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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Utilities to send payments and manage outbound payment information.
  11
  12 use bitcoin::hashes::Hash;
  13 use bitcoin::hashes::sha256::Hash as Sha256;
  14 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
  15
  16 use crate::sign::{EntropySource, NodeSigner, Recipient};
  17 use crate::events::{self, PaymentFailureReason};
  18 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  19 use crate::ln::channelmanager::{ChannelDetails, EventCompletionAction, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
  20 use crate::ln::onion_utils::HTLCFailReason;
  21 use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteParameters, Router};
  22 use crate::util::errors::APIError;
  23 use crate::util::logger::Logger;
  24 use crate::util::time::Time;
  25 #[cfg(all(not(feature = "no-std"), test))]
  26 use crate::util::time::tests::SinceEpoch;
  27 use crate::util::ser::ReadableArgs;
  28
  29 use core::fmt::{self, Display, Formatter};
  30 use core::ops::Deref;
  31
  32 use crate::prelude::*;
  33 use crate::sync::Mutex;
  34
  35 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  36 /// and later, also stores information for retrying the payment.
  37 pub(crate) enum PendingOutboundPayment {
  38         Legacy {
  39                 session_privs: HashSet<[u8; 32]>,
  40         },
  41         Retryable {
  42                 retry_strategy: Option<Retry>,
  43                 attempts: PaymentAttempts,
  44                 payment_params: Option<PaymentParameters>,
  45                 session_privs: HashSet<[u8; 32]>,
  46                 payment_hash: PaymentHash,
  47                 payment_secret: Option<PaymentSecret>,
  48                 payment_metadata: Option<Vec<u8>>,
  49                 keysend_preimage: Option<PaymentPreimage>,
  50                 pending_amt_msat: u64,
  51                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  52                 pending_fee_msat: Option<u64>,
  53                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  54                 total_msat: u64,
  55                 /// Our best known block height at the time this payment was initiated.
  56                 starting_block_height: u32,
  57         },
  58         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  59         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  60         /// and add a pending payment that was already fulfilled.
  61         Fulfilled {
  62                 session_privs: HashSet<[u8; 32]>,
  63                 /// Filled in for any payment which moved to `Fulfilled` on LDK 0.0.104 or later.
  64                 payment_hash: Option<PaymentHash>,
  65                 timer_ticks_without_htlcs: u8,
  66         },
  67         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  68         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  69         Abandoned {
  70                 session_privs: HashSet<[u8; 32]>,
  71                 payment_hash: PaymentHash,
  72                 /// Will be `None` if the payment was serialized before 0.0.115.
  73                 reason: Option<PaymentFailureReason>,
  74         },
  75 }
  76
  77 impl PendingOutboundPayment {
  78         fn increment_attempts(&mut self) {
  79                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  80                         attempts.count += 1;
  81                 }
  82         }
  83         fn is_auto_retryable_now(&self) -> bool {
  84                 match self {
  85                         PendingOutboundPayment::Retryable {
  86                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
  87                         } => {
  88                                 strategy.is_retryable_now(&attempts)
  89                         },
  90                         _ => false,
  91                 }
  92         }
  93         fn is_retryable_now(&self) -> bool {
  94                 match self {
  95                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
  96                                 // We're handling retries manually, we can always retry.
  97                                 true
  98                         },
  99                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
 100                                 strategy.is_retryable_now(&attempts)
 101                         },
 102                         _ => false,
 103                 }
 104         }
 105         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 106                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 107                         params.previously_failed_channels.push(scid);
 108                 }
 109         }
 110         pub(super) fn is_fulfilled(&self) -> bool {
 111                 match self {
 112                         PendingOutboundPayment::Fulfilled { .. } => true,
 113                         _ => false,
 114                 }
 115         }
 116         pub(super) fn abandoned(&self) -> bool {
 117                 match self {
 118                         PendingOutboundPayment::Abandoned { .. } => true,
 119                         _ => false,
 120                 }
 121         }
 122         fn get_pending_fee_msat(&self) -> Option<u64> {
 123                 match self {
 124                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 125                         _ => None,
 126                 }
 127         }
 128
 129         fn payment_hash(&self) -> Option<PaymentHash> {
 130                 match self {
 131                         PendingOutboundPayment::Legacy { .. } => None,
 132                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 133                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 134                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 135                 }
 136         }
 137
 138         fn mark_fulfilled(&mut self) {
 139                 let mut session_privs = HashSet::new();
 140                 core::mem::swap(&mut session_privs, match self {
 141                         PendingOutboundPayment::Legacy { session_privs } |
 142                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 143                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 144                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 145                         => session_privs,
 146                 });
 147                 let payment_hash = self.payment_hash();
 148                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 149         }
 150
 151         fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
 152                 if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
 153                         let mut our_session_privs = HashSet::new();
 154                         core::mem::swap(&mut our_session_privs, session_privs);
 155                         *self = PendingOutboundPayment::Abandoned {
 156                                 session_privs: our_session_privs,
 157                                 payment_hash: *payment_hash,
 158                                 reason: Some(reason)
 159                         };
 160                 }
 161         }
 162
 163         /// panics if path is None and !self.is_fulfilled
 164         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Path>) -> bool {
 165                 let remove_res = match self {
 166                         PendingOutboundPayment::Legacy { session_privs } |
 167                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 168                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 169                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 170                                         session_privs.remove(session_priv)
 171                                 }
 172                 };
 173                 if remove_res {
 174                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 175                                 let path = path.expect("Fulfilling a payment should always come with a path");
 176                                 *pending_amt_msat -= path.final_value_msat();
 177                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 178                                         *fee_msat -= path.fee_msat();
 179                                 }
 180                         }
 181                 }
 182                 remove_res
 183         }
 184
 185         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Path) -> bool {
 186                 let insert_res = match self {
 187                         PendingOutboundPayment::Legacy { session_privs } |
 188                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 189                                         session_privs.insert(session_priv)
 190                                 }
 191                         PendingOutboundPayment::Fulfilled { .. } => false,
 192                         PendingOutboundPayment::Abandoned { .. } => false,
 193                 };
 194                 if insert_res {
 195                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 196                                 *pending_amt_msat += path.final_value_msat();
 197                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 198                                         *fee_msat += path.fee_msat();
 199                                 }
 200                         }
 201                 }
 202                 insert_res
 203         }
 204
 205         pub(super) fn remaining_parts(&self) -> usize {
 206                 match self {
 207                         PendingOutboundPayment::Legacy { session_privs } |
 208                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 209                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 210                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 211                                         session_privs.len()
 212                                 }
 213                 }
 214         }
 215 }
 216
 217 /// Strategies available to retry payment path failures.
 218 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 219 pub enum Retry {
 220         /// Max number of attempts to retry payment.
 221         ///
 222         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 223         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 224         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 225         Attempts(usize),
 226         #[cfg(not(feature = "no-std"))]
 227         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 228         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 229         ///
 230         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 231         Timeout(core::time::Duration),
 232 }
 233
 234 impl Retry {
 235         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 236                 match (self, attempts) {
 237                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 238                                 max_retry_count > count
 239                         },
 240                         #[cfg(all(not(feature = "no-std"), not(test)))]
 241                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 242                                 *max_duration >= crate::util::time::MonotonicTime::now().duration_since(*first_attempted_at),
 243                         #[cfg(all(not(feature = "no-std"), test))]
 244                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 245                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 246                 }
 247         }
 248 }
 249
 250 #[cfg(feature = "std")]
 251 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 252         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 253                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 254                         return elapsed > core::time::Duration::from_secs(expiry_time)
 255                 }
 256         }
 257         false
 258 }
 259
 260 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 261
 262 /// Storing minimal payment attempts information required for determining if a outbound payment can
 263 /// be retried.
 264 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 265         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 266         /// it means the result of the first attempt is not known yet.
 267         pub(crate) count: usize,
 268         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 269         #[cfg(not(feature = "no-std"))]
 270         first_attempted_at: T,
 271         #[cfg(feature = "no-std")]
 272         phantom: core::marker::PhantomData<T>,
 273
 274 }
 275
 276 #[cfg(not(any(feature = "no-std", test)))]
 277 type ConfiguredTime = crate::util::time::MonotonicTime;
 278 #[cfg(feature = "no-std")]
 279 type ConfiguredTime = crate::util::time::Eternity;
 280 #[cfg(all(not(feature = "no-std"), test))]
 281 type ConfiguredTime = SinceEpoch;
 282
 283 impl<T: Time> PaymentAttemptsUsingTime<T> {
 284         pub(crate) fn new() -> Self {
 285                 PaymentAttemptsUsingTime {
 286                         count: 0,
 287                         #[cfg(not(feature = "no-std"))]
 288                         first_attempted_at: T::now(),
 289                         #[cfg(feature = "no-std")]
 290                         phantom: core::marker::PhantomData,
 291                 }
 292         }
 293 }
 294
 295 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 296         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 297                 #[cfg(feature = "no-std")]
 298                 return write!(f, "attempts: {}", self.count);
 299                 #[cfg(not(feature = "no-std"))]
 300                 return write!(
 301                         f,
 302                         "attempts: {}, duration: {}s",
 303                         self.count,
 304                         T::now().duration_since(self.first_attempted_at).as_secs()
 305                 );
 306         }
 307 }
 308
 309 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 310 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 311 ///
 312 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 313 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 314 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 315 #[derive(Clone, Debug, PartialEq, Eq)]
 316 pub enum RetryableSendFailure {
 317         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 318         /// that this error is *not* caused by [`Retry::Timeout`].
 319         ///
 320         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 321         PaymentExpired,
 322         /// We were unable to find a route to the destination.
 323         RouteNotFound,
 324         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 325         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 326         ///
 327         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 328         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 329         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 330         DuplicatePayment,
 331 }
 332
 333 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 334 /// of several states. This enum is returned as the Err() type describing which state the payment
 335 /// is in, see the description of individual enum states for more.
 336 ///
 337 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 338 #[derive(Clone, Debug)]
 339 pub enum PaymentSendFailure {
 340         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 341         /// send the payment at all.
 342         ///
 343         /// You can freely resend the payment in full (with the parameter error fixed).
 344         ///
 345         /// Because the payment failed outright, no payment tracking is done and no
 346         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 347         ///
 348         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 349         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 350         ParameterError(APIError),
 351         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 352         /// from attempting to send the payment at all.
 353         ///
 354         /// You can freely resend the payment in full (with the parameter error fixed).
 355         ///
 356         /// Because the payment failed outright, no payment tracking is done and no
 357         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 358         ///
 359         /// The results here are ordered the same as the paths in the route object which was passed to
 360         /// send_payment.
 361         ///
 362         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 363         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 364         PathParameterError(Vec<Result<(), APIError>>),
 365         /// All paths which were attempted failed to send, with no channel state change taking place.
 366         /// You can freely resend the payment in full (though you probably want to do so over different
 367         /// paths than the ones selected).
 368         ///
 369         /// Because the payment failed outright, no payment tracking is done and no
 370         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 371         ///
 372         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 373         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 374         AllFailedResendSafe(Vec<APIError>),
 375         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 376         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 377         ///
 378         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 379         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 380         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 381         DuplicatePayment,
 382         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 383         /// some paths have irrevocably committed to the HTLC.
 384         ///
 385         /// The results here are ordered the same as the paths in the route object that was passed to
 386         /// send_payment.
 387         ///
 388         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 389         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 390         ///
 391         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 392         PartialFailure {
 393                 /// The errors themselves, in the same order as the paths from the route.
 394                 results: Vec<Result<(), APIError>>,
 395                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 396                 /// contain a [`RouteParameters`] object for the failing paths.
 397                 failed_paths_retry: Option<RouteParameters>,
 398                 /// The payment id for the payment, which is now at least partially pending.
 399                 payment_id: PaymentId,
 400         },
 401 }
 402
 403 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 404 ///
 405 /// This should generally be constructed with data communicated to us from the recipient (via a
 406 /// BOLT11 or BOLT12 invoice).
 407 #[derive(Clone, Debug, PartialEq, Eq)]
 408 pub struct RecipientOnionFields {
 409         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 410         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 411         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 412         /// attacks.
 413         ///
 414         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 415         /// multi-path payments require a recipient-provided secret.
 416         ///
 417         /// Some implementations may reject spontaneous payments with payment secrets, so you may only
 418         /// want to provide a secret for a spontaneous payment if MPP is needed and you know your
 419         /// recipient will not reject it.
 420         pub payment_secret: Option<PaymentSecret>,
 421         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 422         /// arbitrary length. This gives recipients substantially more flexibility to receive
 423         /// additional data.
 424         ///
 425         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 426         /// scheme to authenticate received payments against expected payments and invoices, this field
 427         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 428         /// invoices which will be received with the payment.
 429         ///
 430         /// Note that this field was added to the lightning specification more recently than
 431         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 432         /// may not be supported as universally.
 433         pub payment_metadata: Option<Vec<u8>>,
 434 }
 435
 436 impl_writeable_tlv_based!(RecipientOnionFields, {
 437         (0, payment_secret, option),
 438         (2, payment_metadata, option),
 439 });
 440
 441 impl RecipientOnionFields {
 442         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 443         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 444         /// but do not require or provide any further data.
 445         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 446                 Self { payment_secret: Some(payment_secret), payment_metadata: None }
 447         }
 448
 449         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 450         /// payable HTLCs except for single-path spontaneous payments, i.e. this should generally
 451         /// only be used for calls to [`ChannelManager::send_spontaneous_payment`]. If you are sending
 452         /// a spontaneous MPP this will not work as all MPP require payment secrets; you may
 453         /// instead want to use [`RecipientOnionFields::secret_only`].
 454         ///
 455         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 456         /// [`RecipientOnionFields::secret_only`]: RecipientOnionFields::secret_only
 457         pub fn spontaneous_empty() -> Self {
 458                 Self { payment_secret: None, payment_metadata: None }
 459         }
 460
 461         /// When we have received some HTLC(s) towards an MPP payment, as we receive further HTLC(s) we
 462         /// have to make sure that some fields match exactly across the parts. For those that aren't
 463         /// required to match, if they don't match we should remove them so as to not expose data
 464         /// that's dependent on the HTLC receive order to users.
 465         ///
 466         /// Here we implement this, first checking compatibility then mutating two objects and then
 467         /// dropping any remaining non-matching fields from both.
 468         pub(super) fn check_merge(&mut self, further_htlc_fields: &mut Self) -> Result<(), ()> {
 469                 if self.payment_secret != further_htlc_fields.payment_secret { return Err(()); }
 470                 if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 471                 // For custom TLVs we should just drop non-matching ones, but not reject the payment.
 472                 Ok(())
 473         }
 474 }
 475
 476 pub(super) struct OutboundPayments {
 477         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 478         pub(super) retry_lock: Mutex<()>,
 479 }
 480
 481 impl OutboundPayments {
 482         pub(super) fn new() -> Self {
 483                 Self {
 484                         pending_outbound_payments: Mutex::new(HashMap::new()),
 485                         retry_lock: Mutex::new(()),
 486                 }
 487         }
 488
 489         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 490                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 491                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 492                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 493                 node_signer: &NS, best_block_height: u32, logger: &L,
 494                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 495         ) -> Result<(), RetryableSendFailure>
 496         where
 497                 R::Target: Router,
 498                 ES::Target: EntropySource,
 499                 NS::Target: NodeSigner,
 500                 L::Target: Logger,
 501                 IH: Fn() -> InFlightHtlcs,
 502                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 503                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 504         {
 505                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 506                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 507                         best_block_height, logger, pending_events, &send_payment_along_path)
 508         }
 509
 510         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 511                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 512                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 513                 send_payment_along_path: F
 514         ) -> Result<(), PaymentSendFailure>
 515         where
 516                 ES::Target: EntropySource,
 517                 NS::Target: NodeSigner,
 518                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 519                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 520         {
 521                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(), payment_id, None, route, None, None, entropy_source, best_block_height)?;
 522                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 523                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 524                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 525         }
 526
 527         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 528                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 529                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 530                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 531                 node_signer: &NS, best_block_height: u32, logger: &L,
 532                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP
 533         ) -> Result<PaymentHash, RetryableSendFailure>
 534         where
 535                 R::Target: Router,
 536                 ES::Target: EntropySource,
 537                 NS::Target: NodeSigner,
 538                 L::Target: Logger,
 539                 IH: Fn() -> InFlightHtlcs,
 540                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 541                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 542         {
 543                 let preimage = payment_preimage
 544                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 545                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 546                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 547                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 548                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 549                         .map(|()| payment_hash)
 550         }
 551
 552         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 553                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 554                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 555                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 556         ) -> Result<PaymentHash, PaymentSendFailure>
 557         where
 558                 ES::Target: EntropySource,
 559                 NS::Target: NodeSigner,
 560                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 561                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 562         {
 563                 let preimage = payment_preimage
 564                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 565                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 566                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 567                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 568
 569                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 570                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 571                 ) {
 572                         Ok(()) => Ok(payment_hash),
 573                         Err(e) => {
 574                                 self.remove_outbound_if_all_failed(payment_id, &e);
 575                                 Err(e)
 576                         }
 577                 }
 578         }
 579
 580         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 581                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 582                 best_block_height: u32,
 583                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
 584                 send_payment_along_path: SP,
 585         )
 586         where
 587                 R::Target: Router,
 588                 ES::Target: EntropySource,
 589                 NS::Target: NodeSigner,
 590                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 591                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
 592                 IH: Fn() -> InFlightHtlcs,
 593                 FH: Fn() -> Vec<ChannelDetails>,
 594                 L::Target: Logger,
 595         {
 596                 let _single_thread = self.retry_lock.lock().unwrap();
 597                 loop {
 598                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 599                         let mut retry_id_route_params = None;
 600                         for (pmt_id, pmt) in outbounds.iter_mut() {
 601                                 if pmt.is_auto_retryable_now() {
 602                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 603                                                 if pending_amt_msat < total_msat {
 604                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 605                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 606                                                                 payment_params: params.clone(),
 607                                                         }));
 608                                                         break
 609                                                 }
 610                                         } else { debug_assert!(false); }
 611                                 }
 612                         }
 613                         core::mem::drop(outbounds);
 614                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 615                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops(), &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path)
 616                         } else { break }
 617                 }
 618
 619                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 620                 outbounds.retain(|pmt_id, pmt| {
 621                         let mut retain = true;
 622                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
 623                                 pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
 624                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
 625                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 626                                                 payment_id: *pmt_id,
 627                                                 payment_hash: *payment_hash,
 628                                                 reason: *reason,
 629                                         }, None));
 630                                         retain = false;
 631                                 }
 632                         }
 633                         retain
 634                 });
 635         }
 636
 637         pub(super) fn needs_abandon(&self) -> bool {
 638                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 639                 outbounds.iter().any(|(_, pmt)|
 640                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled())
 641         }
 642
 643         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 644         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 645         ///
 646         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 647         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 648         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 649                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 650                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 651                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 652                 node_signer: &NS, best_block_height: u32, logger: &L,
 653                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 654         ) -> Result<(), RetryableSendFailure>
 655         where
 656                 R::Target: Router,
 657                 ES::Target: EntropySource,
 658                 NS::Target: NodeSigner,
 659                 L::Target: Logger,
 660                 IH: Fn() -> InFlightHtlcs,
 661                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 662                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 663         {
 664                 #[cfg(feature = "std")] {
 665                         if has_expired(&route_params) {
 666                                 return Err(RetryableSendFailure::PaymentExpired)
 667                         }
 668                 }
 669
 670                 let route = router.find_route_with_id(
 671                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 672                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 673                         payment_hash, payment_id,
 674                 ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 675
 676                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 677                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 678                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 679                         .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 680
 681                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, None, payment_id, None,
 682                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 683                 log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
 684                 if let Err(e) = res {
 685                         self.handle_pay_route_err(e, payment_id, payment_hash, route, route_params, router, first_hops, &inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, &send_payment_along_path);
 686                 }
 687                 Ok(())
 688         }
 689
 690         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 691                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 692                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 693                 node_signer: &NS, best_block_height: u32, logger: &L,
 694                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 695         )
 696         where
 697                 R::Target: Router,
 698                 ES::Target: EntropySource,
 699                 NS::Target: NodeSigner,
 700                 L::Target: Logger,
 701                 IH: Fn() -> InFlightHtlcs,
 702                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 703                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 704         {
 705                 #[cfg(feature = "std")] {
 706                         if has_expired(&route_params) {
 707                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
 708                                 self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
 709                                 return
 710                         }
 711                 }
 712
 713                 let route = match router.find_route_with_id(
 714                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 715                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 716                         payment_hash, payment_id,
 717                 ) {
 718                         Ok(route) => route,
 719                         Err(e) => {
 720                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
 721                                 self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
 722                                 return
 723                         }
 724                 };
 725                 for path in route.paths.iter() {
 726                         if path.hops.len() == 0 {
 727                                 log_error!(logger, "Unusable path in route (path.hops.len() must be at least 1");
 728                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 729                                 return
 730                         }
 731                 }
 732
 733                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 734                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 735                 for _ in 0..route.paths.len() {
 736                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 737                 }
 738
 739                 macro_rules! abandon_with_entry {
 740                         ($payment: expr, $reason: expr) => {
 741                                 $payment.get_mut().mark_abandoned($reason);
 742                                 if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
 743                                         if $payment.get().remaining_parts() == 0 {
 744                                                 pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 745                                                         payment_id,
 746                                                         payment_hash,
 747                                                         reason: *reason,
 748                                                 }, None));
 749                                                 $payment.remove();
 750                                         }
 751                                 }
 752                         }
 753                 }
 754                 let (total_msat, recipient_onion, keysend_preimage) = {
 755                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 756                         match outbounds.entry(payment_id) {
 757                                 hash_map::Entry::Occupied(mut payment) => {
 758                                         let res = match payment.get() {
 759                                                 PendingOutboundPayment::Retryable {
 760                                                         total_msat, keysend_preimage, payment_secret, payment_metadata, pending_amt_msat, ..
 761                                                 } => {
 762                                                         let retry_amt_msat = route.get_total_amount();
 763                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 764                                                                 log_error!(logger, "retry_amt_msat of {} will put pending_amt_msat (currently: {}) more than 10% over total_payment_amt_msat of {}", retry_amt_msat, pending_amt_msat, total_msat);
 765                                                                 abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
 766                                                                 return
 767                                                         }
 768                                                         (*total_msat, RecipientOnionFields {
 769                                                                         payment_secret: *payment_secret,
 770                                                                         payment_metadata: payment_metadata.clone(),
 771                                                                 }, *keysend_preimage)
 772                                                 },
 773                                                 PendingOutboundPayment::Legacy { .. } => {
 774                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 775                                                         return
 776                                                 },
 777                                                 PendingOutboundPayment::Fulfilled { .. } => {
 778                                                         log_error!(logger, "Payment already completed");
 779                                                         return
 780                                                 },
 781                                                 PendingOutboundPayment::Abandoned { .. } => {
 782                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 783                                                         return
 784                                                 },
 785                                         };
 786                                         if !payment.get().is_retryable_now() {
 787                                                 log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
 788                                                 abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
 789                                                 return
 790                                         }
 791                                         payment.get_mut().increment_attempts();
 792                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 793                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 794                                         }
 795                                         res
 796                                 },
 797                                 hash_map::Entry::Vacant(_) => {
 798                                         log_error!(logger, "Payment with ID {} not found", log_bytes!(payment_id.0));
 799                                         return
 800                                 }
 801                         }
 802                 };
 803                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
 804                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 805                         &send_payment_along_path);
 806                 log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
 807                 if let Err(e) = res {
 808                         self.handle_pay_route_err(e, payment_id, payment_hash, route, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 809                 }
 810         }
 811
 812         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 813                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 814                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 815                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 816                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 817         )
 818         where
 819                 R::Target: Router,
 820                 ES::Target: EntropySource,
 821                 NS::Target: NodeSigner,
 822                 L::Target: Logger,
 823                 IH: Fn() -> InFlightHtlcs,
 824                 SP: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 825                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 826         {
 827                 match err {
 828                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 829                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, errs.into_iter().map(|e| Err(e)), logger, pending_events);
 830                                 self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 831                         },
 832                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 833                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
 834                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 835                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 836                                 // return `Ok()` here, ignoring any retry errors.
 837                                 self.retry_payment_internal(payment_hash, payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
 838                         },
 839                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 840                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 841                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 842                                 // initial HTLC-Add messages yet.
 843                         },
 844                         PaymentSendFailure::PathParameterError(results) => {
 845                                 log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
 846                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
 847                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 848                         },
 849                         PaymentSendFailure::ParameterError(e) => {
 850                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 851                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 852                         },
 853                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 854                 }
 855         }
 856
 857         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
 858                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 859                 paths: Vec<Path>, path_results: I, logger: &L,
 860                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
 861         ) where L::Target: Logger {
 862                 let mut events = pending_events.lock().unwrap();
 863                 debug_assert_eq!(paths.len(), path_results.len());
 864                 for (path, path_res) in paths.into_iter().zip(path_results) {
 865                         if let Err(e) = path_res {
 866                                 if let APIError::MonitorUpdateInProgress = e { continue }
 867                                 log_error!(logger, "Failed to send along path due to error: {:?}", e);
 868                                 let mut failed_scid = None;
 869                                 if let APIError::ChannelUnavailable { .. } = e {
 870                                         let scid = path.hops[0].short_channel_id;
 871                                         failed_scid = Some(scid);
 872                                         route_params.payment_params.previously_failed_channels.push(scid);
 873                                 }
 874                                 events.push_back((events::Event::PaymentPathFailed {
 875                                         payment_id: Some(payment_id),
 876                                         payment_hash,
 877                                         payment_failed_permanently: false,
 878                                         failure: events::PathFailure::InitialSend { err: e },
 879                                         path,
 880                                         short_channel_id: failed_scid,
 881                                         #[cfg(test)]
 882                                         error_code: None,
 883                                         #[cfg(test)]
 884                                         error_data: None,
 885                                 }, None));
 886                         }
 887                 }
 888         }
 889
 890         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 891                 &self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
 892                 best_block_height: u32, send_payment_along_path: F
 893         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 894         where
 895                 ES::Target: EntropySource,
 896                 NS::Target: NodeSigner,
 897                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 898                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 899         {
 900                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 901
 902                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 903
 904                 if path.hops.len() < 2 && path.blinded_tail.is_none() {
 905                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 906                                 err: "No need probing a path with less than two hops".to_string()
 907                         }))
 908                 }
 909
 910                 let route = Route { paths: vec![path], payment_params: None };
 911                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 912                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
 913                         entropy_source, best_block_height)?;
 914
 915                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
 916                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 917                 ) {
 918                         Ok(()) => Ok((payment_hash, payment_id)),
 919                         Err(e) => {
 920                                 self.remove_outbound_if_all_failed(payment_id, &e);
 921                                 Err(e)
 922                         }
 923                 }
 924         }
 925
 926         #[cfg(test)]
 927         pub(super) fn test_set_payment_metadata(
 928                 &self, payment_id: PaymentId, new_payment_metadata: Option<Vec<u8>>
 929         ) {
 930                 match self.pending_outbound_payments.lock().unwrap().get_mut(&payment_id).unwrap() {
 931                         PendingOutboundPayment::Retryable { payment_metadata, .. } => {
 932                                 *payment_metadata = new_payment_metadata;
 933                         },
 934                         _ => panic!("Need a retryable payment to update metadata on"),
 935                 }
 936         }
 937
 938         #[cfg(test)]
 939         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 940                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 941                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
 942         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 943                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
 944         }
 945
 946         pub(super) fn add_new_pending_payment<ES: Deref>(
 947                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 948                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
 949                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
 950         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 951                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 952                 for _ in 0..route.paths.len() {
 953                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 954                 }
 955
 956                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 957                 match pending_outbounds.entry(payment_id) {
 958                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 959                         hash_map::Entry::Vacant(entry) => {
 960                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 961                                         retry_strategy,
 962                                         attempts: PaymentAttempts::new(),
 963                                         payment_params,
 964                                         session_privs: HashSet::new(),
 965                                         pending_amt_msat: 0,
 966                                         pending_fee_msat: Some(0),
 967                                         payment_hash,
 968                                         payment_secret: recipient_onion.payment_secret,
 969                                         payment_metadata: recipient_onion.payment_metadata,
 970                                         keysend_preimage,
 971                                         starting_block_height: best_block_height,
 972                                         total_msat: route.get_total_amount(),
 973                                 });
 974
 975                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 976                                         assert!(payment.insert(*session_priv_bytes, path));
 977                                 }
 978
 979                                 Ok(onion_session_privs)
 980                         },
 981                 }
 982         }
 983
 984         fn pay_route_internal<NS: Deref, F>(
 985                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 986                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 987                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 988                 send_payment_along_path: &F
 989         ) -> Result<(), PaymentSendFailure>
 990         where
 991                 NS::Target: NodeSigner,
 992                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
 993                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 994         {
 995                 if route.paths.len() < 1 {
 996                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
 997                 }
 998                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
 999                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
1000                 }
1001                 let mut total_value = 0;
1002                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
1003                 let mut path_errs = Vec::with_capacity(route.paths.len());
1004                 'path_check: for path in route.paths.iter() {
1005                         if path.hops.len() < 1 || path.hops.len() > 20 {
1006                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
1007                                 continue 'path_check;
1008                         }
1009                         if path.blinded_tail.is_some() {
1010                                 path_errs.push(Err(APIError::InvalidRoute{err: "Sending to blinded paths isn't supported yet".to_owned()}));
1011                                 continue 'path_check;
1012                         }
1013                         let dest_hop_idx = if path.blinded_tail.is_some() && path.blinded_tail.as_ref().unwrap().hops.len() > 1 {
1014                                 usize::max_value() } else { path.hops.len() - 1 };
1015                         for (idx, hop) in path.hops.iter().enumerate() {
1016                                 if idx != dest_hop_idx && hop.pubkey == our_node_id {
1017                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
1018                                         continue 'path_check;
1019                                 }
1020                         }
1021                         total_value += path.final_value_msat();
1022                         path_errs.push(Ok(()));
1023                 }
1024                 if path_errs.iter().any(|e| e.is_err()) {
1025                         return Err(PaymentSendFailure::PathParameterError(path_errs));
1026                 }
1027                 if let Some(amt_msat) = recv_value_msat {
1028                         total_value = amt_msat;
1029                 }
1030
1031                 let cur_height = best_block_height + 1;
1032                 let mut results = Vec::new();
1033                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
1034                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
1035                         let mut path_res = send_payment_along_path(&path, &payment_hash, recipient_onion.clone(),
1036                                 total_value, cur_height, payment_id, &keysend_preimage, session_priv);
1037                         match path_res {
1038                                 Ok(_) => {},
1039                                 Err(APIError::MonitorUpdateInProgress) => {
1040                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
1041                                         // considered "in flight" and we shouldn't remove it from the
1042                                         // PendingOutboundPayment set.
1043                                 },
1044                                 Err(_) => {
1045                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1046                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1047                                                 let removed = payment.remove(&session_priv, Some(path));
1048                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1049                                         } else {
1050                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1051                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1052                                         }
1053                                 }
1054                         }
1055                         results.push(path_res);
1056                 }
1057                 let mut has_ok = false;
1058                 let mut has_err = false;
1059                 let mut pending_amt_unsent = 0;
1060                 for (res, path) in results.iter().zip(route.paths.iter()) {
1061                         if res.is_ok() { has_ok = true; }
1062                         if res.is_err() { has_err = true; }
1063                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1064                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1065                                 // PartialFailure.
1066                                 has_err = true;
1067                                 has_ok = true;
1068                         } else if res.is_err() {
1069                                 pending_amt_unsent += path.final_value_msat();
1070                         }
1071                 }
1072                 if has_err && has_ok {
1073                         Err(PaymentSendFailure::PartialFailure {
1074                                 results,
1075                                 payment_id,
1076                                 failed_paths_retry: if pending_amt_unsent != 0 {
1077                                         if let Some(payment_params) = &route.payment_params {
1078                                                 Some(RouteParameters {
1079                                                         payment_params: payment_params.clone(),
1080                                                         final_value_msat: pending_amt_unsent,
1081                                                 })
1082                                         } else { None }
1083                                 } else { None },
1084                         })
1085                 } else if has_err {
1086                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1087                 } else {
1088                         Ok(())
1089                 }
1090         }
1091
1092         #[cfg(test)]
1093         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1094                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1095                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1096                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1097                 send_payment_along_path: F
1098         ) -> Result<(), PaymentSendFailure>
1099         where
1100                 NS::Target: NodeSigner,
1101                 F: Fn(&Path, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
1102                         &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
1103         {
1104                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1105                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1106                         &send_payment_along_path)
1107                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1108         }
1109
1110         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1111         // map as the payment is free to be resent.
1112         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1113                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1114                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1115                         debug_assert!(removed, "We should always have a pending payment to remove here");
1116                 }
1117         }
1118
1119         pub(super) fn claim_htlc<L: Deref>(
1120                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1121                 path: Path, from_onchain: bool,
1122                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1123                 logger: &L,
1124         ) where L::Target: Logger {
1125                 let mut session_priv_bytes = [0; 32];
1126                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1127                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1128                 let mut pending_events = pending_events.lock().unwrap();
1129                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1130                         if !payment.get().is_fulfilled() {
1131                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1132                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1133                                 pending_events.push_back((events::Event::PaymentSent {
1134                                         payment_id: Some(payment_id),
1135                                         payment_preimage,
1136                                         payment_hash,
1137                                         fee_paid_msat,
1138                                 }, None));
1139                                 payment.get_mut().mark_fulfilled();
1140                         }
1141
1142                         if from_onchain {
1143                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1144                                 // This could potentially lead to removing a pending payment too early,
1145                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1146                                 // restart.
1147                                 // TODO: We should have a second monitor event that informs us of payments
1148                                 // irrevocably fulfilled.
1149                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1150                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1151                                         pending_events.push_back((events::Event::PaymentPathSuccessful {
1152                                                 payment_id,
1153                                                 payment_hash,
1154                                                 path,
1155                                         }, None));
1156                                 }
1157                         }
1158                 } else {
1159                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
1160                 }
1161         }
1162
1163         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>,
1164                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1165         {
1166                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1167                 let mut pending_events = pending_events.lock().unwrap();
1168                 for source in sources {
1169                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1170                                 let mut session_priv_bytes = [0; 32];
1171                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1172                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1173                                         assert!(payment.get().is_fulfilled());
1174                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1175                                                 let payment_hash = payment.get().payment_hash();
1176                                                 debug_assert!(payment_hash.is_some());
1177                                                 pending_events.push_back((events::Event::PaymentPathSuccessful {
1178                                                         payment_id,
1179                                                         payment_hash,
1180                                                         path,
1181                                                 }, None));
1182                                         }
1183                                 }
1184                         }
1185                 }
1186         }
1187
1188         pub(super) fn remove_stale_resolved_payments(&self,
1189                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1190         {
1191                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1192                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1193                 // this could race the user making a duplicate send_payment call and our idempotency
1194                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1195                 // removal. This should be more than sufficient to ensure the idempotency of any
1196                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1197                 // processed.
1198                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1199                 let pending_events = pending_events.lock().unwrap();
1200                 pending_outbound_payments.retain(|payment_id, payment| {
1201                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1202                                 let mut no_remaining_entries = session_privs.is_empty();
1203                                 if no_remaining_entries {
1204                                         for (ev, _) in pending_events.iter() {
1205                                                 match ev {
1206                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1207                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1208                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1209                                                                         if payment_id == ev_payment_id {
1210                                                                                 no_remaining_entries = false;
1211                                                                                 break;
1212                                                                         }
1213                                                                 },
1214                                                         _ => {},
1215                                                 }
1216                                         }
1217                                 }
1218                                 if no_remaining_entries {
1219                                         *timer_ticks_without_htlcs += 1;
1220                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1221                                 } else {
1222                                         *timer_ticks_without_htlcs = 0;
1223                                         true
1224                                 }
1225                         } else { true }
1226                 });
1227         }
1228
1229         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1230         pub(super) fn fail_htlc<L: Deref>(
1231                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1232                 path: &Path, session_priv: &SecretKey, payment_id: &PaymentId,
1233                 probing_cookie_secret: [u8; 32], secp_ctx: &Secp256k1<secp256k1::All>,
1234                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
1235         ) -> bool where L::Target: Logger {
1236                 #[cfg(test)]
1237                 let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1238                 #[cfg(not(test))]
1239                 let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1240
1241                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1242                 let mut session_priv_bytes = [0; 32];
1243                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1244                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1245
1246                 // If any payments already need retry, there's no need to generate a redundant
1247                 // `PendingHTLCsForwardable`.
1248                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1249                         let mut awaiting_retry = false;
1250                         if pmt.is_auto_retryable_now() {
1251                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1252                                         if pending_amt_msat < total_msat {
1253                                                 awaiting_retry = true;
1254                                         }
1255                                 }
1256                         }
1257                         awaiting_retry
1258                 });
1259
1260                 let mut full_failure_ev = None;
1261                 let mut pending_retry_ev = false;
1262                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1263                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1264                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1265                                 return false
1266                         }
1267                         if payment.get().is_fulfilled() {
1268                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
1269                                 return false
1270                         }
1271                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1272                         if let Some(scid) = short_channel_id {
1273                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1274                                 // process_onion_failure we should close that channel as it implies our
1275                                 // next-hop is needlessly blaming us!
1276                                 payment.get_mut().insert_previously_failed_scid(scid);
1277                         }
1278
1279                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1280                                 let reason = if !payment_retryable {
1281                                         PaymentFailureReason::RecipientRejected
1282                                 } else {
1283                                         PaymentFailureReason::RetriesExhausted
1284                                 };
1285                                 payment.get_mut().mark_abandoned(reason);
1286                                 is_retryable_now = false;
1287                         }
1288                         if payment.get().remaining_parts() == 0 {
1289                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
1290                                         if !payment_is_probe {
1291                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1292                                                         payment_id: *payment_id,
1293                                                         payment_hash: *payment_hash,
1294                                                         reason: *reason,
1295                                                 });
1296                                         }
1297                                         payment.remove();
1298                                 }
1299                         }
1300                         is_retryable_now
1301                 } else {
1302                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1303                         return false
1304                 };
1305                 core::mem::drop(outbounds);
1306                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
1307
1308                 let path_failure = {
1309                         if payment_is_probe {
1310                                 if !payment_retryable {
1311                                         events::Event::ProbeSuccessful {
1312                                                 payment_id: *payment_id,
1313                                                 payment_hash: payment_hash.clone(),
1314                                                 path: path.clone(),
1315                                         }
1316                                 } else {
1317                                         events::Event::ProbeFailed {
1318                                                 payment_id: *payment_id,
1319                                                 payment_hash: payment_hash.clone(),
1320                                                 path: path.clone(),
1321                                                 short_channel_id,
1322                                         }
1323                                 }
1324                         } else {
1325                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1326                                 // payment will sit in our outbounds forever.
1327                                 if attempts_remaining && !already_awaiting_retry {
1328                                         debug_assert!(full_failure_ev.is_none());
1329                                         pending_retry_ev = true;
1330                                 }
1331                                 events::Event::PaymentPathFailed {
1332                                         payment_id: Some(*payment_id),
1333                                         payment_hash: payment_hash.clone(),
1334                                         payment_failed_permanently: !payment_retryable,
1335                                         failure: events::PathFailure::OnPath { network_update },
1336                                         path: path.clone(),
1337                                         short_channel_id,
1338                                         #[cfg(test)]
1339                                         error_code: onion_error_code,
1340                                         #[cfg(test)]
1341                                         error_data: onion_error_data
1342                                 }
1343                         }
1344                 };
1345                 let mut pending_events = pending_events.lock().unwrap();
1346                 pending_events.push_back((path_failure, None));
1347                 if let Some(ev) = full_failure_ev { pending_events.push_back((ev, None)); }
1348                 pending_retry_ev
1349         }
1350
1351         pub(super) fn abandon_payment(
1352                 &self, payment_id: PaymentId, reason: PaymentFailureReason,
1353                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>
1354         ) {
1355                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1356                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1357                         payment.get_mut().mark_abandoned(reason);
1358                         if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
1359                                 if payment.get().remaining_parts() == 0 {
1360                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
1361                                                 payment_id,
1362                                                 payment_hash: *payment_hash,
1363                                                 reason: *reason,
1364                                         }, None));
1365                                         payment.remove();
1366                                 }
1367                         }
1368                 }
1369         }
1370
1371         #[cfg(test)]
1372         pub fn has_pending_payments(&self) -> bool {
1373                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1374         }
1375
1376         #[cfg(test)]
1377         pub fn clear_pending_payments(&self) {
1378                 self.pending_outbound_payments.lock().unwrap().clear()
1379         }
1380 }
1381
1382 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1383 /// payment probe.
1384 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1385         probing_cookie_secret: [u8; 32]) -> bool
1386 {
1387         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1388         target_payment_hash == *payment_hash
1389 }
1390
1391 /// Returns the 'probing cookie' for the given [`PaymentId`].
1392 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1393         let mut preimage = [0u8; 64];
1394         preimage[..32].copy_from_slice(&probing_cookie_secret);
1395         preimage[32..].copy_from_slice(&payment_id.0);
1396         PaymentHash(Sha256::hash(&preimage).into_inner())
1397 }
1398
1399 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1400         (0, Legacy) => {
1401                 (0, session_privs, required),
1402         },
1403         (1, Fulfilled) => {
1404                 (0, session_privs, required),
1405                 (1, payment_hash, option),
1406                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1407         },
1408         (2, Retryable) => {
1409                 (0, session_privs, required),
1410                 (1, pending_fee_msat, option),
1411                 (2, payment_hash, required),
1412                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1413                 // never see it - `payment_params` was added here after the field was added/required.
1414                 (3, payment_params, (option: ReadableArgs, 0)),
1415                 (4, payment_secret, option),
1416                 (5, keysend_preimage, option),
1417                 (6, total_msat, required),
1418                 (7, payment_metadata, option),
1419                 (8, pending_amt_msat, required),
1420                 (10, starting_block_height, required),
1421                 (not_written, retry_strategy, (static_value, None)),
1422                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1423         },
1424         (3, Abandoned) => {
1425                 (0, session_privs, required),
1426                 (1, reason, option),
1427                 (2, payment_hash, required),
1428         },
1429 );
1430
1431 #[cfg(test)]
1432 mod tests {
1433         use bitcoin::network::constants::Network;
1434         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1435
1436         use crate::events::{Event, PathFailure, PaymentFailureReason};
1437         use crate::ln::PaymentHash;
1438         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1439         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1440         use crate::ln::msgs::{ErrorAction, LightningError};
1441         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1442         use crate::routing::gossip::NetworkGraph;
1443         use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters};
1444         use crate::sync::{Arc, Mutex};
1445         use crate::util::errors::APIError;
1446         use crate::util::test_utils;
1447
1448         use alloc::collections::VecDeque;
1449
1450         #[test]
1451         #[cfg(feature = "std")]
1452         fn fails_paying_after_expiration() {
1453                 do_fails_paying_after_expiration(false);
1454                 do_fails_paying_after_expiration(true);
1455         }
1456         #[cfg(feature = "std")]
1457         fn do_fails_paying_after_expiration(on_retry: bool) {
1458                 let outbound_payments = OutboundPayments::new();
1459                 let logger = test_utils::TestLogger::new();
1460                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1461                 let scorer = Mutex::new(test_utils::TestScorer::new());
1462                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1463                 let secp_ctx = Secp256k1::new();
1464                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1465
1466                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1467                 let payment_params = PaymentParameters::from_node_id(
1468                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1469                                 0
1470                         ).with_expiry_time(past_expiry_time);
1471                 let expired_route_params = RouteParameters {
1472                         payment_params,
1473                         final_value_msat: 0,
1474                 };
1475                 let pending_events = Mutex::new(VecDeque::new());
1476                 if on_retry {
1477                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1478                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1479                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1480                                 &&keys_manager, 0).unwrap();
1481                         outbound_payments.retry_payment_internal(
1482                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1483                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1484                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1485                         let events = pending_events.lock().unwrap();
1486                         assert_eq!(events.len(), 1);
1487                         if let Event::PaymentFailed { ref reason, .. } = events[0].0 {
1488                                 assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
1489                         } else { panic!("Unexpected event"); }
1490                 } else {
1491                         let err = outbound_payments.send_payment(
1492                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1493                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1494                                 &&keys_manager, &&keys_manager, 0, &&logger,
1495                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1496                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1497                 }
1498         }
1499
1500         #[test]
1501         fn find_route_error() {
1502                 do_find_route_error(false);
1503                 do_find_route_error(true);
1504         }
1505         fn do_find_route_error(on_retry: bool) {
1506                 let outbound_payments = OutboundPayments::new();
1507                 let logger = test_utils::TestLogger::new();
1508                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1509                 let scorer = Mutex::new(test_utils::TestScorer::new());
1510                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1511                 let secp_ctx = Secp256k1::new();
1512                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1513
1514                 let payment_params = PaymentParameters::from_node_id(
1515                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1516                 let route_params = RouteParameters {
1517                         payment_params,
1518                         final_value_msat: 0,
1519                 };
1520                 router.expect_find_route(route_params.clone(),
1521                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1522
1523                 let pending_events = Mutex::new(VecDeque::new());
1524                 if on_retry {
1525                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1526                                 PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
1527                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1528                                 &&keys_manager, 0).unwrap();
1529                         outbound_payments.retry_payment_internal(
1530                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1531                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
1532                                 &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
1533                         let events = pending_events.lock().unwrap();
1534                         assert_eq!(events.len(), 1);
1535                         if let Event::PaymentFailed { .. } = events[0].0 { } else { panic!("Unexpected event"); }
1536                 } else {
1537                         let err = outbound_payments.send_payment(
1538                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1539                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1540                                 &&keys_manager, &&keys_manager, 0, &&logger,
1541                                 &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
1542                         if let RetryableSendFailure::RouteNotFound = err {
1543                         } else { panic!("Unexpected error"); }
1544                 }
1545         }
1546
1547         #[test]
1548         fn initial_send_payment_path_failed_evs() {
1549                 let outbound_payments = OutboundPayments::new();
1550                 let logger = test_utils::TestLogger::new();
1551                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1552                 let scorer = Mutex::new(test_utils::TestScorer::new());
1553                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1554                 let secp_ctx = Secp256k1::new();
1555                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1556
1557                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1558                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1559                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1560                 let route_params = RouteParameters {
1561                         payment_params: payment_params.clone(),
1562                         final_value_msat: 0,
1563                 };
1564                 let failed_scid = 42;
1565                 let route = Route {
1566                         paths: vec![Path { hops: vec![RouteHop {
1567                                 pubkey: receiver_pk,
1568                                 node_features: NodeFeatures::empty(),
1569                                 short_channel_id: failed_scid,
1570                                 channel_features: ChannelFeatures::empty(),
1571                                 fee_msat: 0,
1572                                 cltv_expiry_delta: 0,
1573                         }], blinded_tail: None }],
1574                         payment_params: Some(payment_params),
1575                 };
1576                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1577                 let mut route_params_w_failed_scid = route_params.clone();
1578                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1579                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1580                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1581                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1582
1583                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1584                 // PaymentPathFailed event.
1585                 let pending_events = Mutex::new(VecDeque::new());
1586                 outbound_payments.send_payment(
1587                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1588                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1589                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1590                         |_, _, _, _, _, _, _, _| Err(APIError::ChannelUnavailable { err: "test".to_owned() }))
1591                         .unwrap();
1592                 let mut events = pending_events.lock().unwrap();
1593                 assert_eq!(events.len(), 2);
1594                 if let Event::PaymentPathFailed {
1595                         short_channel_id,
1596                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0].0
1597                 {
1598                         assert_eq!(short_channel_id, Some(failed_scid));
1599                 } else { panic!("Unexpected event"); }
1600                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1601                 events.clear();
1602                 core::mem::drop(events);
1603
1604                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1605                 outbound_payments.send_payment(
1606                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1607                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1608                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1609                         |_, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress)).unwrap();
1610                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1611
1612                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1613                 outbound_payments.send_payment(
1614                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1615                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1616                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1617                         |_, _, _, _, _, _, _, _| Err(APIError::APIMisuseError { err: "test".to_owned() }))
1618                         .unwrap();
1619                 let events = pending_events.lock().unwrap();
1620                 assert_eq!(events.len(), 2);
1621                 if let Event::PaymentPathFailed {
1622                         short_channel_id,
1623                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0].0
1624                 {
1625                         assert_eq!(short_channel_id, None);
1626                 } else { panic!("Unexpected event"); }
1627                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1628         }
1629 }