_ 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
  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<ES: Deref, NS: Deref, F>(
 275                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 276                 payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 277                 send_payment_along_path: F
 278         ) -> Result<(), PaymentSendFailure>
 279         where
 280                 ES::Target: EntropySource,
 281                 NS::Target: NodeSigner,
 282                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 283                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 284         {
 285                 let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, route, entropy_source, best_block_height)?;
 286                 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)
 287         }
 288
 289         pub(super) fn send_spontaneous_payment<ES: Deref, NS: Deref, F>(
 290                 &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
 291                 entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 292         ) -> Result<PaymentHash, PaymentSendFailure>
 293         where
 294                 ES::Target: EntropySource,
 295                 NS::Target: NodeSigner,
 296                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 297                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 298         {
 299                 let preimage = match payment_preimage {
 300                         Some(p) => p,
 301                         None => PaymentPreimage(entropy_source.get_secure_random_bytes()),
 302                 };
 303                 let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
 304                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, &route, entropy_source, best_block_height)?;
 305
 306                 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) {
 307                         Ok(()) => Ok(payment_hash),
 308                         Err(e) => Err(e)
 309                 }
 310         }
 311
 312         pub(super) fn retry_payment_with_route<ES: Deref, NS: Deref, F>(
 313                 &self, route: &Route, payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
 314                 send_payment_along_path: F
 315         ) -> Result<(), PaymentSendFailure>
 316         where
 317                 ES::Target: EntropySource,
 318                 NS::Target: NodeSigner,
 319                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 320                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 321         {
 322                 const RETRY_OVERFLOW_PERCENTAGE: u64 = 10;
 323                 for path in route.paths.iter() {
 324                         if path.len() == 0 {
 325                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 326                                         err: "length-0 path in route".to_string()
 327                                 }))
 328                         }
 329                 }
 330
 331                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 332                 for _ in 0..route.paths.len() {
 333                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 334                 }
 335
 336                 let (total_msat, payment_hash, payment_secret) = {
 337                         let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 338                         match outbounds.get_mut(&payment_id) {
 339                                 Some(payment) => {
 340                                         let res = match payment {
 341                                                 PendingOutboundPayment::Retryable {
 342                                                         total_msat, payment_hash, payment_secret, pending_amt_msat, ..
 343                                                 } => {
 344                                                         let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
 345                                                         if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
 346                                                                 return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 347                                                                         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()
 348                                                                 }))
 349                                                         }
 350                                                         (*total_msat, *payment_hash, *payment_secret)
 351                                                 },
 352                                                 PendingOutboundPayment::Legacy { .. } => {
 353                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 354                                                                 err: "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102".to_string()
 355                                                         }))
 356                                                 },
 357                                                 PendingOutboundPayment::Fulfilled { .. } => {
 358                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 359                                                                 err: "Payment already completed".to_owned()
 360                                                         }));
 361                                                 },
 362                                                 PendingOutboundPayment::Abandoned { .. } => {
 363                                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 364                                                                 err: "Payment already abandoned (with some HTLCs still pending)".to_owned()
 365                                                         }));
 366                                                 },
 367                                         };
 368                                         for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 369                                                 assert!(payment.insert(*session_priv_bytes, path));
 370                                         }
 371                                         res
 372                                 },
 373                                 None =>
 374                                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 375                                                 err: format!("Payment with ID {} not found", log_bytes!(payment_id.0)),
 376                                         })),
 377                         }
 378                 };
 379                 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)
 380         }
 381
 382         pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
 383                 &self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
 384                 node_signer: &NS, best_block_height: u32, send_payment_along_path: F
 385         ) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 386         where
 387                 ES::Target: EntropySource,
 388                 NS::Target: NodeSigner,
 389                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 390                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 391         {
 392                 let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
 393
 394                 let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 395
 396                 if hops.len() < 2 {
 397                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 398                                 err: "No need probing a path with less than two hops".to_string()
 399                         }))
 400                 }
 401
 402                 let route = Route { paths: vec![hops], payment_params: None };
 403                 let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, &route, entropy_source, best_block_height)?;
 404
 405                 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) {
 406                         Ok(()) => Ok((payment_hash, payment_id)),
 407                         Err(e) => Err(e)
 408                 }
 409         }
 410
 411         #[cfg(test)]
 412         pub(super) fn test_add_new_pending_payment<ES: Deref>(
 413                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 414                 route: &Route, entropy_source: &ES, best_block_height: u32
 415         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 416                 self.add_new_pending_payment(payment_hash, payment_secret, payment_id, route, entropy_source, best_block_height)
 417         }
 418
 419         pub(super) fn add_new_pending_payment<ES: Deref>(
 420                 &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
 421                 route: &Route, entropy_source: &ES, best_block_height: u32
 422         ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
 423                 let mut onion_session_privs = Vec::with_capacity(route.paths.len());
 424                 for _ in 0..route.paths.len() {
 425                         onion_session_privs.push(entropy_source.get_secure_random_bytes());
 426                 }
 427
 428                 let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 429                 match pending_outbounds.entry(payment_id) {
 430                         hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
 431                         hash_map::Entry::Vacant(entry) => {
 432                                 let payment = entry.insert(PendingOutboundPayment::Retryable {
 433                                         session_privs: HashSet::new(),
 434                                         pending_amt_msat: 0,
 435                                         pending_fee_msat: Some(0),
 436                                         payment_hash,
 437                                         payment_secret,
 438                                         starting_block_height: best_block_height,
 439                                         total_msat: route.get_total_amount(),
 440                                 });
 441
 442                                 for (path, session_priv_bytes) in route.paths.iter().zip(onion_session_privs.iter()) {
 443                                         assert!(payment.insert(*session_priv_bytes, path));
 444                                 }
 445
 446                                 Ok(onion_session_privs)
 447                         },
 448                 }
 449         }
 450
 451         fn send_payment_internal<NS: Deref, F>(
 452                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 453                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 454                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 455                 send_payment_along_path: F
 456         ) -> Result<(), PaymentSendFailure>
 457         where
 458                 NS::Target: NodeSigner,
 459                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 460                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 461         {
 462                 if route.paths.len() < 1 {
 463                         return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over"}));
 464                 }
 465                 if payment_secret.is_none() && route.paths.len() > 1 {
 466                         return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_string()}));
 467                 }
 468                 let mut total_value = 0;
 469                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap(); // TODO no unwrap
 470                 let mut path_errs = Vec::with_capacity(route.paths.len());
 471                 'path_check: for path in route.paths.iter() {
 472                         if path.len() < 1 || path.len() > 20 {
 473                                 path_errs.push(Err(APIError::InvalidRoute{err: "Path didn't go anywhere/had bogus size"}));
 474                                 continue 'path_check;
 475                         }
 476                         for (idx, hop) in path.iter().enumerate() {
 477                                 if idx != path.len() - 1 && hop.pubkey == our_node_id {
 478                                         path_errs.push(Err(APIError::InvalidRoute{err: "Path went through us but wasn't a simple rebalance loop to us"}));
 479                                         continue 'path_check;
 480                                 }
 481                         }
 482                         total_value += path.last().unwrap().fee_msat;
 483                         path_errs.push(Ok(()));
 484                 }
 485                 if path_errs.iter().any(|e| e.is_err()) {
 486                         return Err(PaymentSendFailure::PathParameterError(path_errs));
 487                 }
 488                 if let Some(amt_msat) = recv_value_msat {
 489                         debug_assert!(amt_msat >= total_value);
 490                         total_value = amt_msat;
 491                 }
 492
 493                 let cur_height = best_block_height + 1;
 494                 let mut results = Vec::new();
 495                 debug_assert_eq!(route.paths.len(), onion_session_privs.len());
 496                 for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
 497                         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);
 498                         match path_res {
 499                                 Ok(_) => {},
 500                                 Err(APIError::MonitorUpdateInProgress) => {
 501                                         // While a MonitorUpdateInProgress is an Err(_), the payment is still
 502                                         // considered "in flight" and we shouldn't remove it from the
 503                                         // PendingOutboundPayment set.
 504                                 },
 505                                 Err(_) => {
 506                                         let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
 507                                         if let Some(payment) = pending_outbounds.get_mut(&payment_id) {
 508                                                 let removed = payment.remove(&session_priv, Some(path));
 509                                                 debug_assert!(removed, "This can't happen as the payment has an entry for this path added by callers");
 510                                         } else {
 511                                                 debug_assert!(false, "This can't happen as the payment was added by callers");
 512                                                 path_res = Err(APIError::APIMisuseError { err: "Internal error: payment disappeared during processing. Please report this bug!".to_owned() });
 513                                         }
 514                                 }
 515                         }
 516                         results.push(path_res);
 517                 }
 518                 let mut has_ok = false;
 519                 let mut has_err = false;
 520                 let mut pending_amt_unsent = 0;
 521                 let mut max_unsent_cltv_delta = 0;
 522                 for (res, path) in results.iter().zip(route.paths.iter()) {
 523                         if res.is_ok() { has_ok = true; }
 524                         if res.is_err() { has_err = true; }
 525                         if let &Err(APIError::MonitorUpdateInProgress) = res {
 526                                 // MonitorUpdateInProgress is inherently unsafe to retry, so we call it a
 527                                 // PartialFailure.
 528                                 has_err = true;
 529                                 has_ok = true;
 530                         } else if res.is_err() {
 531                                 pending_amt_unsent += path.last().unwrap().fee_msat;
 532                                 max_unsent_cltv_delta = cmp::max(max_unsent_cltv_delta, path.last().unwrap().cltv_expiry_delta);
 533                         }
 534                 }
 535                 if has_err && has_ok {
 536                         Err(PaymentSendFailure::PartialFailure {
 537                                 results,
 538                                 payment_id,
 539                                 failed_paths_retry: if pending_amt_unsent != 0 {
 540                                         if let Some(payment_params) = &route.payment_params {
 541                                                 Some(RouteParameters {
 542                                                         payment_params: payment_params.clone(),
 543                                                         final_value_msat: pending_amt_unsent,
 544                                                         final_cltv_expiry_delta: max_unsent_cltv_delta,
 545                                                 })
 546                                         } else { None }
 547                                 } else { None },
 548                         })
 549                 } else if has_err {
 550                         // If we failed to send any paths, we should remove the new PaymentId from the
 551                         // `pending_outbound_payments` map, as the user isn't expected to `abandon_payment`.
 552                         let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
 553                         debug_assert!(removed, "We should always have a pending payment to remove here");
 554                         Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
 555                 } else {
 556                         Ok(())
 557                 }
 558         }
 559
 560         #[cfg(test)]
 561         pub(super) fn test_send_payment_internal<NS: Deref, F>(
 562                 &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 563                 keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
 564                 onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
 565                 send_payment_along_path: F
 566         ) -> Result<(), PaymentSendFailure>
 567         where
 568                 NS::Target: NodeSigner,
 569                 F: Fn(&Vec<RouteHop>, &Option<PaymentParameters>, &PaymentHash, &Option<PaymentSecret>, u64,
 570                    u32, PaymentId, &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
 571         {
 572                 self.send_payment_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
 573                         recv_value_msat, onion_session_privs, node_signer, best_block_height,
 574                         send_payment_along_path)
 575         }
 576
 577         pub(super) fn claim_htlc<L: Deref>(
 578                 &self, payment_id: PaymentId, payment_preimage: PaymentPreimage, session_priv: SecretKey,
 579                 path: Vec<RouteHop>, from_onchain: bool, pending_events: &Mutex<Vec<events::Event>>, logger: &L
 580         ) where L::Target: Logger {
 581                 let mut session_priv_bytes = [0; 32];
 582                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 583                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 584                 let mut pending_events = pending_events.lock().unwrap();
 585                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 586                         if !payment.get().is_fulfilled() {
 587                                 let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 588                                 let fee_paid_msat = payment.get().get_pending_fee_msat();
 589                                 pending_events.push(
 590                                         events::Event::PaymentSent {
 591                                                 payment_id: Some(payment_id),
 592                                                 payment_preimage,
 593                                                 payment_hash,
 594                                                 fee_paid_msat,
 595                                         }
 596                                 );
 597                                 payment.get_mut().mark_fulfilled();
 598                         }
 599
 600                         if from_onchain {
 601                                 // We currently immediately remove HTLCs which were fulfilled on-chain.
 602                                 // This could potentially lead to removing a pending payment too early,
 603                                 // with a reorg of one block causing us to re-add the fulfilled payment on
 604                                 // restart.
 605                                 // TODO: We should have a second monitor event that informs us of payments
 606                                 // irrevocably fulfilled.
 607                                 if payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
 608                                         let payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0).into_inner()));
 609                                         pending_events.push(
 610                                                 events::Event::PaymentPathSuccessful {
 611                                                         payment_id,
 612                                                         payment_hash,
 613                                                         path,
 614                                                 }
 615                                         );
 616                                 }
 617                         }
 618                 } else {
 619                         log_trace!(logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
 620                 }
 621         }
 622
 623         pub(super) fn finalize_claims(&self, sources: Vec<HTLCSource>, pending_events: &Mutex<Vec<events::Event>>) {
 624                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 625                 let mut pending_events = pending_events.lock().unwrap();
 626                 for source in sources {
 627                         if let HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } = source {
 628                                 let mut session_priv_bytes = [0; 32];
 629                                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 630                                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 631                                         assert!(payment.get().is_fulfilled());
 632                                         if payment.get_mut().remove(&session_priv_bytes, None) {
 633                                                 pending_events.push(
 634                                                         events::Event::PaymentPathSuccessful {
 635                                                                 payment_id,
 636                                                                 payment_hash: payment.get().payment_hash(),
 637                                                                 path,
 638                                                         }
 639                                                 );
 640                                         }
 641                                 }
 642                         }
 643                 }
 644         }
 645
 646         pub(super) fn remove_stale_resolved_payments(&self, pending_events: &Mutex<Vec<events::Event>>) {
 647                 // If an outbound payment was completed, and no pending HTLCs remain, we should remove it
 648                 // from the map. However, if we did that immediately when the last payment HTLC is claimed,
 649                 // this could race the user making a duplicate send_payment call and our idempotency
 650                 // guarantees would be violated. Instead, we wait a few timer ticks to do the actual
 651                 // removal. This should be more than sufficient to ensure the idempotency of any
 652                 // `send_payment` calls that were made at the same time the `PaymentSent` event was being
 653                 // processed.
 654                 let mut pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
 655                 let pending_events = pending_events.lock().unwrap();
 656                 pending_outbound_payments.retain(|payment_id, payment| {
 657                         if let PendingOutboundPayment::Fulfilled { session_privs, timer_ticks_without_htlcs, .. } = payment {
 658                                 let mut no_remaining_entries = session_privs.is_empty();
 659                                 if no_remaining_entries {
 660                                         for ev in pending_events.iter() {
 661                                                 match ev {
 662                                                         events::Event::PaymentSent { payment_id: Some(ev_payment_id), .. } |
 663                                                                 events::Event::PaymentPathSuccessful { payment_id: ev_payment_id, .. } |
 664                                                                 events::Event::PaymentPathFailed { payment_id: Some(ev_payment_id), .. } => {
 665                                                                         if payment_id == ev_payment_id {
 666                                                                                 no_remaining_entries = false;
 667                                                                                 break;
 668                                                                         }
 669                                                                 },
 670                                                         _ => {},
 671                                                 }
 672                                         }
 673                                 }
 674                                 if no_remaining_entries {
 675                                         *timer_ticks_without_htlcs += 1;
 676                                         *timer_ticks_without_htlcs <= IDEMPOTENCY_TIMEOUT_TICKS
 677                                 } else {
 678                                         *timer_ticks_without_htlcs = 0;
 679                                         true
 680                                 }
 681                         } else { true }
 682                 });
 683         }
 684
 685         pub(super) fn fail_htlc<L: Deref>(
 686                 &self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason,
 687                 path: &Vec<RouteHop>, session_priv: &SecretKey, payment_id: &PaymentId,
 688                 payment_params: &Option<PaymentParameters>, probing_cookie_secret: [u8; 32],
 689                 secp_ctx: &Secp256k1<secp256k1::All>, pending_events: &Mutex<Vec<events::Event>>, logger: &L
 690         ) where L::Target: Logger {
 691                 let mut session_priv_bytes = [0; 32];
 692                 session_priv_bytes.copy_from_slice(&session_priv[..]);
 693                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 694                 let mut all_paths_failed = false;
 695                 let mut full_failure_ev = None;
 696                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(*payment_id) {
 697                         if !payment.get_mut().remove(&session_priv_bytes, Some(&path)) {
 698                                 log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 699                                 return
 700                         }
 701                         if payment.get().is_fulfilled() {
 702                                 log_trace!(logger, "Received failure of HTLC with payment_hash {} after payment completion", log_bytes!(payment_hash.0));
 703                                 return
 704                         }
 705                         if payment.get().remaining_parts() == 0 {
 706                                 all_paths_failed = true;
 707                                 if payment.get().abandoned() {
 708                                         full_failure_ev = Some(events::Event::PaymentFailed {
 709                                                 payment_id: *payment_id,
 710                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
 711                                         });
 712                                         payment.remove();
 713                                 }
 714                         }
 715                 } else {
 716                         log_trace!(logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 717                         return
 718                 }
 719                 let mut retry = if let Some(payment_params_data) = payment_params {
 720                         let path_last_hop = path.last().expect("Outbound payments must have had a valid path");
 721                         Some(RouteParameters {
 722                                 payment_params: payment_params_data.clone(),
 723                                 final_value_msat: path_last_hop.fee_msat,
 724                                 final_cltv_expiry_delta: path_last_hop.cltv_expiry_delta,
 725                         })
 726                 } else { None };
 727                 log_trace!(logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 728
 729                 let path_failure = {
 730                         #[cfg(test)]
 731                         let (network_update, short_channel_id, payment_retryable, onion_error_code, onion_error_data) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
 732                         #[cfg(not(test))]
 733                         let (network_update, short_channel_id, payment_retryable, _, _) = onion_error.decode_onion_failure(secp_ctx, logger, &source);
 734
 735                         if payment_is_probe(payment_hash, &payment_id, probing_cookie_secret) {
 736                                 if !payment_retryable {
 737                                         events::Event::ProbeSuccessful {
 738                                                 payment_id: *payment_id,
 739                                                 payment_hash: payment_hash.clone(),
 740                                                 path: path.clone(),
 741                                         }
 742                                 } else {
 743                                         events::Event::ProbeFailed {
 744                                                 payment_id: *payment_id,
 745                                                 payment_hash: payment_hash.clone(),
 746                                                 path: path.clone(),
 747                                                 short_channel_id,
 748                                         }
 749                                 }
 750                         } else {
 751                                 // TODO: If we decided to blame ourselves (or one of our channels) in
 752                                 // process_onion_failure we should close that channel as it implies our
 753                                 // next-hop is needlessly blaming us!
 754                                 if let Some(scid) = short_channel_id {
 755                                         retry.as_mut().map(|r| r.payment_params.previously_failed_channels.push(scid));
 756                                 }
 757                                 events::Event::PaymentPathFailed {
 758                                         payment_id: Some(*payment_id),
 759                                         payment_hash: payment_hash.clone(),
 760                                         payment_failed_permanently: !payment_retryable,
 761                                         network_update,
 762                                         all_paths_failed,
 763                                         path: path.clone(),
 764                                         short_channel_id,
 765                                         retry,
 766                                         #[cfg(test)]
 767                                         error_code: onion_error_code,
 768                                         #[cfg(test)]
 769                                         error_data: onion_error_data
 770                                 }
 771                         }
 772                 };
 773                 let mut pending_events = pending_events.lock().unwrap();
 774                 pending_events.push(path_failure);
 775                 if let Some(ev) = full_failure_ev { pending_events.push(ev); }
 776         }
 777
 778         pub(super) fn abandon_payment(&self, payment_id: PaymentId) -> Option<events::Event> {
 779                 let mut failed_ev = None;
 780                 let mut outbounds = self.pending_outbound_payments.lock().unwrap();
 781                 if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 782                         if let Ok(()) = payment.get_mut().mark_abandoned() {
 783                                 if payment.get().remaining_parts() == 0 {
 784                                         failed_ev = Some(events::Event::PaymentFailed {
 785                                                 payment_id,
 786                                                 payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
 787                                         });
 788                                         payment.remove();
 789                                 }
 790                         }
 791                 }
 792                 failed_ev
 793         }
 794
 795         #[cfg(test)]
 796         pub fn has_pending_payments(&self) -> bool {
 797                 !self.pending_outbound_payments.lock().unwrap().is_empty()
 798         }
 799
 800         #[cfg(test)]
 801         pub fn clear_pending_payments(&self) {
 802                 self.pending_outbound_payments.lock().unwrap().clear()
 803         }
 804 }
 805
 806 /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
 807 /// payment probe.
 808 pub(super) fn payment_is_probe(payment_hash: &PaymentHash, payment_id: &PaymentId,
 809         probing_cookie_secret: [u8; 32]) -> bool
 810 {
 811         let target_payment_hash = probing_cookie_from_id(payment_id, probing_cookie_secret);
 812         target_payment_hash == *payment_hash
 813 }
 814
 815 /// Returns the 'probing cookie' for the given [`PaymentId`].
 816 fn probing_cookie_from_id(payment_id: &PaymentId, probing_cookie_secret: [u8; 32]) -> PaymentHash {
 817         let mut preimage = [0u8; 64];
 818         preimage[..32].copy_from_slice(&probing_cookie_secret);
 819         preimage[32..].copy_from_slice(&payment_id.0);
 820         PaymentHash(Sha256::hash(&preimage).into_inner())
 821 }
 822
 823 impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
 824         (0, Legacy) => {
 825                 (0, session_privs, required),
 826         },
 827         (1, Fulfilled) => {
 828                 (0, session_privs, required),
 829                 (1, payment_hash, option),
 830                 (3, timer_ticks_without_htlcs, (default_value, 0)),
 831         },
 832         (2, Retryable) => {
 833                 (0, session_privs, required),
 834                 (1, pending_fee_msat, option),
 835                 (2, payment_hash, required),
 836                 (4, payment_secret, option),
 837                 (6, total_msat, required),
 838                 (8, pending_amt_msat, required),
 839                 (10, starting_block_height, required),
 840         },
 841         (3, Abandoned) => {
 842                 (0, session_privs, required),
 843                 (2, payment_hash, required),
 844         },
 845 );