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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Utilities to send payments and manage outbound payment information.
  11
  12 use bitcoin::hashes::Hash;
  13 use bitcoin::hashes::sha256::Hash as Sha256;
  14 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
  15
  16 use crate::sign::{EntropySource, NodeSigner, Recipient};
  17 use crate::events::{self, PaymentFailureReason};
  18 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  19 use crate::ln::channelmanager::{ChannelDetails, EventCompletionAction, HTLCSource, PaymentId};
  20 use crate::ln::onion_utils::{DecodedOnionFailure, HTLCFailReason};
  21 use crate::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 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until we time-out the idempotency
  36 /// of payments by [`PaymentId`]. See [`OutboundPayments::remove_stale_payments`].
  37 ///
  38 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  39 pub(crate) const IDEMPOTENCY_TIMEOUT_TICKS: u8 = 7;
  40
  41 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until an invoice request without
  42 /// a response is timed out.
  43 ///
  44 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  45 const INVOICE_REQUEST_TIMEOUT_TICKS: u8 = 3;
  46
  47 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  48 /// and later, also stores information for retrying the payment.
  49 pub(crate) enum PendingOutboundPayment {
  50         Legacy {
  51                 session_privs: HashSet<[u8; 32]>,
  52         },
  53         AwaitingInvoice {
  54                 timer_ticks_without_response: u8,
  55         },
  56         Retryable {
  57                 retry_strategy: Option<Retry>,
  58                 attempts: PaymentAttempts,
  59                 payment_params: Option<PaymentParameters>,
  60                 session_privs: HashSet<[u8; 32]>,
  61                 payment_hash: PaymentHash,
  62                 payment_secret: Option<PaymentSecret>,
  63                 payment_metadata: Option<Vec<u8>>,
  64                 keysend_preimage: Option<PaymentPreimage>,
  65                 custom_tlvs: Vec<(u64, Vec<u8>)>,
  66                 pending_amt_msat: u64,
  67                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  68                 pending_fee_msat: Option<u64>,
  69                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  70                 total_msat: u64,
  71                 /// Our best known block height at the time this payment was initiated.
  72                 starting_block_height: u32,
  73         },
  74         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  75         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  76         /// and add a pending payment that was already fulfilled.
  77         Fulfilled {
  78                 session_privs: HashSet<[u8; 32]>,
  79                 /// Filled in for any payment which moved to `Fulfilled` on LDK 0.0.104 or later.
  80                 payment_hash: Option<PaymentHash>,
  81                 timer_ticks_without_htlcs: u8,
  82         },
  83         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  84         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  85         Abandoned {
  86                 session_privs: HashSet<[u8; 32]>,
  87                 payment_hash: PaymentHash,
  88                 /// Will be `None` if the payment was serialized before 0.0.115.
  89                 reason: Option<PaymentFailureReason>,
  90         },
  91 }
  92
  93 impl PendingOutboundPayment {
  94         fn increment_attempts(&mut self) {
  95                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  96                         attempts.count += 1;
  97                 }
  98         }
  99         fn is_auto_retryable_now(&self) -> bool {
 100                 match self {
 101                         PendingOutboundPayment::Retryable {
 102                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
 103                         } => {
 104                                 strategy.is_retryable_now(&attempts)
 105                         },
 106                         _ => false,
 107                 }
 108         }
 109         fn is_retryable_now(&self) -> bool {
 110                 match self {
 111                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
 112                                 // We're handling retries manually, we can always retry.
 113                                 true
 114                         },
 115                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
 116                                 strategy.is_retryable_now(&attempts)
 117                         },
 118                         _ => false,
 119                 }
 120         }
 121         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 122                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 123                         params.previously_failed_channels.push(scid);
 124                 }
 125         }
 126         fn is_awaiting_invoice(&self) -> bool {
 127                 match self {
 128                         PendingOutboundPayment::AwaitingInvoice { .. } => true,
 129                         _ => false,
 130                 }
 131         }
 132         pub(super) fn is_fulfilled(&self) -> bool {
 133                 match self {
 134                         PendingOutboundPayment::Fulfilled { .. } => true,
 135                         _ => false,
 136                 }
 137         }
 138         pub(super) fn abandoned(&self) -> bool {
 139                 match self {
 140                         PendingOutboundPayment::Abandoned { .. } => true,
 141                         _ => false,
 142                 }
 143         }
 144         fn get_pending_fee_msat(&self) -> Option<u64> {
 145                 match self {
 146                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 147                         _ => None,
 148                 }
 149         }
 150
 151         fn payment_hash(&self) -> Option<PaymentHash> {
 152                 match self {
 153                         PendingOutboundPayment::Legacy { .. } => None,
 154                         PendingOutboundPayment::AwaitingInvoice { .. } => None,
 155                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 156                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 157                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 158                 }
 159         }
 160
 161         fn mark_fulfilled(&mut self) {
 162                 let mut session_privs = HashSet::new();
 163                 core::mem::swap(&mut session_privs, match self {
 164                         PendingOutboundPayment::Legacy { session_privs } |
 165                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 166                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 167                                 PendingOutboundPayment::Abandoned { session_privs, .. } => session_privs,
 168                         PendingOutboundPayment::AwaitingInvoice { .. } => {
 169                                 debug_assert!(false);
 170                                 return;
 171                         },
 172                 });
 173                 let payment_hash = self.payment_hash();
 174                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 175         }
 176
 177         fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
 178                 if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
 179                         let mut our_session_privs = HashSet::new();
 180                         core::mem::swap(&mut our_session_privs, session_privs);
 181                         *self = PendingOutboundPayment::Abandoned {
 182                                 session_privs: our_session_privs,
 183                                 payment_hash: *payment_hash,
 184                                 reason: Some(reason)
 185                         };
 186                 }
 187         }
 188
 189         /// panics if path is None and !self.is_fulfilled
 190         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Path>) -> bool {
 191                 let remove_res = match self {
 192                         PendingOutboundPayment::Legacy { session_privs } |
 193                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 194                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 195                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 196                                         session_privs.remove(session_priv)
 197                                 },
 198                         PendingOutboundPayment::AwaitingInvoice { .. } => {
 199                                 debug_assert!(false);
 200                                 false
 201                         },
 202                 };
 203                 if remove_res {
 204                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 205                                 let path = path.expect("Fulfilling a payment should always come with a path");
 206                                 *pending_amt_msat -= path.final_value_msat();
 207                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 208                                         *fee_msat -= path.fee_msat();
 209                                 }
 210                         }
 211                 }
 212                 remove_res
 213         }
 214
 215         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Path) -> bool {
 216                 let insert_res = match self {
 217                         PendingOutboundPayment::Legacy { session_privs } |
 218                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 219                                         session_privs.insert(session_priv)
 220                                 }
 221                         PendingOutboundPayment::AwaitingInvoice { .. } => {
 222                                 debug_assert!(false);
 223                                 false
 224                         },
 225                         PendingOutboundPayment::Fulfilled { .. } => false,
 226                         PendingOutboundPayment::Abandoned { .. } => false,
 227                 };
 228                 if insert_res {
 229                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 230                                 *pending_amt_msat += path.final_value_msat();
 231                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 232                                         *fee_msat += path.fee_msat();
 233                                 }
 234                         }
 235                 }
 236                 insert_res
 237         }
 238
 239         pub(super) fn remaining_parts(&self) -> usize {
 240                 match self {
 241                         PendingOutboundPayment::Legacy { session_privs } |
 242                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 243                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 244                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 245                                         session_privs.len()
 246                                 },
 247                         PendingOutboundPayment::AwaitingInvoice { .. } => 0,
 248                 }
 249         }
 250 }
 251
 252 /// Strategies available to retry payment path failures.
 253 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 254 pub enum Retry {
 255         /// Max number of attempts to retry payment.
 256         ///
 257         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 258         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 259         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 260         Attempts(usize),
 261         #[cfg(not(feature = "no-std"))]
 262         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 263         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 264         ///
 265         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 266         Timeout(core::time::Duration),
 267 }
 268
 269 impl Retry {
 270         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 271                 match (self, attempts) {
 272                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 273                                 max_retry_count > count
 274                         },
 275                         #[cfg(all(not(feature = "no-std"), not(test)))]
 276                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 277                                 *max_duration >= crate::util::time::MonotonicTime::now().duration_since(*first_attempted_at),
 278                         #[cfg(all(not(feature = "no-std"), test))]
 279                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 280                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 281                 }
 282         }
 283 }
 284
 285 #[cfg(feature = "std")]
 286 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 287         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 288                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 289                         return elapsed > core::time::Duration::from_secs(expiry_time)
 290                 }
 291         }
 292         false
 293 }
 294
 295 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 296
 297 /// Storing minimal payment attempts information required for determining if a outbound payment can
 298 /// be retried.
 299 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 300         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 301         /// it means the result of the first attempt is not known yet.
 302         pub(crate) count: usize,
 303         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 304         #[cfg(not(feature = "no-std"))]
 305         first_attempted_at: T,
 306         #[cfg(feature = "no-std")]
 307         phantom: core::marker::PhantomData<T>,
 308
 309 }
 310
 311 #[cfg(not(any(feature = "no-std", test)))]
 312 type ConfiguredTime = crate::util::time::MonotonicTime;
 313 #[cfg(feature = "no-std")]
 314 type ConfiguredTime = crate::util::time::Eternity;
 315 #[cfg(all(not(feature = "no-std"), test))]
 316 type ConfiguredTime = SinceEpoch;
 317
 318 impl<T: Time> PaymentAttemptsUsingTime<T> {
 319         pub(crate) fn new() -> Self {
 320                 PaymentAttemptsUsingTime {
 321                         count: 0,
 322                         #[cfg(not(feature = "no-std"))]
 323                         first_attempted_at: T::now(),
 324                         #[cfg(feature = "no-std")]
 325                         phantom: core::marker::PhantomData,
 326                 }
 327         }
 328 }
 329
 330 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 331         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 332                 #[cfg(feature = "no-std")]
 333                 return write!(f, "attempts: {}", self.count);
 334                 #[cfg(not(feature = "no-std"))]
 335                 return write!(
 336                         f,
 337                         "attempts: {}, duration: {}s",
 338                         self.count,
 339                         T::now().duration_since(self.first_attempted_at).as_secs()
 340                 );
 341         }
 342 }
 343
 344 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 345 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 346 ///
 347 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 348 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 349 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 350 #[derive(Clone, Debug, PartialEq, Eq)]
 351 pub enum RetryableSendFailure {
 352         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 353         /// that this error is *not* caused by [`Retry::Timeout`].
 354         ///
 355         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 356         PaymentExpired,
 357         /// We were unable to find a route to the destination.
 358         RouteNotFound,
 359         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 360         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 361         ///
 362         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 363         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 364         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 365         DuplicatePayment,
 366 }
 367
 368 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 369 /// of several states. This enum is returned as the Err() type describing which state the payment
 370 /// is in, see the description of individual enum states for more.
 371 ///
 372 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 373 #[derive(Clone, Debug)]
 374 pub enum PaymentSendFailure {
 375         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 376         /// send the payment at all.
 377         ///
 378         /// You can freely resend the payment in full (with the parameter error fixed).
 379         ///
 380         /// Because the payment failed outright, no payment tracking is done and no
 381         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 382         ///
 383         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 384         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 385         ParameterError(APIError),
 386         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 387         /// from attempting to send the payment at all.
 388         ///
 389         /// You can freely resend the payment in full (with the parameter error fixed).
 390         ///
 391         /// Because the payment failed outright, no payment tracking is done and no
 392         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 393         ///
 394         /// The results here are ordered the same as the paths in the route object which was passed to
 395         /// send_payment.
 396         ///
 397         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 398         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 399         PathParameterError(Vec<Result<(), APIError>>),
 400         /// All paths which were attempted failed to send, with no channel state change taking place.
 401         /// You can freely resend the payment in full (though you probably want to do so over different
 402         /// paths than the ones selected).
 403         ///
 404         /// Because the payment failed outright, no payment tracking is done and no
 405         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 406         ///
 407         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 408         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 409         AllFailedResendSafe(Vec<APIError>),
 410         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 411         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 412         ///
 413         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 414         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 415         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 416         DuplicatePayment,
 417         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 418         /// some paths have irrevocably committed to the HTLC.
 419         ///
 420         /// The results here are ordered the same as the paths in the route object that was passed to
 421         /// send_payment.
 422         ///
 423         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 424         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 425         ///
 426         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 427         PartialFailure {
 428                 /// The errors themselves, in the same order as the paths from the route.
 429                 results: Vec<Result<(), APIError>>,
 430                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 431                 /// contain a [`RouteParameters`] object for the failing paths.
 432                 failed_paths_retry: Option<RouteParameters>,
 433                 /// The payment id for the payment, which is now at least partially pending.
 434                 payment_id: PaymentId,
 435         },
 436 }
 437
 438 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 439 ///
 440 /// This should generally be constructed with data communicated to us from the recipient (via a
 441 /// BOLT11 or BOLT12 invoice).
 442 #[derive(Clone, Debug, PartialEq, Eq)]
 443 pub struct RecipientOnionFields {
 444         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 445         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 446         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 447         /// attacks.
 448         ///
 449         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 450         /// multi-path payments require a recipient-provided secret.
 451         ///
 452         /// Some implementations may reject spontaneous payments with payment secrets, so you may only
 453         /// want to provide a secret for a spontaneous payment if MPP is needed and you know your
 454         /// recipient will not reject it.
 455         pub payment_secret: Option<PaymentSecret>,
 456         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 457         /// arbitrary length. This gives recipients substantially more flexibility to receive
 458         /// additional data.
 459         ///
 460         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 461         /// scheme to authenticate received payments against expected payments and invoices, this field
 462         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 463         /// invoices which will be received with the payment.
 464         ///
 465         /// Note that this field was added to the lightning specification more recently than
 466         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 467         /// may not be supported as universally.
 468         pub payment_metadata: Option<Vec<u8>>,
 469         /// See [`Self::custom_tlvs`] for more info.
 470         pub(super) custom_tlvs: Vec<(u64, Vec<u8>)>,
 471 }
 472
 473 impl_writeable_tlv_based!(RecipientOnionFields, {
 474         (0, payment_secret, option),
 475         (1, custom_tlvs, optional_vec),
 476         (2, payment_metadata, option),
 477 });
 478
 479 impl RecipientOnionFields {
 480         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 481         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 482         /// but do not require or provide any further data.
 483         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 484                 Self { payment_secret: Some(payment_secret), payment_metadata: None, custom_tlvs: Vec::new() }
 485         }
 486
 487         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 488         /// payable HTLCs except for single-path spontaneous payments, i.e. this should generally
 489         /// only be used for calls to [`ChannelManager::send_spontaneous_payment`]. If you are sending
 490         /// a spontaneous MPP this will not work as all MPP require payment secrets; you may
 491         /// instead want to use [`RecipientOnionFields::secret_only`].
 492         ///
 493         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 494         /// [`RecipientOnionFields::secret_only`]: RecipientOnionFields::secret_only
 495         pub fn spontaneous_empty() -> Self {
 496                 Self { payment_secret: None, payment_metadata: None, custom_tlvs: Vec::new() }
 497         }
 498
 499         /// Creates a new [`RecipientOnionFields`] from an existing one, adding custom TLVs. Each
 500         /// TLV is provided as a `(u64, Vec<u8>)` for the type number and serialized value
 501         /// respectively. TLV type numbers must be unique and within the range
 502         /// reserved for custom types, i.e. >= 2^16, otherwise this method will return `Err(())`.
 503         ///
 504         /// This method will also error for types in the experimental range which have been
 505         /// standardized within the protocol, which only includes 5482373484 (keysend) for now.
 506         ///
 507         /// See [`Self::custom_tlvs`] for more info.
 508         pub fn with_custom_tlvs(mut self, mut custom_tlvs: Vec<(u64, Vec<u8>)>) -> Result<Self, ()> {
 509                 custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
 510                 let mut prev_type = None;
 511                 for (typ, _) in custom_tlvs.iter() {
 512                         if *typ < 1 << 16 { return Err(()); }
 513                         if *typ == 5482373484 { return Err(()); } // keysend
 514                         match prev_type {
 515                                 Some(prev) if prev >= *typ => return Err(()),
 516                                 _ => {},
 517                         }
 518                         prev_type = Some(*typ);
 519                 }
 520                 self.custom_tlvs = custom_tlvs;
 521                 Ok(self)
 522         }
 523
 524         /// Gets the custom TLVs that will be sent or have been received.
 525         ///
 526         /// Custom TLVs allow sending extra application-specific data with a payment. They provide
 527         /// additional flexibility on top of payment metadata, as while other implementations may
 528         /// require `payment_metadata` to reflect metadata provided in an invoice, custom TLVs
 529         /// do not have this restriction.
 530         ///
 531         /// Note that if this field is non-empty, it will contain strictly increasing TLVs, each
 532         /// represented by a `(u64, Vec<u8>)` for its type number and serialized value respectively.
 533         /// This is validated when setting this field using [`Self::with_custom_tlvs`].
 534         pub fn custom_tlvs(&self) -> &Vec<(u64, Vec<u8>)> {
 535                 &self.custom_tlvs
 536         }
 537
 538         /// When we have received some HTLC(s) towards an MPP payment, as we receive further HTLC(s) we
 539         /// have to make sure that some fields match exactly across the parts. For those that aren't
 540         /// required to match, if they don't match we should remove them so as to not expose data
 541         /// that's dependent on the HTLC receive order to users.
 542         ///
 543         /// Here we implement this, first checking compatibility then mutating two objects and then
 544         /// dropping any remaining non-matching fields from both.
 545         pub(super) fn check_merge(&mut self, further_htlc_fields: &mut Self) -> Result<(), ()> {
 546                 if self.payment_secret != further_htlc_fields.payment_secret { return Err(()); }
 547                 if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 548
 549                 let tlvs = &mut self.custom_tlvs;
 550                 let further_tlvs = &mut further_htlc_fields.custom_tlvs;
 551
 552                 let even_tlvs = tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 553                 let further_even_tlvs = further_tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 554                 if even_tlvs.ne(further_even_tlvs) { return Err(()) }
 555
 556                 tlvs.retain(|tlv| further_tlvs.iter().any(|further_tlv| tlv == further_tlv));
 557                 further_tlvs.retain(|further_tlv| tlvs.iter().any(|tlv| tlv == further_tlv));
 558
 559                 Ok(())
 560         }
 561 }
 562
 563 /// Arguments for [`super::channelmanager::ChannelManager::send_payment_along_path`].
 564 pub(super) struct SendAlongPathArgs<'a> {
 565         pub path: &'a Path,
 566         pub payment_hash: &'a PaymentHash,
 567         pub recipient_onion: RecipientOnionFields,
 568         pub total_value: u64,
 569         pub cur_height: u32,
 570         pub payment_id: PaymentId,
 571         pub keysend_preimage: &'a Option<PaymentPreimage>,
 572         pub session_priv_bytes: [u8; 32],
 573 }
 574
 575 pub(super) struct OutboundPayments {
 576         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 577         pub(super) retry_lock: Mutex<()>,
 578 }
 579
 580 impl OutboundPayments {
 581         pub(super) fn new() -> Self {
 582                 Self {
 583                         pending_outbound_payments: Mutex::new(HashMap::new()),
 584                         retry_lock: Mutex::new(()),
 585                 }
 586         }
 587
 588         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 589                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 590                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 591                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 592                 node_signer: &NS, best_block_height: u32, logger: &L,
 593                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 594         ) -> Result<(), RetryableSendFailure>
 595         where
 596                 R::Target: Router,
 597                 ES::Target: EntropySource,
 598                 NS::Target: NodeSigner,
 599                 L::Target: Logger,
 600                 IH: Fn() -> InFlightHtlcs,
 601                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 602         {
 603                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 604                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 605                         best_block_height, logger, pending_events, &send_payment_along_path)
 606         }
 607
 608         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 609                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 610                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 611                 send_payment_along_path: F
 612         ) -> Result<(), PaymentSendFailure>
 613         where
 614                 ES::Target: EntropySource,
 615                 NS::Target: NodeSigner,
 616                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>
 617         {
 618                 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)?;
 619                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 620                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 621                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 622         }
 623
 624         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 625                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 626                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 627                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 628                 node_signer: &NS, best_block_height: u32, logger: &L,
 629                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP
 630         ) -> Result<PaymentHash, RetryableSendFailure>
 631         where
 632                 R::Target: Router,
 633                 ES::Target: EntropySource,
 634                 NS::Target: NodeSigner,
 635                 L::Target: Logger,
 636                 IH: Fn() -> InFlightHtlcs,
 637                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 638         {
 639                 let preimage = payment_preimage
 640                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 641                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 642                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 643                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 644                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 645                         .map(|()| payment_hash)
 646         }
 647
 648         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 649                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 650                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 651                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 652         ) -> Result<PaymentHash, PaymentSendFailure>
 653         where
 654                 ES::Target: EntropySource,
 655                 NS::Target: NodeSigner,
 656                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 657         {
 658                 let preimage = payment_preimage
 659                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 660                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 661                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 662                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 663
 664                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 665                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 666                 ) {
 667                         Ok(()) => Ok(payment_hash),
 668                         Err(e) => {
 669                                 self.remove_outbound_if_all_failed(payment_id, &e);
 670                                 Err(e)
 671                         }
 672                 }
 673         }
 674
 675         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 676                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 677                 best_block_height: u32,
 678                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
 679                 send_payment_along_path: SP,
 680         )
 681         where
 682                 R::Target: Router,
 683                 ES::Target: EntropySource,
 684                 NS::Target: NodeSigner,
 685                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 686                 IH: Fn() -> InFlightHtlcs,
 687                 FH: Fn() -> Vec<ChannelDetails>,
 688                 L::Target: Logger,
 689         {
 690                 let _single_thread = self.retry_lock.lock().unwrap();
 691                 loop {
 692                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 693                         let mut retry_id_route_params = None;
 694                         for (pmt_id, pmt) in outbounds.iter_mut() {
 695                                 if pmt.is_auto_retryable_now() {
 696                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 697                                                 if pending_amt_msat < total_msat {
 698                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 699                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 700                                                                 payment_params: params.clone(),
 701                                                         }));
 702                                                         break
 703                                                 }
 704                                         } else { debug_assert!(false); }
 705                                 }
 706                         }
 707                         core::mem::drop(outbounds);
 708                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 709                                 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)
 710                         } else { break }
 711                 }
 712
 713                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 714                 outbounds.retain(|pmt_id, pmt| {
 715                         let mut retain = true;
 716                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_awaiting_invoice() {
 717                                 pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
 718                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
 719                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 720                                                 payment_id: *pmt_id,
 721                                                 payment_hash: *payment_hash,
 722                                                 reason: *reason,
 723                                         }, None));
 724                                         retain = false;
 725                                 }
 726                         }
 727                         retain
 728                 });
 729         }
 730
 731         pub(super) fn needs_abandon(&self) -> bool {
 732                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 733                 outbounds.iter().any(|(_, pmt)|
 734                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled() &&
 735                         !pmt.is_awaiting_invoice())
 736         }
 737
 738         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 739         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 740         ///
 741         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 742         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 743         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 744                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 745                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 746                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 747                 node_signer: &NS, best_block_height: u32, logger: &L,
 748                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 749         ) -> Result<(), RetryableSendFailure>
 750         where
 751                 R::Target: Router,
 752                 ES::Target: EntropySource,
 753                 NS::Target: NodeSigner,
 754                 L::Target: Logger,
 755                 IH: Fn() -> InFlightHtlcs,
 756                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 757         {
 758                 #[cfg(feature = "std")] {
 759                         if has_expired(&route_params) {
 760                                 log_error!(logger, "Payment with id {} and hash {} had expired before we started paying",
 761                                         payment_id, payment_hash);
 762                                 return Err(RetryableSendFailure::PaymentExpired)
 763                         }
 764                 }
 765
 766                 let route = router.find_route_with_id(
 767                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 768                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 769                         payment_hash, payment_id,
 770                 ).map_err(|_| {
 771                         log_error!(logger, "Failed to find route for payment with id {} and hash {}",
 772                                 payment_id, payment_hash);
 773                         RetryableSendFailure::RouteNotFound
 774                 })?;
 775
 776                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 777                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 778                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 779                         .map_err(|_| {
 780                                 log_error!(logger, "Payment with id {} is already pending. New payment had payment hash {}",
 781                                         payment_id, payment_hash);
 782                                 RetryableSendFailure::DuplicatePayment
 783                         })?;
 784
 785                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage, payment_id, None,
 786                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 787                 log_info!(logger, "Sending payment with id {} and hash {} returned {:?}",
 788                         payment_id, payment_hash, res);
 789                 if let Err(e) = res {
 790                         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);
 791                 }
 792                 Ok(())
 793         }
 794
 795         fn retry_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 796                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 797                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 798                 node_signer: &NS, best_block_height: u32, logger: &L,
 799                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 800         )
 801         where
 802                 R::Target: Router,
 803                 ES::Target: EntropySource,
 804                 NS::Target: NodeSigner,
 805                 L::Target: Logger,
 806                 IH: Fn() -> InFlightHtlcs,
 807                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 808         {
 809                 #[cfg(feature = "std")] {
 810                         if has_expired(&route_params) {
 811                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", &payment_id);
 812                                 self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
 813                                 return
 814                         }
 815                 }
 816
 817                 let route = match router.find_route_with_id(
 818                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 819                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 820                         payment_hash, payment_id,
 821                 ) {
 822                         Ok(route) => route,
 823                         Err(e) => {
 824                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", &payment_id, e);
 825                                 self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
 826                                 return
 827                         }
 828                 };
 829                 for path in route.paths.iter() {
 830                         if path.hops.len() == 0 {
 831                                 log_error!(logger, "Unusable path in route (path.hops.len() must be at least 1");
 832                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 833                                 return
 834                         }
 835                 }
 836
 837                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 838                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 839                 for _ in 0..route.paths.len() {
 840                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 841                 }
 842
 843                 macro_rules! abandon_with_entry {
 844                         ($payment: expr, $reason: expr) => {
 845                                 $payment.get_mut().mark_abandoned($reason);
 846                                 if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
 847                                         if $payment.get().remaining_parts() == 0 {
 848                                                 pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 849                                                         payment_id,
 850                                                         payment_hash,
 851                                                         reason: *reason,
 852                                                 }, None));
 853                                                 $payment.remove();
 854                                         }
 855                                 }
 856                         }
 857                 }
 858                 let (total_msat, recipient_onion, keysend_preimage) = {
 859                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 860                         match outbounds.entry(payment_id) {
 861                                 hash_map::Entry::Occupied(mut payment) => {
 862                                         let res = match payment.get() {
 863                                                 PendingOutboundPayment::Retryable {
 864                                                         total_msat, keysend_preimage, payment_secret, payment_metadata,
 865                                                         custom_tlvs, pending_amt_msat, ..
 866                                                 } => {
 867                                                         let retry_amt_msat = route.get_total_amount();
 868                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 869                                                                 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);
 870                                                                 abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
 871                                                                 return
 872                                                         }
 873                                                         (*total_msat, RecipientOnionFields {
 874                                                                         payment_secret: *payment_secret,
 875                                                                         payment_metadata: payment_metadata.clone(),
 876                                                                         custom_tlvs: custom_tlvs.clone(),
 877                                                                 }, *keysend_preimage)
 878                                                 },
 879                                                 PendingOutboundPayment::Legacy { .. } => {
 880                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 881                                                         return
 882                                                 },
 883                                                 PendingOutboundPayment::AwaitingInvoice { .. } => {
 884                                                         log_error!(logger, "Payment not yet sent");
 885                                                         return
 886                                                 },
 887                                                 PendingOutboundPayment::Fulfilled { .. } => {
 888                                                         log_error!(logger, "Payment already completed");
 889                                                         return
 890                                                 },
 891                                                 PendingOutboundPayment::Abandoned { .. } => {
 892                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
 893                                                         return
 894                                                 },
 895                                         };
 896                                         if !payment.get().is_retryable_now() {
 897                                                 log_error!(logger, "Retries exhausted for payment id {}", &payment_id);
 898                                                 abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
 899                                                 return
 900                                         }
 901                                         payment.get_mut().increment_attempts();
 902                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 903                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 904                                         }
 905                                         res
 906                                 },
 907                                 hash_map::Entry::Vacant(_) => {
 908                                         log_error!(logger, "Payment with ID {} not found", &payment_id);
 909                                         return
 910                                 }
 911                         }
 912                 };
 913                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
 914                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
 915                         &send_payment_along_path);
 916                 log_info!(logger, "Result retrying payment id {}: {:?}", &payment_id, res);
 917                 if let Err(e) = res {
 918                         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);
 919                 }
 920         }
 921
 922         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 923                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
 924                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
 925                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
 926                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 927         )
 928         where
 929                 R::Target: Router,
 930                 ES::Target: EntropySource,
 931                 NS::Target: NodeSigner,
 932                 L::Target: Logger,
 933                 IH: Fn() -> InFlightHtlcs,
 934                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 935         {
 936                 match err {
 937                         PaymentSendFailure::AllFailedResendSafe(errs) => {
 938                                 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);
 939                                 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);
 940                         },
 941                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
 942                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
 943                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
 944                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
 945                                 // return `Ok()` here, ignoring any retry errors.
 946                                 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);
 947                         },
 948                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
 949                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
 950                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
 951                                 // initial HTLC-Add messages yet.
 952                         },
 953                         PaymentSendFailure::PathParameterError(results) => {
 954                                 log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
 955                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
 956                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 957                         },
 958                         PaymentSendFailure::ParameterError(e) => {
 959                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
 960                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 961                         },
 962                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
 963                 }
 964         }
 965
 966         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
 967                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
 968                 paths: Vec<Path>, path_results: I, logger: &L,
 969                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
 970         ) where L::Target: Logger {
 971                 let mut events = pending_events.lock().unwrap();
 972                 debug_assert_eq!(paths.len(), path_results.len());
 973                 for (path, path_res) in paths.into_iter().zip(path_results) {
 974                         if let Err(e) = path_res {
 975                                 if let APIError::MonitorUpdateInProgress = e { continue }
 976                                 log_error!(logger, "Failed to send along path due to error: {:?}", e);
 977                                 let mut failed_scid = None;
 978                                 if let APIError::ChannelUnavailable { .. } = e {
 979                                         let scid = path.hops[0].short_channel_id;
 980                                         failed_scid = Some(scid);
 981                                         route_params.payment_params.previously_failed_channels.push(scid);
 982                                 }
 983                                 events.push_back((events::Event::PaymentPathFailed {
 984                                         payment_id: Some(payment_id),
 985                                         payment_hash,
 986                                         payment_failed_permanently: false,
 987                                         failure: events::PathFailure::InitialSend { err: e },
 988                                         path,
 989                                         short_channel_id: failed_scid,
 990                                         #[cfg(test)]
 991                                         error_code: None,
 992                                         #[cfg(test)]
 993                                         error_data: None,
 994                                 }, None));
 995                         }
 996                 }
 997         }
 998
 999         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
1000                 &self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
1001                 best_block_height: u32, send_payment_along_path: F
1002         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
1003         where
1004                 ES::Target: EntropySource,
1005                 NS::Target: NodeSigner,
1006                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1007         {
1008                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
1009
1010                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
1011
1012                 if path.hops.len() < 2 && path.blinded_tail.is_none() {
1013                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
1014                                 err: "No need probing a path with less than two hops".to_string()
1015                         }))
1016                 }
1017
1018                 let route = Route { paths: vec![path], route_params: None };
1019                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
1020                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
1021                         entropy_source, best_block_height)?;
1022
1023                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
1024                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
1025                 ) {
1026                         Ok(()) => Ok((payment_hash, payment_id)),
1027                         Err(e) => {
1028                                 self.remove_outbound_if_all_failed(payment_id, &e);
1029                                 Err(e)
1030                         }
1031                 }
1032         }
1033
1034         #[cfg(test)]
1035         pub(super) fn test_set_payment_metadata(
1036                 &self, payment_id: PaymentId, new_payment_metadata: Option<Vec<u8>>
1037         ) {
1038                 match self.pending_outbound_payments.lock().unwrap().get_mut(&payment_id).unwrap() {
1039                         PendingOutboundPayment::Retryable { payment_metadata, .. } => {
1040                                 *payment_metadata = new_payment_metadata;
1041                         },
1042                         _ => panic!("Need a retryable payment to update metadata on"),
1043                 }
1044         }
1045
1046         #[cfg(test)]
1047         pub(super) fn test_add_new_pending_payment<ES: Deref>(
1048                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1049                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
1050         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1051                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
1052         }
1053
1054         pub(super) fn add_new_pending_payment<ES: Deref>(
1055                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1056                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
1057                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
1058         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1059                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
1060                 for _ in 0..route.paths.len() {
1061                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
1062                 }
1063
1064                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1065                 match pending_outbounds.entry(payment_id) {
1066                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
1067                         hash_map::Entry::Vacant(entry) => {
1068                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
1069                                         retry_strategy,
1070                                         attempts: PaymentAttempts::new(),
1071                                         payment_params,
1072                                         session_privs: HashSet::new(),
1073                                         pending_amt_msat: 0,
1074                                         pending_fee_msat: Some(0),
1075                                         payment_hash,
1076                                         payment_secret: recipient_onion.payment_secret,
1077                                         payment_metadata: recipient_onion.payment_metadata,
1078                                         keysend_preimage,
1079                                         custom_tlvs: recipient_onion.custom_tlvs,
1080                                         starting_block_height: best_block_height,
1081                                         total_msat: route.get_total_amount(),
1082                                 });
1083
1084                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
1085                                         assert!(payment.insert(*session_priv_bytes, path));
1086                                 }
1087
1088                                 Ok(onion_session_privs)
1089                         },
1090                 }
1091         }
1092
1093         #[allow(unused)]
1094         pub(super) fn add_new_awaiting_invoice(&self, payment_id: PaymentId) -> Result<(), ()> {
1095                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1096                 match pending_outbounds.entry(payment_id) {
1097                         hash_map::Entry::Occupied(_) => Err(()),
1098                         hash_map::Entry::Vacant(entry) => {
1099                                 entry.insert(PendingOutboundPayment::AwaitingInvoice {
1100                                         timer_ticks_without_response: 0,
1101                                 });
1102
1103                                 Ok(())
1104                         },
1105                 }
1106         }
1107
1108         fn pay_route_internal<NS: Deref, F>(
1109                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1110                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1111                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1112                 send_payment_along_path: &F
1113         ) -> Result<(), PaymentSendFailure>
1114         where
1115                 NS::Target: NodeSigner,
1116                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1117         {
1118                 if route.paths.len() < 1 {
1119                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
1120                 }
1121                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
1122                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
1123                 }
1124                 let mut total_value = 0;
1125                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
1126                 let mut path_errs = Vec::with_capacity(route.paths.len());
1127                 'path_check: for path in route.paths.iter() {
1128                         if path.hops.len() < 1 || path.hops.len() > 20 {
1129                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
1130                                 continue 'path_check;
1131                         }
1132                         if path.blinded_tail.is_some() {
1133                                 path_errs.push(Err(APIError::InvalidRoute{err: "Sending to blinded paths isn't supported yet".to_owned()}));
1134                                 continue 'path_check;
1135                         }
1136                         let dest_hop_idx = if path.blinded_tail.is_some() && path.blinded_tail.as_ref().unwrap().hops.len() > 1 {
1137                                 usize::max_value() } else { path.hops.len() - 1 };
1138                         for (idx, hop) in path.hops.iter().enumerate() {
1139                                 if idx != dest_hop_idx && hop.pubkey == our_node_id {
1140                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
1141                                         continue 'path_check;
1142                                 }
1143                         }
1144                         total_value += path.final_value_msat();
1145                         path_errs.push(Ok(()));
1146                 }
1147                 if path_errs.iter().any(|e| e.is_err()) {
1148                         return Err(PaymentSendFailure::PathParameterError(path_errs));
1149                 }
1150                 if let Some(amt_msat) = recv_value_msat {
1151                         total_value = amt_msat;
1152                 }
1153
1154                 let cur_height = best_block_height + 1;
1155                 let mut results = Vec::new();
1156                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
1157                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.into_iter()) {
1158                         let mut path_res = send_payment_along_path(SendAlongPathArgs {
1159                                 path: &path, payment_hash: &payment_hash, recipient_onion: recipient_onion.clone(),
1160                                 total_value, cur_height, payment_id, keysend_preimage: &keysend_preimage, session_priv_bytes
1161                         });
1162                         match path_res {
1163                                 Ok(_) => {},
1164                                 Err(APIError::MonitorUpdateInProgress) => {
1165                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
1166                                         // considered "in flight" and we shouldn't remove it from the
1167                                         // PendingOutboundPayment set.
1168                                 },
1169                                 Err(_) => {
1170                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1171                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1172                                                 let removed = payment.remove(&session_priv_bytes, Some(path));
1173                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1174                                         } else {
1175                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1176                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1177                                         }
1178                                 }
1179                         }
1180                         results.push(path_res);
1181                 }
1182                 let mut has_ok = false;
1183                 let mut has_err = false;
1184                 let mut pending_amt_unsent = 0;
1185                 for (res, path) in results.iter().zip(route.paths.iter()) {
1186                         if res.is_ok() { has_ok = true; }
1187                         if res.is_err() { has_err = true; }
1188                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1189                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1190                                 // PartialFailure.
1191                                 has_err = true;
1192                                 has_ok = true;
1193                         } else if res.is_err() {
1194                                 pending_amt_unsent += path.final_value_msat();
1195                         }
1196                 }
1197                 if has_err && has_ok {
1198                         Err(PaymentSendFailure::PartialFailure {
1199                                 results,
1200                                 payment_id,
1201                                 failed_paths_retry: if pending_amt_unsent != 0 {
1202                                         if let Some(payment_params) = route.route_params.as_ref().map(|p| p.payment_params.clone()) {
1203                                                 Some(RouteParameters {
1204                                                         payment_params: payment_params,
1205                                                         final_value_msat: pending_amt_unsent,
1206                                                 })
1207                                         } else { None }
1208                                 } else { None },
1209                         })
1210                 } else if has_err {
1211                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1212                 } else {
1213                         Ok(())
1214                 }
1215         }
1216
1217         #[cfg(test)]
1218         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1219                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1220                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1221                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1222                 send_payment_along_path: F
1223         ) -> Result<(), PaymentSendFailure>
1224         where
1225                 NS::Target: NodeSigner,
1226                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1227         {
1228                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1229                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1230                         &send_payment_along_path)
1231                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1232         }
1233
1234         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1235         // map as the payment is free to be resent.
1236         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1237                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1238                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1239                         debug_assert!(removed, "We should always have a pending payment to remove here");
1240                 }
1241         }
1242
1243         pub(super) fn claim_htlc<L: Deref>(
1244                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1245                 path: Path, from_onchain: bool, ev_completion_action: EventCompletionAction,
1246                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1247                 logger: &L,
1248         ) where L::Target: Logger {
1249                 let mut session_priv_bytes = [0; 32];
1250                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1251                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1252                 let mut pending_events = pending_events.lock().unwrap();
1253                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1254                         if !payment.get().is_fulfilled() {
1255                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1256                                 log_info!(logger, "Payment with id {} and hash {} sent!", payment_id, payment_hash);
1257                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1258                                 pending_events.push_back((events::Event::PaymentSent {
1259                                         payment_id: Some(payment_id),
1260                                         payment_preimage,
1261                                         payment_hash,
1262                                         fee_paid_msat,
1263                                 }, Some(ev_completion_action.clone())));
1264                                 payment.get_mut().mark_fulfilled();
1265                         }
1266
1267                         if from_onchain {
1268                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1269                                 // This could potentially lead to removing a pending payment too early,
1270                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1271                                 // restart.
1272                                 // TODO: We should have a second monitor event that informs us of payments
1273                                 // irrevocably fulfilled.
1274                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1275                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1276                                         pending_events.push_back((events::Event::PaymentPathSuccessful {
1277                                                 payment_id,
1278                                                 payment_hash,
1279                                                 path,
1280                                         }, Some(ev_completion_action)));
1281                                 }
1282                         }
1283                 } else {
1284                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", &payment_preimage);
1285                 }
1286         }
1287
1288         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>,
1289                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1290         {
1291                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1292                 let mut pending_events = pending_events.lock().unwrap();
1293                 for source in sources {
1294                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1295                                 let mut session_priv_bytes = [0; 32];
1296                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1297                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1298                                         assert!(payment.get().is_fulfilled());
1299                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1300                                                 let payment_hash = payment.get().payment_hash();
1301                                                 debug_assert!(payment_hash.is_some());
1302                                                 pending_events.push_back((events::Event::PaymentPathSuccessful {
1303                                                         payment_id,
1304                                                         payment_hash,
1305                                                         path,
1306                                                 }, None));
1307                                         }
1308                                 }
1309                         }
1310                 }
1311         }
1312
1313         pub(super) fn remove_stale_payments(
1314                 &self, pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1315         {
1316                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1317                 let mut pending_events = pending_events.lock().unwrap();
1318                 pending_outbound_payments.retain(|payment_id, payment| {
1319                         // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1320                         // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1321                         // this could race the user making a duplicate send_payment call and our idempotency
1322                         // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1323                         // removal. This should be more than sufficient to ensure the idempotency of any
1324                         // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1325                         // processed.
1326                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1327                                 let mut no_remaining_entries = session_privs.is_empty();
1328                                 if no_remaining_entries {
1329                                         for (ev, _) in pending_events.iter() {
1330                                                 match ev {
1331                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1332                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1333                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1334                                                                         if payment_id == ev_payment_id {
1335                                                                                 no_remaining_entries = false;
1336                                                                                 break;
1337                                                                         }
1338                                                                 },
1339                                                         _ => {},
1340                                                 }
1341                                         }
1342                                 }
1343                                 if no_remaining_entries {
1344                                         *timer_ticks_without_htlcs += 1;
1345                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1346                                 } else {
1347                                         *timer_ticks_without_htlcs = 0;
1348                                         true
1349                                 }
1350                         } else if let PendingOutboundPayment::AwaitingInvoice { timer_ticks_without_response, .. } = payment {
1351                                 *timer_ticks_without_response += 1;
1352                                 if *timer_ticks_without_response <= INVOICE_REQUEST_TIMEOUT_TICKS {
1353                                         true
1354                                 } else {
1355                                         pending_events.push_back(
1356                                                 (events::Event::InvoiceRequestFailed { payment_id: *payment_id }, None)
1357                                         );
1358                                         false
1359                                 }
1360                         } else { true }
1361                 });
1362         }
1363
1364         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1365         pub(super) fn fail_htlc<L: Deref>(
1366                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1367                 path: &Path, session_priv: &SecretKey, payment_id: &PaymentId,
1368                 probing_cookie_secret: [u8; 32], secp_ctx: &Secp256k1<secp256k1::All>,
1369                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
1370         ) -> bool where L::Target: Logger {
1371                 #[cfg(test)]
1372                 let DecodedOnionFailure {
1373                         network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data
1374                 } = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1375                 #[cfg(not(test))]
1376                 let DecodedOnionFailure { network_update, short_channel_id, payment_retryable } =
1377                         onion_error.decode_onion_failure(secp_ctx, logger, &source);
1378
1379                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1380                 let mut session_priv_bytes = [0; 32];
1381                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1382                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1383
1384                 // If any payments already need retry, there's no need to generate a redundant
1385                 // `PendingHTLCsForwardable`.
1386                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1387                         let mut awaiting_retry = false;
1388                         if pmt.is_auto_retryable_now() {
1389                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1390                                         if pending_amt_msat < total_msat {
1391                                                 awaiting_retry = true;
1392                                         }
1393                                 }
1394                         }
1395                         awaiting_retry
1396                 });
1397
1398                 let mut full_failure_ev = None;
1399                 let mut pending_retry_ev = false;
1400                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1401                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1402                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1403                                 return false
1404                         }
1405                         if payment.get().is_fulfilled() {
1406                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", &payment_hash);
1407                                 return false
1408                         }
1409                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1410                         if let Some(scid) = short_channel_id {
1411                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1412                                 // process_onion_failure we should close that channel as it implies our
1413                                 // next-hop is needlessly blaming us!
1414                                 payment.get_mut().insert_previously_failed_scid(scid);
1415                         }
1416
1417                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1418                                 let reason = if !payment_retryable {
1419                                         PaymentFailureReason::RecipientRejected
1420                                 } else {
1421                                         PaymentFailureReason::RetriesExhausted
1422                                 };
1423                                 payment.get_mut().mark_abandoned(reason);
1424                                 is_retryable_now = false;
1425                         }
1426                         if payment.get().remaining_parts() == 0 {
1427                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
1428                                         if !payment_is_probe {
1429                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1430                                                         payment_id: *payment_id,
1431                                                         payment_hash: *payment_hash,
1432                                                         reason: *reason,
1433                                                 });
1434                                         }
1435                                         payment.remove();
1436                                 }
1437                         }
1438                         is_retryable_now
1439                 } else {
1440                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1441                         return false
1442                 };
1443                 core::mem::drop(outbounds);
1444                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", &payment_hash);
1445
1446                 let path_failure = {
1447                         if payment_is_probe {
1448                                 if !payment_retryable {
1449                                         events::Event::ProbeSuccessful {
1450                                                 payment_id: *payment_id,
1451                                                 payment_hash: payment_hash.clone(),
1452                                                 path: path.clone(),
1453                                         }
1454                                 } else {
1455                                         events::Event::ProbeFailed {
1456                                                 payment_id: *payment_id,
1457                                                 payment_hash: payment_hash.clone(),
1458                                                 path: path.clone(),
1459                                                 short_channel_id,
1460                                         }
1461                                 }
1462                         } else {
1463                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1464                                 // payment will sit in our outbounds forever.
1465                                 if attempts_remaining && !already_awaiting_retry {
1466                                         debug_assert!(full_failure_ev.is_none());
1467                                         pending_retry_ev = true;
1468                                 }
1469                                 events::Event::PaymentPathFailed {
1470                                         payment_id: Some(*payment_id),
1471                                         payment_hash: payment_hash.clone(),
1472                                         payment_failed_permanently: !payment_retryable,
1473                                         failure: events::PathFailure::OnPath { network_update },
1474                                         path: path.clone(),
1475                                         short_channel_id,
1476                                         #[cfg(test)]
1477                                         error_code: onion_error_code,
1478                                         #[cfg(test)]
1479                                         error_data: onion_error_data
1480                                 }
1481                         }
1482                 };
1483                 let mut pending_events = pending_events.lock().unwrap();
1484                 pending_events.push_back((path_failure, None));
1485                 if let Some(ev) = full_failure_ev { pending_events.push_back((ev, None)); }
1486                 pending_retry_ev
1487         }
1488
1489         pub(super) fn abandon_payment(
1490                 &self, payment_id: PaymentId, reason: PaymentFailureReason,
1491                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>
1492         ) {
1493                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1494                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1495                         payment.get_mut().mark_abandoned(reason);
1496                         if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
1497                                 if payment.get().remaining_parts() == 0 {
1498                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
1499                                                 payment_id,
1500                                                 payment_hash: *payment_hash,
1501                                                 reason: *reason,
1502                                         }, None));
1503                                         payment.remove();
1504                                 }
1505                         } else if let PendingOutboundPayment::AwaitingInvoice { .. } = payment.get() {
1506                                 pending_events.lock().unwrap().push_back((events::Event::InvoiceRequestFailed {
1507                                         payment_id,
1508                                 }, None));
1509                                 payment.remove();
1510                         }
1511                 }
1512         }
1513
1514         #[cfg(test)]
1515         pub fn has_pending_payments(&self) -> bool {
1516                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1517         }
1518
1519         #[cfg(test)]
1520         pub fn clear_pending_payments(&self) {
1521                 self.pending_outbound_payments.lock().unwrap().clear()
1522         }
1523 }
1524
1525 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1526 /// payment probe.
1527 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1528         probing_cookie_secret: [u8; 32]) -> bool
1529 {
1530         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1531         target_payment_hash == *payment_hash
1532 }
1533
1534 /// Returns the 'probing cookie' for the given [`PaymentId`].
1535 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1536         let mut preimage = [0u8; 64];
1537         preimage[..32].copy_from_slice(&probing_cookie_secret);
1538         preimage[32..].copy_from_slice(&payment_id.0);
1539         PaymentHash(Sha256::hash(&preimage).into_inner())
1540 }
1541
1542 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1543         (0, Legacy) => {
1544                 (0, session_privs, required),
1545         },
1546         (1, Fulfilled) => {
1547                 (0, session_privs, required),
1548                 (1, payment_hash, option),
1549                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1550         },
1551         (2, Retryable) => {
1552                 (0, session_privs, required),
1553                 (1, pending_fee_msat, option),
1554                 (2, payment_hash, required),
1555                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1556                 // never see it - `payment_params` was added here after the field was added/required.
1557                 (3, payment_params, (option: ReadableArgs, 0)),
1558                 (4, payment_secret, option),
1559                 (5, keysend_preimage, option),
1560                 (6, total_msat, required),
1561                 (7, payment_metadata, option),
1562                 (8, pending_amt_msat, required),
1563                 (9, custom_tlvs, optional_vec),
1564                 (10, starting_block_height, required),
1565                 (not_written, retry_strategy, (static_value, None)),
1566                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1567         },
1568         (3, Abandoned) => {
1569                 (0, session_privs, required),
1570                 (1, reason, option),
1571                 (2, payment_hash, required),
1572         },
1573         (5, AwaitingInvoice) => {
1574                 (0, timer_ticks_without_response, required),
1575         },
1576 );
1577
1578 #[cfg(test)]
1579 mod tests {
1580         use bitcoin::network::constants::Network;
1581         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1582
1583         use crate::events::{Event, PathFailure, PaymentFailureReason};
1584         use crate::ln::PaymentHash;
1585         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1586         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1587         use crate::ln::msgs::{ErrorAction, LightningError};
1588         use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
1589         use crate::routing::gossip::NetworkGraph;
1590         use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters};
1591         use crate::sync::{Arc, Mutex, RwLock};
1592         use crate::util::errors::APIError;
1593         use crate::util::test_utils;
1594
1595         use alloc::collections::VecDeque;
1596
1597         #[test]
1598         fn test_recipient_onion_fields_with_custom_tlvs() {
1599                 let onion_fields = RecipientOnionFields::spontaneous_empty();
1600
1601                 let bad_type_range_tlvs = vec![
1602                         (0, vec![42]),
1603                         (1, vec![42; 32]),
1604                 ];
1605                 assert!(onion_fields.clone().with_custom_tlvs(bad_type_range_tlvs).is_err());
1606
1607                 let keysend_tlv = vec![
1608                         (5482373484, vec![42; 32]),
1609                 ];
1610                 assert!(onion_fields.clone().with_custom_tlvs(keysend_tlv).is_err());
1611
1612                 let good_tlvs = vec![
1613                         ((1 << 16) + 1, vec![42]),
1614                         ((1 << 16) + 3, vec![42; 32]),
1615                 ];
1616                 assert!(onion_fields.with_custom_tlvs(good_tlvs).is_ok());
1617         }
1618
1619         #[test]
1620         #[cfg(feature = "std")]
1621         fn fails_paying_after_expiration() {
1622                 do_fails_paying_after_expiration(false);
1623                 do_fails_paying_after_expiration(true);
1624         }
1625         #[cfg(feature = "std")]
1626         fn do_fails_paying_after_expiration(on_retry: bool) {
1627                 let outbound_payments = OutboundPayments::new();
1628                 let logger = test_utils::TestLogger::new();
1629                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1630                 let scorer = RwLock::new(test_utils::TestScorer::new());
1631                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1632                 let secp_ctx = Secp256k1::new();
1633                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1634
1635                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1636                 let payment_params = PaymentParameters::from_node_id(
1637                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1638                                 0
1639                         ).with_expiry_time(past_expiry_time);
1640                 let expired_route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1641                 let pending_events = Mutex::new(VecDeque::new());
1642                 if on_retry {
1643                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1644                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1645                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1646                                 &&keys_manager, 0).unwrap();
1647                         outbound_payments.retry_payment_internal(
1648                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1649                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1650                                 &|_| Ok(()));
1651                         let events = pending_events.lock().unwrap();
1652                         assert_eq!(events.len(), 1);
1653                         if let Event::PaymentFailed { ref reason, .. } = events[0].0 {
1654                                 assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
1655                         } else { panic!("Unexpected event"); }
1656                 } else {
1657                         let err = outbound_payments.send_payment(
1658                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1659                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1660                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1661                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1662                 }
1663         }
1664
1665         #[test]
1666         fn find_route_error() {
1667                 do_find_route_error(false);
1668                 do_find_route_error(true);
1669         }
1670         fn do_find_route_error(on_retry: bool) {
1671                 let outbound_payments = OutboundPayments::new();
1672                 let logger = test_utils::TestLogger::new();
1673                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1674                 let scorer = RwLock::new(test_utils::TestScorer::new());
1675                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1676                 let secp_ctx = Secp256k1::new();
1677                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1678
1679                 let payment_params = PaymentParameters::from_node_id(
1680                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1681                 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1682                 router.expect_find_route(route_params.clone(),
1683                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1684
1685                 let pending_events = Mutex::new(VecDeque::new());
1686                 if on_retry {
1687                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1688                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1689                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1690                                 &&keys_manager, 0).unwrap();
1691                         outbound_payments.retry_payment_internal(
1692                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1693                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1694                                 &|_| Ok(()));
1695                         let events = pending_events.lock().unwrap();
1696                         assert_eq!(events.len(), 1);
1697                         if let Event::PaymentFailed { .. } = events[0].0 { } else { panic!("Unexpected event"); }
1698                 } else {
1699                         let err = outbound_payments.send_payment(
1700                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1701                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1702                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1703                         if let RetryableSendFailure::RouteNotFound = err {
1704                         } else { panic!("Unexpected error"); }
1705                 }
1706         }
1707
1708         #[test]
1709         fn initial_send_payment_path_failed_evs() {
1710                 let outbound_payments = OutboundPayments::new();
1711                 let logger = test_utils::TestLogger::new();
1712                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1713                 let scorer = RwLock::new(test_utils::TestScorer::new());
1714                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1715                 let secp_ctx = Secp256k1::new();
1716                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1717
1718                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1719                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1720                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1721                 let route_params = RouteParameters::from_payment_params_and_value(payment_params.clone(), 0);
1722                 let failed_scid = 42;
1723                 let route = Route {
1724                         paths: vec![Path { hops: vec![RouteHop {
1725                                 pubkey: receiver_pk,
1726                                 node_features: NodeFeatures::empty(),
1727                                 short_channel_id: failed_scid,
1728                                 channel_features: ChannelFeatures::empty(),
1729                                 fee_msat: 0,
1730                                 cltv_expiry_delta: 0,
1731                         }], blinded_tail: None }],
1732                         route_params: Some(route_params.clone()),
1733                 };
1734                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1735                 let mut route_params_w_failed_scid = route_params.clone();
1736                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1737                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1738                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1739                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1740
1741                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1742                 // PaymentPathFailed event.
1743                 let pending_events = Mutex::new(VecDeque::new());
1744                 outbound_payments.send_payment(
1745                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1746                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1747                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1748                         |_| Err(APIError::ChannelUnavailable { err: "test".to_owned() })).unwrap();
1749                 let mut events = pending_events.lock().unwrap();
1750                 assert_eq!(events.len(), 2);
1751                 if let Event::PaymentPathFailed {
1752                         short_channel_id,
1753                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0].0
1754                 {
1755                         assert_eq!(short_channel_id, Some(failed_scid));
1756                 } else { panic!("Unexpected event"); }
1757                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1758                 events.clear();
1759                 core::mem::drop(events);
1760
1761                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1762                 outbound_payments.send_payment(
1763                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1764                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1765                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1766                         |_| Err(APIError::MonitorUpdateInProgress)).unwrap();
1767                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1768
1769                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1770                 outbound_payments.send_payment(
1771                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1772                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1773                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1774                         |_| Err(APIError::APIMisuseError { err: "test".to_owned() })).unwrap();
1775                 let events = pending_events.lock().unwrap();
1776                 assert_eq!(events.len(), 2);
1777                 if let Event::PaymentPathFailed {
1778                         short_channel_id,
1779                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0].0
1780                 {
1781                         assert_eq!(short_channel_id, None);
1782                 } else { panic!("Unexpected event"); }
1783                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1784         }
1785 }