_ Git - rust-lightning/blob - lightning/src/ln/outbound_payment.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Utilities to send payments and manage outbound payment information.
  11
  12 use bitcoin::hashes::Hash;
  13 use bitcoin::hashes::sha256::Hash as Sha256;
  14 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
  15
  16 use crate::chain::keysinterface::{EntropySource, NodeSigner, Recipient};
  17 use crate::events::{self, PaymentFailureReason};
  18 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  19 use crate::ln::channelmanager::{ChannelDetails, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
  20 use crate::ln::onion_utils::HTLCFailReason;
  21 use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteParameters, Router};
  22 use crate::util::errors::APIError;
  23 use crate::util::logger::Logger;
  24 use crate::util::time::Time;
  25 #[cfg(all(not(feature = "no-std"), test))]
  26 use crate::util::time::tests::SinceEpoch;
  27 use crate::util::ser::ReadableArgs;
  28
  29 use core::fmt::{self, Display, Formatter};
  30 use core::ops::Deref;
  31
  32 use crate::prelude::*;
  33 use crate::sync::Mutex;
  34
  35 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  36 /// and later, also stores information for retrying the payment.
  37 pub(crate) enum PendingOutboundPayment {
  38         Legacy {
  39                 session_privs: HashSet<[u8; 32]>,
  40         },
  41         Retryable {
  42                 retry_strategy: Option<Retry>,
  43                 attempts: PaymentAttempts,
  44                 payment_params: Option<PaymentParameters>,
  45                 session_privs: HashSet<[u8; 32]>,
  46                 payment_hash: PaymentHash,
  47                 payment_secret: Option<PaymentSecret>,
  48                 payment_metadata: Option<Vec<u8>>,
  49                 keysend_preimage: Option<PaymentPreimage>,
  50                 pending_amt_msat: u64,
  51                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  52                 pending_fee_msat: Option<u64>,
  53                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  54                 total_msat: u64,
  55                 /// Our best known block height at the time this payment was initiated.
  56                 starting_block_height: u32,
  57         },
  58         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  59         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  60         /// and add a pending payment that was already fulfilled.
  61         Fulfilled {
  62                 session_privs: HashSet<[u8; 32]>,
  63                 payment_hash: Option<PaymentHash>,
  64                 timer_ticks_without_htlcs: u8,
  65         },
  66         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  67         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  68         Abandoned {
  69                 session_privs: HashSet<[u8; 32]>,
  70                 payment_hash: PaymentHash,
  71                 /// Will be `None` if the payment was serialized before 0.0.115.
  72                 reason: Option<PaymentFailureReason>,
  73         },
  74 }
  75
  76 impl PendingOutboundPayment {
  77         fn increment_attempts(&mut self) {
  78                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  79                         attempts.count += 1;
  80                 }
  81         }
  82         fn is_auto_retryable_now(&self) -> bool {
  83                 match self {
  84                         PendingOutboundPayment::Retryable {
  85                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
  86                         } => {
  87                                 strategy.is_retryable_now(&attempts)
  88                         },
  89                         _ => false,
  90                 }
  91         }
  92         fn is_retryable_now(&self) -> bool {
  93                 match self {
  94                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
  95                                 // We're handling retries manually, we can always retry.
  96                                 true
  97                         },
  98                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
  99                                 strategy.is_retryable_now(&attempts)
 100                         },
 101                         _ => false,
 102                 }
 103         }
 104         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 105                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 106                         params.previously_failed_channels.push(scid);
 107                 }
 108         }
 109         pub(super) fn is_fulfilled(&self) -> bool {
 110                 match self {
 111                         PendingOutboundPayment::Fulfilled { .. } => true,
 112                         _ => false,
 113                 }
 114         }
 115         pub(super) fn abandoned(&self) -> bool {
 116                 match self {
 117                         PendingOutboundPayment::Abandoned { .. } => true,
 118                         _ => false,
 119                 }
 120         }
 121         fn get_pending_fee_msat(&self) -> Option<u64> {
 122                 match self {
 123                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 124                         _ => None,
 125                 }
 126         }
 127
 128         fn payment_hash(&self) -> Option<PaymentHash> {
 129                 match self {
 130                         PendingOutboundPayment::Legacy { .. } => None,
 131                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 132                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 133                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 134                 }
 135         }
 136
 137         fn mark_fulfilled(&mut self) {
 138                 let mut session_privs = HashSet::new();
 139                 core::mem::swap(&mut session_privs, match self {
 140                         PendingOutboundPayment::Legacy { session_privs } |
 141                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 142                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 143                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 144                         => session_privs,
 145                 });
 146                 let payment_hash = self.payment_hash();
 147                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 148         }
 149
 150         fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
 151                 if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
 152                         let mut our_session_privs = HashSet::new();
 153                         core::mem::swap(&mut our_session_privs, session_privs);
 154                         *self = PendingOutboundPayment::Abandoned {
 155                                 session_privs: our_session_privs,
 156                                 payment_hash: *payment_hash,
 157                                 reason: Some(reason)
 158                         };
 159                 }
 160         }
 161
 162         /// panics if path is None and !self.is_fulfilled
 163         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Path>) -> bool {
 164                 let remove_res = match self {
 165                         PendingOutboundPayment::Legacy { session_privs } |
 166                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 167                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 168                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 169                                         session_privs.remove(session_priv)
 170                                 }
 171                 };
 172                 if remove_res {
 173                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 174                                 let path = path.expect("Fulfilling a payment should always come with a path");
 175                                 *pending_amt_msat -= path.final_value_msat();
 176                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 177                                         *fee_msat -= path.fee_msat();
 178                                 }
 179                         }
 180                 }
 181                 remove_res
 182         }
 183
 184         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Path) -> bool {
 185                 let insert_res = match self {
 186                         PendingOutboundPayment::Legacy { session_privs } |
 187                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 188                                         session_privs.insert(session_priv)
 189                                 }
 190                         PendingOutboundPayment::Fulfilled { .. } => false,
 191                         PendingOutboundPayment::Abandoned { .. } => false,
 192                 };
 193                 if insert_res {
 194                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 195                                 *pending_amt_msat += path.final_value_msat();
 196                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 197                                         *fee_msat += path.fee_msat();
 198                                 }
 199                         }
 200                 }
 201                 insert_res
 202         }
 203
 204         pub(super) fn remaining_parts(&self) -> usize {
 205                 match self {
 206                         PendingOutboundPayment::Legacy { session_privs } |
 207                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 208                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 209                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 210                                         session_privs.len()
 211                                 }
 212                 }
 213         }
 214 }
 215
 216 /// Strategies available to retry payment path failures.
 217 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 218 pub enum Retry {
 219         /// Max number of attempts to retry payment.
 220         ///
 221         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 222         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 223         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 224         Attempts(usize),
 225         #[cfg(not(feature = "no-std"))]
 226         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 227         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 228         ///
 229         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 230         Timeout(core::time::Duration),
 231 }
 232
 233 impl Retry {
 234         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 235                 match (self, attempts) {
 236                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 237                                 max_retry_count > count
 238                         },
 239                         #[cfg(all(not(feature = "no-std"), not(test)))]
 240                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 241                                 *max_duration >= std::time::Instant::now().duration_since(*first_attempted_at),
 242                         #[cfg(all(not(feature = "no-std"), test))]
 243                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 244                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 245                 }
 246         }
 247 }
 248
 249 #[cfg(feature = "std")]
 250 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 251         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 252                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 253                         return elapsed > core::time::Duration::from_secs(expiry_time)
 254                 }
 255         }
 256         false
 257 }
 258
 259 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 260
 261 /// Storing minimal payment attempts information required for determining if a outbound payment can
 262 /// be retried.
 263 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 264         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 265         /// it means the result of the first attempt is not known yet.
 266         pub(crate) count: usize,
 267         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 268         #[cfg(not(feature = "no-std"))]
 269         first_attempted_at: T,
 270         #[cfg(feature = "no-std")]
 271         phantom: core::marker::PhantomData<T>,
 272
 273 }
 274
 275 #[cfg(not(any(feature = "no-std", test)))]
 276 type ConfiguredTime = std::time::Instant;
 277 #[cfg(feature = "no-std")]
 278 type ConfiguredTime = crate::util::time::Eternity;
 279 #[cfg(all(not(feature = "no-std"), test))]
 280 type ConfiguredTime = SinceEpoch;
 281
 282 impl<T: Time> PaymentAttemptsUsingTime<T> {
 283         pub(crate) fn new() -> Self {
 284                 PaymentAttemptsUsingTime {
 285                         count: 0,
 286                         #[cfg(not(feature = "no-std"))]
 287                         first_attempted_at: T::now(),
 288                         #[cfg(feature = "no-std")]
 289                         phantom: core::marker::PhantomData,
 290                 }
 291         }
 292 }
 293
 294 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 295         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 296                 #[cfg(feature = "no-std")]
 297                 return write!(f, "attempts: {}", self.count);
 298                 #[cfg(not(feature = "no-std"))]
 299                 return write!(
 300                         f,
 301                         "attempts: {}, duration: {}s",
 302                         self.count,
 303                         T::now().duration_since(self.first_attempted_at).as_secs()
 304                 );
 305         }
 306 }
 307
 308 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 309 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 310 ///
 311 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 312 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 313 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 314 #[derive(Clone, Debug)]
 315 pub enum RetryableSendFailure {
 316         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 317         /// that this error is *not* caused by [`Retry::Timeout`].
 318         ///
 319         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 320         PaymentExpired,
 321         /// We were unable to find a route to the destination.
 322         RouteNotFound,
 323         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 324         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 325         ///
 326         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 327         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 328         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 329         DuplicatePayment,
 330 }
 331
 332 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 333 /// of several states. This enum is returned as the Err() type describing which state the payment
 334 /// is in, see the description of individual enum states for more.
 335 ///
 336 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 337 #[derive(Clone, Debug)]
 338 pub enum PaymentSendFailure {
 339         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 340         /// send the payment at all.
 341         ///
 342         /// You can freely resend the payment in full (with the parameter error fixed).
 343         ///
 344         /// Because the payment failed outright, no payment tracking is done and no
 345         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 346         ///
 347         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 348         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 349         ParameterError(APIError),
 350         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 351         /// from attempting to send the payment at all.
 352         ///
 353         /// You can freely resend the payment in full (with the parameter error fixed).
 354         ///
 355         /// Because the payment failed outright, no payment tracking is done and no
 356         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 357         ///
 358         /// The results here are ordered the same as the paths in the route object which was passed to
 359         /// send_payment.
 360         ///
 361         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 362         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 363         PathParameterError(Vec<Result<(), APIError>>),
 364         /// All paths which were attempted failed to send, with no channel state change taking place.
 365         /// You can freely resend the payment in full (though you probably want to do so over different
 366         /// paths than the ones selected).
 367         ///
 368         /// Because the payment failed outright, no payment tracking is done and no
 369         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 370         ///
 371         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 372         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 373         AllFailedResendSafe(Vec<APIError>),
 374         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 375         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 376         ///
 377         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 378         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 379         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 380         DuplicatePayment,
 381         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 382         /// some paths have irrevocably committed to the HTLC.
 383         ///
 384         /// The results here are ordered the same as the paths in the route object that was passed to
 385         /// send_payment.
 386         ///
 387         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 388         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 389         ///
 390         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 391         PartialFailure {
 392                 /// The errors themselves, in the same order as the paths from the route.
 393                 results: Vec<Result<(), APIError>>,
 394                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 395                 /// contain a [`RouteParameters`] object for the failing paths.
 396                 failed_paths_retry: Option<RouteParameters>,
 397                 /// The payment id for the payment, which is now at least partially pending.
 398                 payment_id: PaymentId,
 399         },
 400 }
 401
 402 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 403 ///
 404 /// This should generally be constructed with data communicated to us from the recipient (via a
 405 /// BOLT11 or BOLT12 invoice).
 406 #[derive(Clone, Debug, PartialEq, Eq)]
 407 pub struct RecipientOnionFields {
 408         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 409         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 410         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 411         /// attacks.
 412         ///
 413         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 414         /// multi-path payments require a recipient-provided secret.
 415         ///
 416         /// Note that for spontaneous payments most lightning nodes do not currently support MPP
 417         /// receives, thus you should generally never be providing a secret here for spontaneous
 418         /// payments.
 419         pub payment_secret: Option<PaymentSecret>,
 420         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 421         /// arbitrary length. This gives recipients substantially more flexibility to receive
 422         /// additional data.
 423         ///
 424         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 425         /// scheme to authenticate received payments against expected payments and invoices, this field
 426         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 427         /// invoices which will be received with the payment.
 428         ///
 429         /// Note that this field was added to the lightning specification more recently than
 430         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 431         /// may not be supported as universally.
 432         pub payment_metadata: Option<Vec<u8>>,
 433 }
 434
 435 impl_writeable_tlv_based!(RecipientOnionFields, {
 436         (0, payment_secret, option),
 437         (2, payment_metadata, option),
 438 });
 439
 440 impl RecipientOnionFields {
 441         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 442         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 443         /// but do not require or provide any further data.
 444         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 445                 Self { payment_secret: Some(payment_secret), payment_metadata: None }
 446         }
 447
 448         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 449         /// payable HTLCs except for spontaneous payments, i.e. this should generally only be used for
 450         /// calls to [`ChannelManager::send_spontaneous_payment`].
 451         ///
 452         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 453         pub fn spontaneous_empty() -> Self {
 454                 Self { payment_secret: None, payment_metadata: None }
 455         }
 456
 457         /// When we have received some HTLC(s) towards an MPP payment, as we receive further HTLC(s) we
 458         /// have to make sure that some fields match exactly across the parts. For those that aren't
 459         /// required to match, if they don't match we should remove them so as to not expose data
 460         /// that's dependent on the HTLC receive order to users.
 461         ///
 462         /// Here we implement this, first checking compatibility then mutating two objects and then
 463         /// dropping any remaining non-matching fields from both.
 464         pub(super) fn check_merge(&mut self, further_htlc_fields: &mut Self) -> Result<(), ()> {
 465                 if self.payment_secret != further_htlc_fields.payment_secret { return Err(()); }
 466                 if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 467                 // For custom TLVs we should just drop non-matching ones, but not reject the payment.
 468                 Ok(())
 469         }
 470 }
 471
 472 pub(super) struct OutboundPayments {
 473         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 474         pub(super) retry_lock: Mutex<()>,
 475 }
 476
 477 impl OutboundPayments {
 478         pub(super) fn new() -> Self {
 479                 Self {
 480                         pending_outbound_payments: Mutex::new(HashMap::new()),
 481                         retry_lock: Mutex::new(()),
 482                 }
 483         }
 484
 485         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 486                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 487                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 488                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 489                 node_signer: &NS, best_block_height: u32, logger: &L,
 490                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 491         ) -> Result<(), RetryableSendFailure>
 492         where
 493                 R::Target: Router,
 494                 ES::Target: EntropySource,
 495                 NS::Target: NodeSigner,
 496                 L::Target: Logger,
 497                 IH: Fn() -> InFlightHtlcs,
 498                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 499                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 500         {
 501                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 502                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 503                         best_block_height, logger, pending_events, &send_payment_along_path)
 504         }
 505
 506         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 507                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 508                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 509                 send_payment_along_path: F
 510         ) -> Result<(), PaymentSendFailure>
 511         where
 512                 ES::Target: EntropySource,
 513                 NS::Target: NodeSigner,
 514                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 515                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 516         {
 517                 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)?;
 518                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 519                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 520                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 521         }
 522
 523         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 524                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 525                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 526                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 527                 node_signer: &NS, best_block_height: u32, logger: &L,
 528                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
 529         ) -> Result<PaymentHash, RetryableSendFailure>
 530         where
 531                 R::Target: Router,
 532                 ES::Target: EntropySource,
 533                 NS::Target: NodeSigner,
 534                 L::Target: Logger,
 535                 IH: Fn() -> InFlightHtlcs,
 536                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 537                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 538         {
 539                 let preimage = payment_preimage
 540                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 541                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 542                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 543                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 544                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 545                         .map(|()| payment_hash)
 546         }
 547
 548         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 549                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 550                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 551                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 552         ) -> Result<PaymentHash, PaymentSendFailure>
 553         where
 554                 ES::Target: EntropySource,
 555                 NS::Target: NodeSigner,
 556                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 557                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 558         {
 559                 let preimage = payment_preimage
 560                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 561                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 562                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 563                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 564
 565                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 566                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 567                 ) {
 568                         Ok(()) => Ok(payment_hash),
 569                         Err(e) => {
 570                                 self.remove_outbound_if_all_failed(payment_id, &e);
 571                                 Err(e)
 572                         }
 573                 }
 574         }
 575
 576         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 577                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 578                 best_block_height: u32, pending_events: &Mutex<Vec<events::Event>>, logger: &L,
 579                 send_payment_along_path: SP,
 580         )
 581         where
 582                 R::Target: Router,
 583                 ES::Target: EntropySource,
 584                 NS::Target: NodeSigner,
 585                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 586                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 587                 IH: Fn() -> InFlightHtlcs,
 588                 FH: Fn() -> Vec<ChannelDetails>,
 589                 L::Target: Logger,
 590         {
 591                 let _single_thread = self.retry_lock.lock().unwrap();
 592                 loop {
 593                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 594                         let mut retry_id_route_params = None;
 595                         for (pmt_id, pmt) in outbounds.iter_mut() {
 596                                 if pmt.is_auto_retryable_now() {
 597                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 598                                                 if pending_amt_msat < total_msat {
 599                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 600                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 601                                                                 payment_params: params.clone(),
 602                                                         }));
 603                                                         break
 604                                                 }
 605                                         } else { debug_assert!(false); }
 606                                 }
 607                         }
 608                         core::mem::drop(outbounds);
 609                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 610                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops(), &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path)
 611                         } else { break }
 612                 }
 613
 614                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 615                 outbounds.retain(|pmt_id, pmt| {
 616                         let mut retain = true;
 617                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 618                                 pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
 619                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
 620                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 621                                                 payment_id: *pmt_id,
 622                                                 payment_hash: *payment_hash,
 623                                                 reason: *reason,
 624                                         });
 625                                         retain = false;
 626                                 }
 627                         }
 628                         retain
 629                 });
 630         }
 631
 632         pub(super) fn needs_abandon(&self) -> bool {
 633                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 634                 outbounds.iter().any(|(_, pmt)|
 635                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 636         }
 637
 638         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 639         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 640         ///
 641         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 642         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 643         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 644                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 645                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 646                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 647                 node_signer: &NS, best_block_height: u32, logger: &L,
 648                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 649         ) -> Result<(), RetryableSendFailure>
 650         where
 651                 R::Target: Router,
 652                 ES::Target: EntropySource,
 653                 NS::Target: NodeSigner,
 654                 L::Target: Logger,
 655                 IH: Fn() -> InFlightHtlcs,
 656                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 657                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 658         {
 659                 #[cfg(feature = "std")] {
 660                         if has_expired(&route_params) {
 661                                 return Err(RetryableSendFailure::PaymentExpired)
 662                         }
 663                 }
 664
 665                 let route = router.find_route_with_id(
 666                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 667                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs(),
 668                         payment_hash, payment_id,
 669                 ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 670
 671                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 672                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 673                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 674                         .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 675
 676                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, None, payment_id, None,
 677                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 678                 log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
 679                 if let Err(e) = res {
 680                         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);
 681                 }
 682                 Ok(())
 683         }
 684
 685         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 686                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 687                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 688                 node_signer: &NS, best_block_height: u32, logger: &L,
 689                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 690         )
 691         where
 692                 R::Target: Router,
 693                 ES::Target: EntropySource,
 694                 NS::Target: NodeSigner,
 695                 L::Target: Logger,
 696                 IH: Fn() -> InFlightHtlcs,
 697                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 698                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 699         {
 700                 #[cfg(feature = "std")] {
 701                         if has_expired(&route_params) {
 702                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
 703                                 self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
 704                                 return
 705                         }
 706                 }
 707
 708                 let route = match router.find_route_with_id(
 709                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 710                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs(),
 711                         payment_hash, payment_id,
 712                 ) {
 713                         Ok(route) => route,
 714                         Err(e) => {
 715                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
 716                                 self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
 717                                 return
 718                         }
 719                 };
 720                 for path in route.paths.iter() {
 721                         if path.hops.len() == 0 {
 722                                 log_error!(logger, "Unusable path in route (path.hops.len() must be at least 1");
 723                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 724                                 return
 725                         }
 726                 }
 727
 728                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 729                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 730                 for _ in 0..route.paths.len() {
 731                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 732                 }
 733
 734                 macro_rules! abandon_with_entry {
 735                         ($payment: expr, $reason: expr) => {
 736                                 $payment.get_mut().mark_abandoned($reason);
 737                                 if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
 738                                         if $payment.get().remaining_parts() == 0 {
 739                                                 pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 740                                                         payment_id,
 741                                                         payment_hash,
 742                                                         reason: *reason,
 743                                                 });
 744                                                 $payment.remove();
 745                                         }
 746                                 }
 747                         }
 748                 }
 749                 let (total_msat, recipient_onion, keysend_preimage) = {
 750                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 751                         match outbounds.entry(payment_id) {
 752                                 hash_map::Entry::Occupied(mut payment) => {
 753                                         let res = match payment.get() {
 754                                                 PendingOutboundPayment::Retryable {
 755                                                         total_msat, keysend_preimage, payment_secret, payment_metadata, pending_amt_msat, ..
 756                                                 } => {
 757                                                         let retry_amt_msat = route.get_total_amount();
 758                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 759                                                                 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);
 760                                                                 abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
 761                                                                 return
 762                                                         }
 763                                                         (*total_msat, RecipientOnionFields {
 764                                                                         payment_secret: *payment_secret,
 765                                                                         payment_metadata: payment_metadata.clone(),
 766                                                                 }, *keysend_preimage)
 767                                                 },
 768                                                 PendingOutboundPayment::Legacy { .. } => {
 769                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 770                                                         return
 771                                                 },
 772                                                 PendingOutboundPayment::Fulfilled { .. } => {
 773                                                         log_error!(logger, "Payment already completed");
 774                                                         return
 775                                                 },
 776                                                 PendingOutboundPayment::Abandoned { .. } => {
 777                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 778                                                         return
 779                                                 },
 780                                         };
 781                                         if !payment.get().is_retryable_now() {
 782                                                 log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
 783                                                 abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
 784                                                 return
 785                                         }
 786                                         payment.get_mut().increment_attempts();
 787                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 788                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 789                                         }
 790                                         res
 791                                 },
 792                                 hash_map::Entry::Vacant(_) => {
 793                                         log_error!(logger, "Payment with ID {} not found", log_bytes!(payment_id.0));
 794                                         return
 795                                 }
 796                         }
 797                 };
 798                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
 799                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 800                         &send_payment_along_path);
 801                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
 802                 if let Err(e) = res {
 803                         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);
 804                 }
 805         }
 806
 807         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 808                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 809                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 810                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 811                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 812         )
 813         where
 814                 R::Target: Router,
 815                 ES::Target: EntropySource,
 816                 NS::Target: NodeSigner,
 817                 L::Target: Logger,
 818                 IH: Fn() -> InFlightHtlcs,
 819                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 820                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 821         {
 822                 match err {
 823                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 824                                 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);
 825                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 826                         },
 827                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 828                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
 829                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 830                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 831                                 // return `Ok()` here, ignoring any retry errors.
 832                                 self.retry_payment_internal(payment_hash, payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 833                         },
 834                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 835                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 836                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 837                                 // initial HTLC-Add messages yet.
 838                         },
 839                         PaymentSendFailure::PathParameterError(results) => {
 840                                 log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
 841                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
 842                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 843                         },
 844                         PaymentSendFailure::ParameterError(e) => {
 845                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 846                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 847                         },
 848                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 849                 }
 850         }
 851
 852         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
 853                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 854                 paths: Vec<Path>, path_results: I, logger: &L, pending_events: &Mutex<Vec<events::Event>>
 855         ) where L::Target: Logger {
 856                 let mut events = pending_events.lock().unwrap();
 857                 debug_assert_eq!(paths.len(), path_results.len());
 858                 for (path, path_res) in paths.into_iter().zip(path_results) {
 859                         if let Err(e) = path_res {
 860                                 if let APIError::MonitorUpdateInProgress = e { continue }
 861                                 log_error!(logger, "Failed to send along path due to error: {:?}", e);
 862                                 let mut failed_scid = None;
 863                                 if let APIError::ChannelUnavailable { .. } = e {
 864                                         let scid = path.hops[0].short_channel_id;
 865                                         failed_scid = Some(scid);
 866                                         route_params.payment_params.previously_failed_channels.push(scid);
 867                                 }
 868                                 events.push(events::Event::PaymentPathFailed {
 869                                         payment_id: Some(payment_id),
 870                                         payment_hash,
 871                                         payment_failed_permanently: false,
 872                                         failure: events::PathFailure::InitialSend { err: e },
 873                                         path,
 874                                         short_channel_id: failed_scid,
 875                                         #[cfg(test)]
 876                                         error_code: None,
 877                                         #[cfg(test)]
 878                                         error_data: None,
 879                                 });
 880                         }
 881                 }
 882         }
 883
 884         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 885                 &self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
 886                 best_block_height: u32, send_payment_along_path: F
 887         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 888         where
 889                 ES::Target: EntropySource,
 890                 NS::Target: NodeSigner,
 891                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 892                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 893         {
 894                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 895
 896                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 897
 898                 if path.hops.len() < 2 && path.blinded_tail.is_none() {
 899                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 900                                 err: "No need probing a path with less than two hops".to_string()
 901                         }))
 902                 }
 903
 904                 let route = Route { paths: vec![path], payment_params: None };
 905                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 906                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
 907                         entropy_source, best_block_height)?;
 908
 909                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
 910                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 911                 ) {
 912                         Ok(()) => Ok((payment_hash, payment_id)),
 913                         Err(e) => {
 914                                 self.remove_outbound_if_all_failed(payment_id, &e);
 915                                 Err(e)
 916                         }
 917                 }
 918         }
 919
 920         #[cfg(test)]
 921         pub(super) fn test_set_payment_metadata(
 922                 &self, payment_id: PaymentId, new_payment_metadata: Option<Vec<u8>>
 923         ) {
 924                 match self.pending_outbound_payments.lock().unwrap().get_mut(&payment_id).unwrap() {
 925                         PendingOutboundPayment::Retryable { payment_metadata, .. } => {
 926                                 *payment_metadata = new_payment_metadata;
 927                         },
 928                         _ => panic!("Need a retryable payment to update metadata on"),
 929                 }
 930         }
 931
 932         #[cfg(test)]
 933         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 934                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 935                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 936         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 937                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 938         }
 939
 940         pub(super) fn add_new_pending_payment<ES: Deref>(
 941                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 942                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 943                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 944         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 945                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 946                 for _ in 0..route.paths.len() {
 947                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 948                 }
 949
 950                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 951                 match pending_outbounds.entry(payment_id) {
 952                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 953                         hash_map::Entry::Vacant(entry) => {
 954                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 955                                         retry_strategy,
 956                                         attempts: PaymentAttempts::new(),
 957                                         payment_params,
 958                                         session_privs: HashSet::new(),
 959                                         pending_amt_msat: 0,
 960                                         pending_fee_msat: Some(0),
 961                                         payment_hash,
 962                                         payment_secret: recipient_onion.payment_secret,
 963                                         payment_metadata: recipient_onion.payment_metadata,
 964                                         keysend_preimage,
 965                                         starting_block_height: best_block_height,
 966                                         total_msat: route.get_total_amount(),
 967                                 });
 968
 969                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 970                                         assert!(payment.insert(*session_priv_bytes, path));
 971                                 }
 972
 973                                 Ok(onion_session_privs)
 974                         },
 975                 }
 976         }
 977
 978         fn pay_route_internal<NS: Deref, F>(
 979                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 980                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 981                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 982                 send_payment_along_path: &F
 983         ) -> Result<(), PaymentSendFailure>
 984         where
 985                 NS::Target: NodeSigner,
 986                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 987                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 988         {
 989                 if route.paths.len() < 1 {
 990                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
 991                 }
 992                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
 993                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
 994                 }
 995                 let mut total_value = 0;
 996                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 997                 let mut path_errs = Vec::with_capacity(route.paths.len());
 998                 'path_check: for path in route.paths.iter() {
 999                         if path.hops.len() < 1 || path.hops.len() > 20 {
1000                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
1001                                 continue 'path_check;
1002                         }
1003                         if path.blinded_tail.is_some() {
1004                                 path_errs.push(Err(APIError::InvalidRoute{err: "Sending to blinded paths isn't supported yet".to_owned()}));
1005                                 continue 'path_check;
1006                         }
1007                         let dest_hop_idx = if path.blinded_tail.is_some() && path.blinded_tail.as_ref().unwrap().hops.len() > 1 {
1008                                 usize::max_value() } else { path.hops.len() - 1 };
1009                         for (idx, hop) in path.hops.iter().enumerate() {
1010                                 if idx != dest_hop_idx && hop.pubkey == our_node_id {
1011                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
1012                                         continue 'path_check;
1013                                 }
1014                         }
1015                         total_value += path.final_value_msat();
1016                         path_errs.push(Ok(()));
1017                 }
1018                 if path_errs.iter().any(|e| e.is_err()) {
1019                         return Err(PaymentSendFailure::PathParameterError(path_errs));
1020                 }
1021                 if let Some(amt_msat) = recv_value_msat {
1022                         total_value = amt_msat;
1023                 }
1024
1025                 let cur_height = best_block_height + 1;
1026                 let mut results = Vec::new();
1027                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
1028                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
1029                         let mut path_res = send_payment_along_path(&path, &payment_hash, recipient_onion.clone(),
1030                                 total_value, cur_height, payment_id, &keysend_preimage, session_priv);
1031                         match path_res {
1032                                 Ok(_) => {},
1033                                 Err(APIError::MonitorUpdateInProgress) => {
1034                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
1035                                         // considered "in flight" and we shouldn't remove it from the
1036                                         // PendingOutboundPayment set.
1037                                 },
1038                                 Err(_) => {
1039                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1040                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1041                                                 let removed = payment.remove(&session_priv, Some(path));
1042                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1043                                         } else {
1044                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1045                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1046                                         }
1047                                 }
1048                         }
1049                         results.push(path_res);
1050                 }
1051                 let mut has_ok = false;
1052                 let mut has_err = false;
1053                 let mut pending_amt_unsent = 0;
1054                 for (res, path) in results.iter().zip(route.paths.iter()) {
1055                         if res.is_ok() { has_ok = true; }
1056                         if res.is_err() { has_err = true; }
1057                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1058                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1059                                 // PartialFailure.
1060                                 has_err = true;
1061                                 has_ok = true;
1062                         } else if res.is_err() {
1063                                 pending_amt_unsent += path.final_value_msat();
1064                         }
1065                 }
1066                 if has_err && has_ok {
1067                         Err(PaymentSendFailure::PartialFailure {
1068                                 results,
1069                                 payment_id,
1070                                 failed_paths_retry: if pending_amt_unsent != 0 {
1071                                         if let Some(payment_params) = &route.payment_params {
1072                                                 Some(RouteParameters {
1073                                                         payment_params: payment_params.clone(),
1074                                                         final_value_msat: pending_amt_unsent,
1075                                                 })
1076                                         } else { None }
1077                                 } else { None },
1078                         })
1079                 } else if has_err {
1080                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1081                 } else {
1082                         Ok(())
1083                 }
1084         }
1085
1086         #[cfg(test)]
1087         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1088                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1089                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1090                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1091                 send_payment_along_path: F
1092         ) -> Result<(), PaymentSendFailure>
1093         where
1094                 NS::Target: NodeSigner,
1095                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
1096                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
1097         {
1098                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1099                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1100                         &send_payment_along_path)
1101                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1102         }
1103
1104         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1105         // map as the payment is free to be resent.
1106         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1107                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1108                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1109                         debug_assert!(removed, "We should always have a pending payment to remove here");
1110                 }
1111         }
1112
1113         pub(super) fn claim_htlc<L: Deref>(
1114                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1115                 path: Path, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1116         ) where L::Target: Logger {
1117                 let mut session_priv_bytes = [0; 32];
1118                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1119                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1120                 let mut pending_events = pending_events.lock().unwrap();
1121                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1122                         if !payment.get().is_fulfilled() {
1123                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1124                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1125                                 pending_events.push(
1126                                         events::Event::PaymentSent {
1127                                                 payment_id: Some(payment_id),
1128                                                 payment_preimage,
1129                                                 payment_hash,
1130                                                 fee_paid_msat,
1131                                         }
1132                                 );
1133                                 payment.get_mut().mark_fulfilled();
1134                         }
1135
1136                         if from_onchain {
1137                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1138                                 // This could potentially lead to removing a pending payment too early,
1139                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1140                                 // restart.
1141                                 // TODO: We should have a second monitor event that informs us of payments
1142                                 // irrevocably fulfilled.
1143                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1144                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1145                                         pending_events.push(
1146                                                 events::Event::PaymentPathSuccessful {
1147                                                         payment_id,
1148                                                         payment_hash,
1149                                                         path,
1150                                                 }
1151                                         );
1152                                 }
1153                         }
1154                 } else {
1155                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
1156                 }
1157         }
1158
1159         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
1160                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1161                 let mut pending_events = pending_events.lock().unwrap();
1162                 for source in sources {
1163                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1164                                 let mut session_priv_bytes = [0; 32];
1165                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1166                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1167                                         assert!(payment.get().is_fulfilled());
1168                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1169                                                 pending_events.push(
1170                                                         events::Event::PaymentPathSuccessful {
1171                                                                 payment_id,
1172                                                                 payment_hash: payment.get().payment_hash(),
1173                                                                 path,
1174                                                         }
1175                                                 );
1176                                         }
1177                                 }
1178                         }
1179                 }
1180         }
1181
1182         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
1183                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1184                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1185                 // this could race the user making a duplicate send_payment call and our idempotency
1186                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1187                 // removal. This should be more than sufficient to ensure the idempotency of any
1188                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1189                 // processed.
1190                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1191                 let pending_events = pending_events.lock().unwrap();
1192                 pending_outbound_payments.retain(|payment_id, payment| {
1193                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1194                                 let mut no_remaining_entries = session_privs.is_empty();
1195                                 if no_remaining_entries {
1196                                         for ev in pending_events.iter() {
1197                                                 match ev {
1198                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1199                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1200                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1201                                                                         if payment_id == ev_payment_id {
1202                                                                                 no_remaining_entries = false;
1203                                                                                 break;
1204                                                                         }
1205                                                                 },
1206                                                         _ => {},
1207                                                 }
1208                                         }
1209                                 }
1210                                 if no_remaining_entries {
1211                                         *timer_ticks_without_htlcs += 1;
1212                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1213                                 } else {
1214                                         *timer_ticks_without_htlcs = 0;
1215                                         true
1216                                 }
1217                         } else { true }
1218                 });
1219         }
1220
1221         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1222         pub(super) fn fail_htlc<L: Deref>(
1223                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1224                 path: &Path, session_priv: &SecretKey, payment_id: &PaymentId, probing_cookie_secret: [u8; 32],
1225                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1226         ) -> bool where L::Target: Logger {
1227                 #[cfg(test)]
1228                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1229                 #[cfg(not(test))]
1230                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1231
1232                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1233                 let mut session_priv_bytes = [0; 32];
1234                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1235                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1236
1237                 // If any payments already need retry, there's no need to generate a redundant
1238                 // `PendingHTLCsForwardable`.
1239                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1240                         let mut awaiting_retry = false;
1241                         if pmt.is_auto_retryable_now() {
1242                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1243                                         if pending_amt_msat < total_msat {
1244                                                 awaiting_retry = true;
1245                                         }
1246                                 }
1247                         }
1248                         awaiting_retry
1249                 });
1250
1251                 let mut full_failure_ev = None;
1252                 let mut pending_retry_ev = false;
1253                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1254                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1255                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1256                                 return false
1257                         }
1258                         if payment.get().is_fulfilled() {
1259                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1260                                 return false
1261                         }
1262                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1263                         if let Some(scid) = short_channel_id {
1264                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1265                                 // process_onion_failure we should close that channel as it implies our
1266                                 // next-hop is needlessly blaming us!
1267                                 payment.get_mut().insert_previously_failed_scid(scid);
1268                         }
1269
1270                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1271                                 let reason = if !payment_retryable {
1272                                         PaymentFailureReason::RecipientRejected
1273                                 } else {
1274                                         PaymentFailureReason::RetriesExhausted
1275                                 };
1276                                 payment.get_mut().mark_abandoned(reason);
1277                                 is_retryable_now = false;
1278                         }
1279                         if payment.get().remaining_parts() == 0 {
1280                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
1281                                         if !payment_is_probe {
1282                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1283                                                         payment_id: *payment_id,
1284                                                         payment_hash: *payment_hash,
1285                                                         reason: *reason,
1286                                                 });
1287                                         }
1288                                         payment.remove();
1289                                 }
1290                         }
1291                         is_retryable_now
1292                 } else {
1293                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1294                         return false
1295                 };
1296                 core::mem::drop(outbounds);
1297                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1298
1299                 let path_failure = {
1300                         if payment_is_probe {
1301                                 if !payment_retryable {
1302                                         events::Event::ProbeSuccessful {
1303                                                 payment_id: *payment_id,
1304                                                 payment_hash: payment_hash.clone(),
1305                                                 path: path.clone(),
1306                                         }
1307                                 } else {
1308                                         events::Event::ProbeFailed {
1309                                                 payment_id: *payment_id,
1310                                                 payment_hash: payment_hash.clone(),
1311                                                 path: path.clone(),
1312                                                 short_channel_id,
1313                                         }
1314                                 }
1315                         } else {
1316                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1317                                 // payment will sit in our outbounds forever.
1318                                 if attempts_remaining && !already_awaiting_retry {
1319                                         debug_assert!(full_failure_ev.is_none());
1320                                         pending_retry_ev = true;
1321                                 }
1322                                 events::Event::PaymentPathFailed {
1323                                         payment_id: Some(*payment_id),
1324                                         payment_hash: payment_hash.clone(),
1325                                         payment_failed_permanently: !payment_retryable,
1326                                         failure: events::PathFailure::OnPath { network_update },
1327                                         path: path.clone(),
1328                                         short_channel_id,
1329                                         #[cfg(test)]
1330                                         error_code: onion_error_code,
1331                                         #[cfg(test)]
1332                                         error_data: onion_error_data
1333                                 }
1334                         }
1335                 };
1336                 let mut pending_events = pending_events.lock().unwrap();
1337                 pending_events.push(path_failure);
1338                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
1339                 pending_retry_ev
1340         }
1341
1342         pub(super) fn abandon_payment(
1343                 &self, payment_id: PaymentId, reason: PaymentFailureReason, pending_events: &Mutex<Vec<events::Event>>
1344         ) {
1345                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1346                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1347                         payment.get_mut().mark_abandoned(reason);
1348                         if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
1349                                 if payment.get().remaining_parts() == 0 {
1350                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
1351                                                 payment_id,
1352                                                 payment_hash: *payment_hash,
1353                                                 reason: *reason,
1354                                         });
1355                                         payment.remove();
1356                                 }
1357                         }
1358                 }
1359         }
1360
1361         #[cfg(test)]
1362         pub fn has_pending_payments(&self) -> bool {
1363                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1364         }
1365
1366         #[cfg(test)]
1367         pub fn clear_pending_payments(&self) {
1368                 self.pending_outbound_payments.lock().unwrap().clear()
1369         }
1370 }
1371
1372 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1373 /// payment probe.
1374 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1375         probing_cookie_secret: [u8; 32]) -> bool
1376 {
1377         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1378         target_payment_hash == *payment_hash
1379 }
1380
1381 /// Returns the 'probing cookie' for the given [`PaymentId`].
1382 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1383         let mut preimage = [0u8; 64];
1384         preimage[..32].copy_from_slice(&probing_cookie_secret);
1385         preimage[32..].copy_from_slice(&payment_id.0);
1386         PaymentHash(Sha256::hash(&preimage).into_inner())
1387 }
1388
1389 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1390         (0, Legacy) => {
1391                 (0, session_privs, required),
1392         },
1393         (1, Fulfilled) => {
1394                 (0, session_privs, required),
1395                 (1, payment_hash, option),
1396                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1397         },
1398         (2, Retryable) => {
1399                 (0, session_privs, required),
1400                 (1, pending_fee_msat, option),
1401                 (2, payment_hash, required),
1402                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1403                 // never see it - `payment_params` was added here after the field was added/required.
1404                 (3, payment_params, (option: ReadableArgs, 0)),
1405                 (4, payment_secret, option),
1406                 (5, keysend_preimage, option),
1407                 (6, total_msat, required),
1408                 (7, payment_metadata, option),
1409                 (8, pending_amt_msat, required),
1410                 (10, starting_block_height, required),
1411                 (not_written, retry_strategy, (static_value, None)),
1412                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1413         },
1414         (3, Abandoned) => {
1415                 (0, session_privs, required),
1416                 (1, reason, option),
1417                 (2, payment_hash, required),
1418         },
1419 );
1420
1421 #[cfg(test)]
1422 mod tests {
1423         use bitcoin::network::constants::Network;
1424         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1425
1426         use crate::events::{Event, PathFailure, PaymentFailureReason};
1427         use crate::ln::PaymentHash;
1428         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1429         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1430         use crate::ln::msgs::{ErrorAction, LightningError};
1431         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1432         use crate::routing::gossip::NetworkGraph;
1433         use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters};
1434         use crate::sync::{Arc, Mutex};
1435         use crate::util::errors::APIError;
1436         use crate::util::test_utils;
1437
1438         #[test]
1439         #[cfg(feature = "std")]
1440         fn fails_paying_after_expiration() {
1441                 do_fails_paying_after_expiration(false);
1442                 do_fails_paying_after_expiration(true);
1443         }
1444         #[cfg(feature = "std")]
1445         fn do_fails_paying_after_expiration(on_retry: bool) {
1446                 let outbound_payments = OutboundPayments::new();
1447                 let logger = test_utils::TestLogger::new();
1448                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1449                 let scorer = Mutex::new(test_utils::TestScorer::new());
1450                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1451                 let secp_ctx = Secp256k1::new();
1452                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1453
1454                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1455                 let payment_params = PaymentParameters::from_node_id(
1456                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1457                                 0
1458                         ).with_expiry_time(past_expiry_time);
1459                 let expired_route_params = RouteParameters {
1460                         payment_params,
1461                         final_value_msat: 0,
1462                 };
1463                 let pending_events = Mutex::new(Vec::new());
1464                 if on_retry {
1465                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1466                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1467                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1468                                 &&keys_manager, 0).unwrap();
1469                         outbound_payments.retry_payment_internal(
1470                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1471                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1472                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1473                         let events = pending_events.lock().unwrap();
1474                         assert_eq!(events.len(), 1);
1475                         if let Event::PaymentFailed { ref reason, .. } = events[0] {
1476                                 assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
1477                         } else { panic!("Unexpected event"); }
1478                 } else {
1479                         let err = outbound_payments.send_payment(
1480                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1481                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1482                                 &&keys_manager, &&keys_manager, 0, &&logger,
1483                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1484                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1485                 }
1486         }
1487
1488         #[test]
1489         fn find_route_error() {
1490                 do_find_route_error(false);
1491                 do_find_route_error(true);
1492         }
1493         fn do_find_route_error(on_retry: bool) {
1494                 let outbound_payments = OutboundPayments::new();
1495                 let logger = test_utils::TestLogger::new();
1496                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1497                 let scorer = Mutex::new(test_utils::TestScorer::new());
1498                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1499                 let secp_ctx = Secp256k1::new();
1500                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1501
1502                 let payment_params = PaymentParameters::from_node_id(
1503                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1504                 let route_params = RouteParameters {
1505                         payment_params,
1506                         final_value_msat: 0,
1507                 };
1508                 router.expect_find_route(route_params.clone(),
1509                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1510
1511                 let pending_events = Mutex::new(Vec::new());
1512                 if on_retry {
1513                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1514                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1515                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1516                                 &&keys_manager, 0).unwrap();
1517                         outbound_payments.retry_payment_internal(
1518                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1519                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1520                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1521                         let events = pending_events.lock().unwrap();
1522                         assert_eq!(events.len(), 1);
1523                         if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
1524                 } else {
1525                         let err = outbound_payments.send_payment(
1526                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1527                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1528                                 &&keys_manager, &&keys_manager, 0, &&logger,
1529                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1530                         if let RetryableSendFailure::RouteNotFound = err {
1531                         } else { panic!("Unexpected error"); }
1532                 }
1533         }
1534
1535         #[test]
1536         fn initial_send_payment_path_failed_evs() {
1537                 let outbound_payments = OutboundPayments::new();
1538                 let logger = test_utils::TestLogger::new();
1539                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1540                 let scorer = Mutex::new(test_utils::TestScorer::new());
1541                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1542                 let secp_ctx = Secp256k1::new();
1543                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1544
1545                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1546                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1547                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1548                 let route_params = RouteParameters {
1549                         payment_params: payment_params.clone(),
1550                         final_value_msat: 0,
1551                 };
1552                 let failed_scid = 42;
1553                 let route = Route {
1554                         paths: vec![Path { hops: vec![RouteHop {
1555                                 pubkey: receiver_pk,
1556                                 node_features: NodeFeatures::empty(),
1557                                 short_channel_id: failed_scid,
1558                                 channel_features: ChannelFeatures::empty(),
1559                                 fee_msat: 0,
1560                                 cltv_expiry_delta: 0,
1561                         }], blinded_tail: None }],
1562                         payment_params: Some(payment_params),
1563                 };
1564                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1565                 let mut route_params_w_failed_scid = route_params.clone();
1566                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1567                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1568                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1569                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1570
1571                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1572                 // PaymentPathFailed event.
1573                 let pending_events = Mutex::new(Vec::new());
1574                 outbound_payments.send_payment(
1575                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1576                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1577                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1578                         |_, _, _, _, _, _, _, _| Err(APIError::ChannelUnavailable { err: "test".to_owned() }))
1579                         .unwrap();
1580                 let mut events = pending_events.lock().unwrap();
1581                 assert_eq!(events.len(), 2);
1582                 if let Event::PaymentPathFailed {
1583                         short_channel_id,
1584                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0]
1585                 {
1586                         assert_eq!(short_channel_id, Some(failed_scid));
1587                 } else { panic!("Unexpected event"); }
1588                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1589                 events.clear();
1590                 core::mem::drop(events);
1591
1592                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1593                 outbound_payments.send_payment(
1594                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1595                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1596                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1597                         |_, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress)).unwrap();
1598                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1599
1600                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1601                 outbound_payments.send_payment(
1602                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1603                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1604                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1605                         |_, _, _, _, _, _, _, _| Err(APIError::APIMisuseError { err: "test".to_owned() }))
1606                         .unwrap();
1607                 let events = pending_events.lock().unwrap();
1608                 assert_eq!(events.len(), 2);
1609                 if let Event::PaymentPathFailed {
1610                         short_channel_id,
1611                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0]
1612                 {
1613                         assert_eq!(short_channel_id, None);
1614                 } else { panic!("Unexpected event"); }
1615                 if let Event::PaymentFailed { .. } = events[1] { } else { panic!("Unexpected event"); }
1616         }
1617 }