_ 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,
 401                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP,
 402         ) -> Result<(), PaymentSendFailure>
 403         where
 404                 R::Target: Router,
 405                 ES::Target: EntropySource,
 406                 NS::Target: NodeSigner,
 407                 L::Target: Logger,
 408                 IH: Fn() -> InFlightHtlcs,
 409                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 410                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 411         {
 412                 self.pay_internal(payment_id, payment_hash, Some((payment_secret, None, retry_strategy)),
 413                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 414                         best_block_height, logger, pending_events, &send_payment_along_path)
 415                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 416         }
 417
 418         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 419                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 420                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 421                 send_payment_along_path: F
 422         ) -> Result<(), PaymentSendFailure>
 423         where
 424                 ES::Target: EntropySource,
 425                 NS::Target: NodeSigner,
 426                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 427                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 428         {
 429                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, None, route, None, None, entropy_source, best_block_height)?;
 430                 self.pay_route_internal(route, payment_hash, payment_secret, None, payment_id, None,
 431                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 432                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 433         }
 434
 435         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 436                 &self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 437                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 438                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 439                 node_signer: &NS, best_block_height: u32, logger: &L,
 440                 pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
 441         ) -> Result<PaymentHash, PaymentSendFailure>
 442         where
 443                 R::Target: Router,
 444                 ES::Target: EntropySource,
 445                 NS::Target: NodeSigner,
 446                 L::Target: Logger,
 447                 IH: Fn() -> InFlightHtlcs,
 448                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 449                          u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 450         {
 451                 let preimage = payment_preimage
 452                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 453                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 454                 self.pay_internal(payment_id, payment_hash, Some((&None, Some(preimage), retry_strategy)),
 455                         route_params, router, first_hops, &inflight_htlcs, entropy_source, node_signer,
 456                         best_block_height, logger, pending_events, &send_payment_along_path)
 457                         .map(|()| payment_hash)
 458                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 459         }
 460
 461         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 462                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 463                 entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 464         ) -> Result<PaymentHash, PaymentSendFailure>
 465         where
 466                 ES::Target: EntropySource,
 467                 NS::Target: NodeSigner,
 468                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 469                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 470         {
 471                 let preimage = payment_preimage
 472                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 473                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 474                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 475
 476                 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) {
 477                         Ok(()) => Ok(payment_hash),
 478                         Err(e) => {
 479                                 self.remove_outbound_if_all_failed(payment_id, &e);
 480                                 Err(e)
 481                         }
 482                 }
 483         }
 484
 485         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 486                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 487                 best_block_height: u32, pending_events: &Mutex<Vec<events::Event>>, logger: &L,
 488                 send_payment_along_path: SP,
 489         )
 490         where
 491                 R::Target: Router,
 492                 ES::Target: EntropySource,
 493                 NS::Target: NodeSigner,
 494                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 495                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 496                 IH: Fn() -> InFlightHtlcs,
 497                 FH: Fn() -> Vec<ChannelDetails>,
 498                 L::Target: Logger,
 499         {
 500                 let _single_thread = self.retry_lock.lock().unwrap();
 501                 loop {
 502                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 503                         let mut retry_id_route_params = None;
 504                         for (pmt_id, pmt) in outbounds.iter_mut() {
 505                                 if pmt.is_auto_retryable_now() {
 506                                         if let PendingOutboundPayment::Retryable { payment_hash, pending_amt_msat, total_msat, payment_params: Some(params), .. } = pmt {
 507                                                 if pending_amt_msat < total_msat {
 508                                                         retry_id_route_params = Some((*pmt_id, *payment_hash, RouteParameters {
 509                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 510                                                                 final_cltv_expiry_delta:
 511                                                                         if let Some(delta) = params.final_cltv_expiry_delta { delta }
 512                                                                         else {
 513                                                                                 debug_assert!(false, "We always set the final_cltv_expiry_delta when a path fails");
 514                                                                                 LDK_DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA.into()
 515                                                                         },
 516                                                                 payment_params: params.clone(),
 517                                                         }));
 518                                                         break
 519                                                 }
 520                                         }
 521                                 }
 522                         }
 523                         core::mem::drop(outbounds);
 524                         if let Some((payment_id, payment_hash, route_params)) = retry_id_route_params {
 525                                 if let Err(e) = self.pay_internal(payment_id, payment_hash, None, route_params, router, first_hops(), &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path) {
 526                                         log_info!(logger, "Errored retrying payment: {:?}", e);
 527                                         // If we error on retry, there is no chance of the payment succeeding and no HTLCs have
 528                                         // been irrevocably committed to, so we can safely abandon.
 529                                         self.abandon_payment(payment_id, pending_events);
 530                                 }
 531                         } else { break }
 532                 }
 533
 534                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 535                 outbounds.retain(|pmt_id, pmt| {
 536                         let mut retain = true;
 537                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 538                                 if pmt.mark_abandoned().is_ok() {
 539                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
 540                                                 payment_id: *pmt_id,
 541                                                 payment_hash: pmt.payment_hash().expect("PendingOutboundPayments::Retryable always has a payment hash set"),
 542                                         });
 543                                         retain = false;
 544                                 }
 545                         }
 546                         retain
 547                 });
 548         }
 549
 550         pub(super) fn needs_abandon(&self) -> bool {
 551                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 552                 outbounds.iter().any(|(_, pmt)|
 553                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 554         }
 555
 556         /// Will return `Ok(())` iff at least one HTLC is sent for the payment.
 557         fn pay_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 558                 &self, payment_id: PaymentId, payment_hash: PaymentHash,
 559                 initial_send_info: Option<(&Option<PaymentSecret>, Option<PaymentPreimage>, Retry)>,
 560                 route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 561                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 562                 logger: &L, pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: &SP,
 563         ) -> Result<(), PaymentSendFailure>
 564         where
 565                 R::Target: Router,
 566                 ES::Target: EntropySource,
 567                 NS::Target: NodeSigner,
 568                 L::Target: Logger,
 569                 IH: Fn() -> InFlightHtlcs,
 570                 SP: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 571                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 572         {
 573                 #[cfg(feature = "std")] {
 574                         if has_expired(&route_params) {
 575                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 576                                         err: format!("Invoice expired for payment id {}", log_bytes!(payment_id.0)),
 577                                 }))
 578                         }
 579                 }
 580
 581                 let route = router.find_route(
 582                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 583                         Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs(),
 584                 ).map_err(|e| PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 585                         err: format!("Failed to find a route for payment {}: {:?}", log_bytes!(payment_id.0), e), // TODO: add APIError::RouteNotFound
 586                 }))?;
 587
 588                 let res = if let Some((payment_secret, keysend_preimage, retry_strategy)) = initial_send_info {
 589                         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)?;
 590                         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)
 591                 } else {
 592                         self.retry_payment_with_route(&route, payment_id, entropy_source, node_signer, best_block_height, send_payment_along_path)
 593                 };
 594                 match res {
 595                         Err(PaymentSendFailure::AllFailedResendSafe(_)) => {
 596                                 let retry_res = self.pay_internal(payment_id, payment_hash, None, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 597                                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), retry_res);
 598                                 if let Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError { err })) = &retry_res {
 599                                         if err.starts_with("Retries exhausted ") { return res; }
 600                                 }
 601                                 retry_res
 602                         },
 603                         Err(PaymentSendFailure::PartialFailure { failed_paths_retry: Some(retry), .. }) => {
 604                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 605                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 606                                 // return `Ok()` here, ignoring any retry errors.
 607                                 let retry_res = self.pay_internal(payment_id, payment_hash, None, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 608                                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), retry_res);
 609                                 Ok(())
 610                         },
 611                         Err(PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. }) => {
 612                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 613                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 614                                 // initial HTLC-Add messages yet.
 615                                 Ok(())
 616                         },
 617                         res => res,
 618                 }
 619         }
 620
 621         pub(super) fn retry_payment_with_route<ES: Deref, NS: Deref, F>(
 622                 &self, route: &Route, payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 623                 send_payment_along_path: F
 624         ) -> Result<(), PaymentSendFailure>
 625         where
 626                 ES::Target: EntropySource,
 627                 NS::Target: NodeSigner,
 628                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 629                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 630         {
 631                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 632                 for path in route.paths.iter() {
 633                         if path.len() == 0 {
 634                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 635                                         err: "length-0 path in route".to_string()
 636                                 }))
 637                         }
 638                 }
 639
 640                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 641                 for _ in 0..route.paths.len() {
 642                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 643                 }
 644
 645                 let (total_msat, payment_hash, payment_secret, keysend_preimage) = {
 646                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 647                         match outbounds.get_mut(&payment_id) {
 648                                 Some(payment) => {
 649                                         let res = match payment {
 650                                                 PendingOutboundPayment::Retryable {
 651                                                         total_msat, payment_hash, keysend_preimage, payment_secret, pending_amt_msat, ..
 652                                                 } => {
 653                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 654                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 655                                                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 656                                                                         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()
 657                                                                 }))
 658                                                         }
 659                                                         (*total_msat, *payment_hash, *payment_secret, *keysend_preimage)
 660                                                 },
 661                                                 PendingOutboundPayment::Legacy { .. } => {
 662                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 663                                                                 err: "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102".to_string()
 664                                                         }))
 665                                                 },
 666                                                 PendingOutboundPayment::Fulfilled { .. } => {
 667                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 668                                                                 err: "Payment already completed".to_owned()
 669                                                         }));
 670                                                 },
 671                                                 PendingOutboundPayment::Abandoned { .. } => {
 672                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 673                                                                 err: "Payment already abandoned (with some HTLCs still pending)".to_owned()
 674                                                         }));
 675                                                 },
 676                                         };
 677                                         if !payment.is_retryable_now() {
 678                                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 679                                                         err: format!("Retries exhausted for payment id {}", log_bytes!(payment_id.0)),
 680                                                 }))
 681                                         }
 682                                         payment.increment_attempts();
 683                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 684                                                 assert!(payment.insert(*session_priv_bytes, path));
 685                                         }
 686                                         res
 687                                 },
 688                                 None =>
 689                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 690                                                 err: format!("Payment with ID {} not found", log_bytes!(payment_id.0)),
 691                                         })),
 692                         }
 693                 };
 694                 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)
 695         }
 696
 697         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 698                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 699                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 700         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 701         where
 702                 ES::Target: EntropySource,
 703                 NS::Target: NodeSigner,
 704                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 705                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 706         {
 707                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 708
 709                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 710
 711                 if hops.len() < 2 {
 712                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 713                                 err: "No need probing a path with less than two hops".to_string()
 714                         }))
 715                 }
 716
 717                 let route = Route { paths: vec![hops], payment_params: None };
 718                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, None, &route, None, None, entropy_source, best_block_height)?;
 719
 720                 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) {
 721                         Ok(()) => Ok((payment_hash, payment_id)),
 722                         Err(e) => {
 723                                 self.remove_outbound_if_all_failed(payment_id, &e);
 724                                 Err(e)
 725                         }
 726                 }
 727         }
 728
 729         #[cfg(test)]
 730         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 731                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 732                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 733         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 734                 self.add_new_pending_payment(payment_hash, payment_secret, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 735         }
 736
 737         pub(super) fn add_new_pending_payment<ES: Deref>(
 738                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 739                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 740                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 741         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 742                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 743                 for _ in 0..route.paths.len() {
 744                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 745                 }
 746
 747                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 748                 match pending_outbounds.entry(payment_id) {
 749                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 750                         hash_map::Entry::Vacant(entry) => {
 751                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 752                                         retry_strategy,
 753                                         attempts: PaymentAttempts::new(),
 754                                         payment_params,
 755                                         session_privs: HashSet::new(),
 756                                         pending_amt_msat: 0,
 757                                         pending_fee_msat: Some(0),
 758                                         payment_hash,
 759                                         payment_secret,
 760                                         keysend_preimage,
 761                                         starting_block_height: best_block_height,
 762                                         total_msat: route.get_total_amount(),
 763                                 });
 764
 765                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 766                                         assert!(payment.insert(*session_priv_bytes, path));
 767                                 }
 768
 769                                 Ok(onion_session_privs)
 770                         },
 771                 }
 772         }
 773
 774         fn pay_route_internal<NS: Deref, F>(
 775                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 776                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 777                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 778                 send_payment_along_path: &F
 779         ) -> Result<(), PaymentSendFailure>
 780         where
 781                 NS::Target: NodeSigner,
 782                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 783                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 784         {
 785                 if route.paths.len() < 1 {
 786                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over"}));
 787                 }
 788                 if payment_secret.is_none() && route.paths.len() > 1 {
 789                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_string()}));
 790                 }
 791                 let mut total_value = 0;
 792                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 793                 let mut path_errs = Vec::with_capacity(route.paths.len());
 794                 'path_check: for path in route.paths.iter() {
 795                         if path.len() < 1 || path.len() > 20 {
 796                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size"}));
 797                                 continue 'path_check;
 798                         }
 799                         for (idx, hop) in path.iter().enumerate() {
 800                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 801                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us"}));
 802                                         continue 'path_check;
 803                                 }
 804                         }
 805                         total_value += path.last().unwrap().fee_msat;
 806                         path_errs.push(Ok(()));
 807                 }
 808                 if path_errs.iter().any(|e| e.is_err()) {
 809                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 810                 }
 811                 if let Some(amt_msat) = recv_value_msat {
 812                         debug_assert!(amt_msat >= total_value);
 813                         total_value = amt_msat;
 814                 }
 815
 816                 let cur_height = best_block_height + 1;
 817                 let mut results = Vec::new();
 818                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 819                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 820                         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);
 821                         match path_res {
 822                                 Ok(_) => {},
 823                                 Err(APIError::MonitorUpdateInProgress) => {
 824                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 825                                         // considered "in flight" and we shouldn't remove it from the
 826                                         // PendingOutboundPayment set.
 827                                 },
 828                                 Err(_) => {
 829                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 830                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
 831                                                 let removed = payment.remove(&session_priv, Some(path));
 832                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
 833                                         } else {
 834                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
 835                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
 836                                         }
 837                                 }
 838                         }
 839                         results.push(path_res);
 840                 }
 841                 let mut has_ok = false;
 842                 let mut has_err = false;
 843                 let mut pending_amt_unsent = 0;
 844                 let mut max_unsent_cltv_delta = 0;
 845                 for (res, path) in results.iter().zip(route.paths.iter()) {
 846                         if res.is_ok() { has_ok = true; }
 847                         if res.is_err() { has_err = true; }
 848                         if let &Err(APIError::MonitorUpdateInProgress) = res {
 849                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
 850                                 // PartialFailure.
 851                                 has_err = true;
 852                                 has_ok = true;
 853                         } else if res.is_err() {
 854                                 pending_amt_unsent += path.last().unwrap().fee_msat;
 855                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
 856                         }
 857                 }
 858                 if has_err && has_ok {
 859                         Err(PaymentSendFailure::PartialFailure {
 860                                 results,
 861                                 payment_id,
 862                                 failed_paths_retry: if pending_amt_unsent != 0 {
 863                                         if let Some(payment_params) = &route.payment_params {
 864                                                 Some(RouteParameters {
 865                                                         payment_params: payment_params.clone(),
 866                                                         final_value_msat: pending_amt_unsent,
 867                                                         final_cltv_expiry_delta:
 868                                                                 if let Some(delta) = payment_params.final_cltv_expiry_delta { delta }
 869                                                                 else { max_unsent_cltv_delta },
 870                                                 })
 871                                         } else { None }
 872                                 } else { None },
 873                         })
 874                 } else if has_err {
 875                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
 876                 } else {
 877                         Ok(())
 878                 }
 879         }
 880
 881         #[cfg(test)]
 882         pub(super) fn test_send_payment_internal<NS: Deref, F>(
 883                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 884                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 885                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 886                 send_payment_along_path: F
 887         ) -> Result<(), PaymentSendFailure>
 888         where
 889                 NS::Target: NodeSigner,
 890                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 891                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 892         {
 893                 self.pay_route_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
 894                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
 895                         &send_payment_along_path)
 896                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 897         }
 898
 899         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
 900         // map as the payment is free to be resent.
 901         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
 902                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
 903                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
 904                         debug_assert!(removed, "We should always have a pending payment to remove here");
 905                 }
 906         }
 907
 908         pub(super) fn claim_htlc<L: Deref>(
 909                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
 910                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
 911         ) where L::Target: Logger {
 912                 let mut session_priv_bytes = [0; 32];
 913                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 914                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 915                 let mut pending_events = pending_events.lock().unwrap();
 916                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 917                         if !payment.get().is_fulfilled() {
 918                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 919                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
 920                                 pending_events.push(
 921                                         events::Event::PaymentSent {
 922                                                 payment_id: Some(payment_id),
 923                                                 payment_preimage,
 924                                                 payment_hash,
 925                                                 fee_paid_msat,
 926                                         }
 927                                 );
 928                                 payment.get_mut().mark_fulfilled();
 929                         }
 930
 931                         if from_onchain {
 932                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
 933                                 // This could potentially lead to removing a pending payment too early,
 934                                 // with a reorg of one block causing us to re-add the fulfilled payment on
 935                                 // restart.
 936                                 // TODO: We should have a second monitor event that informs us of payments
 937                                 // irrevocably fulfilled.
 938                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
 939                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
 940                                         pending_events.push(
 941                                                 events::Event::PaymentPathSuccessful {
 942                                                         payment_id,
 943                                                         payment_hash,
 944                                                         path,
 945                                                 }
 946                                         );
 947                                 }
 948                         }
 949                 } else {
 950                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
 951                 }
 952         }
 953
 954         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
 955                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 956                 let mut pending_events = pending_events.lock().unwrap();
 957                 for source in sources {
 958                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
 959                                 let mut session_priv_bytes = [0; 32];
 960                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 961                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 962                                         assert!(payment.get().is_fulfilled());
 963                                         if payment.get_mut().remove(&session_priv_bytes, None) {
 964                                                 pending_events.push(
 965                                                         events::Event::PaymentPathSuccessful {
 966                                                                 payment_id,
 967                                                                 payment_hash: payment.get().payment_hash(),
 968                                                                 path,
 969                                                         }
 970                                                 );
 971                                         }
 972                                 }
 973                         }
 974                 }
 975         }
 976
 977         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
 978                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
 979                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
 980                 // this could race the user making a duplicate send_payment call and our idempotency
 981                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
 982                 // removal. This should be more than sufficient to ensure the idempotency of any
 983                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
 984                 // processed.
 985                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
 986                 let pending_events = pending_events.lock().unwrap();
 987                 pending_outbound_payments.retain(|payment_id, payment| {
 988                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
 989                                 let mut no_remaining_entries = session_privs.is_empty();
 990                                 if no_remaining_entries {
 991                                         for ev in pending_events.iter() {
 992                                                 match ev {
 993                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
 994                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
 995                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
 996                                                                         if payment_id == ev_payment_id {
 997                                                                                 no_remaining_entries = false;
 998                                                                                 break;
 999                                                                         }
1000                                                                 },
1001                                                         _ => {},
1002                                                 }
1003                                         }
1004                                 }
1005                                 if no_remaining_entries {
1006                                         *timer_ticks_without_htlcs += 1;
1007                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1008                                 } else {
1009                                         *timer_ticks_without_htlcs = 0;
1010                                         true
1011                                 }
1012                         } else { true }
1013                 });
1014         }
1015
1016         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1017         pub(super) fn fail_htlc<L: Deref>(
1018                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1019                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
1020                 payment_params: &Option<PaymentParameters>, probing_cookie_secret: [u8; 32],
1021                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
1022         ) -> bool where L::Target: Logger {
1023                 #[cfg(test)]
1024                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1025                 #[cfg(not(test))]
1026                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1027
1028                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1029                 let mut session_priv_bytes = [0; 32];
1030                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1031                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1032
1033                 // If any payments already need retry, there's no need to generate a redundant
1034                 // `PendingHTLCsForwardable`.
1035                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1036                         let mut awaiting_retry = false;
1037                         if pmt.is_auto_retryable_now() {
1038                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1039                                         if pending_amt_msat < total_msat {
1040                                                 awaiting_retry = true;
1041                                         }
1042                                 }
1043                         }
1044                         awaiting_retry
1045                 });
1046
1047                 let mut all_paths_failed = false;
1048                 let mut full_failure_ev = None;
1049                 let mut pending_retry_ev = false;
1050                 let mut retry = None;
1051                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1052                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1053                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1054                                 return false
1055                         }
1056                         if payment.get().is_fulfilled() {
1057                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1058                                 return false
1059                         }
1060                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1061                         if let Some(scid) = short_channel_id {
1062                                 payment.get_mut().insert_previously_failed_scid(scid);
1063                         }
1064
1065                         // We want to move towards only using the `PaymentParameters` in the outbound payments
1066                         // map. However, for backwards-compatibility, we still need to support passing the
1067                         // `PaymentParameters` data that was shoved in the HTLC (and given to us via
1068                         // `payment_params`) back to the user.
1069                         let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
1070                         if let Some(params) = payment.get_mut().payment_parameters() {
1071                                 if params.final_cltv_expiry_delta.is_none() {
1072                                         // This should be rare, but a user could provide None for the payment data, and
1073                                         // we need it when we go to retry the payment, so fill it in.
1074                                         params.final_cltv_expiry_delta = Some(path_last_hop.cltv_expiry_delta);
1075                                 }
1076                                 retry = Some(RouteParameters {
1077                                         payment_params: params.clone(),
1078                                         final_value_msat: path_last_hop.fee_msat,
1079                                         final_cltv_expiry_delta: params.final_cltv_expiry_delta.unwrap(),
1080                                 });
1081                         } else if let Some(params) = payment_params {
1082                                 retry = Some(RouteParameters {
1083                                         payment_params: params.clone(),
1084                                         final_value_msat: path_last_hop.fee_msat,
1085                                         final_cltv_expiry_delta:
1086                                                 if let Some(delta) = params.final_cltv_expiry_delta { delta }
1087                                                 else { path_last_hop.cltv_expiry_delta },
1088                                 });
1089                         }
1090
1091                         if payment_is_probe || !is_retryable_now || !payment_retryable || retry.is_none() {
1092                                 let _ = payment.get_mut().mark_abandoned(); // we'll only Err if it's a legacy payment
1093                                 is_retryable_now = false;
1094                         }
1095                         if payment.get().remaining_parts() == 0 {
1096                                 all_paths_failed = true;
1097                                 if payment.get().abandoned() {
1098                                         if !payment_is_probe {
1099                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1100                                                         payment_id: *payment_id,
1101                                                         payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1102                                                 });
1103                                         }
1104                                         payment.remove();
1105                                 }
1106                         }
1107                         is_retryable_now
1108                 } else {
1109                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1110                         return false
1111                 };
1112                 core::mem::drop(outbounds);
1113                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1114
1115                 let path_failure = {
1116                         if payment_is_probe {
1117                                 if !payment_retryable {
1118                                         events::Event::ProbeSuccessful {
1119                                                 payment_id: *payment_id,
1120                                                 payment_hash: payment_hash.clone(),
1121                                                 path: path.clone(),
1122                                         }
1123                                 } else {
1124                                         events::Event::ProbeFailed {
1125                                                 payment_id: *payment_id,
1126                                                 payment_hash: payment_hash.clone(),
1127                                                 path: path.clone(),
1128                                                 short_channel_id,
1129                                         }
1130                                 }
1131                         } else {
1132                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1133                                 // process_onion_failure we should close that channel as it implies our
1134                                 // next-hop is needlessly blaming us!
1135                                 if let Some(scid) = short_channel_id {
1136                                         retry.as_mut().map(|r| r.payment_params.previously_failed_channels.push(scid));
1137                                 }
1138                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1139                                 // payment will sit in our outbounds forever.
1140                                 if attempts_remaining && !already_awaiting_retry {
1141                                         debug_assert!(full_failure_ev.is_none());
1142                                         pending_retry_ev = true;
1143                                 }
1144                                 events::Event::PaymentPathFailed {
1145                                         payment_id: Some(*payment_id),
1146                                         payment_hash: payment_hash.clone(),
1147                                         payment_failed_permanently: !payment_retryable,
1148                                         network_update,
1149                                         all_paths_failed,
1150                                         path: path.clone(),
1151                                         short_channel_id,
1152                                         retry,
1153                                         #[cfg(test)]
1154                                         error_code: onion_error_code,
1155                                         #[cfg(test)]
1156                                         error_data: onion_error_data
1157                                 }
1158                         }
1159                 };
1160                 let mut pending_events = pending_events.lock().unwrap();
1161                 pending_events.push(path_failure);
1162                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
1163                 pending_retry_ev
1164         }
1165
1166         pub(super) fn abandon_payment(
1167                 &self, payment_id: PaymentId, pending_events: &Mutex<Vec<events::Event>>
1168         ) {
1169                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1170                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1171                         if let Ok(()) = payment.get_mut().mark_abandoned() {
1172                                 if payment.get().remaining_parts() == 0 {
1173                                         pending_events.lock().unwrap().push(events::Event::PaymentFailed {
1174                                                 payment_id,
1175                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
1176                                         });
1177                                         payment.remove();
1178                                 }
1179                         }
1180                 }
1181         }
1182
1183         #[cfg(test)]
1184         pub fn has_pending_payments(&self) -> bool {
1185                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1186         }
1187
1188         #[cfg(test)]
1189         pub fn clear_pending_payments(&self) {
1190                 self.pending_outbound_payments.lock().unwrap().clear()
1191         }
1192 }
1193
1194 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1195 /// payment probe.
1196 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1197         probing_cookie_secret: [u8; 32]) -> bool
1198 {
1199         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1200         target_payment_hash == *payment_hash
1201 }
1202
1203 /// Returns the 'probing cookie' for the given [`PaymentId`].
1204 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1205         let mut preimage = [0u8; 64];
1206         preimage[..32].copy_from_slice(&probing_cookie_secret);
1207         preimage[32..].copy_from_slice(&payment_id.0);
1208         PaymentHash(Sha256::hash(&preimage).into_inner())
1209 }
1210
1211 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1212         (0, Legacy) => {
1213                 (0, session_privs, required),
1214         },
1215         (1, Fulfilled) => {
1216                 (0, session_privs, required),
1217                 (1, payment_hash, option),
1218                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1219         },
1220         (2, Retryable) => {
1221                 (0, session_privs, required),
1222                 (1, pending_fee_msat, option),
1223                 (2, payment_hash, required),
1224                 (3, payment_params, option),
1225                 (4, payment_secret, option),
1226                 (5, keysend_preimage, option),
1227                 (6, total_msat, required),
1228                 (8, pending_amt_msat, required),
1229                 (10, starting_block_height, required),
1230                 (not_written, retry_strategy, (static_value, None)),
1231                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1232         },
1233         (3, Abandoned) => {
1234                 (0, session_privs, required),
1235                 (2, payment_hash, required),
1236         },
1237 );
1238
1239 #[cfg(test)]
1240 mod tests {
1241         use bitcoin::blockdata::constants::genesis_block;
1242         use bitcoin::network::constants::Network;
1243         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1244
1245         use crate::ln::PaymentHash;
1246         use crate::ln::channelmanager::{PaymentId, PaymentSendFailure};
1247         use crate::ln::msgs::{ErrorAction, LightningError};
1248         use crate::ln::outbound_payment::{OutboundPayments, Retry};
1249         use crate::routing::gossip::NetworkGraph;
1250         use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteParameters};
1251         use crate::sync::{Arc, Mutex};
1252         use crate::util::errors::APIError;
1253         use crate::util::test_utils;
1254
1255         #[test]
1256         #[cfg(feature = "std")]
1257         fn fails_paying_after_expiration() {
1258                 do_fails_paying_after_expiration(false);
1259                 do_fails_paying_after_expiration(true);
1260         }
1261         #[cfg(feature = "std")]
1262         fn do_fails_paying_after_expiration(on_retry: bool) {
1263                 let outbound_payments = OutboundPayments::new();
1264                 let logger = test_utils::TestLogger::new();
1265                 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
1266                 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, &logger));
1267                 let scorer = Mutex::new(test_utils::TestScorer::new());
1268                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1269                 let secp_ctx = Secp256k1::new();
1270                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1271
1272                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1273                 let payment_params = PaymentParameters::from_node_id(
1274                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1275                                 0
1276                         ).with_expiry_time(past_expiry_time);
1277                 let expired_route_params = RouteParameters {
1278                         payment_params,
1279                         final_value_msat: 0,
1280                         final_cltv_expiry_delta: 0,
1281                 };
1282                 let pending_events = Mutex::new(Vec::new());
1283                 let err = if on_retry {
1284                         outbound_payments.pay_internal(
1285                                 PaymentId([0; 32]), PaymentHash([0; 32]), None, expired_route_params, &&router, vec![],
1286                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1287                                 &|_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err()
1288                 } else {
1289                         outbound_payments.send_payment(
1290                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), expired_route_params,
1291                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1292                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err()
1293                 };
1294                 if let PaymentSendFailure::ParameterError(APIError::APIMisuseError { err }) = err {
1295                         assert!(err.contains("Invoice expired"));
1296                 } else { panic!("Unexpected error"); }
1297         }
1298
1299         #[test]
1300         fn find_route_error() {
1301                 do_find_route_error(false);
1302                 do_find_route_error(true);
1303         }
1304         fn do_find_route_error(on_retry: bool) {
1305                 let outbound_payments = OutboundPayments::new();
1306                 let logger = test_utils::TestLogger::new();
1307                 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
1308                 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, &logger));
1309                 let scorer = Mutex::new(test_utils::TestScorer::new());
1310                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1311                 let secp_ctx = Secp256k1::new();
1312                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1313
1314                 let payment_params = PaymentParameters::from_node_id(
1315                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1316                 let route_params = RouteParameters {
1317                         payment_params,
1318                         final_value_msat: 0,
1319                         final_cltv_expiry_delta: 0,
1320                 };
1321                 router.expect_find_route(route_params.clone(),
1322                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1323
1324                 let pending_events = Mutex::new(Vec::new());
1325                 let err = if on_retry {
1326                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
1327                                 &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
1328                                 Some(route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
1329                         outbound_payments.pay_internal(
1330                                 PaymentId([0; 32]), PaymentHash([0; 32]), None, route_params, &&router, vec![],
1331                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1332                                 &|_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err()
1333                 } else {
1334                         outbound_payments.send_payment(
1335                                 PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params,
1336                                 &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1337                                 &pending_events, |_, _, _, _, _, _, _, _, _| Ok(())).unwrap_err()
1338                 };
1339                 if let PaymentSendFailure::ParameterError(APIError::APIMisuseError { err }) = err {
1340                         assert!(err.contains("Failed to find a route"));
1341                 } else { panic!("Unexpected error"); }
1342         }
1343 }