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