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