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::chain::keysinterface::{EntropySource, NodeSigner, Recipient};
  17 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  18 use crate::ln::channelmanager::{HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
  19 use crate::ln::msgs::DecodeError;
  20 use crate::ln::onion_utils::HTLCFailReason;
  21 use crate::routing::router::{PaymentParameters, Route, RouteHop, RouteParameters, RoutePath};
  22 use crate::util::errors::APIError;
  23 use crate::util::events;
  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
  29 use core::cmp;
  30 use core::fmt::{self, Display, Formatter};
  31 use core::ops::Deref;
  32
  33 use crate::prelude::*;
  34 use crate::sync::Mutex;
  35
  36 /// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
  37 /// and later, also stores information for retrying the payment.
  38 pub(crate) enum PendingOutboundPayment {
  39         Legacy {
  40                 session_privs: HashSet<[u8; 32]>,
  41         },
  42         Retryable {
  43                 retry_strategy: Retry,
  44                 attempts: PaymentAttempts,
  45                 route_params: Option<RouteParameters>,
  46                 session_privs: HashSet<[u8; 32]>,
  47                 payment_hash: PaymentHash,
  48                 payment_secret: Option<PaymentSecret>,
  49                 pending_amt_msat: u64,
  50                 /// Used to track the fee paid. Only present if the payment was serialized on 0.0.103+.
  51                 pending_fee_msat: Option<u64>,
  52                 /// The total payment amount across all paths, used to verify that a retry is not overpaying.
  53                 total_msat: u64,
  54                 /// Our best known block height at the time this payment was initiated.
  55                 starting_block_height: u32,
  56         },
  57         /// When a pending payment is fulfilled, we continue tracking it until all pending HTLCs have
  58         /// been resolved. This ensures we don't look up pending payments in ChannelMonitors on restart
  59         /// and add a pending payment that was already fulfilled.
  60         Fulfilled {
  61                 session_privs: HashSet<[u8; 32]>,
  62                 payment_hash: Option<PaymentHash>,
  63                 timer_ticks_without_htlcs: u8,
  64         },
  65         /// When a payer gives up trying to retry a payment, they inform us, letting us generate a
  66         /// `PaymentFailed` event when all HTLCs have irrevocably failed. This avoids a number of race
  67         /// conditions in MPP-aware payment retriers (1), where the possibility of multiple
  68         /// `PaymentPathFailed` events with `all_paths_failed` can be pending at once, confusing a
  69         /// downstream event handler as to when a payment has actually failed.
  70         ///
  71         /// (1) <https://github.com/lightningdevkit/rust-lightning/issues/1164>
  72         Abandoned {
  73                 session_privs: HashSet<[u8; 32]>,
  74                 payment_hash: PaymentHash,
  75         },
  76 }
  77
  78 impl PendingOutboundPayment {
  79         fn increment_attempts(&mut self) {
  80                 if let PendingOutboundPayment::Retryable { attempts, .. } = self {
  81                         attempts.count += 1;
  82                 }
  83         }
  84         fn is_retryable_now(&self) -> bool {
  85                 if let PendingOutboundPayment::Retryable { retry_strategy, attempts, .. } = self {
  86                         return retry_strategy.is_retryable_now(&attempts)
  87                 }
  88                 false
  89         }
  90         pub(super) fn is_fulfilled(&self) -> bool {
  91                 match self {
  92                         PendingOutboundPayment::Fulfilled { .. } => true,
  93                         _ => false,
  94                 }
  95         }
  96         pub(super) fn abandoned(&self) -> bool {
  97                 match self {
  98                         PendingOutboundPayment::Abandoned { .. } => true,
  99                         _ => false,
 100                 }
 101         }
 102         fn get_pending_fee_msat(&self) -> Option<u64> {
 103                 match self {
 104                         PendingOutboundPayment::Retryable { pending_fee_msat, .. } => pending_fee_msat.clone(),
 105                         _ => None,
 106                 }
 107         }
 108
 109         fn payment_hash(&self) -> Option<PaymentHash> {
 110                 match self {
 111                         PendingOutboundPayment::Legacy { .. } => None,
 112                         PendingOutboundPayment::Retryable { payment_hash, .. } => Some(*payment_hash),
 113                         PendingOutboundPayment::Fulfilled { payment_hash, .. } => *payment_hash,
 114                         PendingOutboundPayment::Abandoned { payment_hash, .. } => Some(*payment_hash),
 115                 }
 116         }
 117
 118         fn mark_fulfilled(&mut self) {
 119                 let mut session_privs = HashSet::new();
 120                 core::mem::swap(&mut session_privs, match self {
 121                         PendingOutboundPayment::Legacy { session_privs } |
 122                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 123                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 124                                 PendingOutboundPayment::Abandoned { session_privs, .. }
 125                         => session_privs,
 126                 });
 127                 let payment_hash = self.payment_hash();
 128                 *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
 129         }
 130
 131         fn mark_abandoned(&mut self) -> Result<(), ()> {
 132                 let mut session_privs = HashSet::new();
 133                 let our_payment_hash;
 134                 core::mem::swap(&mut session_privs, match self {
 135                         PendingOutboundPayment::Legacy { .. } |
 136                                 PendingOutboundPayment::Fulfilled { .. } =>
 137                                 return Err(()),
 138                                 PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } |
 139                                         PendingOutboundPayment::Abandoned { session_privs, payment_hash, .. } => {
 140                                                 our_payment_hash = *payment_hash;
 141                                                 session_privs
 142                                         },
 143                 });
 144                 *self = PendingOutboundPayment::Abandoned { session_privs, payment_hash: our_payment_hash };
 145                 Ok(())
 146         }
 147
 148         /// panics if path is None and !self.is_fulfilled
 149         fn remove(&mut self, session_priv: &[u8; 32], path: Option<&Vec<RouteHop>>) -> bool {
 150                 let remove_res = match self {
 151                         PendingOutboundPayment::Legacy { session_privs } |
 152                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 153                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 154                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 155                                         session_privs.remove(session_priv)
 156                                 }
 157                 };
 158                 if remove_res {
 159                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 160                                 let path = path.expect("Fulfilling a payment should always come with a path");
 161                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 162                                 *pending_amt_msat -= path_last_hop.fee_msat;
 163                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 164                                         *fee_msat -= path.get_path_fees();
 165                                 }
 166                         }
 167                 }
 168                 remove_res
 169         }
 170
 171         pub(super) fn insert(&mut self, session_priv: [u8; 32], path: &Vec<RouteHop>) -> bool {
 172                 let insert_res = match self {
 173                         PendingOutboundPayment::Legacy { session_privs } |
 174                                 PendingOutboundPayment::Retryable { session_privs, .. } => {
 175                                         session_privs.insert(session_priv)
 176                                 }
 177                         PendingOutboundPayment::Fulfilled { .. } => false,
 178                         PendingOutboundPayment::Abandoned { .. } => false,
 179                 };
 180                 if insert_res {
 181                         if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, ref mut pending_fee_msat, .. } = self {
 182                                 let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 183                                 *pending_amt_msat += path_last_hop.fee_msat;
 184                                 if let Some(fee_msat) = pending_fee_msat.as_mut() {
 185                                         *fee_msat += path.get_path_fees();
 186                                 }
 187                         }
 188                 }
 189                 insert_res
 190         }
 191
 192         pub(super) fn remaining_parts(&self) -> usize {
 193                 match self {
 194                         PendingOutboundPayment::Legacy { session_privs } |
 195                                 PendingOutboundPayment::Retryable { session_privs, .. } |
 196                                 PendingOutboundPayment::Fulfilled { session_privs, .. } |
 197                                 PendingOutboundPayment::Abandoned { session_privs, .. } => {
 198                                         session_privs.len()
 199                                 }
 200                 }
 201         }
 202 }
 203
 204 /// Strategies available to retry payment path failures.
 205 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 206 pub enum Retry {
 207         /// Max number of attempts to retry payment.
 208         ///
 209         /// Note that this is the number of *path* failures, not full payment retries. For multi-path
 210         /// payments, if this is less than the total number of paths, we will never even retry all of the
 211         /// payment's paths.
 212         Attempts(usize),
 213         #[cfg(not(feature = "no-std"))]
 214         /// Time elapsed before abandoning retries for a payment.
 215         Timeout(core::time::Duration),
 216 }
 217
 218 impl Retry {
 219         pub(crate) fn is_retryable_now(&self, attempts: &PaymentAttempts) -> bool {
 220                 match (self, attempts) {
 221                         (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
 222                                 max_retry_count > count
 223                         },
 224                         #[cfg(all(not(feature = "no-std"), not(test)))]
 225                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 226                                 *max_duration >= std::time::Instant::now().duration_since(*first_attempted_at),
 227                         #[cfg(all(not(feature = "no-std"), test))]
 228                         (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. }) =>
 229                                 *max_duration >= SinceEpoch::now().duration_since(*first_attempted_at),
 230                 }
 231         }
 232 }
 233
 234 pub(crate) type PaymentAttempts = PaymentAttemptsUsingTime<ConfiguredTime>;
 235
 236 /// Storing minimal payment attempts information required for determining if a outbound payment can
 237 /// be retried.
 238 pub(crate) struct PaymentAttemptsUsingTime<T: Time> {
 239         /// This count will be incremented only after the result of the attempt is known. When it's 0,
 240         /// it means the result of the first attempt is not known yet.
 241         pub(crate) count: usize,
 242         /// This field is only used when retry is `Retry::Timeout` which is only build with feature std
 243         first_attempted_at: T
 244 }
 245
 246 #[cfg(not(any(feature = "no-std", test)))]
 247 type ConfiguredTime = std::time::Instant;
 248 #[cfg(feature = "no-std")]
 249 type ConfiguredTime = crate::util::time::Eternity;
 250 #[cfg(all(not(feature = "no-std"), test))]
 251 type ConfiguredTime = SinceEpoch;
 252
 253 impl<T: Time> PaymentAttemptsUsingTime<T> {
 254         pub(crate) fn new() -> Self {
 255                 PaymentAttemptsUsingTime {
 256                         count: 0,
 257                         first_attempted_at: T::now()
 258                 }
 259         }
 260 }
 261
 262 impl<T: Time> Display for PaymentAttemptsUsingTime<T> {
 263         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 264                 #[cfg(feature = "no-std")]
 265                 return write!(f, "attempts: {}", self.count);
 266                 #[cfg(not(feature = "no-std"))]
 267                 return write!(
 268                         f,
 269                         "attempts: {}, duration: {}s",
 270                         self.count,
 271                         T::now().duration_since(self.first_attempted_at).as_secs()
 272                 );
 273         }
 274 }
 275
 276 /// If a payment fails to send, it can be in one of several states. This enum is returned as the
 277 /// Err() type describing which state the payment is in, see the description of individual enum
 278 /// states for more.
 279 #[derive(Clone, Debug)]
 280 pub enum PaymentSendFailure {
 281         /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
 282         /// send the payment at all.
 283         ///
 284         /// You can freely resend the payment in full (with the parameter error fixed).
 285         ///
 286         /// Because the payment failed outright, no payment tracking is done, you do not need to call
 287         /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
 288         /// for this payment.
 289         ///
 290         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 291         /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 292         ParameterError(APIError),
 293         /// A parameter in a single path which was passed to send_payment was invalid, preventing us
 294         /// from attempting to send the payment at all.
 295         ///
 296         /// You can freely resend the payment in full (with the parameter error fixed).
 297         ///
 298         /// The results here are ordered the same as the paths in the route object which was passed to
 299         /// send_payment.
 300         ///
 301         /// Because the payment failed outright, no payment tracking is done, you do not need to call
 302         /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
 303         /// for this payment.
 304         ///
 305         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 306         /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 307         PathParameterError(Vec<Result<(), APIError>>),
 308         /// All paths which were attempted failed to send, with no channel state change taking place.
 309         /// You can freely resend the payment in full (though you probably want to do so over different
 310         /// paths than the ones selected).
 311         ///
 312         /// Because the payment failed outright, no payment tracking is done, you do not need to call
 313         /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
 314         /// for this payment.
 315         ///
 316         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 317         /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 318         AllFailedResendSafe(Vec<APIError>),
 319         /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
 320         /// yet completed (i.e. generated an [`Event::PaymentSent`]) or been abandoned (via
 321         /// [`ChannelManager::abandon_payment`]).
 322         ///
 323         /// [`PaymentId`]: crate::ln::channelmanager::PaymentId
 324         /// [`Event::PaymentSent`]: crate::util::events::Event::PaymentSent
 325         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 326         DuplicatePayment,
 327         /// Some paths which were attempted failed to send, though possibly not all. At least some
 328         /// paths have irrevocably committed to the HTLC and retrying the payment in full would result
 329         /// in over-/re-payment.
 330         ///
 331         /// The results here are ordered the same as the paths in the route object which was passed to
 332         /// send_payment, and any `Err`s which are not [`APIError::MonitorUpdateInProgress`] can be
 333         /// safely retried via [`ChannelManager::retry_payment`].
 334         ///
 335         /// Any entries which contain `Err(APIError::MonitorUpdateInprogress)` or `Ok(())` MUST NOT be
 336         /// retried as they will result in over-/re-payment. These HTLCs all either successfully sent
 337         /// (in the case of `Ok(())`) or will send once a [`MonitorEvent::Completed`] is provided for
 338         /// the next-hop channel with the latest update_id.
 339         ///
 340         /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 341         /// [`MonitorEvent::Completed`]: crate::chain::channelmonitor::MonitorEvent::Completed
 342         PartialFailure {
 343                 /// The errors themselves, in the same order as the route hops.
 344                 results: Vec<Result<(), APIError>>,
 345                 /// If some paths failed without irrevocably committing to the new HTLC(s), this will
 346                 /// contain a [`RouteParameters`] object which can be used to calculate a new route that
 347                 /// will pay all remaining unpaid balance.
 348                 failed_paths_retry: Option<RouteParameters>,
 349                 /// The payment id for the payment, which is now at least partially pending.
 350                 payment_id: PaymentId,
 351         },
 352 }
 353
 354 pub(super) struct OutboundPayments {
 355         pub(super) pending_outbound_payments: Mutex<HashMap<PaymentId, PendingOutboundPayment>>,
 356 }
 357
 358 impl OutboundPayments {
 359         pub(super) fn new() -> Self {
 360                 Self {
 361                         pending_outbound_payments: Mutex::new(HashMap::new())
 362                 }
 363         }
 364
 365         pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
 366                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 367                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 368                 send_payment_along_path: F
 369         ) -> Result<(), PaymentSendFailure>
 370         where
 371                 ES::Target: EntropySource,
 372                 NS::Target: NodeSigner,
 373                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 374                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 375         {
 376                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, route, Retry::Attempts(0), None, entropy_source, best_block_height)?;
 377                 self.send_payment_internal(route, payment_hash, payment_secret, None, payment_id, None, onion_session_privs, node_signer, best_block_height, send_payment_along_path)
 378         }
 379
 380         pub(super) fn send_spontaneous_payment<ES: Deref, NS: Deref, F>(
 381                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 382                 entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 383         ) -> Result<PaymentHash, PaymentSendFailure>
 384         where
 385                 ES::Target: EntropySource,
 386                 NS::Target: NodeSigner,
 387                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 388                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 389         {
 390                 let preimage = match payment_preimage {
 391                         Some(p) => p,
 392                         None => PaymentPreimage(entropy_source.get_secure_random_bytes()),
 393                 };
 394                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 395                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, &route, Retry::Attempts(0), None, entropy_source, best_block_height)?;
 396
 397                 match self.send_payment_internal(route, payment_hash, &None, Some(preimage), payment_id, None, onion_session_privs, node_signer, best_block_height, send_payment_along_path) {
 398                         Ok(()) => Ok(payment_hash),
 399                         Err(e) => Err(e)
 400                 }
 401         }
 402
 403         pub(super) fn retry_payment_with_route<ES: Deref, NS: Deref, F>(
 404                 &self, route: &Route, payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 405                 send_payment_along_path: F
 406         ) -> Result<(), PaymentSendFailure>
 407         where
 408                 ES::Target: EntropySource,
 409                 NS::Target: NodeSigner,
 410                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 411                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 412         {
 413                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 414                 for path in route.paths.iter() {
 415                         if path.len() == 0 {
 416                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 417                                         err: "length-0 path in route".to_string()
 418                                 }))
 419                         }
 420                 }
 421
 422                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 423                 for _ in 0..route.paths.len() {
 424                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 425                 }
 426
 427                 let (total_msat, payment_hash, payment_secret) = {
 428                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 429                         match outbounds.get_mut(&payment_id) {
 430                                 Some(payment) => {
 431                                         let res = match payment {
 432                                                 PendingOutboundPayment::Retryable {
 433                                                         total_msat, payment_hash, payment_secret, pending_amt_msat, ..
 434                                                 } => {
 435                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 436                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 437                                                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 438                                                                         err: format!("retry_amt_msat of {} will put pending_amt_msat (currently: {}) more than 10% over total_payment_amt_msat of {}", retry_amt_msat, pending_amt_msat, total_msat).to_string()
 439                                                                 }))
 440                                                         }
 441                                                         (*total_msat, *payment_hash, *payment_secret)
 442                                                 },
 443                                                 PendingOutboundPayment::Legacy { .. } => {
 444                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 445                                                                 err: "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102".to_string()
 446                                                         }))
 447                                                 },
 448                                                 PendingOutboundPayment::Fulfilled { .. } => {
 449                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 450                                                                 err: "Payment already completed".to_owned()
 451                                                         }));
 452                                                 },
 453                                                 PendingOutboundPayment::Abandoned { .. } => {
 454                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 455                                                                 err: "Payment already abandoned (with some HTLCs still pending)".to_owned()
 456                                                         }));
 457                                                 },
 458                                         };
 459                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 460                                                 assert!(payment.insert(*session_priv_bytes, path));
 461                                         }
 462                                         res
 463                                 },
 464                                 None =>
 465                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 466                                                 err: format!("Payment with ID {} not found", log_bytes!(payment_id.0)),
 467                                         })),
 468                         }
 469                 };
 470                 self.send_payment_internal(route, payment_hash, &payment_secret, None, payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height, send_payment_along_path)
 471         }
 472
 473         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 474                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 475                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 476         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 477         where
 478                 ES::Target: EntropySource,
 479                 NS::Target: NodeSigner,
 480                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 481                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 482         {
 483                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 484
 485                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 486
 487                 if hops.len() < 2 {
 488                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 489                                 err: "No need probing a path with less than two hops".to_string()
 490                         }))
 491                 }
 492
 493                 let route = Route { paths: vec![hops], payment_params: None };
 494                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, &route, Retry::Attempts(0), None, entropy_source, best_block_height)?;
 495
 496                 match self.send_payment_internal(&route, payment_hash, &None, None, payment_id, None, onion_session_privs, node_signer, best_block_height, send_payment_along_path) {
 497                         Ok(()) => Ok((payment_hash, payment_id)),
 498                         Err(e) => Err(e)
 499                 }
 500         }
 501
 502         #[cfg(test)]
 503         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 504                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 505                 route: &Route, retry_strategy: Retry, entropy_source: &ES, best_block_height: u32
 506         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 507                 self.add_new_pending_payment(payment_hash, payment_secret, payment_id, route, retry_strategy, None, entropy_source, best_block_height)
 508         }
 509
 510         pub(super) fn add_new_pending_payment<ES: Deref>(
 511                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 512                 route: &Route, retry_strategy: Retry, route_params: Option<RouteParameters>,
 513                 entropy_source: &ES, best_block_height: u32
 514         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 515                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 516                 for _ in 0..route.paths.len() {
 517                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 518                 }
 519
 520                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 521                 match pending_outbounds.entry(payment_id) {
 522                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 523                         hash_map::Entry::Vacant(entry) => {
 524                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 525                                         retry_strategy,
 526                                         attempts: PaymentAttempts::new(),
 527                                         route_params,
 528                                         session_privs: HashSet::new(),
 529                                         pending_amt_msat: 0,
 530                                         pending_fee_msat: Some(0),
 531                                         payment_hash,
 532                                         payment_secret,
 533                                         starting_block_height: best_block_height,
 534                                         total_msat: route.get_total_amount(),
 535                                 });
 536
 537                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 538                                         assert!(payment.insert(*session_priv_bytes, path));
 539                                 }
 540
 541                                 Ok(onion_session_privs)
 542                         },
 543                 }
 544         }
 545
 546         fn send_payment_internal<NS: Deref, F>(
 547                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 548                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 549                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 550                 send_payment_along_path: F
 551         ) -> Result<(), PaymentSendFailure>
 552         where
 553                 NS::Target: NodeSigner,
 554                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 555                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 556         {
 557                 if route.paths.len() < 1 {
 558                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over"}));
 559                 }
 560                 if payment_secret.is_none() && route.paths.len() > 1 {
 561                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_string()}));
 562                 }
 563                 let mut total_value = 0;
 564                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 565                 let mut path_errs = Vec::with_capacity(route.paths.len());
 566                 'path_check: for path in route.paths.iter() {
 567                         if path.len() < 1 || path.len() > 20 {
 568                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size"}));
 569                                 continue 'path_check;
 570                         }
 571                         for (idx, hop) in path.iter().enumerate() {
 572                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 573                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us"}));
 574                                         continue 'path_check;
 575                                 }
 576                         }
 577                         total_value += path.last().unwrap().fee_msat;
 578                         path_errs.push(Ok(()));
 579                 }
 580                 if path_errs.iter().any(|e| e.is_err()) {
 581                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 582                 }
 583                 if let Some(amt_msat) = recv_value_msat {
 584                         debug_assert!(amt_msat >= total_value);
 585                         total_value = amt_msat;
 586                 }
 587
 588                 let cur_height = best_block_height + 1;
 589                 let mut results = Vec::new();
 590                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 591                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 592                         let mut path_res = send_payment_along_path(&path, &route.payment_params, &payment_hash, payment_secret, total_value, cur_height, payment_id, &keysend_preimage, session_priv);
 593                         match path_res {
 594                                 Ok(_) => {},
 595                                 Err(APIError::MonitorUpdateInProgress) => {
 596                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 597                                         // considered "in flight" and we shouldn't remove it from the
 598                                         // PendingOutboundPayment set.
 599                                 },
 600                                 Err(_) => {
 601                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 602                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
 603                                                 let removed = payment.remove(&session_priv, Some(path));
 604                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
 605                                         } else {
 606                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
 607                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
 608                                         }
 609                                 }
 610                         }
 611                         results.push(path_res);
 612                 }
 613                 let mut has_ok = false;
 614                 let mut has_err = false;
 615                 let mut pending_amt_unsent = 0;
 616                 let mut max_unsent_cltv_delta = 0;
 617                 for (res, path) in results.iter().zip(route.paths.iter()) {
 618                         if res.is_ok() { has_ok = true; }
 619                         if res.is_err() { has_err = true; }
 620                         if let &Err(APIError::MonitorUpdateInProgress) = res {
 621                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
 622                                 // PartialFailure.
 623                                 has_err = true;
 624                                 has_ok = true;
 625                         } else if res.is_err() {
 626                                 pending_amt_unsent += path.last().unwrap().fee_msat;
 627                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
 628                         }
 629                 }
 630                 if has_err && has_ok {
 631                         Err(PaymentSendFailure::PartialFailure {
 632                                 results,
 633                                 payment_id,
 634                                 failed_paths_retry: if pending_amt_unsent != 0 {
 635                                         if let Some(payment_params) = &route.payment_params {
 636                                                 Some(RouteParameters {
 637                                                         payment_params: payment_params.clone(),
 638                                                         final_value_msat: pending_amt_unsent,
 639                                                         final_cltv_expiry_delta: max_unsent_cltv_delta,
 640                                                 })
 641                                         } else { None }
 642                                 } else { None },
 643                         })
 644                 } else if has_err {
 645                         // If we failed to send any paths, we should remove the new PaymentId from the
 646                         // `pending_outbound_payments` map, as the user isn't expected to `abandon_payment`.
 647                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
 648                         debug_assert!(removed, "We should always have a pending payment to remove here");
 649                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
 650                 } else {
 651                         Ok(())
 652                 }
 653         }
 654
 655         #[cfg(test)]
 656         pub(super) fn test_send_payment_internal<NS: Deref, F>(
 657                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 658                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 659                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 660                 send_payment_along_path: F
 661         ) -> Result<(), PaymentSendFailure>
 662         where
 663                 NS::Target: NodeSigner,
 664                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 665                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 666         {
 667                 self.send_payment_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
 668                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
 669                         send_payment_along_path)
 670         }
 671
 672         pub(super) fn claim_htlc<L: Deref>(
 673                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
 674                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
 675         ) where L::Target: Logger {
 676                 let mut session_priv_bytes = [0; 32];
 677                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 678                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 679                 let mut pending_events = pending_events.lock().unwrap();
 680                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 681                         if !payment.get().is_fulfilled() {
 682                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 683                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
 684                                 pending_events.push(
 685                                         events::Event::PaymentSent {
 686                                                 payment_id: Some(payment_id),
 687                                                 payment_preimage,
 688                                                 payment_hash,
 689                                                 fee_paid_msat,
 690                                         }
 691                                 );
 692                                 payment.get_mut().mark_fulfilled();
 693                         }
 694
 695                         if from_onchain {
 696                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
 697                                 // This could potentially lead to removing a pending payment too early,
 698                                 // with a reorg of one block causing us to re-add the fulfilled payment on
 699                                 // restart.
 700                                 // TODO: We should have a second monitor event that informs us of payments
 701                                 // irrevocably fulfilled.
 702                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
 703                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
 704                                         pending_events.push(
 705                                                 events::Event::PaymentPathSuccessful {
 706                                                         payment_id,
 707                                                         payment_hash,
 708                                                         path,
 709                                                 }
 710                                         );
 711                                 }
 712                         }
 713                 } else {
 714                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
 715                 }
 716         }
 717
 718         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
 719                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 720                 let mut pending_events = pending_events.lock().unwrap();
 721                 for source in sources {
 722                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
 723                                 let mut session_priv_bytes = [0; 32];
 724                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 725                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 726                                         assert!(payment.get().is_fulfilled());
 727                                         if payment.get_mut().remove(&session_priv_bytes, None) {
 728                                                 pending_events.push(
 729                                                         events::Event::PaymentPathSuccessful {
 730                                                                 payment_id,
 731                                                                 payment_hash: payment.get().payment_hash(),
 732                                                                 path,
 733                                                         }
 734                                                 );
 735                                         }
 736                                 }
 737                         }
 738                 }
 739         }
 740
 741         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
 742                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
 743                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
 744                 // this could race the user making a duplicate send_payment call and our idempotency
 745                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
 746                 // removal. This should be more than sufficient to ensure the idempotency of any
 747                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
 748                 // processed.
 749                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
 750                 let pending_events = pending_events.lock().unwrap();
 751                 pending_outbound_payments.retain(|payment_id, payment| {
 752                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
 753                                 let mut no_remaining_entries = session_privs.is_empty();
 754                                 if no_remaining_entries {
 755                                         for ev in pending_events.iter() {
 756                                                 match ev {
 757                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
 758                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
 759                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
 760                                                                         if payment_id == ev_payment_id {
 761                                                                                 no_remaining_entries = false;
 762                                                                                 break;
 763                                                                         }
 764                                                                 },
 765                                                         _ => {},
 766                                                 }
 767                                         }
 768                                 }
 769                                 if no_remaining_entries {
 770                                         *timer_ticks_without_htlcs += 1;
 771                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
 772                                 } else {
 773                                         *timer_ticks_without_htlcs = 0;
 774                                         true
 775                                 }
 776                         } else { true }
 777                 });
 778         }
 779
 780         pub(super) fn fail_htlc<L: Deref>(
 781                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
 782                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
 783                 payment_params: &Option<PaymentParameters>, probing_cookie_secret: [u8; 32],
 784                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
 785         ) where L::Target: Logger {
 786                 let mut session_priv_bytes = [0; 32];
 787                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 788                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 789                 let mut all_paths_failed = false;
 790                 let mut full_failure_ev = None;
 791                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
 792                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
 793                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 794                                 return
 795                         }
 796                         if payment.get().is_fulfilled() {
 797                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
 798                                 return
 799                         }
 800                         if payment.get().remaining_parts() == 0 {
 801                                 all_paths_failed = true;
 802                                 if payment.get().abandoned() {
 803                                         full_failure_ev = Some(events::Event::PaymentFailed {
 804                                                 payment_id: *payment_id,
 805                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
 806                                         });
 807                                         payment.remove();
 808                                 }
 809                         }
 810                 } else {
 811                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 812                         return
 813                 }
 814                 let mut retry = if let Some(payment_params_data) = payment_params {
 815                         let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 816                         Some(RouteParameters {
 817                                 payment_params: payment_params_data.clone(),
 818                                 final_value_msat: path_last_hop.fee_msat,
 819                                 final_cltv_expiry_delta: path_last_hop.cltv_expiry_delta,
 820                         })
 821                 } else { None };
 822                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 823
 824                 let path_failure = {
 825                         #[cfg(test)]
 826                         let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
 827                         #[cfg(not(test))]
 828                         let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
 829
 830                         if payment_is_probe(payment_hash, &payment_id, probing_cookie_secret) {
 831                                 if !payment_retryable {
 832                                         events::Event::ProbeSuccessful {
 833                                                 payment_id: *payment_id,
 834                                                 payment_hash: payment_hash.clone(),
 835                                                 path: path.clone(),
 836                                         }
 837                                 } else {
 838                                         events::Event::ProbeFailed {
 839                                                 payment_id: *payment_id,
 840                                                 payment_hash: payment_hash.clone(),
 841                                                 path: path.clone(),
 842                                                 short_channel_id,
 843                                         }
 844                                 }
 845                         } else {
 846                                 // TODO: If we decided to blame ourselves (or one of our channels) in
 847                                 // process_onion_failure we should close that channel as it implies our
 848                                 // next-hop is needlessly blaming us!
 849                                 if let Some(scid) = short_channel_id {
 850                                         retry.as_mut().map(|r| r.payment_params.previously_failed_channels.push(scid));
 851                                 }
 852                                 events::Event::PaymentPathFailed {
 853                                         payment_id: Some(*payment_id),
 854                                         payment_hash: payment_hash.clone(),
 855                                         payment_failed_permanently: !payment_retryable,
 856                                         network_update,
 857                                         all_paths_failed,
 858                                         path: path.clone(),
 859                                         short_channel_id,
 860                                         retry,
 861                                         #[cfg(test)]
 862                                         error_code: onion_error_code,
 863                                         #[cfg(test)]
 864                                         error_data: onion_error_data
 865                                 }
 866                         }
 867                 };
 868                 let mut pending_events = pending_events.lock().unwrap();
 869                 pending_events.push(path_failure);
 870                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
 871         }
 872
 873         pub(super) fn abandon_payment(&self, payment_id: PaymentId) -> Option<events::Event> {
 874                 let mut failed_ev = None;
 875                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 876                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 877                         if let Ok(()) = payment.get_mut().mark_abandoned() {
 878                                 if payment.get().remaining_parts() == 0 {
 879                                         failed_ev = Some(events::Event::PaymentFailed {
 880                                                 payment_id,
 881                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
 882                                         });
 883                                         payment.remove();
 884                                 }
 885                         }
 886                 }
 887                 failed_ev
 888         }
 889
 890         #[cfg(test)]
 891         pub fn has_pending_payments(&self) -> bool {
 892                 !self.pending_outbound_payments.lock().unwrap().is_empty()
 893         }
 894
 895         #[cfg(test)]
 896         pub fn clear_pending_payments(&self) {
 897                 self.pending_outbound_payments.lock().unwrap().clear()
 898         }
 899 }
 900
 901 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
 902 /// payment probe.
 903 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
 904         probing_cookie_secret: [u8; 32]) -> bool
 905 {
 906         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
 907         target_payment_hash == *payment_hash
 908 }
 909
 910 /// Returns the 'probing cookie' for the given [`PaymentId`].
 911 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
 912         let mut preimage = [0u8; 64];
 913         preimage[..32].copy_from_slice(&probing_cookie_secret);
 914         preimage[32..].copy_from_slice(&payment_id.0);
 915         PaymentHash(Sha256::hash(&preimage).into_inner())
 916 }
 917
 918 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
 919         (0, Legacy) => {
 920                 (0, session_privs, required),
 921         },
 922         (1, Fulfilled) => {
 923                 (0, session_privs, required),
 924                 (1, payment_hash, option),
 925                 (3, timer_ticks_without_htlcs, (default_value, 0)),
 926         },
 927         (2, Retryable) => {
 928                 (0, session_privs, required),
 929                 (1, pending_fee_msat, option),
 930                 (2, payment_hash, required),
 931                 (not_written, retry_strategy, (static_value, Retry::Attempts(0))),
 932                 (4, payment_secret, option),
 933                 (not_written, attempts, (static_value, PaymentAttempts::new())),
 934                 (6, total_msat, required),
 935                 (not_written, route_params, (static_value, None)),
 936                 (8, pending_amt_msat, required),
 937                 (10, starting_block_height, required),
 938         },
 939         (3, Abandoned) => {
 940                 (0, session_privs, required),
 941                 (2, payment_hash, required),
 942         },
 943 );