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

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