_ 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::sign::{EntropySource, NodeSigner, Recipient};
  17 use crate::events::{self, PaymentFailureReason};
  18 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  19 use crate::ln::channelmanager::{ChannelDetails, EventCompletionAction, HTLCSource, PaymentId};
  20 use crate::ln::onion_utils::{DecodedOnionFailure, HTLCFailReason};
  21 use crate::offers::invoice::Bolt12Invoice;
  22 use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteParameters, Router};
  23 use crate::util::errors::APIError;
  24 use crate::util::logger::Logger;
  25 use crate::util::time::Time;
  26 #[cfg(all(not(feature = "no-std"), test))]
  27 use crate::util::time::tests::SinceEpoch;
  28 use crate::util::ser::ReadableArgs;
  29
  30 use core::fmt::{self, Display, Formatter};
  31 use core::ops::Deref;
  32
  33 use crate::prelude::*;
  34 use crate::sync::Mutex;
  35
  36 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until we time-out the idempotency
  37 /// of payments by [`PaymentId`]. See [`OutboundPayments::remove_stale_payments`].
  38 ///
  39 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  40 pub(crate) const IDEMPOTENCY_TIMEOUT_TICKS: u8 = 7;
  41
  42 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until an invoice request without
  43 /// a response is timed out.
  44 ///
  45 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  46 const INVOICE_REQUEST_TIMEOUT_TICKS: u8 = 3;
  47
  48 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  49 /// and later, also stores information for retrying the payment.
  50 pub(crate) enum PendingOutboundPayment {
  51         Legacy {
  52                 session_privs: HashSet<[u8; 32]>,
  53         },
  54         AwaitingInvoice {
  55                 timer_ticks_without_response: u8,
  56         },
  57         InvoiceReceived {
  58                 payment_hash: PaymentHash,
  59         },
  60         Retryable {
  61                 retry_strategy: Option<Retry>,
  62                 attempts: PaymentAttempts,
  63                 payment_params: Option<PaymentParameters>,
  64                 session_privs: HashSet<[u8; 32]>,
  65                 payment_hash: PaymentHash,
  66                 payment_secret: Option<PaymentSecret>,
  67                 payment_metadata: Option<Vec<u8>>,
  68                 keysend_preimage: Option<PaymentPreimage>,
  69                 custom_tlvs: Vec<(u64, Vec<u8>)>,
  70                 pending_amt_msat: u64,
  71                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  72                 pending_fee_msat: Option<u64>,
  73                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  74                 total_msat: u64,
  75                 /// Our best known block height at the time this payment was initiated.
  76                 starting_block_height: u32,
  77         },
  78         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  79         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  80         /// and add a pending payment that was already fulfilled.
  81         Fulfilled {
  82                 session_privs: HashSet<[u8; 32]>,
  83                 /// Filled in for any payment which moved to `Fulfilled` on LDK 0.0.104 or later.
  84                 payment_hash: Option<PaymentHash>,
  85                 timer_ticks_without_htlcs: u8,
  86         },
  87         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  88         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  89         Abandoned {
  90                 session_privs: HashSet<[u8; 32]>,
  91                 payment_hash: PaymentHash,
  92                 /// Will be `None` if the payment was serialized before 0.0.115.
  93                 reason: Option<PaymentFailureReason>,
  94         },
  95 }
  96
  97 impl PendingOutboundPayment {
  98         fn increment_attempts(&mut self) {
  99                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
 100                         attempts.count += 1;
 101                 }
 102         }
 103         fn is_auto_retryable_now(&self) -> bool {
 104                 match self {
 105                         PendingOutboundPayment::Retryable {
 106                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
 107                         } => {
 108                                 strategy.is_retryable_now(&attempts)
 109                         },
 110                         _ => false,
 111                 }
 112         }
 113         fn is_retryable_now(&self) -> bool {
 114                 match self {
 115                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
 116                                 // We're handling retries manually, we can always retry.
 117                                 true
 118                         },
 119                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
 120                                 strategy.is_retryable_now(&attempts)
 121                         },
 122                         _ => false,
 123                 }
 124         }
 125         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 126                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 127                         params.previously_failed_channels.push(scid);
 128                 }
 129         }
 130         fn is_awaiting_invoice(&self) -> bool {
 131                 match self {
 132                         PendingOutboundPayment::AwaitingInvoice { .. } => true,
 133                         _ => false,
 134                 }
 135         }
 136         pub(super) fn is_fulfilled(&self) -> bool {
 137                 match self {
 138                         PendingOutboundPayment::Fulfilled { .. } => true,
 139                         _ => false,
 140                 }
 141         }
 142         pub(super) fn abandoned(&self) -> bool {
 143                 match self {
 144                         PendingOutboundPayment::Abandoned { .. } => true,
 145                         _ => false,
 146                 }
 147         }
 148         fn get_pending_fee_msat(&self) -> Option<u64> {
 149                 match self {
 150                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 151                         _ => None,
 152                 }
 153         }
 154
 155         fn payment_hash(&self) -> Option<PaymentHash> {
 156                 match self {
 157                         PendingOutboundPayment::Legacy { .. } => None,
 158                         PendingOutboundPayment::AwaitingInvoice { .. } => None,
 159                         PendingOutboundPayment::InvoiceReceived { payment_hash } => Some(*payment_hash),
 160                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 161                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 162                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 163                 }
 164         }
 165
 166         fn mark_fulfilled(&mut self) {
 167                 let mut session_privs = HashSet::new();
 168                 core::mem::swap(&mut session_privs, match self {
 169                         PendingOutboundPayment::Legacy { session_privs } |
 170                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 171                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 172                                 PendingOutboundPayment::Abandoned { session_privs, .. } => session_privs,
 173                         PendingOutboundPayment::AwaitingInvoice { .. } |
 174                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); return; },
 175                 });
 176                 let payment_hash = self.payment_hash();
 177                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 178         }
 179
 180         fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
 181                 if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
 182                         let mut our_session_privs = HashSet::new();
 183                         core::mem::swap(&mut our_session_privs, session_privs);
 184                         *self = PendingOutboundPayment::Abandoned {
 185                                 session_privs: our_session_privs,
 186                                 payment_hash: *payment_hash,
 187                                 reason: Some(reason)
 188                         };
 189                 } else if let PendingOutboundPayment::InvoiceReceived { payment_hash } = self {
 190                         *self = PendingOutboundPayment::Abandoned {
 191                                 session_privs: HashSet::new(),
 192                                 payment_hash: *payment_hash,
 193                                 reason: Some(reason)
 194                         };
 195                 }
 196         }
 197
 198         /// panics if path is None and !self.is_fulfilled
 199         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Path>) -> bool {
 200                 let remove_res = match self {
 201                         PendingOutboundPayment::Legacy { session_privs } |
 202                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 203                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 204                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 205                                         session_privs.remove(session_priv)
 206                                 },
 207                         PendingOutboundPayment::AwaitingInvoice { .. } |
 208                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); false },
 209                 };
 210                 if remove_res {
 211                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 212                                 let path = path.expect("Fulfilling a payment should always come with a path");
 213                                 *pending_amt_msat -= path.final_value_msat();
 214                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 215                                         *fee_msat -= path.fee_msat();
 216                                 }
 217                         }
 218                 }
 219                 remove_res
 220         }
 221
 222         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Path) -> bool {
 223                 let insert_res = match self {
 224                         PendingOutboundPayment::Legacy { session_privs } |
 225                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 226                                         session_privs.insert(session_priv)
 227                                 },
 228                         PendingOutboundPayment::AwaitingInvoice { .. } |
 229                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); false },
 230                         PendingOutboundPayment::Fulfilled { .. } => false,
 231                         PendingOutboundPayment::Abandoned { .. } => false,
 232                 };
 233                 if insert_res {
 234                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 235                                 *pending_amt_msat += path.final_value_msat();
 236                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 237                                         *fee_msat += path.fee_msat();
 238                                 }
 239                         }
 240                 }
 241                 insert_res
 242         }
 243
 244         pub(super) fn remaining_parts(&self) -> usize {
 245                 match self {
 246                         PendingOutboundPayment::Legacy { session_privs } |
 247                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 248                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 249                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 250                                         session_privs.len()
 251                                 },
 252                         PendingOutboundPayment::AwaitingInvoice { .. } => 0,
 253                         PendingOutboundPayment::InvoiceReceived { .. } => 0,
 254                 }
 255         }
 256 }
 257
 258 /// Strategies available to retry payment path failures.
 259 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 260 pub enum Retry {
 261         /// Max number of attempts to retry payment.
 262         ///
 263         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 264         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 265         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 266         Attempts(usize),
 267         #[cfg(not(feature = "no-std"))]
 268         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 269         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 270         ///
 271         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 272         Timeout(core::time::Duration),
 273 }
 274
 275 impl Retry {
 276         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 277                 match (self, attempts) {
 278                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 279                                 max_retry_count > count
 280                         },
 281                         #[cfg(all(not(feature = "no-std"), not(test)))]
 282                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 283                                 *max_duration >= crate::util::time::MonotonicTime::now().duration_since(*first_attempted_at),
 284                         #[cfg(all(not(feature = "no-std"), test))]
 285                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 286                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 287                 }
 288         }
 289 }
 290
 291 #[cfg(feature = "std")]
 292 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 293         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 294                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 295                         return elapsed > core::time::Duration::from_secs(expiry_time)
 296                 }
 297         }
 298         false
 299 }
 300
 301 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 302
 303 /// Storing minimal payment attempts information required for determining if a outbound payment can
 304 /// be retried.
 305 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 306         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 307         /// it means the result of the first attempt is not known yet.
 308         pub(crate) count: usize,
 309         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 310         #[cfg(not(feature = "no-std"))]
 311         first_attempted_at: T,
 312         #[cfg(feature = "no-std")]
 313         phantom: core::marker::PhantomData<T>,
 314
 315 }
 316
 317 #[cfg(not(any(feature = "no-std", test)))]
 318 type ConfiguredTime = crate::util::time::MonotonicTime;
 319 #[cfg(feature = "no-std")]
 320 type ConfiguredTime = crate::util::time::Eternity;
 321 #[cfg(all(not(feature = "no-std"), test))]
 322 type ConfiguredTime = SinceEpoch;
 323
 324 impl<T: Time> PaymentAttemptsUsingTime<T> {
 325         pub(crate) fn new() -> Self {
 326                 PaymentAttemptsUsingTime {
 327                         count: 0,
 328                         #[cfg(not(feature = "no-std"))]
 329                         first_attempted_at: T::now(),
 330                         #[cfg(feature = "no-std")]
 331                         phantom: core::marker::PhantomData,
 332                 }
 333         }
 334 }
 335
 336 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 337         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 338                 #[cfg(feature = "no-std")]
 339                 return write!(f, "attempts: {}", self.count);
 340                 #[cfg(not(feature = "no-std"))]
 341                 return write!(
 342                         f,
 343                         "attempts: {}, duration: {}s",
 344                         self.count,
 345                         T::now().duration_since(self.first_attempted_at).as_secs()
 346                 );
 347         }
 348 }
 349
 350 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 351 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 352 ///
 353 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 354 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 355 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 356 #[derive(Clone, Debug, PartialEq, Eq)]
 357 pub enum RetryableSendFailure {
 358         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 359         /// that this error is *not* caused by [`Retry::Timeout`].
 360         ///
 361         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 362         PaymentExpired,
 363         /// We were unable to find a route to the destination.
 364         RouteNotFound,
 365         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 366         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 367         ///
 368         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 369         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 370         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 371         DuplicatePayment,
 372 }
 373
 374 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 375 /// of several states. This enum is returned as the Err() type describing which state the payment
 376 /// is in, see the description of individual enum states for more.
 377 ///
 378 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 379 #[derive(Clone, Debug)]
 380 pub enum PaymentSendFailure {
 381         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 382         /// send the payment at all.
 383         ///
 384         /// You can freely resend the payment in full (with the parameter error fixed).
 385         ///
 386         /// Because the payment failed outright, no payment tracking is done and no
 387         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 388         ///
 389         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 390         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 391         ParameterError(APIError),
 392         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 393         /// from attempting to send the payment at all.
 394         ///
 395         /// You can freely resend the payment in full (with the parameter error fixed).
 396         ///
 397         /// Because the payment failed outright, no payment tracking is done and no
 398         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 399         ///
 400         /// The results here are ordered the same as the paths in the route object which was passed to
 401         /// send_payment.
 402         ///
 403         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 404         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 405         PathParameterError(Vec<Result<(), APIError>>),
 406         /// All paths which were attempted failed to send, with no channel state change taking place.
 407         /// You can freely resend the payment in full (though you probably want to do so over different
 408         /// paths than the ones selected).
 409         ///
 410         /// Because the payment failed outright, no payment tracking is done and no
 411         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 412         ///
 413         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 414         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 415         AllFailedResendSafe(Vec<APIError>),
 416         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 417         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 418         ///
 419         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 420         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 421         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 422         DuplicatePayment,
 423         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 424         /// some paths have irrevocably committed to the HTLC.
 425         ///
 426         /// The results here are ordered the same as the paths in the route object that was passed to
 427         /// send_payment.
 428         ///
 429         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 430         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 431         ///
 432         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 433         PartialFailure {
 434                 /// The errors themselves, in the same order as the paths from the route.
 435                 results: Vec<Result<(), APIError>>,
 436                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 437                 /// contain a [`RouteParameters`] object for the failing paths.
 438                 failed_paths_retry: Option<RouteParameters>,
 439                 /// The payment id for the payment, which is now at least partially pending.
 440                 payment_id: PaymentId,
 441         },
 442 }
 443
 444 /// An error when attempting to pay a BOLT 12 invoice.
 445 pub(super) enum Bolt12PaymentError {
 446         /// The invoice was not requested.
 447         UnexpectedInvoice,
 448         /// Payment for an invoice with the corresponding [`PaymentId`] was already initiated.
 449         DuplicateInvoice,
 450 }
 451
 452 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 453 ///
 454 /// This should generally be constructed with data communicated to us from the recipient (via a
 455 /// BOLT11 or BOLT12 invoice).
 456 #[derive(Clone, Debug, PartialEq, Eq)]
 457 pub struct RecipientOnionFields {
 458         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 459         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 460         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 461         /// attacks.
 462         ///
 463         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 464         /// multi-path payments require a recipient-provided secret.
 465         ///
 466         /// Some implementations may reject spontaneous payments with payment secrets, so you may only
 467         /// want to provide a secret for a spontaneous payment if MPP is needed and you know your
 468         /// recipient will not reject it.
 469         pub payment_secret: Option<PaymentSecret>,
 470         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 471         /// arbitrary length. This gives recipients substantially more flexibility to receive
 472         /// additional data.
 473         ///
 474         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 475         /// scheme to authenticate received payments against expected payments and invoices, this field
 476         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 477         /// invoices which will be received with the payment.
 478         ///
 479         /// Note that this field was added to the lightning specification more recently than
 480         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 481         /// may not be supported as universally.
 482         pub payment_metadata: Option<Vec<u8>>,
 483         /// See [`Self::custom_tlvs`] for more info.
 484         pub(super) custom_tlvs: Vec<(u64, Vec<u8>)>,
 485 }
 486
 487 impl_writeable_tlv_based!(RecipientOnionFields, {
 488         (0, payment_secret, option),
 489         (1, custom_tlvs, optional_vec),
 490         (2, payment_metadata, option),
 491 });
 492
 493 impl RecipientOnionFields {
 494         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 495         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 496         /// but do not require or provide any further data.
 497         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 498                 Self { payment_secret: Some(payment_secret), payment_metadata: None, custom_tlvs: Vec::new() }
 499         }
 500
 501         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 502         /// payable HTLCs except for single-path spontaneous payments, i.e. this should generally
 503         /// only be used for calls to [`ChannelManager::send_spontaneous_payment`]. If you are sending
 504         /// a spontaneous MPP this will not work as all MPP require payment secrets; you may
 505         /// instead want to use [`RecipientOnionFields::secret_only`].
 506         ///
 507         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 508         /// [`RecipientOnionFields::secret_only`]: RecipientOnionFields::secret_only
 509         pub fn spontaneous_empty() -> Self {
 510                 Self { payment_secret: None, payment_metadata: None, custom_tlvs: Vec::new() }
 511         }
 512
 513         /// Creates a new [`RecipientOnionFields`] from an existing one, adding custom TLVs. Each
 514         /// TLV is provided as a `(u64, Vec<u8>)` for the type number and serialized value
 515         /// respectively. TLV type numbers must be unique and within the range
 516         /// reserved for custom types, i.e. >= 2^16, otherwise this method will return `Err(())`.
 517         ///
 518         /// This method will also error for types in the experimental range which have been
 519         /// standardized within the protocol, which only includes 5482373484 (keysend) for now.
 520         ///
 521         /// See [`Self::custom_tlvs`] for more info.
 522         pub fn with_custom_tlvs(mut self, mut custom_tlvs: Vec<(u64, Vec<u8>)>) -> Result<Self, ()> {
 523                 custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
 524                 let mut prev_type = None;
 525                 for (typ, _) in custom_tlvs.iter() {
 526                         if *typ < 1 << 16 { return Err(()); }
 527                         if *typ == 5482373484 { return Err(()); } // keysend
 528                         match prev_type {
 529                                 Some(prev) if prev >= *typ => return Err(()),
 530                                 _ => {},
 531                         }
 532                         prev_type = Some(*typ);
 533                 }
 534                 self.custom_tlvs = custom_tlvs;
 535                 Ok(self)
 536         }
 537
 538         /// Gets the custom TLVs that will be sent or have been received.
 539         ///
 540         /// Custom TLVs allow sending extra application-specific data with a payment. They provide
 541         /// additional flexibility on top of payment metadata, as while other implementations may
 542         /// require `payment_metadata` to reflect metadata provided in an invoice, custom TLVs
 543         /// do not have this restriction.
 544         ///
 545         /// Note that if this field is non-empty, it will contain strictly increasing TLVs, each
 546         /// represented by a `(u64, Vec<u8>)` for its type number and serialized value respectively.
 547         /// This is validated when setting this field using [`Self::with_custom_tlvs`].
 548         pub fn custom_tlvs(&self) -> &Vec<(u64, Vec<u8>)> {
 549                 &self.custom_tlvs
 550         }
 551
 552         /// When we have received some HTLC(s) towards an MPP payment, as we receive further HTLC(s) we
 553         /// have to make sure that some fields match exactly across the parts. For those that aren't
 554         /// required to match, if they don't match we should remove them so as to not expose data
 555         /// that's dependent on the HTLC receive order to users.
 556         ///
 557         /// Here we implement this, first checking compatibility then mutating two objects and then
 558         /// dropping any remaining non-matching fields from both.
 559         pub(super) fn check_merge(&mut self, further_htlc_fields: &mut Self) -> Result<(), ()> {
 560                 if self.payment_secret != further_htlc_fields.payment_secret { return Err(()); }
 561                 if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 562
 563                 let tlvs = &mut self.custom_tlvs;
 564                 let further_tlvs = &mut further_htlc_fields.custom_tlvs;
 565
 566                 let even_tlvs = tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 567                 let further_even_tlvs = further_tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 568                 if even_tlvs.ne(further_even_tlvs) { return Err(()) }
 569
 570                 tlvs.retain(|tlv| further_tlvs.iter().any(|further_tlv| tlv == further_tlv));
 571                 further_tlvs.retain(|further_tlv| tlvs.iter().any(|tlv| tlv == further_tlv));
 572
 573                 Ok(())
 574         }
 575 }
 576
 577 /// Arguments for [`super::channelmanager::ChannelManager::send_payment_along_path`].
 578 pub(super) struct SendAlongPathArgs<'a> {
 579         pub path: &'a Path,
 580         pub payment_hash: &'a PaymentHash,
 581         pub recipient_onion: RecipientOnionFields,
 582         pub total_value: u64,
 583         pub cur_height: u32,
 584         pub payment_id: PaymentId,
 585         pub keysend_preimage: &'a Option<PaymentPreimage>,
 586         pub session_priv_bytes: [u8; 32],
 587 }
 588
 589 const BOLT_12_INVOICE_RETRY_STRATEGY: Retry = Retry::Attempts(3);
 590
 591 pub(super) struct OutboundPayments {
 592         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 593         pub(super) retry_lock: Mutex<()>,
 594 }
 595
 596 impl OutboundPayments {
 597         pub(super) fn new() -> Self {
 598                 Self {
 599                         pending_outbound_payments: Mutex::new(HashMap::new()),
 600                         retry_lock: Mutex::new(()),
 601                 }
 602         }
 603
 604         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 605                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 606                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 607                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 608                 node_signer: &NS, best_block_height: u32, logger: &L,
 609                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 610         ) -> Result<(), RetryableSendFailure>
 611         where
 612                 R::Target: Router,
 613                 ES::Target: EntropySource,
 614                 NS::Target: NodeSigner,
 615                 L::Target: Logger,
 616                 IH: Fn() -> InFlightHtlcs,
 617                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 618         {
 619                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 620                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 621                         best_block_height, logger, pending_events, &send_payment_along_path)
 622         }
 623
 624         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 625                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 626                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 627                 send_payment_along_path: F
 628         ) -> Result<(), PaymentSendFailure>
 629         where
 630                 ES::Target: EntropySource,
 631                 NS::Target: NodeSigner,
 632                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>
 633         {
 634                 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)?;
 635                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 636                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 637                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 638         }
 639
 640         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 641                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 642                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 643                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 644                 node_signer: &NS, best_block_height: u32, logger: &L,
 645                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP
 646         ) -> Result<PaymentHash, RetryableSendFailure>
 647         where
 648                 R::Target: Router,
 649                 ES::Target: EntropySource,
 650                 NS::Target: NodeSigner,
 651                 L::Target: Logger,
 652                 IH: Fn() -> InFlightHtlcs,
 653                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 654         {
 655                 let preimage = payment_preimage
 656                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 657                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 658                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 659                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 660                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 661                         .map(|()| payment_hash)
 662         }
 663
 664         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 665                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 666                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 667                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 668         ) -> Result<PaymentHash, PaymentSendFailure>
 669         where
 670                 ES::Target: EntropySource,
 671                 NS::Target: NodeSigner,
 672                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 673         {
 674                 let preimage = payment_preimage
 675                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 676                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 677                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 678                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 679
 680                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 681                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 682                 ) {
 683                         Ok(()) => Ok(payment_hash),
 684                         Err(e) => {
 685                                 self.remove_outbound_if_all_failed(payment_id, &e);
 686                                 Err(e)
 687                         }
 688                 }
 689         }
 690
 691         #[allow(unused)]
 692         pub(super) fn send_payment_for_bolt12_invoice<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 693                 &self, invoice: &Bolt12Invoice, payment_id: PaymentId, router: &R,
 694                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 695                 best_block_height: u32, logger: &L,
 696                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
 697                 send_payment_along_path: SP,
 698         ) -> Result<(), Bolt12PaymentError>
 699         where
 700                 R::Target: Router,
 701                 ES::Target: EntropySource,
 702                 NS::Target: NodeSigner,
 703                 L::Target: Logger,
 704                 IH: Fn() -> InFlightHtlcs,
 705                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 706         {
 707                 let payment_hash = invoice.payment_hash();
 708                 match self.pending_outbound_payments.lock().unwrap().entry(payment_id) {
 709                         hash_map::Entry::Occupied(entry) if entry.get().is_awaiting_invoice() => {
 710                                 *entry.into_mut() = PendingOutboundPayment::InvoiceReceived { payment_hash };
 711                         },
 712                         hash_map::Entry::Occupied(_) => return Err(Bolt12PaymentError::DuplicateInvoice),
 713                         hash_map::Entry::Vacant(_) => return Err(Bolt12PaymentError::UnexpectedInvoice),
 714                 };
 715
 716                 let route_params = RouteParameters {
 717                         payment_params: PaymentParameters::from_bolt12_invoice(&invoice),
 718                         final_value_msat: invoice.amount_msats(),
 719                 };
 720
 721                 self.find_route_and_send_payment(
 722                         payment_hash, payment_id, route_params, router, first_hops, &inflight_htlcs,
 723                         entropy_source, node_signer, best_block_height, logger, pending_events,
 724                         &send_payment_along_path
 725                 );
 726
 727                 Ok(())
 728         }
 729
 730         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 731                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 732                 best_block_height: u32,
 733                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
 734                 send_payment_along_path: SP,
 735         )
 736         where
 737                 R::Target: Router,
 738                 ES::Target: EntropySource,
 739                 NS::Target: NodeSigner,
 740                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 741                 IH: Fn() -> InFlightHtlcs,
 742                 FH: Fn() -> Vec<ChannelDetails>,
 743                 L::Target: Logger,
 744         {
 745                 let _single_thread = self.retry_lock.lock().unwrap();
 746                 loop {
 747                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 748                         let mut retry_id_route_params = None;
 749                         for (pmt_id, pmt) in outbounds.iter_mut() {
 750                                 if pmt.is_auto_retryable_now() {
 751                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 752                                                 if pending_amt_msat < total_msat {
 753                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 754                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 755                                                                 payment_params: params.clone(),
 756                                                         }));
 757                                                         break
 758                                                 }
 759                                         } else { debug_assert!(false); }
 760                                 }
 761                         }
 762                         core::mem::drop(outbounds);
 763                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 764                                 self.find_route_and_send_payment(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)
 765                         } else { break }
 766                 }
 767
 768                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 769                 outbounds.retain(|pmt_id, pmt| {
 770                         let mut retain = true;
 771                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_awaiting_invoice() {
 772                                 pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
 773                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
 774                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 775                                                 payment_id: *pmt_id,
 776                                                 payment_hash: *payment_hash,
 777                                                 reason: *reason,
 778                                         }, None));
 779                                         retain = false;
 780                                 }
 781                         }
 782                         retain
 783                 });
 784         }
 785
 786         pub(super) fn needs_abandon(&self) -> bool {
 787                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 788                 outbounds.iter().any(|(_, pmt)|
 789                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled() &&
 790                         !pmt.is_awaiting_invoice())
 791         }
 792
 793         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 794         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 795         ///
 796         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 797         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 798         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 799                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 800                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 801                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 802                 node_signer: &NS, best_block_height: u32, logger: &L,
 803                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 804         ) -> Result<(), RetryableSendFailure>
 805         where
 806                 R::Target: Router,
 807                 ES::Target: EntropySource,
 808                 NS::Target: NodeSigner,
 809                 L::Target: Logger,
 810                 IH: Fn() -> InFlightHtlcs,
 811                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 812         {
 813                 #[cfg(feature = "std")] {
 814                         if has_expired(&route_params) {
 815                                 log_error!(logger, "Payment with id {} and hash {} had expired before we started paying",
 816                                         payment_id, payment_hash);
 817                                 return Err(RetryableSendFailure::PaymentExpired)
 818                         }
 819                 }
 820
 821                 let route = router.find_route_with_id(
 822                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 823                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 824                         payment_hash, payment_id,
 825                 ).map_err(|_| {
 826                         log_error!(logger, "Failed to find route for payment with id {} and hash {}",
 827                                 payment_id, payment_hash);
 828                         RetryableSendFailure::RouteNotFound
 829                 })?;
 830
 831                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 832                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 833                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 834                         .map_err(|_| {
 835                                 log_error!(logger, "Payment with id {} is already pending. New payment had payment hash {}",
 836                                         payment_id, payment_hash);
 837                                 RetryableSendFailure::DuplicatePayment
 838                         })?;
 839
 840                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage, payment_id, None,
 841                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 842                 log_info!(logger, "Sending payment with id {} and hash {} returned {:?}",
 843                         payment_id, payment_hash, res);
 844                 if let Err(e) = res {
 845                         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);
 846                 }
 847                 Ok(())
 848         }
 849
 850         fn find_route_and_send_payment<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 851                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 852                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 853                 node_signer: &NS, best_block_height: u32, logger: &L,
 854                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 855         )
 856         where
 857                 R::Target: Router,
 858                 ES::Target: EntropySource,
 859                 NS::Target: NodeSigner,
 860                 L::Target: Logger,
 861                 IH: Fn() -> InFlightHtlcs,
 862                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 863         {
 864                 #[cfg(feature = "std")] {
 865                         if has_expired(&route_params) {
 866                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", &payment_id);
 867                                 self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
 868                                 return
 869                         }
 870                 }
 871
 872                 let route = match router.find_route_with_id(
 873                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 874                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 875                         payment_hash, payment_id,
 876                 ) {
 877                         Ok(route) => route,
 878                         Err(e) => {
 879                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", &payment_id, e);
 880                                 self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
 881                                 return
 882                         }
 883                 };
 884                 for path in route.paths.iter() {
 885                         if path.hops.len() == 0 {
 886                                 log_error!(logger, "Unusable path in route (path.hops.len() must be at least 1");
 887                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 888                                 return
 889                         }
 890                 }
 891
 892                 macro_rules! abandon_with_entry {
 893                         ($payment: expr, $reason: expr) => {
 894                                 $payment.get_mut().mark_abandoned($reason);
 895                                 if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
 896                                         if $payment.get().remaining_parts() == 0 {
 897                                                 pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 898                                                         payment_id,
 899                                                         payment_hash,
 900                                                         reason: *reason,
 901                                                 }, None));
 902                                                 $payment.remove();
 903                                         }
 904                                 }
 905                         }
 906                 }
 907                 let (total_msat, recipient_onion, keysend_preimage, onion_session_privs) = {
 908                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 909                         match outbounds.entry(payment_id) {
 910                                 hash_map::Entry::Occupied(mut payment) => {
 911                                         match payment.get() {
 912                                                 PendingOutboundPayment::Retryable {
 913                                                         total_msat, keysend_preimage, payment_secret, payment_metadata,
 914                                                         custom_tlvs, pending_amt_msat, ..
 915                                                 } => {
 916                                                         const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 917                                                         let retry_amt_msat = route.get_total_amount();
 918                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 919                                                                 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);
 920                                                                 abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
 921                                                                 return
 922                                                         }
 923
 924                                                         if !payment.get().is_retryable_now() {
 925                                                                 log_error!(logger, "Retries exhausted for payment id {}", &payment_id);
 926                                                                 abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
 927                                                                 return
 928                                                         }
 929
 930                                                         let total_msat = *total_msat;
 931                                                         let recipient_onion = RecipientOnionFields {
 932                                                                 payment_secret: *payment_secret,
 933                                                                 payment_metadata: payment_metadata.clone(),
 934                                                                 custom_tlvs: custom_tlvs.clone(),
 935                                                         };
 936                                                         let keysend_preimage = *keysend_preimage;
 937
 938                                                         let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 939                                                         for _ in 0..route.paths.len() {
 940                                                                 onion_session_privs.push(entropy_source.get_secure_random_bytes());
 941                                                         }
 942
 943                                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 944                                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 945                                                         }
 946
 947                                                         payment.get_mut().increment_attempts();
 948
 949                                                         (total_msat, recipient_onion, keysend_preimage, onion_session_privs)
 950                                                 },
 951                                                 PendingOutboundPayment::Legacy { .. } => {
 952                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 953                                                         return
 954                                                 },
 955                                                 PendingOutboundPayment::AwaitingInvoice { .. } => {
 956                                                         log_error!(logger, "Payment not yet sent");
 957                                                         return
 958                                                 },
 959                                                 PendingOutboundPayment::InvoiceReceived { payment_hash } => {
 960                                                         let total_amount = route_params.final_value_msat;
 961                                                         let recipient_onion = RecipientOnionFields {
 962                                                                 payment_secret: None,
 963                                                                 payment_metadata: None,
 964                                                                 custom_tlvs: vec![],
 965                                                         };
 966                                                         let retry_strategy = Some(BOLT_12_INVOICE_RETRY_STRATEGY);
 967                                                         let payment_params = Some(route_params.payment_params.clone());
 968                                                         let (retryable_payment, onion_session_privs) = self.create_pending_payment(
 969                                                                 *payment_hash, recipient_onion.clone(), None, &route,
 970                                                                 retry_strategy, payment_params, entropy_source, best_block_height
 971                                                         );
 972                                                         *payment.into_mut() = retryable_payment;
 973                                                         (total_amount, recipient_onion, None, onion_session_privs)
 974                                                 },
 975                                                 PendingOutboundPayment::Fulfilled { .. } => {
 976                                                         log_error!(logger, "Payment already completed");
 977                                                         return
 978                                                 },
 979                                                 PendingOutboundPayment::Abandoned { .. } => {
 980                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 981                                                         return
 982                                                 },
 983                                         }
 984                                 },
 985                                 hash_map::Entry::Vacant(_) => {
 986                                         log_error!(logger, "Payment with ID {} not found", &payment_id);
 987                                         return
 988                                 }
 989                         }
 990                 };
 991                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
 992                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 993                         &send_payment_along_path);
 994                 log_info!(logger, "Result retrying payment id {}: {:?}", &payment_id, res);
 995                 if let Err(e) = res {
 996                         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);
 997                 }
 998         }
 999
1000         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
1001                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
1002                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
1003                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
1004                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
1005         )
1006         where
1007                 R::Target: Router,
1008                 ES::Target: EntropySource,
1009                 NS::Target: NodeSigner,
1010                 L::Target: Logger,
1011                 IH: Fn() -> InFlightHtlcs,
1012                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1013         {
1014                 match err {
1015                         PaymentSendFailure::AllFailedResendSafe(errs) => {
1016                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, errs.into_iter().map(|e| Err(e)), logger, pending_events);
1017                                 self.find_route_and_send_payment(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);
1018                         },
1019                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
1020                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
1021                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
1022                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
1023                                 // return `Ok()` here, ignoring any retry errors.
1024                                 self.find_route_and_send_payment(payment_hash, payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
1025                         },
1026                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
1027                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
1028                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
1029                                 // initial HTLC-Add messages yet.
1030                         },
1031                         PaymentSendFailure::PathParameterError(results) => {
1032                                 log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
1033                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
1034                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
1035                         },
1036                         PaymentSendFailure::ParameterError(e) => {
1037                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
1038                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
1039                         },
1040                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
1041                 }
1042         }
1043
1044         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
1045                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
1046                 paths: Vec<Path>, path_results: I, logger: &L,
1047                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1048         ) where L::Target: Logger {
1049                 let mut events = pending_events.lock().unwrap();
1050                 debug_assert_eq!(paths.len(), path_results.len());
1051                 for (path, path_res) in paths.into_iter().zip(path_results) {
1052                         if let Err(e) = path_res {
1053                                 if let APIError::MonitorUpdateInProgress = e { continue }
1054                                 log_error!(logger, "Failed to send along path due to error: {:?}", e);
1055                                 let mut failed_scid = None;
1056                                 if let APIError::ChannelUnavailable { .. } = e {
1057                                         let scid = path.hops[0].short_channel_id;
1058                                         failed_scid = Some(scid);
1059                                         route_params.payment_params.previously_failed_channels.push(scid);
1060                                 }
1061                                 events.push_back((events::Event::PaymentPathFailed {
1062                                         payment_id: Some(payment_id),
1063                                         payment_hash,
1064                                         payment_failed_permanently: false,
1065                                         failure: events::PathFailure::InitialSend { err: e },
1066                                         path,
1067                                         short_channel_id: failed_scid,
1068                                         #[cfg(test)]
1069                                         error_code: None,
1070                                         #[cfg(test)]
1071                                         error_data: None,
1072                                 }, None));
1073                         }
1074                 }
1075         }
1076
1077         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
1078                 &self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
1079                 best_block_height: u32, send_payment_along_path: F
1080         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
1081         where
1082                 ES::Target: EntropySource,
1083                 NS::Target: NodeSigner,
1084                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1085         {
1086                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
1087
1088                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
1089
1090                 if path.hops.len() < 2 && path.blinded_tail.is_none() {
1091                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
1092                                 err: "No need probing a path with less than two hops".to_string()
1093                         }))
1094                 }
1095
1096                 let route = Route { paths: vec![path], route_params: None };
1097                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
1098                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
1099                         entropy_source, best_block_height)?;
1100
1101                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
1102                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
1103                 ) {
1104                         Ok(()) => Ok((payment_hash, payment_id)),
1105                         Err(e) => {
1106                                 self.remove_outbound_if_all_failed(payment_id, &e);
1107                                 Err(e)
1108                         }
1109                 }
1110         }
1111
1112         #[cfg(test)]
1113         pub(super) fn test_set_payment_metadata(
1114                 &self, payment_id: PaymentId, new_payment_metadata: Option<Vec<u8>>
1115         ) {
1116                 match self.pending_outbound_payments.lock().unwrap().get_mut(&payment_id).unwrap() {
1117                         PendingOutboundPayment::Retryable { payment_metadata, .. } => {
1118                                 *payment_metadata = new_payment_metadata;
1119                         },
1120                         _ => panic!("Need a retryable payment to update metadata on"),
1121                 }
1122         }
1123
1124         #[cfg(test)]
1125         pub(super) fn test_add_new_pending_payment<ES: Deref>(
1126                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1127                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
1128         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1129                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
1130         }
1131
1132         pub(super) fn add_new_pending_payment<ES: Deref>(
1133                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1134                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
1135                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
1136         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1137                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1138                 match pending_outbounds.entry(payment_id) {
1139                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
1140                         hash_map::Entry::Vacant(entry) => {
1141                                 let (payment, onion_session_privs) = self.create_pending_payment(
1142                                         payment_hash, recipient_onion, keysend_preimage, route, retry_strategy,
1143                                         payment_params, entropy_source, best_block_height
1144                                 );
1145                                 entry.insert(payment);
1146                                 Ok(onion_session_privs)
1147                         },
1148                 }
1149         }
1150
1151         fn create_pending_payment<ES: Deref>(
1152                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1153                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
1154                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
1155         ) -> (PendingOutboundPayment, Vec<[u8; 32]>)
1156         where
1157                 ES::Target: EntropySource,
1158         {
1159                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
1160                 for _ in 0..route.paths.len() {
1161                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
1162                 }
1163
1164                 let mut payment = PendingOutboundPayment::Retryable {
1165                         retry_strategy,
1166                         attempts: PaymentAttempts::new(),
1167                         payment_params,
1168                         session_privs: HashSet::new(),
1169                         pending_amt_msat: 0,
1170                         pending_fee_msat: Some(0),
1171                         payment_hash,
1172                         payment_secret: recipient_onion.payment_secret,
1173                         payment_metadata: recipient_onion.payment_metadata,
1174                         keysend_preimage,
1175                         custom_tlvs: recipient_onion.custom_tlvs,
1176                         starting_block_height: best_block_height,
1177                         total_msat: route.get_total_amount(),
1178                 };
1179
1180                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
1181                         assert!(payment.insert(*session_priv_bytes, path));
1182                 }
1183
1184                 (payment, onion_session_privs)
1185         }
1186
1187         #[allow(unused)]
1188         pub(super) fn add_new_awaiting_invoice(&self, payment_id: PaymentId) -> Result<(), ()> {
1189                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1190                 match pending_outbounds.entry(payment_id) {
1191                         hash_map::Entry::Occupied(_) => Err(()),
1192                         hash_map::Entry::Vacant(entry) => {
1193                                 entry.insert(PendingOutboundPayment::AwaitingInvoice {
1194                                         timer_ticks_without_response: 0,
1195                                 });
1196
1197                                 Ok(())
1198                         },
1199                 }
1200         }
1201
1202         fn pay_route_internal<NS: Deref, F>(
1203                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1204                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1205                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1206                 send_payment_along_path: &F
1207         ) -> Result<(), PaymentSendFailure>
1208         where
1209                 NS::Target: NodeSigner,
1210                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1211         {
1212                 if route.paths.len() < 1 {
1213                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
1214                 }
1215                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
1216                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
1217                 }
1218                 let mut total_value = 0;
1219                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
1220                 let mut path_errs = Vec::with_capacity(route.paths.len());
1221                 'path_check: for path in route.paths.iter() {
1222                         if path.hops.len() < 1 || path.hops.len() > 20 {
1223                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
1224                                 continue 'path_check;
1225                         }
1226                         if path.blinded_tail.is_some() {
1227                                 path_errs.push(Err(APIError::InvalidRoute{err: "Sending to blinded paths isn't supported yet".to_owned()}));
1228                                 continue 'path_check;
1229                         }
1230                         let dest_hop_idx = if path.blinded_tail.is_some() && path.blinded_tail.as_ref().unwrap().hops.len() > 1 {
1231                                 usize::max_value() } else { path.hops.len() - 1 };
1232                         for (idx, hop) in path.hops.iter().enumerate() {
1233                                 if idx != dest_hop_idx && hop.pubkey == our_node_id {
1234                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
1235                                         continue 'path_check;
1236                                 }
1237                         }
1238                         total_value += path.final_value_msat();
1239                         path_errs.push(Ok(()));
1240                 }
1241                 if path_errs.iter().any(|e| e.is_err()) {
1242                         return Err(PaymentSendFailure::PathParameterError(path_errs));
1243                 }
1244                 if let Some(amt_msat) = recv_value_msat {
1245                         total_value = amt_msat;
1246                 }
1247
1248                 let cur_height = best_block_height + 1;
1249                 let mut results = Vec::new();
1250                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
1251                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.into_iter()) {
1252                         let mut path_res = send_payment_along_path(SendAlongPathArgs {
1253                                 path: &path, payment_hash: &payment_hash, recipient_onion: recipient_onion.clone(),
1254                                 total_value, cur_height, payment_id, keysend_preimage: &keysend_preimage, session_priv_bytes
1255                         });
1256                         match path_res {
1257                                 Ok(_) => {},
1258                                 Err(APIError::MonitorUpdateInProgress) => {
1259                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
1260                                         // considered "in flight" and we shouldn't remove it from the
1261                                         // PendingOutboundPayment set.
1262                                 },
1263                                 Err(_) => {
1264                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1265                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1266                                                 let removed = payment.remove(&session_priv_bytes, Some(path));
1267                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1268                                         } else {
1269                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1270                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1271                                         }
1272                                 }
1273                         }
1274                         results.push(path_res);
1275                 }
1276                 let mut has_ok = false;
1277                 let mut has_err = false;
1278                 let mut pending_amt_unsent = 0;
1279                 for (res, path) in results.iter().zip(route.paths.iter()) {
1280                         if res.is_ok() { has_ok = true; }
1281                         if res.is_err() { has_err = true; }
1282                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1283                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1284                                 // PartialFailure.
1285                                 has_err = true;
1286                                 has_ok = true;
1287                         } else if res.is_err() {
1288                                 pending_amt_unsent += path.final_value_msat();
1289                         }
1290                 }
1291                 if has_err && has_ok {
1292                         Err(PaymentSendFailure::PartialFailure {
1293                                 results,
1294                                 payment_id,
1295                                 failed_paths_retry: if pending_amt_unsent != 0 {
1296                                         if let Some(payment_params) = route.route_params.as_ref().map(|p| p.payment_params.clone()) {
1297                                                 Some(RouteParameters {
1298                                                         payment_params: payment_params,
1299                                                         final_value_msat: pending_amt_unsent,
1300                                                 })
1301                                         } else { None }
1302                                 } else { None },
1303                         })
1304                 } else if has_err {
1305                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1306                 } else {
1307                         Ok(())
1308                 }
1309         }
1310
1311         #[cfg(test)]
1312         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1313                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1314                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1315                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1316                 send_payment_along_path: F
1317         ) -> Result<(), PaymentSendFailure>
1318         where
1319                 NS::Target: NodeSigner,
1320                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1321         {
1322                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1323                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1324                         &send_payment_along_path)
1325                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1326         }
1327
1328         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1329         // map as the payment is free to be resent.
1330         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1331                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1332                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1333                         debug_assert!(removed, "We should always have a pending payment to remove here");
1334                 }
1335         }
1336
1337         pub(super) fn claim_htlc<L: Deref>(
1338                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1339                 path: Path, from_onchain: bool, ev_completion_action: EventCompletionAction,
1340                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1341                 logger: &L,
1342         ) where L::Target: Logger {
1343                 let mut session_priv_bytes = [0; 32];
1344                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1345                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1346                 let mut pending_events = pending_events.lock().unwrap();
1347                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1348                         if !payment.get().is_fulfilled() {
1349                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1350                                 log_info!(logger, "Payment with id {} and hash {} sent!", payment_id, payment_hash);
1351                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1352                                 pending_events.push_back((events::Event::PaymentSent {
1353                                         payment_id: Some(payment_id),
1354                                         payment_preimage,
1355                                         payment_hash,
1356                                         fee_paid_msat,
1357                                 }, Some(ev_completion_action.clone())));
1358                                 payment.get_mut().mark_fulfilled();
1359                         }
1360
1361                         if from_onchain {
1362                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1363                                 // This could potentially lead to removing a pending payment too early,
1364                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1365                                 // restart.
1366                                 // TODO: We should have a second monitor event that informs us of payments
1367                                 // irrevocably fulfilled.
1368                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1369                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1370                                         pending_events.push_back((events::Event::PaymentPathSuccessful {
1371                                                 payment_id,
1372                                                 payment_hash,
1373                                                 path,
1374                                         }, Some(ev_completion_action)));
1375                                 }
1376                         }
1377                 } else {
1378                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", &payment_preimage);
1379                 }
1380         }
1381
1382         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>,
1383                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1384         {
1385                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1386                 let mut pending_events = pending_events.lock().unwrap();
1387                 for source in sources {
1388                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1389                                 let mut session_priv_bytes = [0; 32];
1390                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1391                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1392                                         assert!(payment.get().is_fulfilled());
1393                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1394                                                 let payment_hash = payment.get().payment_hash();
1395                                                 debug_assert!(payment_hash.is_some());
1396                                                 pending_events.push_back((events::Event::PaymentPathSuccessful {
1397                                                         payment_id,
1398                                                         payment_hash,
1399                                                         path,
1400                                                 }, None));
1401                                         }
1402                                 }
1403                         }
1404                 }
1405         }
1406
1407         pub(super) fn remove_stale_payments(
1408                 &self, pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1409         {
1410                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1411                 let mut pending_events = pending_events.lock().unwrap();
1412                 pending_outbound_payments.retain(|payment_id, payment| {
1413                         // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1414                         // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1415                         // this could race the user making a duplicate send_payment call and our idempotency
1416                         // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1417                         // removal. This should be more than sufficient to ensure the idempotency of any
1418                         // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1419                         // processed.
1420                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1421                                 let mut no_remaining_entries = session_privs.is_empty();
1422                                 if no_remaining_entries {
1423                                         for (ev, _) in pending_events.iter() {
1424                                                 match ev {
1425                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1426                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1427                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1428                                                                         if payment_id == ev_payment_id {
1429                                                                                 no_remaining_entries = false;
1430                                                                                 break;
1431                                                                         }
1432                                                                 },
1433                                                         _ => {},
1434                                                 }
1435                                         }
1436                                 }
1437                                 if no_remaining_entries {
1438                                         *timer_ticks_without_htlcs += 1;
1439                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1440                                 } else {
1441                                         *timer_ticks_without_htlcs = 0;
1442                                         true
1443                                 }
1444                         } else if let PendingOutboundPayment::AwaitingInvoice { timer_ticks_without_response, .. } = payment {
1445                                 *timer_ticks_without_response += 1;
1446                                 if *timer_ticks_without_response <= INVOICE_REQUEST_TIMEOUT_TICKS {
1447                                         true
1448                                 } else {
1449                                         pending_events.push_back(
1450                                                 (events::Event::InvoiceRequestFailed { payment_id: *payment_id }, None)
1451                                         );
1452                                         false
1453                                 }
1454                         } else { true }
1455                 });
1456         }
1457
1458         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1459         pub(super) fn fail_htlc<L: Deref>(
1460                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1461                 path: &Path, session_priv: &SecretKey, payment_id: &PaymentId,
1462                 probing_cookie_secret: [u8; 32], secp_ctx: &Secp256k1<secp256k1::All>,
1463                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
1464         ) -> bool where L::Target: Logger {
1465                 #[cfg(test)]
1466                 let DecodedOnionFailure {
1467                         network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data
1468                 } = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1469                 #[cfg(not(test))]
1470                 let DecodedOnionFailure { network_update, short_channel_id, payment_retryable } =
1471                         onion_error.decode_onion_failure(secp_ctx, logger, &source);
1472
1473                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1474                 let mut session_priv_bytes = [0; 32];
1475                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1476                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1477
1478                 // If any payments already need retry, there's no need to generate a redundant
1479                 // `PendingHTLCsForwardable`.
1480                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1481                         let mut awaiting_retry = false;
1482                         if pmt.is_auto_retryable_now() {
1483                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1484                                         if pending_amt_msat < total_msat {
1485                                                 awaiting_retry = true;
1486                                         }
1487                                 }
1488                         }
1489                         awaiting_retry
1490                 });
1491
1492                 let mut full_failure_ev = None;
1493                 let mut pending_retry_ev = false;
1494                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1495                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1496                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1497                                 return false
1498                         }
1499                         if payment.get().is_fulfilled() {
1500                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", &payment_hash);
1501                                 return false
1502                         }
1503                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1504                         if let Some(scid) = short_channel_id {
1505                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1506                                 // process_onion_failure we should close that channel as it implies our
1507                                 // next-hop is needlessly blaming us!
1508                                 payment.get_mut().insert_previously_failed_scid(scid);
1509                         }
1510
1511                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1512                                 let reason = if !payment_retryable {
1513                                         PaymentFailureReason::RecipientRejected
1514                                 } else {
1515                                         PaymentFailureReason::RetriesExhausted
1516                                 };
1517                                 payment.get_mut().mark_abandoned(reason);
1518                                 is_retryable_now = false;
1519                         }
1520                         if payment.get().remaining_parts() == 0 {
1521                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
1522                                         if !payment_is_probe {
1523                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1524                                                         payment_id: *payment_id,
1525                                                         payment_hash: *payment_hash,
1526                                                         reason: *reason,
1527                                                 });
1528                                         }
1529                                         payment.remove();
1530                                 }
1531                         }
1532                         is_retryable_now
1533                 } else {
1534                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1535                         return false
1536                 };
1537                 core::mem::drop(outbounds);
1538                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", &payment_hash);
1539
1540                 let path_failure = {
1541                         if payment_is_probe {
1542                                 if !payment_retryable {
1543                                         events::Event::ProbeSuccessful {
1544                                                 payment_id: *payment_id,
1545                                                 payment_hash: payment_hash.clone(),
1546                                                 path: path.clone(),
1547                                         }
1548                                 } else {
1549                                         events::Event::ProbeFailed {
1550                                                 payment_id: *payment_id,
1551                                                 payment_hash: payment_hash.clone(),
1552                                                 path: path.clone(),
1553                                                 short_channel_id,
1554                                         }
1555                                 }
1556                         } else {
1557                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1558                                 // payment will sit in our outbounds forever.
1559                                 if attempts_remaining && !already_awaiting_retry {
1560                                         debug_assert!(full_failure_ev.is_none());
1561                                         pending_retry_ev = true;
1562                                 }
1563                                 events::Event::PaymentPathFailed {
1564                                         payment_id: Some(*payment_id),
1565                                         payment_hash: payment_hash.clone(),
1566                                         payment_failed_permanently: !payment_retryable,
1567                                         failure: events::PathFailure::OnPath { network_update },
1568                                         path: path.clone(),
1569                                         short_channel_id,
1570                                         #[cfg(test)]
1571                                         error_code: onion_error_code,
1572                                         #[cfg(test)]
1573                                         error_data: onion_error_data
1574                                 }
1575                         }
1576                 };
1577                 let mut pending_events = pending_events.lock().unwrap();
1578                 pending_events.push_back((path_failure, None));
1579                 if let Some(ev) = full_failure_ev { pending_events.push_back((ev, None)); }
1580                 pending_retry_ev
1581         }
1582
1583         pub(super) fn abandon_payment(
1584                 &self, payment_id: PaymentId, reason: PaymentFailureReason,
1585                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>
1586         ) {
1587                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1588                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1589                         payment.get_mut().mark_abandoned(reason);
1590                         if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
1591                                 if payment.get().remaining_parts() == 0 {
1592                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
1593                                                 payment_id,
1594                                                 payment_hash: *payment_hash,
1595                                                 reason: *reason,
1596                                         }, None));
1597                                         payment.remove();
1598                                 }
1599                         } else if let PendingOutboundPayment::AwaitingInvoice { .. } = payment.get() {
1600                                 pending_events.lock().unwrap().push_back((events::Event::InvoiceRequestFailed {
1601                                         payment_id,
1602                                 }, None));
1603                                 payment.remove();
1604                         }
1605                 }
1606         }
1607
1608         #[cfg(test)]
1609         pub fn has_pending_payments(&self) -> bool {
1610                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1611         }
1612
1613         #[cfg(test)]
1614         pub fn clear_pending_payments(&self) {
1615                 self.pending_outbound_payments.lock().unwrap().clear()
1616         }
1617 }
1618
1619 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1620 /// payment probe.
1621 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1622         probing_cookie_secret: [u8; 32]) -> bool
1623 {
1624         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1625         target_payment_hash == *payment_hash
1626 }
1627
1628 /// Returns the 'probing cookie' for the given [`PaymentId`].
1629 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1630         let mut preimage = [0u8; 64];
1631         preimage[..32].copy_from_slice(&probing_cookie_secret);
1632         preimage[32..].copy_from_slice(&payment_id.0);
1633         PaymentHash(Sha256::hash(&preimage).into_inner())
1634 }
1635
1636 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1637         (0, Legacy) => {
1638                 (0, session_privs, required),
1639         },
1640         (1, Fulfilled) => {
1641                 (0, session_privs, required),
1642                 (1, payment_hash, option),
1643                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1644         },
1645         (2, Retryable) => {
1646                 (0, session_privs, required),
1647                 (1, pending_fee_msat, option),
1648                 (2, payment_hash, required),
1649                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1650                 // never see it - `payment_params` was added here after the field was added/required.
1651                 (3, payment_params, (option: ReadableArgs, 0)),
1652                 (4, payment_secret, option),
1653                 (5, keysend_preimage, option),
1654                 (6, total_msat, required),
1655                 (7, payment_metadata, option),
1656                 (8, pending_amt_msat, required),
1657                 (9, custom_tlvs, optional_vec),
1658                 (10, starting_block_height, required),
1659                 (not_written, retry_strategy, (static_value, None)),
1660                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1661         },
1662         (3, Abandoned) => {
1663                 (0, session_privs, required),
1664                 (1, reason, option),
1665                 (2, payment_hash, required),
1666         },
1667         (5, AwaitingInvoice) => {
1668                 (0, timer_ticks_without_response, required),
1669         },
1670         (7, InvoiceReceived) => {
1671                 (0, payment_hash, required),
1672         },
1673 );
1674
1675 #[cfg(test)]
1676 mod tests {
1677         use bitcoin::network::constants::Network;
1678         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1679
1680         use crate::events::{Event, PathFailure, PaymentFailureReason};
1681         use crate::ln::PaymentHash;
1682         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1683         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1684         use crate::ln::msgs::{ErrorAction, LightningError};
1685         use crate::ln::outbound_payment::{INVOICE_REQUEST_TIMEOUT_TICKS, OutboundPayments, Retry, RetryableSendFailure};
1686         use crate::routing::gossip::NetworkGraph;
1687         use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters};
1688         use crate::sync::{Arc, Mutex, RwLock};
1689         use crate::util::errors::APIError;
1690         use crate::util::test_utils;
1691
1692         use alloc::collections::VecDeque;
1693
1694         #[test]
1695         fn test_recipient_onion_fields_with_custom_tlvs() {
1696                 let onion_fields = RecipientOnionFields::spontaneous_empty();
1697
1698                 let bad_type_range_tlvs = vec![
1699                         (0, vec![42]),
1700                         (1, vec![42; 32]),
1701                 ];
1702                 assert!(onion_fields.clone().with_custom_tlvs(bad_type_range_tlvs).is_err());
1703
1704                 let keysend_tlv = vec![
1705                         (5482373484, vec![42; 32]),
1706                 ];
1707                 assert!(onion_fields.clone().with_custom_tlvs(keysend_tlv).is_err());
1708
1709                 let good_tlvs = vec![
1710                         ((1 << 16) + 1, vec![42]),
1711                         ((1 << 16) + 3, vec![42; 32]),
1712                 ];
1713                 assert!(onion_fields.with_custom_tlvs(good_tlvs).is_ok());
1714         }
1715
1716         #[test]
1717         #[cfg(feature = "std")]
1718         fn fails_paying_after_expiration() {
1719                 do_fails_paying_after_expiration(false);
1720                 do_fails_paying_after_expiration(true);
1721         }
1722         #[cfg(feature = "std")]
1723         fn do_fails_paying_after_expiration(on_retry: bool) {
1724                 let outbound_payments = OutboundPayments::new();
1725                 let logger = test_utils::TestLogger::new();
1726                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1727                 let scorer = RwLock::new(test_utils::TestScorer::new());
1728                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1729                 let secp_ctx = Secp256k1::new();
1730                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1731
1732                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1733                 let payment_params = PaymentParameters::from_node_id(
1734                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1735                                 0
1736                         ).with_expiry_time(past_expiry_time);
1737                 let expired_route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1738                 let pending_events = Mutex::new(VecDeque::new());
1739                 if on_retry {
1740                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1741                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1742                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1743                                 &&keys_manager, 0).unwrap();
1744                         outbound_payments.find_route_and_send_payment(
1745                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1746                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1747                                 &|_| Ok(()));
1748                         let events = pending_events.lock().unwrap();
1749                         assert_eq!(events.len(), 1);
1750                         if let Event::PaymentFailed { ref reason, .. } = events[0].0 {
1751                                 assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
1752                         } else { panic!("Unexpected event"); }
1753                 } else {
1754                         let err = outbound_payments.send_payment(
1755                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1756                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1757                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1758                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1759                 }
1760         }
1761
1762         #[test]
1763         fn find_route_error() {
1764                 do_find_route_error(false);
1765                 do_find_route_error(true);
1766         }
1767         fn do_find_route_error(on_retry: bool) {
1768                 let outbound_payments = OutboundPayments::new();
1769                 let logger = test_utils::TestLogger::new();
1770                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1771                 let scorer = RwLock::new(test_utils::TestScorer::new());
1772                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1773                 let secp_ctx = Secp256k1::new();
1774                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1775
1776                 let payment_params = PaymentParameters::from_node_id(
1777                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1778                 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1779                 router.expect_find_route(route_params.clone(),
1780                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1781
1782                 let pending_events = Mutex::new(VecDeque::new());
1783                 if on_retry {
1784                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1785                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1786                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1787                                 &&keys_manager, 0).unwrap();
1788                         outbound_payments.find_route_and_send_payment(
1789                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1790                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1791                                 &|_| Ok(()));
1792                         let events = pending_events.lock().unwrap();
1793                         assert_eq!(events.len(), 1);
1794                         if let Event::PaymentFailed { .. } = events[0].0 { } else { panic!("Unexpected event"); }
1795                 } else {
1796                         let err = outbound_payments.send_payment(
1797                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1798                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1799                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1800                         if let RetryableSendFailure::RouteNotFound = err {
1801                         } else { panic!("Unexpected error"); }
1802                 }
1803         }
1804
1805         #[test]
1806         fn initial_send_payment_path_failed_evs() {
1807                 let outbound_payments = OutboundPayments::new();
1808                 let logger = test_utils::TestLogger::new();
1809                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1810                 let scorer = RwLock::new(test_utils::TestScorer::new());
1811                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1812                 let secp_ctx = Secp256k1::new();
1813                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1814
1815                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1816                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1817                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1818                 let route_params = RouteParameters::from_payment_params_and_value(payment_params.clone(), 0);
1819                 let failed_scid = 42;
1820                 let route = Route {
1821                         paths: vec![Path { hops: vec![RouteHop {
1822                                 pubkey: receiver_pk,
1823                                 node_features: NodeFeatures::empty(),
1824                                 short_channel_id: failed_scid,
1825                                 channel_features: ChannelFeatures::empty(),
1826                                 fee_msat: 0,
1827                                 cltv_expiry_delta: 0,
1828                         }], blinded_tail: None }],
1829                         route_params: Some(route_params.clone()),
1830                 };
1831                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1832                 let mut route_params_w_failed_scid = route_params.clone();
1833                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1834                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1835                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1836                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1837
1838                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1839                 // PaymentPathFailed event.
1840                 let pending_events = Mutex::new(VecDeque::new());
1841                 outbound_payments.send_payment(
1842                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1843                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1844                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1845                         |_| Err(APIError::ChannelUnavailable { err: "test".to_owned() })).unwrap();
1846                 let mut events = pending_events.lock().unwrap();
1847                 assert_eq!(events.len(), 2);
1848                 if let Event::PaymentPathFailed {
1849                         short_channel_id,
1850                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0].0
1851                 {
1852                         assert_eq!(short_channel_id, Some(failed_scid));
1853                 } else { panic!("Unexpected event"); }
1854                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1855                 events.clear();
1856                 core::mem::drop(events);
1857
1858                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1859                 outbound_payments.send_payment(
1860                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1861                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1862                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1863                         |_| Err(APIError::MonitorUpdateInProgress)).unwrap();
1864                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1865
1866                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1867                 outbound_payments.send_payment(
1868                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1869                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1870                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1871                         |_| Err(APIError::APIMisuseError { err: "test".to_owned() })).unwrap();
1872                 let events = pending_events.lock().unwrap();
1873                 assert_eq!(events.len(), 2);
1874                 if let Event::PaymentPathFailed {
1875                         short_channel_id,
1876                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0].0
1877                 {
1878                         assert_eq!(short_channel_id, None);
1879                 } else { panic!("Unexpected event"); }
1880                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1881         }
1882
1883         #[test]
1884         fn removes_stale_awaiting_invoice() {
1885                 let pending_events = Mutex::new(VecDeque::new());
1886                 let outbound_payments = OutboundPayments::new();
1887                 let payment_id = PaymentId([0; 32]);
1888
1889                 assert!(!outbound_payments.has_pending_payments());
1890                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id).is_ok());
1891                 assert!(outbound_payments.has_pending_payments());
1892
1893                 for _ in 0..INVOICE_REQUEST_TIMEOUT_TICKS {
1894                         outbound_payments.remove_stale_payments(&pending_events);
1895                         assert!(outbound_payments.has_pending_payments());
1896                         assert!(pending_events.lock().unwrap().is_empty());
1897                 }
1898
1899                 outbound_payments.remove_stale_payments(&pending_events);
1900                 assert!(!outbound_payments.has_pending_payments());
1901                 assert!(!pending_events.lock().unwrap().is_empty());
1902                 assert_eq!(
1903                         pending_events.lock().unwrap().pop_front(),
1904                         Some((Event::InvoiceRequestFailed { payment_id }, None)),
1905                 );
1906                 assert!(pending_events.lock().unwrap().is_empty());
1907
1908                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id).is_ok());
1909                 assert!(outbound_payments.has_pending_payments());
1910
1911                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id).is_err());
1912         }
1913
1914         #[test]
1915         fn removes_abandoned_awaiting_invoice() {
1916                 let pending_events = Mutex::new(VecDeque::new());
1917                 let outbound_payments = OutboundPayments::new();
1918                 let payment_id = PaymentId([0; 32]);
1919
1920                 assert!(!outbound_payments.has_pending_payments());
1921                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id).is_ok());
1922                 assert!(outbound_payments.has_pending_payments());
1923
1924                 outbound_payments.abandon_payment(
1925                         payment_id, PaymentFailureReason::UserAbandoned, &pending_events
1926                 );
1927                 assert!(!outbound_payments.has_pending_payments());
1928                 assert!(!pending_events.lock().unwrap().is_empty());
1929                 assert_eq!(
1930                         pending_events.lock().unwrap().pop_front(),
1931                         Some((Event::InvoiceRequestFailed { payment_id }, None)),
1932                 );
1933                 assert!(pending_events.lock().unwrap().is_empty());
1934         }
1935 }