_failed_scid = route_params.clone();
1519                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1520                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1521                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1522                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1523
1524                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1525                 // PaymentPathFailed event.
1526                 let pending_events = Mutex::new(Vec::new());
1527                 outbound_payments.send_payment(
1528                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1529                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1530                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1531                         |_, _, _, _, _, _, _, _| Err(APIError::ChannelUnavailable { err: "test".to_owned() }))
1532                         .unwrap();
1533                 let mut events = pending_events.lock().unwrap();
1534                 assert_eq!(events.len(), 2);
1535                 if let Event::PaymentPathFailed {
1536                         short_channel_id,
1537                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0]
1538                 {
1539                         assert_eq!(short_channel_id, Some(failed_scid));
1540                 } else { panic!("Unexpected event"); }
1541                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1542                 events.clear();
1543                 core::mem::drop(events);
1544
1545                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1546                 outbound_payments.send_payment(
1547                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1548                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1549                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1550                         |_, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress)).unwrap();
1551                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1552
1553                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1554                 outbound_payments.send_payment(
1555                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1556                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1557                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1558                         |_, _, _, _, _, _, _, _| Err(APIError::APIMisuseError { err: "test".to_owned() }))
1559                         .unwrap();
1560                 let events = pending_events.lock().unwrap();
1561                 assert_eq!(events.len(), 2);
1562                 if let Event::PaymentPathFailed {
1563                         short_channel_id,
1564                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0]
1565                 {
1566                         assert_eq!(short_channel_id, None);
1567                 } else { panic!("Unexpected event"); }
1568                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1569         }
1570 }