git.bitcoin.ninja 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::offers::invoice::Bolt12Invoice;
  22 use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteParameters, Router};
  23 use crate::util::errors::APIError;
  24 use crate::util::logger::Logger;
  25 use crate::util::time::Time;
  26 #[cfg(all(not(feature = "no-std"), test))]
  27 use crate::util::time::tests::SinceEpoch;
  28 use crate::util::ser::ReadableArgs;
  29
  30 use core::fmt::{self, Display, Formatter};
  31 use core::ops::Deref;
  32
  33 use crate::prelude::*;
  34 use crate::sync::Mutex;
  35
  36 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until we time-out the idempotency
  37 /// of payments by [`PaymentId`]. See [`OutboundPayments::remove_stale_payments`].
  38 ///
  39 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  40 pub(crate) const IDEMPOTENCY_TIMEOUT_TICKS: u8 = 7;
  41
  42 /// The number of ticks of [`ChannelManager::timer_tick_occurred`] until an invoice request without
  43 /// a response is timed out.
  44 ///
  45 /// [`ChannelManager::timer_tick_occurred`]: crate::ln::channelmanager::ChannelManager::timer_tick_occurred
  46 const INVOICE_REQUEST_TIMEOUT_TICKS: u8 = 3;
  47
  48 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  49 /// and later, also stores information for retrying the payment.
  50 pub(crate) enum PendingOutboundPayment {
  51         Legacy {
  52                 session_privs: HashSet<[u8; 32]>,
  53         },
  54         AwaitingInvoice {
  55                 timer_ticks_without_response: u8,
  56                 retry_strategy: Retry,
  57         },
  58         InvoiceReceived {
  59                 payment_hash: PaymentHash,
  60                 retry_strategy: Retry,
  61         },
  62         Retryable {
  63                 retry_strategy: Option<Retry>,
  64                 attempts: PaymentAttempts,
  65                 payment_params: Option<PaymentParameters>,
  66                 session_privs: HashSet<[u8; 32]>,
  67                 payment_hash: PaymentHash,
  68                 payment_secret: Option<PaymentSecret>,
  69                 payment_metadata: Option<Vec<u8>>,
  70                 keysend_preimage: Option<PaymentPreimage>,
  71                 custom_tlvs: Vec<(u64, Vec<u8>)>,
  72                 pending_amt_msat: u64,
  73                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  74                 pending_fee_msat: Option<u64>,
  75                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  76                 total_msat: u64,
  77                 /// Our best known block height at the time this payment was initiated.
  78                 starting_block_height: u32,
  79         },
  80         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  81         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  82         /// and add a pending payment that was already fulfilled.
  83         Fulfilled {
  84                 session_privs: HashSet<[u8; 32]>,
  85                 /// Filled in for any payment which moved to `Fulfilled` on LDK 0.0.104 or later.
  86                 payment_hash: Option<PaymentHash>,
  87                 timer_ticks_without_htlcs: u8,
  88         },
  89         /// When we've decided to give up retrying a payment, we mark it as abandoned so we can eventually
  90         /// generate a `PaymentFailed` event when all HTLCs have irrevocably failed.
  91         Abandoned {
  92                 session_privs: HashSet<[u8; 32]>,
  93                 payment_hash: PaymentHash,
  94                 /// Will be `None` if the payment was serialized before 0.0.115.
  95                 reason: Option<PaymentFailureReason>,
  96         },
  97 }
  98
  99 impl PendingOutboundPayment {
 100         fn increment_attempts(&mut self) {
 101                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
 102                         attempts.count += 1;
 103                 }
 104         }
 105         fn is_auto_retryable_now(&self) -> bool {
 106                 match self {
 107                         PendingOutboundPayment::Retryable {
 108                                 retry_strategy: Some(strategy), attempts, payment_params: Some(_), ..
 109                         } => {
 110                                 strategy.is_retryable_now(&attempts)
 111                         },
 112                         _ => false,
 113                 }
 114         }
 115         fn is_retryable_now(&self) -> bool {
 116                 match self {
 117                         PendingOutboundPayment::Retryable { retry_strategy: None, .. } => {
 118                                 // We're handling retries manually, we can always retry.
 119                                 true
 120                         },
 121                         PendingOutboundPayment::Retryable { retry_strategy: Some(strategy), attempts, .. } => {
 122                                 strategy.is_retryable_now(&attempts)
 123                         },
 124                         _ => false,
 125                 }
 126         }
 127         pub fn insert_previously_failed_scid(&mut self, scid: u64) {
 128                 if let PendingOutboundPayment::Retryable { payment_params: Some(params), .. } = self {
 129                         params.previously_failed_channels.push(scid);
 130                 }
 131         }
 132         fn is_awaiting_invoice(&self) -> bool {
 133                 match self {
 134                         PendingOutboundPayment::AwaitingInvoice { .. } => true,
 135                         _ => false,
 136                 }
 137         }
 138         pub(super) fn is_fulfilled(&self) -> bool {
 139                 match self {
 140                         PendingOutboundPayment::Fulfilled { .. } => true,
 141                         _ => false,
 142                 }
 143         }
 144         pub(super) fn abandoned(&self) -> bool {
 145                 match self {
 146                         PendingOutboundPayment::Abandoned { .. } => true,
 147                         _ => false,
 148                 }
 149         }
 150         fn get_pending_fee_msat(&self) -> Option<u64> {
 151                 match self {
 152                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 153                         _ => None,
 154                 }
 155         }
 156
 157         fn payment_hash(&self) -> Option<PaymentHash> {
 158                 match self {
 159                         PendingOutboundPayment::Legacy { .. } => None,
 160                         PendingOutboundPayment::AwaitingInvoice { .. } => None,
 161                         PendingOutboundPayment::InvoiceReceived { payment_hash, .. } => Some(*payment_hash),
 162                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 163                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 164                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 165                 }
 166         }
 167
 168         fn mark_fulfilled(&mut self) {
 169                 let mut session_privs = HashSet::new();
 170                 core::mem::swap(&mut session_privs, match self {
 171                         PendingOutboundPayment::Legacy { session_privs } |
 172                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 173                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 174                                 PendingOutboundPayment::Abandoned { session_privs, .. } => session_privs,
 175                         PendingOutboundPayment::AwaitingInvoice { .. } |
 176                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); return; },
 177                 });
 178                 let payment_hash = self.payment_hash();
 179                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 180         }
 181
 182         fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
 183                 if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
 184                         let mut our_session_privs = HashSet::new();
 185                         core::mem::swap(&mut our_session_privs, session_privs);
 186                         *self = PendingOutboundPayment::Abandoned {
 187                                 session_privs: our_session_privs,
 188                                 payment_hash: *payment_hash,
 189                                 reason: Some(reason)
 190                         };
 191                 } else if let PendingOutboundPayment::InvoiceReceived { payment_hash, .. } = self {
 192                         *self = PendingOutboundPayment::Abandoned {
 193                                 session_privs: HashSet::new(),
 194                                 payment_hash: *payment_hash,
 195                                 reason: Some(reason)
 196                         };
 197                 }
 198         }
 199
 200         /// panics if path is None and !self.is_fulfilled
 201         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Path>) -> bool {
 202                 let remove_res = match self {
 203                         PendingOutboundPayment::Legacy { session_privs } |
 204                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 205                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 206                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 207                                         session_privs.remove(session_priv)
 208                                 },
 209                         PendingOutboundPayment::AwaitingInvoice { .. } |
 210                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); false },
 211                 };
 212                 if remove_res {
 213                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 214                                 let path = path.expect("Fulfilling a payment should always come with a path");
 215                                 *pending_amt_msat -= path.final_value_msat();
 216                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 217                                         *fee_msat -= path.fee_msat();
 218                                 }
 219                         }
 220                 }
 221                 remove_res
 222         }
 223
 224         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Path) -> bool {
 225                 let insert_res = match self {
 226                         PendingOutboundPayment::Legacy { session_privs } |
 227                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 228                                         session_privs.insert(session_priv)
 229                                 },
 230                         PendingOutboundPayment::AwaitingInvoice { .. } |
 231                                 PendingOutboundPayment::InvoiceReceived { .. } => { debug_assert!(false); false },
 232                         PendingOutboundPayment::Fulfilled { .. } => false,
 233                         PendingOutboundPayment::Abandoned { .. } => false,
 234                 };
 235                 if insert_res {
 236                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 237                                 *pending_amt_msat += path.final_value_msat();
 238                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 239                                         *fee_msat += path.fee_msat();
 240                                 }
 241                         }
 242                 }
 243                 insert_res
 244         }
 245
 246         pub(super) fn remaining_parts(&self) -> usize {
 247                 match self {
 248                         PendingOutboundPayment::Legacy { session_privs } |
 249                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 250                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 251                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 252                                         session_privs.len()
 253                                 },
 254                         PendingOutboundPayment::AwaitingInvoice { .. } => 0,
 255                         PendingOutboundPayment::InvoiceReceived { .. } => 0,
 256                 }
 257         }
 258 }
 259
 260 /// Strategies available to retry payment path failures.
 261 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 262 pub enum Retry {
 263         /// Max number of attempts to retry payment.
 264         ///
 265         /// Each attempt may be multiple HTLCs along multiple paths if the router decides to split up a
 266         /// retry, and may retry multiple failed HTLCs at once if they failed around the same time and
 267         /// were retried along a route from a single call to [`Router::find_route_with_id`].
 268         Attempts(u32),
 269         #[cfg(not(feature = "no-std"))]
 270         /// Time elapsed before abandoning retries for a payment. At least one attempt at payment is made;
 271         /// see [`PaymentParameters::expiry_time`] to avoid any attempt at payment after a specific time.
 272         ///
 273         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 274         Timeout(core::time::Duration),
 275 }
 276
 277 #[cfg(feature = "no-std")]
 278 impl_writeable_tlv_based_enum!(Retry,
 279         ;
 280         (0, Attempts)
 281 );
 282
 283 #[cfg(not(feature = "no-std"))]
 284 impl_writeable_tlv_based_enum!(Retry,
 285         ;
 286         (0, Attempts),
 287         (2, Timeout)
 288 );
 289
 290 impl Retry {
 291         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 292                 match (self, attempts) {
 293                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 294                                 max_retry_count > count
 295                         },
 296                         #[cfg(all(not(feature = "no-std"), not(test)))]
 297                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 298                                 *max_duration >= crate::util::time::MonotonicTime::now().duration_since(*first_attempted_at),
 299                         #[cfg(all(not(feature = "no-std"), test))]
 300                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 301                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 302                 }
 303         }
 304 }
 305
 306 #[cfg(feature = "std")]
 307 pub(super) fn has_expired(route_params: &RouteParameters) -> bool {
 308         if let Some(expiry_time) = route_params.payment_params.expiry_time {
 309                 if let Ok(elapsed) = std::time::SystemTime::UNIX_EPOCH.elapsed() {
 310                         return elapsed > core::time::Duration::from_secs(expiry_time)
 311                 }
 312         }
 313         false
 314 }
 315
 316 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 317
 318 /// Storing minimal payment attempts information required for determining if a outbound payment can
 319 /// be retried.
 320 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 321         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 322         /// it means the result of the first attempt is not known yet.
 323         pub(crate) count: u32,
 324         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 325         #[cfg(not(feature = "no-std"))]
 326         first_attempted_at: T,
 327         #[cfg(feature = "no-std")]
 328         phantom: core::marker::PhantomData<T>,
 329
 330 }
 331
 332 #[cfg(not(any(feature = "no-std", test)))]
 333 type ConfiguredTime = crate::util::time::MonotonicTime;
 334 #[cfg(feature = "no-std")]
 335 type ConfiguredTime = crate::util::time::Eternity;
 336 #[cfg(all(not(feature = "no-std"), test))]
 337 type ConfiguredTime = SinceEpoch;
 338
 339 impl<T: Time> PaymentAttemptsUsingTime<T> {
 340         pub(crate) fn new() -> Self {
 341                 PaymentAttemptsUsingTime {
 342                         count: 0,
 343                         #[cfg(not(feature = "no-std"))]
 344                         first_attempted_at: T::now(),
 345                         #[cfg(feature = "no-std")]
 346                         phantom: core::marker::PhantomData,
 347                 }
 348         }
 349 }
 350
 351 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 352         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 353                 #[cfg(feature = "no-std")]
 354                 return write!(f, "attempts: {}", self.count);
 355                 #[cfg(not(feature = "no-std"))]
 356                 return write!(
 357                         f,
 358                         "attempts: {}, duration: {}s",
 359                         self.count,
 360                         T::now().duration_since(self.first_attempted_at).as_secs()
 361                 );
 362         }
 363 }
 364
 365 /// Indicates an immediate error on [`ChannelManager::send_payment`]. Further errors may be
 366 /// surfaced later via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 367 ///
 368 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 369 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 370 /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 371 #[derive(Clone, Debug, PartialEq, Eq)]
 372 pub enum RetryableSendFailure {
 373         /// The provided [`PaymentParameters::expiry_time`] indicated that the payment has expired. Note
 374         /// that this error is *not* caused by [`Retry::Timeout`].
 375         ///
 376         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 377         PaymentExpired,
 378         /// We were unable to find a route to the destination.
 379         RouteNotFound,
 380         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 381         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 382         ///
 383         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 384         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 385         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 386         DuplicatePayment,
 387 }
 388
 389 /// If a payment fails to send with [`ChannelManager::send_payment_with_route`], it can be in one
 390 /// of several states. This enum is returned as the Err() type describing which state the payment
 391 /// is in, see the description of individual enum states for more.
 392 ///
 393 /// [`ChannelManager::send_payment_with_route`]: crate::ln::channelmanager::ChannelManager::send_payment_with_route
 394 #[derive(Clone, Debug)]
 395 pub enum PaymentSendFailure {
 396         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 397         /// send the payment at all.
 398         ///
 399         /// You can freely resend the payment in full (with the parameter error fixed).
 400         ///
 401         /// Because the payment failed outright, no payment tracking is done and no
 402         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 403         ///
 404         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 405         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 406         ParameterError(APIError),
 407         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 408         /// from attempting to send the payment at all.
 409         ///
 410         /// You can freely resend the payment in full (with the parameter error fixed).
 411         ///
 412         /// Because the payment failed outright, no payment tracking is done and no
 413         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 414         ///
 415         /// The results here are ordered the same as the paths in the route object which was passed to
 416         /// send_payment.
 417         ///
 418         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 419         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 420         PathParameterError(Vec<Result<(), APIError>>),
 421         /// All paths which were attempted failed to send, with no channel state change taking place.
 422         /// You can freely resend the payment in full (though you probably want to do so over different
 423         /// paths than the ones selected).
 424         ///
 425         /// Because the payment failed outright, no payment tracking is done and no
 426         /// [`Event::PaymentPathFailed`] or [`Event::PaymentFailed`] events will be generated.
 427         ///
 428         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 429         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 430         AllFailedResendSafe(Vec<APIError>),
 431         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 432         /// yet completed (i.e. generated an [`Event::PaymentSent`] or [`Event::PaymentFailed`]).
 433         ///
 434         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 435         /// [`Event::PaymentSent`]: crate::events::Event::PaymentSent
 436         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 437         DuplicatePayment,
 438         /// Some paths that were attempted failed to send, though some paths may have succeeded. At least
 439         /// some paths have irrevocably committed to the HTLC.
 440         ///
 441         /// The results here are ordered the same as the paths in the route object that was passed to
 442         /// send_payment.
 443         ///
 444         /// Any entries that contain `Err(APIError::MonitorUpdateInprogress)` will send once a
 445         /// [`MonitorEvent::Completed`] is provided for the next-hop channel with the latest update_id.
 446         ///
 447         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 448         PartialFailure {
 449                 /// The errors themselves, in the same order as the paths from the route.
 450                 results: Vec<Result<(), APIError>>,
 451                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 452                 /// contain a [`RouteParameters`] object for the failing paths.
 453                 failed_paths_retry: Option<RouteParameters>,
 454                 /// The payment id for the payment, which is now at least partially pending.
 455                 payment_id: PaymentId,
 456         },
 457 }
 458
 459 /// An error when attempting to pay a BOLT 12 invoice.
 460 #[derive(Clone, Debug, PartialEq, Eq)]
 461 pub(super) enum Bolt12PaymentError {
 462         /// The invoice was not requested.
 463         UnexpectedInvoice,
 464         /// Payment for an invoice with the corresponding [`PaymentId`] was already initiated.
 465         DuplicateInvoice,
 466 }
 467
 468 /// Information which is provided, encrypted, to the payment recipient when sending HTLCs.
 469 ///
 470 /// This should generally be constructed with data communicated to us from the recipient (via a
 471 /// BOLT11 or BOLT12 invoice).
 472 #[derive(Clone, Debug, PartialEq, Eq)]
 473 pub struct RecipientOnionFields {
 474         /// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 475         /// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to
 476         /// authenticate the sender to the recipient and prevent payment-probing (deanonymization)
 477         /// attacks.
 478         ///
 479         /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
 480         /// multi-path payments require a recipient-provided secret.
 481         ///
 482         /// Some implementations may reject spontaneous payments with payment secrets, so you may only
 483         /// want to provide a secret for a spontaneous payment if MPP is needed and you know your
 484         /// recipient will not reject it.
 485         pub payment_secret: Option<PaymentSecret>,
 486         /// The payment metadata serves a similar purpose as [`Self::payment_secret`] but is of
 487         /// arbitrary length. This gives recipients substantially more flexibility to receive
 488         /// additional data.
 489         ///
 490         /// In LDK, while the [`Self::payment_secret`] is fixed based on an internal authentication
 491         /// scheme to authenticate received payments against expected payments and invoices, this field
 492         /// is not used in LDK for received payments, and can be used to store arbitrary data in
 493         /// invoices which will be received with the payment.
 494         ///
 495         /// Note that this field was added to the lightning specification more recently than
 496         /// [`Self::payment_secret`] and while nearly all lightning senders support secrets, metadata
 497         /// may not be supported as universally.
 498         pub payment_metadata: Option<Vec<u8>>,
 499         /// See [`Self::custom_tlvs`] for more info.
 500         pub(super) custom_tlvs: Vec<(u64, Vec<u8>)>,
 501 }
 502
 503 impl_writeable_tlv_based!(RecipientOnionFields, {
 504         (0, payment_secret, option),
 505         (1, custom_tlvs, optional_vec),
 506         (2, payment_metadata, option),
 507 });
 508
 509 impl RecipientOnionFields {
 510         /// Creates a [`RecipientOnionFields`] from only a [`PaymentSecret`]. This is the most common
 511         /// set of onion fields for today's BOLT11 invoices - most nodes require a [`PaymentSecret`]
 512         /// but do not require or provide any further data.
 513         pub fn secret_only(payment_secret: PaymentSecret) -> Self {
 514                 Self { payment_secret: Some(payment_secret), payment_metadata: None, custom_tlvs: Vec::new() }
 515         }
 516
 517         /// Creates a new [`RecipientOnionFields`] with no fields. This generally does not create
 518         /// payable HTLCs except for single-path spontaneous payments, i.e. this should generally
 519         /// only be used for calls to [`ChannelManager::send_spontaneous_payment`]. If you are sending
 520         /// a spontaneous MPP this will not work as all MPP require payment secrets; you may
 521         /// instead want to use [`RecipientOnionFields::secret_only`].
 522         ///
 523         /// [`ChannelManager::send_spontaneous_payment`]: super::channelmanager::ChannelManager::send_spontaneous_payment
 524         /// [`RecipientOnionFields::secret_only`]: RecipientOnionFields::secret_only
 525         pub fn spontaneous_empty() -> Self {
 526                 Self { payment_secret: None, payment_metadata: None, custom_tlvs: Vec::new() }
 527         }
 528
 529         /// Creates a new [`RecipientOnionFields`] from an existing one, adding custom TLVs. Each
 530         /// TLV is provided as a `(u64, Vec<u8>)` for the type number and serialized value
 531         /// respectively. TLV type numbers must be unique and within the range
 532         /// reserved for custom types, i.e. >= 2^16, otherwise this method will return `Err(())`.
 533         ///
 534         /// This method will also error for types in the experimental range which have been
 535         /// standardized within the protocol, which only includes 5482373484 (keysend) for now.
 536         ///
 537         /// See [`Self::custom_tlvs`] for more info.
 538         pub fn with_custom_tlvs(mut self, mut custom_tlvs: Vec<(u64, Vec<u8>)>) -> Result<Self, ()> {
 539                 custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
 540                 let mut prev_type = None;
 541                 for (typ, _) in custom_tlvs.iter() {
 542                         if *typ < 1 << 16 { return Err(()); }
 543                         if *typ == 5482373484 { return Err(()); } // keysend
 544                         match prev_type {
 545                                 Some(prev) if prev >= *typ => return Err(()),
 546                                 _ => {},
 547                         }
 548                         prev_type = Some(*typ);
 549                 }
 550                 self.custom_tlvs = custom_tlvs;
 551                 Ok(self)
 552         }
 553
 554         /// Gets the custom TLVs that will be sent or have been received.
 555         ///
 556         /// Custom TLVs allow sending extra application-specific data with a payment. They provide
 557         /// additional flexibility on top of payment metadata, as while other implementations may
 558         /// require `payment_metadata` to reflect metadata provided in an invoice, custom TLVs
 559         /// do not have this restriction.
 560         ///
 561         /// Note that if this field is non-empty, it will contain strictly increasing TLVs, each
 562         /// represented by a `(u64, Vec<u8>)` for its type number and serialized value respectively.
 563         /// This is validated when setting this field using [`Self::with_custom_tlvs`].
 564         pub fn custom_tlvs(&self) -> &Vec<(u64, Vec<u8>)> {
 565                 &self.custom_tlvs
 566         }
 567
 568         /// When we have received some HTLC(s) towards an MPP payment, as we receive further HTLC(s) we
 569         /// have to make sure that some fields match exactly across the parts. For those that aren't
 570         /// required to match, if they don't match we should remove them so as to not expose data
 571         /// that's dependent on the HTLC receive order to users.
 572         ///
 573         /// Here we implement this, first checking compatibility then mutating two objects and then
 574         /// dropping any remaining non-matching fields from both.
 575         pub(super) fn check_merge(&mut self, further_htlc_fields: &mut Self) -> Result<(), ()> {
 576                 if self.payment_secret != further_htlc_fields.payment_secret { return Err(()); }
 577                 if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 578
 579                 let tlvs = &mut self.custom_tlvs;
 580                 let further_tlvs = &mut further_htlc_fields.custom_tlvs;
 581
 582                 let even_tlvs = tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 583                 let further_even_tlvs = further_tlvs.iter().filter(|(typ, _)| *typ % 2 == 0);
 584                 if even_tlvs.ne(further_even_tlvs) { return Err(()) }
 585
 586                 tlvs.retain(|tlv| further_tlvs.iter().any(|further_tlv| tlv == further_tlv));
 587                 further_tlvs.retain(|further_tlv| tlvs.iter().any(|tlv| tlv == further_tlv));
 588
 589                 Ok(())
 590         }
 591 }
 592
 593 /// Arguments for [`super::channelmanager::ChannelManager::send_payment_along_path`].
 594 pub(super) struct SendAlongPathArgs<'a> {
 595         pub path: &'a Path,
 596         pub payment_hash: &'a PaymentHash,
 597         pub recipient_onion: RecipientOnionFields,
 598         pub total_value: u64,
 599         pub cur_height: u32,
 600         pub payment_id: PaymentId,
 601         pub keysend_preimage: &'a Option<PaymentPreimage>,
 602         pub session_priv_bytes: [u8; 32],
 603 }
 604
 605 pub(super) struct OutboundPayments {
 606         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 607         pub(super) retry_lock: Mutex<()>,
 608 }
 609
 610 impl OutboundPayments {
 611         pub(super) fn new() -> Self {
 612                 Self {
 613                         pending_outbound_payments: Mutex::new(HashMap::new()),
 614                         retry_lock: Mutex::new(()),
 615                 }
 616         }
 617
 618         pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 619                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
 620                 retry_strategy: Retry, route_params: RouteParameters, router: &R,
 621                 first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
 622                 node_signer: &NS, best_block_height: u32, logger: &L,
 623                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 624         ) -> Result<(), RetryableSendFailure>
 625         where
 626                 R::Target: Router,
 627                 ES::Target: EntropySource,
 628                 NS::Target: NodeSigner,
 629                 L::Target: Logger,
 630                 IH: Fn() -> InFlightHtlcs,
 631                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 632         {
 633                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
 634                         route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
 635                         best_block_height, logger, pending_events, &send_payment_along_path)
 636         }
 637
 638         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 639                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 640                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 641                 send_payment_along_path: F
 642         ) -> Result<(), PaymentSendFailure>
 643         where
 644                 ES::Target: EntropySource,
 645                 NS::Target: NodeSigner,
 646                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>
 647         {
 648                 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)?;
 649                 self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
 650                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
 651                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
 652         }
 653
 654         pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 655                 &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
 656                 payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
 657                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 658                 node_signer: &NS, best_block_height: u32, logger: &L,
 659                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP
 660         ) -> Result<PaymentHash, RetryableSendFailure>
 661         where
 662                 R::Target: Router,
 663                 ES::Target: EntropySource,
 664                 NS::Target: NodeSigner,
 665                 L::Target: Logger,
 666                 IH: Fn() -> InFlightHtlcs,
 667                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 668         {
 669                 let preimage = payment_preimage
 670                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 671                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 672                 self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
 673                         retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
 674                         node_signer, best_block_height, logger, pending_events, send_payment_along_path)
 675                         .map(|()| payment_hash)
 676         }
 677
 678         pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
 679                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
 680                 recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
 681                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 682         ) -> Result<PaymentHash, PaymentSendFailure>
 683         where
 684                 ES::Target: EntropySource,
 685                 NS::Target: NodeSigner,
 686                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 687         {
 688                 let preimage = payment_preimage
 689                         .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
 690                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 691                 let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
 692                         payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 693
 694                 match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
 695                         payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
 696                 ) {
 697                         Ok(()) => Ok(payment_hash),
 698                         Err(e) => {
 699                                 self.remove_outbound_if_all_failed(payment_id, &e);
 700                                 Err(e)
 701                         }
 702                 }
 703         }
 704
 705         #[allow(unused)]
 706         pub(super) fn send_payment_for_bolt12_invoice<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
 707                 &self, invoice: &Bolt12Invoice, payment_id: PaymentId, router: &R,
 708                 first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 709                 best_block_height: u32, logger: &L,
 710                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
 711                 send_payment_along_path: SP,
 712         ) -> Result<(), Bolt12PaymentError>
 713         where
 714                 R::Target: Router,
 715                 ES::Target: EntropySource,
 716                 NS::Target: NodeSigner,
 717                 L::Target: Logger,
 718                 IH: Fn() -> InFlightHtlcs,
 719                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 720         {
 721                 let payment_hash = invoice.payment_hash();
 722                 match self.pending_outbound_payments.lock().unwrap().entry(payment_id) {
 723                         hash_map::Entry::Occupied(entry) => match entry.get() {
 724                                 PendingOutboundPayment::AwaitingInvoice { retry_strategy, .. } => {
 725                                         *entry.into_mut() = PendingOutboundPayment::InvoiceReceived {
 726                                                 payment_hash,
 727                                                 retry_strategy: *retry_strategy,
 728                                         };
 729                                 },
 730                                 _ => return Err(Bolt12PaymentError::DuplicateInvoice),
 731                         },
 732                         hash_map::Entry::Vacant(_) => return Err(Bolt12PaymentError::UnexpectedInvoice),
 733                 };
 734
 735                 let route_params = RouteParameters {
 736                         payment_params: PaymentParameters::from_bolt12_invoice(&invoice),
 737                         final_value_msat: invoice.amount_msats(),
 738                 };
 739
 740                 self.find_route_and_send_payment(
 741                         payment_hash, payment_id, route_params, router, first_hops, &inflight_htlcs,
 742                         entropy_source, node_signer, best_block_height, logger, pending_events,
 743                         &send_payment_along_path
 744                 );
 745
 746                 Ok(())
 747         }
 748
 749         pub(super) fn check_retry_payments<R: Deref, ES: Deref, NS: Deref, SP, IH, FH, L: Deref>(
 750                 &self, router: &R, first_hops: FH, inflight_htlcs: IH, entropy_source: &ES, node_signer: &NS,
 751                 best_block_height: u32,
 752                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
 753                 send_payment_along_path: SP,
 754         )
 755         where
 756                 R::Target: Router,
 757                 ES::Target: EntropySource,
 758                 NS::Target: NodeSigner,
 759                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 760                 IH: Fn() -> InFlightHtlcs,
 761                 FH: Fn() -> Vec<ChannelDetails>,
 762                 L::Target: Logger,
 763         {
 764                 let _single_thread = self.retry_lock.lock().unwrap();
 765                 loop {
 766                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 767                         let mut retry_id_route_params = None;
 768                         for (pmt_id, pmt) in outbounds.iter_mut() {
 769                                 if pmt.is_auto_retryable_now() {
 770                                         if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, payment_params: Some(params), payment_hash, .. } = pmt {
 771                                                 if pending_amt_msat < total_msat {
 772                                                         retry_id_route_params = Some((*payment_hash, *pmt_id, RouteParameters {
 773                                                                 final_value_msat: *total_msat - *pending_amt_msat,
 774                                                                 payment_params: params.clone(),
 775                                                         }));
 776                                                         break
 777                                                 }
 778                                         } else { debug_assert!(false); }
 779                                 }
 780                         }
 781                         core::mem::drop(outbounds);
 782                         if let Some((payment_hash, payment_id, route_params)) = retry_id_route_params {
 783                                 self.find_route_and_send_payment(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)
 784                         } else { break }
 785                 }
 786
 787                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 788                 outbounds.retain(|pmt_id, pmt| {
 789                         let mut retain = true;
 790                         if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_awaiting_invoice() {
 791                                 pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
 792                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
 793                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 794                                                 payment_id: *pmt_id,
 795                                                 payment_hash: *payment_hash,
 796                                                 reason: *reason,
 797                                         }, None));
 798                                         retain = false;
 799                                 }
 800                         }
 801                         retain
 802                 });
 803         }
 804
 805         pub(super) fn needs_abandon(&self) -> bool {
 806                 let outbounds = self.pending_outbound_payments.lock().unwrap();
 807                 outbounds.iter().any(|(_, pmt)|
 808                         !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 && !pmt.is_fulfilled() &&
 809                         !pmt.is_awaiting_invoice())
 810         }
 811
 812         /// Errors immediately on [`RetryableSendFailure`] error conditions. Otherwise, further errors may
 813         /// be surfaced asynchronously via [`Event::PaymentPathFailed`] and [`Event::PaymentFailed`].
 814         ///
 815         /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 816         /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
 817         fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 818                 &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 819                 keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
 820                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
 821                 node_signer: &NS, best_block_height: u32, logger: &L,
 822                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: SP,
 823         ) -> Result<(), RetryableSendFailure>
 824         where
 825                 R::Target: Router,
 826                 ES::Target: EntropySource,
 827                 NS::Target: NodeSigner,
 828                 L::Target: Logger,
 829                 IH: Fn() -> InFlightHtlcs,
 830                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 831         {
 832                 #[cfg(feature = "std")] {
 833                         if has_expired(&route_params) {
 834                                 log_error!(logger, "Payment with id {} and hash {} had expired before we started paying",
 835                                         payment_id, payment_hash);
 836                                 return Err(RetryableSendFailure::PaymentExpired)
 837                         }
 838                 }
 839
 840                 let route = router.find_route_with_id(
 841                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 842                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 843                         payment_hash, payment_id,
 844                 ).map_err(|_| {
 845                         log_error!(logger, "Failed to find route for payment with id {} and hash {}",
 846                                 payment_id, payment_hash);
 847                         RetryableSendFailure::RouteNotFound
 848                 })?;
 849
 850                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
 851                         recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
 852                         Some(route_params.payment_params.clone()), entropy_source, best_block_height)
 853                         .map_err(|_| {
 854                                 log_error!(logger, "Payment with id {} is already pending. New payment had payment hash {}",
 855                                         payment_id, payment_hash);
 856                                 RetryableSendFailure::DuplicatePayment
 857                         })?;
 858
 859                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage, payment_id, None,
 860                         onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
 861                 log_info!(logger, "Sending payment with id {} and hash {} returned {:?}",
 862                         payment_id, payment_hash, res);
 863                 if let Err(e) = res {
 864                         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);
 865                 }
 866                 Ok(())
 867         }
 868
 869         fn find_route_and_send_payment<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
 870                 &self, payment_hash: PaymentHash, payment_id: PaymentId, route_params: RouteParameters,
 871                 router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: &IH, entropy_source: &ES,
 872                 node_signer: &NS, best_block_height: u32, logger: &L,
 873                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
 874         )
 875         where
 876                 R::Target: Router,
 877                 ES::Target: EntropySource,
 878                 NS::Target: NodeSigner,
 879                 L::Target: Logger,
 880                 IH: Fn() -> InFlightHtlcs,
 881                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
 882         {
 883                 #[cfg(feature = "std")] {
 884                         if has_expired(&route_params) {
 885                                 log_error!(logger, "Payment params expired on retry, abandoning payment {}", &payment_id);
 886                                 self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
 887                                 return
 888                         }
 889                 }
 890
 891                 let route = match router.find_route_with_id(
 892                         &node_signer.get_node_id(Recipient::Node).unwrap(), &route_params,
 893                         Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs(),
 894                         payment_hash, payment_id,
 895                 ) {
 896                         Ok(route) => route,
 897                         Err(e) => {
 898                                 log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", &payment_id, e);
 899                                 self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
 900                                 return
 901                         }
 902                 };
 903                 for path in route.paths.iter() {
 904                         if path.hops.len() == 0 {
 905                                 log_error!(logger, "Unusable path in route (path.hops.len() must be at least 1");
 906                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
 907                                 return
 908                         }
 909                 }
 910
 911                 macro_rules! abandon_with_entry {
 912                         ($payment: expr, $reason: expr) => {
 913                                 $payment.get_mut().mark_abandoned($reason);
 914                                 if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
 915                                         if $payment.get().remaining_parts() == 0 {
 916                                                 pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
 917                                                         payment_id,
 918                                                         payment_hash,
 919                                                         reason: *reason,
 920                                                 }, None));
 921                                                 $payment.remove();
 922                                         }
 923                                 }
 924                         }
 925                 }
 926                 let (total_msat, recipient_onion, keysend_preimage, onion_session_privs) = {
 927                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 928                         match outbounds.entry(payment_id) {
 929                                 hash_map::Entry::Occupied(mut payment) => {
 930                                         match payment.get() {
 931                                                 PendingOutboundPayment::Retryable {
 932                                                         total_msat, keysend_preimage, payment_secret, payment_metadata,
 933                                                         custom_tlvs, pending_amt_msat, ..
 934                                                 } => {
 935                                                         const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 936                                                         let retry_amt_msat = route.get_total_amount();
 937                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 938                                                                 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);
 939                                                                 abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
 940                                                                 return
 941                                                         }
 942
 943                                                         if !payment.get().is_retryable_now() {
 944                                                                 log_error!(logger, "Retries exhausted for payment id {}", &payment_id);
 945                                                                 abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
 946                                                                 return
 947                                                         }
 948
 949                                                         let total_msat = *total_msat;
 950                                                         let recipient_onion = RecipientOnionFields {
 951                                                                 payment_secret: *payment_secret,
 952                                                                 payment_metadata: payment_metadata.clone(),
 953                                                                 custom_tlvs: custom_tlvs.clone(),
 954                                                         };
 955                                                         let keysend_preimage = *keysend_preimage;
 956
 957                                                         let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 958                                                         for _ in 0..route.paths.len() {
 959                                                                 onion_session_privs.push(entropy_source.get_secure_random_bytes());
 960                                                         }
 961
 962                                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 963                                                                 assert!(payment.get_mut().insert(*session_priv_bytes, path));
 964                                                         }
 965
 966                                                         payment.get_mut().increment_attempts();
 967
 968                                                         (total_msat, recipient_onion, keysend_preimage, onion_session_privs)
 969                                                 },
 970                                                 PendingOutboundPayment::Legacy { .. } => {
 971                                                         log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
 972                                                         return
 973                                                 },
 974                                                 PendingOutboundPayment::AwaitingInvoice { .. } => {
 975                                                         log_error!(logger, "Payment not yet sent");
 976                                                         return
 977                                                 },
 978                                                 PendingOutboundPayment::InvoiceReceived { payment_hash, retry_strategy } => {
 979                                                         let total_amount = route_params.final_value_msat;
 980                                                         let recipient_onion = RecipientOnionFields {
 981                                                                 payment_secret: None,
 982                                                                 payment_metadata: None,
 983                                                                 custom_tlvs: vec![],
 984                                                         };
 985                                                         let retry_strategy = Some(*retry_strategy);
 986                                                         let payment_params = Some(route_params.payment_params.clone());
 987                                                         let (retryable_payment, onion_session_privs) = self.create_pending_payment(
 988                                                                 *payment_hash, recipient_onion.clone(), None, &route,
 989                                                                 retry_strategy, payment_params, entropy_source, best_block_height
 990                                                         );
 991                                                         *payment.into_mut() = retryable_payment;
 992                                                         (total_amount, recipient_onion, None, onion_session_privs)
 993                                                 },
 994                                                 PendingOutboundPayment::Fulfilled { .. } => {
 995                                                         log_error!(logger, "Payment already completed");
 996                                                         return
 997                                                 },
 998                                                 PendingOutboundPayment::Abandoned { .. } => {
 999                                                         log_error!(logger, "Payment already abandoned (with some HTLCs still pending)");
1000                                                         return
1001                                                 },
1002                                         }
1003                                 },
1004                                 hash_map::Entry::Vacant(_) => {
1005                                         log_error!(logger, "Payment with ID {} not found", &payment_id);
1006                                         return
1007                                 }
1008                         }
1009                 };
1010                 let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
1011                         payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
1012                         &send_payment_along_path);
1013                 log_info!(logger, "Result retrying payment id {}: {:?}", &payment_id, res);
1014                 if let Err(e) = res {
1015                         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);
1016                 }
1017         }
1018
1019         fn handle_pay_route_err<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
1020                 &self, err: PaymentSendFailure, payment_id: PaymentId, payment_hash: PaymentHash, route: Route,
1021                 mut route_params: RouteParameters, router: &R, first_hops: Vec<ChannelDetails>,
1022                 inflight_htlcs: &IH, entropy_source: &ES, node_signer: &NS, best_block_height: u32, logger: &L,
1023                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, send_payment_along_path: &SP,
1024         )
1025         where
1026                 R::Target: Router,
1027                 ES::Target: EntropySource,
1028                 NS::Target: NodeSigner,
1029                 L::Target: Logger,
1030                 IH: Fn() -> InFlightHtlcs,
1031                 SP: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1032         {
1033                 match err {
1034                         PaymentSendFailure::AllFailedResendSafe(errs) => {
1035                                 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);
1036                                 self.find_route_and_send_payment(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);
1037                         },
1038                         PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
1039                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
1040                                 // Some paths were sent, even if we failed to send the full MPP value our recipient may
1041                                 // misbehave and claim the funds, at which point we have to consider the payment sent, so
1042                                 // return `Ok()` here, ignoring any retry errors.
1043                                 self.find_route_and_send_payment(payment_hash, payment_id, retry, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
1044                         },
1045                         PaymentSendFailure::PartialFailure { failed_paths_retry: None, .. } => {
1046                                 // This may happen if we send a payment and some paths fail, but only due to a temporary
1047                                 // monitor failure or the like, implying they're really in-flight, but we haven't sent the
1048                                 // initial HTLC-Add messages yet.
1049                         },
1050                         PaymentSendFailure::PathParameterError(results) => {
1051                                 log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
1052                                 Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
1053                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
1054                         },
1055                         PaymentSendFailure::ParameterError(e) => {
1056                                 log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
1057                                 self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
1058                         },
1059                         PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
1060                 }
1061         }
1062
1063         fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
1064                 payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
1065                 paths: Vec<Path>, path_results: I, logger: &L,
1066                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1067         ) where L::Target: Logger {
1068                 let mut events = pending_events.lock().unwrap();
1069                 debug_assert_eq!(paths.len(), path_results.len());
1070                 for (path, path_res) in paths.into_iter().zip(path_results) {
1071                         if let Err(e) = path_res {
1072                                 if let APIError::MonitorUpdateInProgress = e { continue }
1073                                 log_error!(logger, "Failed to send along path due to error: {:?}", e);
1074                                 let mut failed_scid = None;
1075                                 if let APIError::ChannelUnavailable { .. } = e {
1076                                         let scid = path.hops[0].short_channel_id;
1077                                         failed_scid = Some(scid);
1078                                         route_params.payment_params.previously_failed_channels.push(scid);
1079                                 }
1080                                 events.push_back((events::Event::PaymentPathFailed {
1081                                         payment_id: Some(payment_id),
1082                                         payment_hash,
1083                                         payment_failed_permanently: false,
1084                                         failure: events::PathFailure::InitialSend { err: e },
1085                                         path,
1086                                         short_channel_id: failed_scid,
1087                                         #[cfg(test)]
1088                                         error_code: None,
1089                                         #[cfg(test)]
1090                                         error_data: None,
1091                                 }, None));
1092                         }
1093                 }
1094         }
1095
1096         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
1097                 &self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
1098                 best_block_height: u32, send_payment_along_path: F
1099         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
1100         where
1101                 ES::Target: EntropySource,
1102                 NS::Target: NodeSigner,
1103                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1104         {
1105                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
1106
1107                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
1108
1109                 if path.hops.len() < 2 && path.blinded_tail.is_none() {
1110                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
1111                                 err: "No need probing a path with less than two hops".to_string()
1112                         }))
1113                 }
1114
1115                 let route = Route { paths: vec![path], route_params: None };
1116                 let onion_session_privs = self.add_new_pending_payment(payment_hash,
1117                         RecipientOnionFields::spontaneous_empty(), payment_id, None, &route, None, None,
1118                         entropy_source, best_block_height)?;
1119
1120                 match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
1121                         None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
1122                 ) {
1123                         Ok(()) => Ok((payment_hash, payment_id)),
1124                         Err(e) => {
1125                                 self.remove_outbound_if_all_failed(payment_id, &e);
1126                                 Err(e)
1127                         }
1128                 }
1129         }
1130
1131         #[cfg(test)]
1132         pub(super) fn test_set_payment_metadata(
1133                 &self, payment_id: PaymentId, new_payment_metadata: Option<Vec<u8>>
1134         ) {
1135                 match self.pending_outbound_payments.lock().unwrap().get_mut(&payment_id).unwrap() {
1136                         PendingOutboundPayment::Retryable { payment_metadata, .. } => {
1137                                 *payment_metadata = new_payment_metadata;
1138                         },
1139                         _ => panic!("Need a retryable payment to update metadata on"),
1140                 }
1141         }
1142
1143         #[cfg(test)]
1144         pub(super) fn test_add_new_pending_payment<ES: Deref>(
1145                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1146                 route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
1147         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1148                 self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
1149         }
1150
1151         pub(super) fn add_new_pending_payment<ES: Deref>(
1152                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
1153                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
1154                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
1155         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
1156                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1157                 match pending_outbounds.entry(payment_id) {
1158                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
1159                         hash_map::Entry::Vacant(entry) => {
1160                                 let (payment, onion_session_privs) = self.create_pending_payment(
1161                                         payment_hash, recipient_onion, keysend_preimage, route, retry_strategy,
1162                                         payment_params, entropy_source, best_block_height
1163                                 );
1164                                 entry.insert(payment);
1165                                 Ok(onion_session_privs)
1166                         },
1167                 }
1168         }
1169
1170         fn create_pending_payment<ES: Deref>(
1171                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1172                 keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
1173                 payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
1174         ) -> (PendingOutboundPayment, Vec<[u8; 32]>)
1175         where
1176                 ES::Target: EntropySource,
1177         {
1178                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
1179                 for _ in 0..route.paths.len() {
1180                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
1181                 }
1182
1183                 let mut payment = PendingOutboundPayment::Retryable {
1184                         retry_strategy,
1185                         attempts: PaymentAttempts::new(),
1186                         payment_params,
1187                         session_privs: HashSet::new(),
1188                         pending_amt_msat: 0,
1189                         pending_fee_msat: Some(0),
1190                         payment_hash,
1191                         payment_secret: recipient_onion.payment_secret,
1192                         payment_metadata: recipient_onion.payment_metadata,
1193                         keysend_preimage,
1194                         custom_tlvs: recipient_onion.custom_tlvs,
1195                         starting_block_height: best_block_height,
1196                         total_msat: route.get_total_amount(),
1197                 };
1198
1199                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
1200                         assert!(payment.insert(*session_priv_bytes, path));
1201                 }
1202
1203                 (payment, onion_session_privs)
1204         }
1205
1206         #[allow(unused)]
1207         pub(super) fn add_new_awaiting_invoice(
1208                 &self, payment_id: PaymentId, retry_strategy: Retry
1209         ) -> Result<(), ()> {
1210                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1211                 match pending_outbounds.entry(payment_id) {
1212                         hash_map::Entry::Occupied(_) => Err(()),
1213                         hash_map::Entry::Vacant(entry) => {
1214                                 entry.insert(PendingOutboundPayment::AwaitingInvoice {
1215                                         timer_ticks_without_response: 0,
1216                                         retry_strategy,
1217                                 });
1218
1219                                 Ok(())
1220                         },
1221                 }
1222         }
1223
1224         fn pay_route_internal<NS: Deref, F>(
1225                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1226                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1227                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1228                 send_payment_along_path: &F
1229         ) -> Result<(), PaymentSendFailure>
1230         where
1231                 NS::Target: NodeSigner,
1232                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1233         {
1234                 if route.paths.len() < 1 {
1235                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
1236                 }
1237                 if recipient_onion.payment_secret.is_none() && route.paths.len() > 1
1238                         && !route.paths.iter().any(|p| p.blinded_tail.is_some())
1239                 {
1240                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
1241                 }
1242                 let mut total_value = 0;
1243                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
1244                 let mut path_errs = Vec::with_capacity(route.paths.len());
1245                 'path_check: for path in route.paths.iter() {
1246                         if path.hops.len() < 1 || path.hops.len() > 20 {
1247                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size".to_owned()}));
1248                                 continue 'path_check;
1249                         }
1250                         let dest_hop_idx = if path.blinded_tail.is_some() && path.blinded_tail.as_ref().unwrap().hops.len() > 1 {
1251                                 usize::max_value() } else { path.hops.len() - 1 };
1252                         for (idx, hop) in path.hops.iter().enumerate() {
1253                                 if idx != dest_hop_idx && hop.pubkey == our_node_id {
1254                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us".to_owned()}));
1255                                         continue 'path_check;
1256                                 }
1257                         }
1258                         total_value += path.final_value_msat();
1259                         path_errs.push(Ok(()));
1260                 }
1261                 if path_errs.iter().any(|e| e.is_err()) {
1262                         return Err(PaymentSendFailure::PathParameterError(path_errs));
1263                 }
1264                 if let Some(amt_msat) = recv_value_msat {
1265                         total_value = amt_msat;
1266                 }
1267
1268                 let cur_height = best_block_height + 1;
1269                 let mut results = Vec::new();
1270                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
1271                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.into_iter()) {
1272                         let mut path_res = send_payment_along_path(SendAlongPathArgs {
1273                                 path: &path, payment_hash: &payment_hash, recipient_onion: recipient_onion.clone(),
1274                                 total_value, cur_height, payment_id, keysend_preimage: &keysend_preimage, session_priv_bytes
1275                         });
1276                         match path_res {
1277                                 Ok(_) => {},
1278                                 Err(APIError::MonitorUpdateInProgress) => {
1279                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
1280                                         // considered "in flight" and we shouldn't remove it from the
1281                                         // PendingOutboundPayment set.
1282                                 },
1283                                 Err(_) => {
1284                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
1285                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
1286                                                 let removed = payment.remove(&session_priv_bytes, Some(path));
1287                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
1288                                         } else {
1289                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
1290                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
1291                                         }
1292                                 }
1293                         }
1294                         results.push(path_res);
1295                 }
1296                 let mut has_ok = false;
1297                 let mut has_err = false;
1298                 let mut pending_amt_unsent = 0;
1299                 for (res, path) in results.iter().zip(route.paths.iter()) {
1300                         if res.is_ok() { has_ok = true; }
1301                         if res.is_err() { has_err = true; }
1302                         if let &Err(APIError::MonitorUpdateInProgress) = res {
1303                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
1304                                 // PartialFailure.
1305                                 has_err = true;
1306                                 has_ok = true;
1307                         } else if res.is_err() {
1308                                 pending_amt_unsent += path.final_value_msat();
1309                         }
1310                 }
1311                 if has_err && has_ok {
1312                         Err(PaymentSendFailure::PartialFailure {
1313                                 results,
1314                                 payment_id,
1315                                 failed_paths_retry: if pending_amt_unsent != 0 {
1316                                         if let Some(payment_params) = route.route_params.as_ref().map(|p| p.payment_params.clone()) {
1317                                                 Some(RouteParameters {
1318                                                         payment_params: payment_params,
1319                                                         final_value_msat: pending_amt_unsent,
1320                                                 })
1321                                         } else { None }
1322                                 } else { None },
1323                         })
1324                 } else if has_err {
1325                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
1326                 } else {
1327                         Ok(())
1328                 }
1329         }
1330
1331         #[cfg(test)]
1332         pub(super) fn test_send_payment_internal<NS: Deref, F>(
1333                 &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
1334                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
1335                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
1336                 send_payment_along_path: F
1337         ) -> Result<(), PaymentSendFailure>
1338         where
1339                 NS::Target: NodeSigner,
1340                 F: Fn(SendAlongPathArgs) -> Result<(), APIError>,
1341         {
1342                 self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
1343                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
1344                         &send_payment_along_path)
1345                         .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
1346         }
1347
1348         // If we failed to send any paths, remove the new PaymentId from the `pending_outbound_payments`
1349         // map as the payment is free to be resent.
1350         fn remove_outbound_if_all_failed(&self, payment_id: PaymentId, err: &PaymentSendFailure) {
1351                 if let &PaymentSendFailure::AllFailedResendSafe(_) = err {
1352                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
1353                         debug_assert!(removed, "We should always have a pending payment to remove here");
1354                 }
1355         }
1356
1357         pub(super) fn claim_htlc<L: Deref>(
1358                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
1359                 path: Path, from_onchain: bool, ev_completion_action: EventCompletionAction,
1360                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>,
1361                 logger: &L,
1362         ) where L::Target: Logger {
1363                 let mut session_priv_bytes = [0; 32];
1364                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1365                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1366                 let mut pending_events = pending_events.lock().unwrap();
1367                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1368                         if !payment.get().is_fulfilled() {
1369                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
1370                                 log_info!(logger, "Payment with id {} and hash {} sent!", payment_id, payment_hash);
1371                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
1372                                 pending_events.push_back((events::Event::PaymentSent {
1373                                         payment_id: Some(payment_id),
1374                                         payment_preimage,
1375                                         payment_hash,
1376                                         fee_paid_msat,
1377                                 }, Some(ev_completion_action.clone())));
1378                                 payment.get_mut().mark_fulfilled();
1379                         }
1380
1381                         if from_onchain {
1382                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
1383                                 // This could potentially lead to removing a pending payment too early,
1384                                 // with a reorg of one block causing us to re-add the fulfilled payment on
1385                                 // restart.
1386                                 // TODO: We should have a second monitor event that informs us of payments
1387                                 // irrevocably fulfilled.
1388                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1389                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
1390                                         pending_events.push_back((events::Event::PaymentPathSuccessful {
1391                                                 payment_id,
1392                                                 payment_hash,
1393                                                 path,
1394                                         }, Some(ev_completion_action)));
1395                                 }
1396                         }
1397                 } else {
1398                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", &payment_preimage);
1399                 }
1400         }
1401
1402         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>,
1403                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1404         {
1405                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1406                 let mut pending_events = pending_events.lock().unwrap();
1407                 for source in sources {
1408                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
1409                                 let mut session_priv_bytes = [0; 32];
1410                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1411                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1412                                         assert!(payment.get().is_fulfilled());
1413                                         if payment.get_mut().remove(&session_priv_bytes, None) {
1414                                                 let payment_hash = payment.get().payment_hash();
1415                                                 debug_assert!(payment_hash.is_some());
1416                                                 pending_events.push_back((events::Event::PaymentPathSuccessful {
1417                                                         payment_id,
1418                                                         payment_hash,
1419                                                         path,
1420                                                 }, None));
1421                                         }
1422                                 }
1423                         }
1424                 }
1425         }
1426
1427         pub(super) fn remove_stale_payments(
1428                 &self, pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>)
1429         {
1430                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
1431                 let mut pending_events = pending_events.lock().unwrap();
1432                 pending_outbound_payments.retain(|payment_id, payment| {
1433                         // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
1434                         // from the map. However, if we did that immediately when the last payment HTLC is claimed,
1435                         // this could race the user making a duplicate send_payment call and our idempotency
1436                         // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
1437                         // removal. This should be more than sufficient to ensure the idempotency of any
1438                         // `send_payment` calls that were made at the same time the `PaymentSent` event was being
1439                         // processed.
1440                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
1441                                 let mut no_remaining_entries = session_privs.is_empty();
1442                                 if no_remaining_entries {
1443                                         for (ev, _) in pending_events.iter() {
1444                                                 match ev {
1445                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
1446                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
1447                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
1448                                                                         if payment_id == ev_payment_id {
1449                                                                                 no_remaining_entries = false;
1450                                                                                 break;
1451                                                                         }
1452                                                                 },
1453                                                         _ => {},
1454                                                 }
1455                                         }
1456                                 }
1457                                 if no_remaining_entries {
1458                                         *timer_ticks_without_htlcs += 1;
1459                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
1460                                 } else {
1461                                         *timer_ticks_without_htlcs = 0;
1462                                         true
1463                                 }
1464                         } else if let PendingOutboundPayment::AwaitingInvoice { timer_ticks_without_response, .. } = payment {
1465                                 *timer_ticks_without_response += 1;
1466                                 if *timer_ticks_without_response <= INVOICE_REQUEST_TIMEOUT_TICKS {
1467                                         true
1468                                 } else {
1469                                         pending_events.push_back(
1470                                                 (events::Event::InvoiceRequestFailed { payment_id: *payment_id }, None)
1471                                         );
1472                                         false
1473                                 }
1474                         } else { true }
1475                 });
1476         }
1477
1478         // Returns a bool indicating whether a PendingHTLCsForwardable event should be generated.
1479         pub(super) fn fail_htlc<L: Deref>(
1480                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
1481                 path: &Path, session_priv: &SecretKey, payment_id: &PaymentId,
1482                 probing_cookie_secret: [u8; 32], secp_ctx: &Secp256k1<secp256k1::All>,
1483                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>, logger: &L,
1484         ) -> bool where L::Target: Logger {
1485                 #[cfg(test)]
1486                 let DecodedOnionFailure {
1487                         network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data
1488                 } = onion_error.decode_onion_failure(secp_ctx, logger, &source);
1489                 #[cfg(not(test))]
1490                 let DecodedOnionFailure { network_update, short_channel_id, payment_retryable } =
1491                         onion_error.decode_onion_failure(secp_ctx, logger, &source);
1492
1493                 let payment_is_probe = payment_is_probe(payment_hash, &payment_id, probing_cookie_secret);
1494                 let mut session_priv_bytes = [0; 32];
1495                 session_priv_bytes.copy_from_slice(&session_priv[..]);
1496                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1497
1498                 // If any payments already need retry, there's no need to generate a redundant
1499                 // `PendingHTLCsForwardable`.
1500                 let already_awaiting_retry = outbounds.iter().any(|(_, pmt)| {
1501                         let mut awaiting_retry = false;
1502                         if pmt.is_auto_retryable_now() {
1503                                 if let PendingOutboundPayment::Retryable { pending_amt_msat, total_msat, .. } = pmt {
1504                                         if pending_amt_msat < total_msat {
1505                                                 awaiting_retry = true;
1506                                         }
1507                                 }
1508                         }
1509                         awaiting_retry
1510                 });
1511
1512                 let mut full_failure_ev = None;
1513                 let mut pending_retry_ev = false;
1514                 let attempts_remaining = if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
1515                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
1516                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1517                                 return false
1518                         }
1519                         if payment.get().is_fulfilled() {
1520                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", &payment_hash);
1521                                 return false
1522                         }
1523                         let mut is_retryable_now = payment.get().is_auto_retryable_now();
1524                         if let Some(scid) = short_channel_id {
1525                                 // TODO: If we decided to blame ourselves (or one of our channels) in
1526                                 // process_onion_failure we should close that channel as it implies our
1527                                 // next-hop is needlessly blaming us!
1528                                 payment.get_mut().insert_previously_failed_scid(scid);
1529                         }
1530
1531                         if payment_is_probe || !is_retryable_now || !payment_retryable {
1532                                 let reason = if !payment_retryable {
1533                                         PaymentFailureReason::RecipientRejected
1534                                 } else {
1535                                         PaymentFailureReason::RetriesExhausted
1536                                 };
1537                                 payment.get_mut().mark_abandoned(reason);
1538                                 is_retryable_now = false;
1539                         }
1540                         if payment.get().remaining_parts() == 0 {
1541                                 if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
1542                                         if !payment_is_probe {
1543                                                 full_failure_ev = Some(events::Event::PaymentFailed {
1544                                                         payment_id: *payment_id,
1545                                                         payment_hash: *payment_hash,
1546                                                         reason: *reason,
1547                                                 });
1548                                         }
1549                                         payment.remove();
1550                                 }
1551                         }
1552                         is_retryable_now
1553                 } else {
1554                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", &payment_hash);
1555                         return false
1556                 };
1557                 core::mem::drop(outbounds);
1558                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", &payment_hash);
1559
1560                 let path_failure = {
1561                         if payment_is_probe {
1562                                 if !payment_retryable {
1563                                         events::Event::ProbeSuccessful {
1564                                                 payment_id: *payment_id,
1565                                                 payment_hash: payment_hash.clone(),
1566                                                 path: path.clone(),
1567                                         }
1568                                 } else {
1569                                         events::Event::ProbeFailed {
1570                                                 payment_id: *payment_id,
1571                                                 payment_hash: payment_hash.clone(),
1572                                                 path: path.clone(),
1573                                                 short_channel_id,
1574                                         }
1575                                 }
1576                         } else {
1577                                 // If we miss abandoning the payment above, we *must* generate an event here or else the
1578                                 // payment will sit in our outbounds forever.
1579                                 if attempts_remaining && !already_awaiting_retry {
1580                                         debug_assert!(full_failure_ev.is_none());
1581                                         pending_retry_ev = true;
1582                                 }
1583                                 events::Event::PaymentPathFailed {
1584                                         payment_id: Some(*payment_id),
1585                                         payment_hash: payment_hash.clone(),
1586                                         payment_failed_permanently: !payment_retryable,
1587                                         failure: events::PathFailure::OnPath { network_update },
1588                                         path: path.clone(),
1589                                         short_channel_id,
1590                                         #[cfg(test)]
1591                                         error_code: onion_error_code,
1592                                         #[cfg(test)]
1593                                         error_data: onion_error_data
1594                                 }
1595                         }
1596                 };
1597                 let mut pending_events = pending_events.lock().unwrap();
1598                 pending_events.push_back((path_failure, None));
1599                 if let Some(ev) = full_failure_ev { pending_events.push_back((ev, None)); }
1600                 pending_retry_ev
1601         }
1602
1603         pub(super) fn abandon_payment(
1604                 &self, payment_id: PaymentId, reason: PaymentFailureReason,
1605                 pending_events: &Mutex<VecDeque<(events::Event, Option<EventCompletionAction>)>>
1606         ) {
1607                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
1608                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
1609                         payment.get_mut().mark_abandoned(reason);
1610                         if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
1611                                 if payment.get().remaining_parts() == 0 {
1612                                         pending_events.lock().unwrap().push_back((events::Event::PaymentFailed {
1613                                                 payment_id,
1614                                                 payment_hash: *payment_hash,
1615                                                 reason: *reason,
1616                                         }, None));
1617                                         payment.remove();
1618                                 }
1619                         } else if let PendingOutboundPayment::AwaitingInvoice { .. } = payment.get() {
1620                                 pending_events.lock().unwrap().push_back((events::Event::InvoiceRequestFailed {
1621                                         payment_id,
1622                                 }, None));
1623                                 payment.remove();
1624                         }
1625                 }
1626         }
1627
1628         #[cfg(test)]
1629         pub fn has_pending_payments(&self) -> bool {
1630                 !self.pending_outbound_payments.lock().unwrap().is_empty()
1631         }
1632
1633         #[cfg(test)]
1634         pub fn clear_pending_payments(&self) {
1635                 self.pending_outbound_payments.lock().unwrap().clear()
1636         }
1637 }
1638
1639 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
1640 /// payment probe.
1641 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
1642         probing_cookie_secret: [u8; 32]) -> bool
1643 {
1644         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
1645         target_payment_hash == *payment_hash
1646 }
1647
1648 /// Returns the 'probing cookie' for the given [`PaymentId`].
1649 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
1650         let mut preimage = [0u8; 64];
1651         preimage[..32].copy_from_slice(&probing_cookie_secret);
1652         preimage[32..].copy_from_slice(&payment_id.0);
1653         PaymentHash(Sha256::hash(&preimage).into_inner())
1654 }
1655
1656 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
1657         (0, Legacy) => {
1658                 (0, session_privs, required),
1659         },
1660         (1, Fulfilled) => {
1661                 (0, session_privs, required),
1662                 (1, payment_hash, option),
1663                 (3, timer_ticks_without_htlcs, (default_value, 0)),
1664         },
1665         (2, Retryable) => {
1666                 (0, session_privs, required),
1667                 (1, pending_fee_msat, option),
1668                 (2, payment_hash, required),
1669                 // Note that while we "default" payment_param's final CLTV expiry delta to 0 we should
1670                 // never see it - `payment_params` was added here after the field was added/required.
1671                 (3, payment_params, (option: ReadableArgs, 0)),
1672                 (4, payment_secret, option),
1673                 (5, keysend_preimage, option),
1674                 (6, total_msat, required),
1675                 (7, payment_metadata, option),
1676                 (8, pending_amt_msat, required),
1677                 (9, custom_tlvs, optional_vec),
1678                 (10, starting_block_height, required),
1679                 (not_written, retry_strategy, (static_value, None)),
1680                 (not_written, attempts, (static_value, PaymentAttempts::new())),
1681         },
1682         (3, Abandoned) => {
1683                 (0, session_privs, required),
1684                 (1, reason, option),
1685                 (2, payment_hash, required),
1686         },
1687         (5, AwaitingInvoice) => {
1688                 (0, timer_ticks_without_response, required),
1689                 (2, retry_strategy, required),
1690         },
1691         (7, InvoiceReceived) => {
1692                 (0, payment_hash, required),
1693                 (2, retry_strategy, required),
1694         },
1695 );
1696
1697 #[cfg(test)]
1698 mod tests {
1699         use bitcoin::network::constants::Network;
1700         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
1701
1702         use crate::events::{Event, PathFailure, PaymentFailureReason};
1703         use crate::ln::PaymentHash;
1704         use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
1705         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1706         use crate::ln::msgs::{ErrorAction, LightningError};
1707         use crate::ln::outbound_payment::{Bolt12PaymentError, INVOICE_REQUEST_TIMEOUT_TICKS, OutboundPayments, Retry, RetryableSendFailure};
1708         use crate::offers::invoice::DEFAULT_RELATIVE_EXPIRY;
1709         use crate::offers::offer::OfferBuilder;
1710         use crate::offers::test_utils::*;
1711         use crate::routing::gossip::NetworkGraph;
1712         use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters};
1713         use crate::sync::{Arc, Mutex, RwLock};
1714         use crate::util::errors::APIError;
1715         use crate::util::test_utils;
1716
1717         use alloc::collections::VecDeque;
1718
1719         #[test]
1720         fn test_recipient_onion_fields_with_custom_tlvs() {
1721                 let onion_fields = RecipientOnionFields::spontaneous_empty();
1722
1723                 let bad_type_range_tlvs = vec![
1724                         (0, vec![42]),
1725                         (1, vec![42; 32]),
1726                 ];
1727                 assert!(onion_fields.clone().with_custom_tlvs(bad_type_range_tlvs).is_err());
1728
1729                 let keysend_tlv = vec![
1730                         (5482373484, vec![42; 32]),
1731                 ];
1732                 assert!(onion_fields.clone().with_custom_tlvs(keysend_tlv).is_err());
1733
1734                 let good_tlvs = vec![
1735                         ((1 << 16) + 1, vec![42]),
1736                         ((1 << 16) + 3, vec![42; 32]),
1737                 ];
1738                 assert!(onion_fields.with_custom_tlvs(good_tlvs).is_ok());
1739         }
1740
1741         #[test]
1742         #[cfg(feature = "std")]
1743         fn fails_paying_after_expiration() {
1744                 do_fails_paying_after_expiration(false);
1745                 do_fails_paying_after_expiration(true);
1746         }
1747         #[cfg(feature = "std")]
1748         fn do_fails_paying_after_expiration(on_retry: bool) {
1749                 let outbound_payments = OutboundPayments::new();
1750                 let logger = test_utils::TestLogger::new();
1751                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1752                 let scorer = RwLock::new(test_utils::TestScorer::new());
1753                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1754                 let secp_ctx = Secp256k1::new();
1755                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1756
1757                 let past_expiry_time = std::time::SystemTime::UNIX_EPOCH.elapsed().unwrap().as_secs() - 2;
1758                 let payment_params = PaymentParameters::from_node_id(
1759                                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()),
1760                                 0
1761                         ).with_expiry_time(past_expiry_time);
1762                 let expired_route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1763                 let pending_events = Mutex::new(VecDeque::new());
1764                 if on_retry {
1765                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1766                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1767                                 Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
1768                                 &&keys_manager, 0).unwrap();
1769                         outbound_payments.find_route_and_send_payment(
1770                                 PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
1771                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1772                                 &|_| Ok(()));
1773                         let events = pending_events.lock().unwrap();
1774                         assert_eq!(events.len(), 1);
1775                         if let Event::PaymentFailed { ref reason, .. } = events[0].0 {
1776                                 assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
1777                         } else { panic!("Unexpected event"); }
1778                 } else {
1779                         let err = outbound_payments.send_payment(
1780                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1781                                 Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
1782                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1783                         if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
1784                 }
1785         }
1786
1787         #[test]
1788         fn find_route_error() {
1789                 do_find_route_error(false);
1790                 do_find_route_error(true);
1791         }
1792         fn do_find_route_error(on_retry: bool) {
1793                 let outbound_payments = OutboundPayments::new();
1794                 let logger = test_utils::TestLogger::new();
1795                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1796                 let scorer = RwLock::new(test_utils::TestScorer::new());
1797                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1798                 let secp_ctx = Secp256k1::new();
1799                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1800
1801                 let payment_params = PaymentParameters::from_node_id(
1802                         PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0);
1803                 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 0);
1804                 router.expect_find_route(route_params.clone(),
1805                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }));
1806
1807                 let pending_events = Mutex::new(VecDeque::new());
1808                 if on_retry {
1809                         outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
1810                                 PaymentId([0; 32]), None, &Route { paths: vec![], route_params: None },
1811                                 Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
1812                                 &&keys_manager, 0).unwrap();
1813                         outbound_payments.find_route_and_send_payment(
1814                                 PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
1815                                 &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1816                                 &|_| Ok(()));
1817                         let events = pending_events.lock().unwrap();
1818                         assert_eq!(events.len(), 1);
1819                         if let Event::PaymentFailed { .. } = events[0].0 { } else { panic!("Unexpected event"); }
1820                 } else {
1821                         let err = outbound_payments.send_payment(
1822                                 PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1823                                 Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
1824                                 &&keys_manager, &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())).unwrap_err();
1825                         if let RetryableSendFailure::RouteNotFound = err {
1826                         } else { panic!("Unexpected error"); }
1827                 }
1828         }
1829
1830         #[test]
1831         fn initial_send_payment_path_failed_evs() {
1832                 let outbound_payments = OutboundPayments::new();
1833                 let logger = test_utils::TestLogger::new();
1834                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1835                 let scorer = RwLock::new(test_utils::TestScorer::new());
1836                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1837                 let secp_ctx = Secp256k1::new();
1838                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1839
1840                 let sender_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1841                 let receiver_pk = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
1842                 let payment_params = PaymentParameters::from_node_id(sender_pk, 0);
1843                 let route_params = RouteParameters::from_payment_params_and_value(payment_params.clone(), 0);
1844                 let failed_scid = 42;
1845                 let route = Route {
1846                         paths: vec![Path { hops: vec![RouteHop {
1847                                 pubkey: receiver_pk,
1848                                 node_features: NodeFeatures::empty(),
1849                                 short_channel_id: failed_scid,
1850                                 channel_features: ChannelFeatures::empty(),
1851                                 fee_msat: 0,
1852                                 cltv_expiry_delta: 0,
1853                         }], blinded_tail: None }],
1854                         route_params: Some(route_params.clone()),
1855                 };
1856                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1857                 let mut route_params_w_failed_scid = route_params.clone();
1858                 route_params_w_failed_scid.payment_params.previously_failed_channels.push(failed_scid);
1859                 router.expect_find_route(route_params_w_failed_scid, Ok(route.clone()));
1860                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1861                 router.expect_find_route(route_params.clone(), Ok(route.clone()));
1862
1863                 // Ensure that a ChannelUnavailable error will result in blaming an scid in the
1864                 // PaymentPathFailed event.
1865                 let pending_events = Mutex::new(VecDeque::new());
1866                 outbound_payments.send_payment(
1867                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1868                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1869                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1870                         |_| Err(APIError::ChannelUnavailable { err: "test".to_owned() })).unwrap();
1871                 let mut events = pending_events.lock().unwrap();
1872                 assert_eq!(events.len(), 2);
1873                 if let Event::PaymentPathFailed {
1874                         short_channel_id,
1875                         failure: PathFailure::InitialSend { err: APIError::ChannelUnavailable { .. }}, .. } = events[0].0
1876                 {
1877                         assert_eq!(short_channel_id, Some(failed_scid));
1878                 } else { panic!("Unexpected event"); }
1879                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1880                 events.clear();
1881                 core::mem::drop(events);
1882
1883                 // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
1884                 outbound_payments.send_payment(
1885                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
1886                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1887                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1888                         |_| Err(APIError::MonitorUpdateInProgress)).unwrap();
1889                 assert_eq!(pending_events.lock().unwrap().len(), 0);
1890
1891                 // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
1892                 outbound_payments.send_payment(
1893                         PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
1894                         Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
1895                         &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
1896                         |_| Err(APIError::APIMisuseError { err: "test".to_owned() })).unwrap();
1897                 let events = pending_events.lock().unwrap();
1898                 assert_eq!(events.len(), 2);
1899                 if let Event::PaymentPathFailed {
1900                         short_channel_id,
1901                         failure: PathFailure::InitialSend { err: APIError::APIMisuseError { .. }}, .. } = events[0].0
1902                 {
1903                         assert_eq!(short_channel_id, None);
1904                 } else { panic!("Unexpected event"); }
1905                 if let Event::PaymentFailed { .. } = events[1].0 { } else { panic!("Unexpected event"); }
1906         }
1907
1908         #[test]
1909         fn removes_stale_awaiting_invoice() {
1910                 let pending_events = Mutex::new(VecDeque::new());
1911                 let outbound_payments = OutboundPayments::new();
1912                 let payment_id = PaymentId([0; 32]);
1913
1914                 assert!(!outbound_payments.has_pending_payments());
1915                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
1916                 assert!(outbound_payments.has_pending_payments());
1917
1918                 for _ in 0..INVOICE_REQUEST_TIMEOUT_TICKS {
1919                         outbound_payments.remove_stale_payments(&pending_events);
1920                         assert!(outbound_payments.has_pending_payments());
1921                         assert!(pending_events.lock().unwrap().is_empty());
1922                 }
1923
1924                 outbound_payments.remove_stale_payments(&pending_events);
1925                 assert!(!outbound_payments.has_pending_payments());
1926                 assert!(!pending_events.lock().unwrap().is_empty());
1927                 assert_eq!(
1928                         pending_events.lock().unwrap().pop_front(),
1929                         Some((Event::InvoiceRequestFailed { payment_id }, None)),
1930                 );
1931                 assert!(pending_events.lock().unwrap().is_empty());
1932
1933                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
1934                 assert!(outbound_payments.has_pending_payments());
1935
1936                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_err());
1937         }
1938
1939         #[test]
1940         fn removes_abandoned_awaiting_invoice() {
1941                 let pending_events = Mutex::new(VecDeque::new());
1942                 let outbound_payments = OutboundPayments::new();
1943                 let payment_id = PaymentId([0; 32]);
1944
1945                 assert!(!outbound_payments.has_pending_payments());
1946                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
1947                 assert!(outbound_payments.has_pending_payments());
1948
1949                 outbound_payments.abandon_payment(
1950                         payment_id, PaymentFailureReason::UserAbandoned, &pending_events
1951                 );
1952                 assert!(!outbound_payments.has_pending_payments());
1953                 assert!(!pending_events.lock().unwrap().is_empty());
1954                 assert_eq!(
1955                         pending_events.lock().unwrap().pop_front(),
1956                         Some((Event::InvoiceRequestFailed { payment_id }, None)),
1957                 );
1958                 assert!(pending_events.lock().unwrap().is_empty());
1959         }
1960
1961         #[cfg(feature = "std")]
1962         #[test]
1963         fn fails_sending_payment_for_expired_bolt12_invoice() {
1964                 let logger = test_utils::TestLogger::new();
1965                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
1966                 let scorer = RwLock::new(test_utils::TestScorer::new());
1967                 let router = test_utils::TestRouter::new(network_graph, &scorer);
1968                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
1969
1970                 let pending_events = Mutex::new(VecDeque::new());
1971                 let outbound_payments = OutboundPayments::new();
1972                 let payment_id = PaymentId([0; 32]);
1973
1974                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
1975                 assert!(outbound_payments.has_pending_payments());
1976
1977                 let created_at = now() - DEFAULT_RELATIVE_EXPIRY;
1978                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1979                         .amount_msats(1000)
1980                         .build().unwrap()
1981                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1982                         .build().unwrap()
1983                         .sign(payer_sign).unwrap()
1984                         .respond_with_no_std(payment_paths(), payment_hash(), created_at).unwrap()
1985                         .build().unwrap()
1986                         .sign(recipient_sign).unwrap();
1987
1988                 assert_eq!(
1989                         outbound_payments.send_payment_for_bolt12_invoice(
1990                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
1991                                 &&keys_manager, 0, &&logger, &pending_events, |_| panic!()
1992                         ),
1993                         Ok(()),
1994                 );
1995                 assert!(!outbound_payments.has_pending_payments());
1996
1997                 let payment_hash = invoice.payment_hash();
1998                 let reason = Some(PaymentFailureReason::PaymentExpired);
1999
2000                 assert!(!pending_events.lock().unwrap().is_empty());
2001                 assert_eq!(
2002                         pending_events.lock().unwrap().pop_front(),
2003                         Some((Event::PaymentFailed { payment_id, payment_hash, reason }, None)),
2004                 );
2005                 assert!(pending_events.lock().unwrap().is_empty());
2006         }
2007
2008         #[test]
2009         fn fails_finding_route_for_bolt12_invoice() {
2010                 let logger = test_utils::TestLogger::new();
2011                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
2012                 let scorer = RwLock::new(test_utils::TestScorer::new());
2013                 let router = test_utils::TestRouter::new(network_graph, &scorer);
2014                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
2015
2016                 let pending_events = Mutex::new(VecDeque::new());
2017                 let outbound_payments = OutboundPayments::new();
2018                 let payment_id = PaymentId([0; 32]);
2019
2020                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
2021                 assert!(outbound_payments.has_pending_payments());
2022
2023                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
2024                         .amount_msats(1000)
2025                         .build().unwrap()
2026                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2027                         .build().unwrap()
2028                         .sign(payer_sign).unwrap()
2029                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2030                         .build().unwrap()
2031                         .sign(recipient_sign).unwrap();
2032
2033                 router.expect_find_route(
2034                         RouteParameters {
2035                                 payment_params: PaymentParameters::from_bolt12_invoice(&invoice),
2036                                 final_value_msat: invoice.amount_msats(),
2037                         },
2038                         Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError }),
2039                 );
2040
2041                 assert_eq!(
2042                         outbound_payments.send_payment_for_bolt12_invoice(
2043                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
2044                                 &&keys_manager, 0, &&logger, &pending_events, |_| panic!()
2045                         ),
2046                         Ok(()),
2047                 );
2048                 assert!(!outbound_payments.has_pending_payments());
2049
2050                 let payment_hash = invoice.payment_hash();
2051                 let reason = Some(PaymentFailureReason::RouteNotFound);
2052
2053                 assert!(!pending_events.lock().unwrap().is_empty());
2054                 assert_eq!(
2055                         pending_events.lock().unwrap().pop_front(),
2056                         Some((Event::PaymentFailed { payment_id, payment_hash, reason }, None)),
2057                 );
2058                 assert!(pending_events.lock().unwrap().is_empty());
2059         }
2060
2061         #[test]
2062         fn fails_paying_for_bolt12_invoice() {
2063                 let logger = test_utils::TestLogger::new();
2064                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
2065                 let scorer = RwLock::new(test_utils::TestScorer::new());
2066                 let router = test_utils::TestRouter::new(network_graph, &scorer);
2067                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
2068
2069                 let pending_events = Mutex::new(VecDeque::new());
2070                 let outbound_payments = OutboundPayments::new();
2071                 let payment_id = PaymentId([0; 32]);
2072
2073                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
2074                 assert!(outbound_payments.has_pending_payments());
2075
2076                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
2077                         .amount_msats(1000)
2078                         .build().unwrap()
2079                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2080                         .build().unwrap()
2081                         .sign(payer_sign).unwrap()
2082                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2083                         .build().unwrap()
2084                         .sign(recipient_sign).unwrap();
2085
2086                 let route_params = RouteParameters {
2087                         payment_params: PaymentParameters::from_bolt12_invoice(&invoice),
2088                         final_value_msat: invoice.amount_msats(),
2089                 };
2090                 router.expect_find_route(
2091                         route_params.clone(), Ok(Route { paths: vec![], route_params: Some(route_params) })
2092                 );
2093
2094                 assert_eq!(
2095                         outbound_payments.send_payment_for_bolt12_invoice(
2096                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
2097                                 &&keys_manager, 0, &&logger, &pending_events, |_| panic!()
2098                         ),
2099                         Ok(()),
2100                 );
2101                 assert!(!outbound_payments.has_pending_payments());
2102
2103                 let payment_hash = invoice.payment_hash();
2104                 let reason = Some(PaymentFailureReason::UnexpectedError);
2105
2106                 assert!(!pending_events.lock().unwrap().is_empty());
2107                 assert_eq!(
2108                         pending_events.lock().unwrap().pop_front(),
2109                         Some((Event::PaymentFailed { payment_id, payment_hash, reason }, None)),
2110                 );
2111                 assert!(pending_events.lock().unwrap().is_empty());
2112         }
2113
2114         #[test]
2115         fn sends_payment_for_bolt12_invoice() {
2116                 let logger = test_utils::TestLogger::new();
2117                 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, &logger));
2118                 let scorer = RwLock::new(test_utils::TestScorer::new());
2119                 let router = test_utils::TestRouter::new(network_graph, &scorer);
2120                 let keys_manager = test_utils::TestKeysInterface::new(&[0; 32], Network::Testnet);
2121
2122                 let pending_events = Mutex::new(VecDeque::new());
2123                 let outbound_payments = OutboundPayments::new();
2124                 let payment_id = PaymentId([0; 32]);
2125
2126                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
2127                         .amount_msats(1000)
2128                         .build().unwrap()
2129                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2130                         .build().unwrap()
2131                         .sign(payer_sign).unwrap()
2132                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2133                         .build().unwrap()
2134                         .sign(recipient_sign).unwrap();
2135
2136                 let route_params = RouteParameters {
2137                         payment_params: PaymentParameters::from_bolt12_invoice(&invoice),
2138                         final_value_msat: invoice.amount_msats(),
2139                 };
2140                 router.expect_find_route(
2141                         route_params.clone(),
2142                         Ok(Route {
2143                                 paths: vec![
2144                                         Path {
2145                                                 hops: vec![
2146                                                         RouteHop {
2147                                                                 pubkey: recipient_pubkey(),
2148                                                                 node_features: NodeFeatures::empty(),
2149                                                                 short_channel_id: 42,
2150                                                                 channel_features: ChannelFeatures::empty(),
2151                                                                 fee_msat: invoice.amount_msats(),
2152                                                                 cltv_expiry_delta: 0,
2153                                                         }
2154                                                 ],
2155                                                 blinded_tail: None,
2156                                         }
2157                                 ],
2158                                 route_params: Some(route_params),
2159                         })
2160                 );
2161
2162                 assert!(!outbound_payments.has_pending_payments());
2163                 assert_eq!(
2164                         outbound_payments.send_payment_for_bolt12_invoice(
2165                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
2166                                 &&keys_manager, 0, &&logger, &pending_events, |_| panic!()
2167                         ),
2168                         Err(Bolt12PaymentError::UnexpectedInvoice),
2169                 );
2170                 assert!(!outbound_payments.has_pending_payments());
2171                 assert!(pending_events.lock().unwrap().is_empty());
2172
2173                 assert!(outbound_payments.add_new_awaiting_invoice(payment_id, Retry::Attempts(0)).is_ok());
2174                 assert!(outbound_payments.has_pending_payments());
2175
2176                 assert_eq!(
2177                         outbound_payments.send_payment_for_bolt12_invoice(
2178                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
2179                                 &&keys_manager, 0, &&logger, &pending_events, |_| Ok(())
2180                         ),
2181                         Ok(()),
2182                 );
2183                 assert!(outbound_payments.has_pending_payments());
2184                 assert!(pending_events.lock().unwrap().is_empty());
2185
2186                 assert_eq!(
2187                         outbound_payments.send_payment_for_bolt12_invoice(
2188                                 &invoice, payment_id, &&router, vec![], || InFlightHtlcs::new(), &&keys_manager,
2189                                 &&keys_manager, 0, &&logger, &pending_events, |_| panic!()
2190                         ),
2191                         Err(Bolt12PaymentError::DuplicateInvoice),
2192                 );
2193                 assert!(outbound_payments.has_pending_payments());
2194                 assert!(pending_events.lock().unwrap().is_empty());
2195         }
2196 }