_ Git - rust-lightning/blob - lightning-invoice/src/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 //! Convenient utilities for paying Lightning invoices.
  11
  12 use crate::Bolt11Invoice;
  13 use crate::prelude::*;
  14
  15 use bitcoin_hashes::Hash;
  16
  17 use lightning::chain;
  18 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  19 use lightning::sign::{NodeSigner, SignerProvider, EntropySource};
  20 use lightning::ln::PaymentHash;
  21 use lightning::ln::channelmanager::{AChannelManager, ChannelManager, PaymentId, Retry, RetryableSendFailure, RecipientOnionFields, ProbeSendFailure};
  22 use lightning::routing::router::{PaymentParameters, RouteParameters, Router};
  23 use lightning::util::logger::Logger;
  24
  25 use core::fmt::Debug;
  26 use core::ops::Deref;
  27 use core::time::Duration;
  28
  29 /// Pays the given [`Bolt11Invoice`], retrying if needed based on [`Retry`].
  30 ///
  31 /// [`Bolt11Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  32 /// as the payment is still pending. If the payment succeeds, you must ensure that a second payment
  33 /// with the same [`PaymentHash`] is never sent.
  34 ///
  35 /// If you wish to use a different payment idempotency token, see [`pay_invoice_with_id`].
  36 pub fn pay_invoice<C: Deref>(
  37         invoice: &Bolt11Invoice, retry_strategy: Retry, channelmanager: C
  38 ) -> Result<PaymentId, PaymentError>
  39 where C::Target: AChannelManager,
  40 {
  41         let payment_id = PaymentId(invoice.payment_hash().into_inner());
  42         pay_invoice_with_id(invoice, payment_id, retry_strategy, channelmanager.get_cm())
  43                 .map(|()| payment_id)
  44 }
  45
  46 /// Pays the given [`Bolt11Invoice`] with a custom idempotency key, retrying if needed based on
  47 /// [`Retry`].
  48 ///
  49 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
  50 /// payment completes or fails, no idempotency guarantees are made.
  51 ///
  52 /// You should ensure that the [`Bolt11Invoice::payment_hash`] is unique and the same
  53 /// [`PaymentHash`] has never been paid before.
  54 ///
  55 /// See [`pay_invoice`] for a variant which uses the [`PaymentHash`] for the idempotency token.
  56 pub fn pay_invoice_with_id<C: Deref>(
  57         invoice: &Bolt11Invoice, payment_id: PaymentId, retry_strategy: Retry, channelmanager: C
  58 ) -> Result<(), PaymentError>
  59 where C::Target: AChannelManager,
  60 {
  61         let amt_msat = invoice.amount_milli_satoshis().ok_or(PaymentError::Invoice("amount missing"))?;
  62         pay_invoice_using_amount(invoice, amt_msat, payment_id, retry_strategy, channelmanager.get_cm())
  63 }
  64
  65 /// Pays the given zero-value [`Bolt11Invoice`] using the given amount, retrying if needed based on
  66 /// [`Retry`].
  67 ///
  68 /// [`Bolt11Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  69 /// as the payment is still pending. If the payment succeeds, you must ensure that a second payment
  70 /// with the same [`PaymentHash`] is never sent.
  71 ///
  72 /// If you wish to use a different payment idempotency token, see
  73 /// [`pay_zero_value_invoice_with_id`].
  74 pub fn pay_zero_value_invoice<C: Deref>(
  75         invoice: &Bolt11Invoice, amount_msats: u64, retry_strategy: Retry, channelmanager: C
  76 ) -> Result<PaymentId, PaymentError>
  77 where C::Target: AChannelManager,
  78 {
  79         let payment_id = PaymentId(invoice.payment_hash().into_inner());
  80         pay_zero_value_invoice_with_id(invoice, amount_msats, payment_id, retry_strategy,
  81                 channelmanager)
  82                 .map(|()| payment_id)
  83 }
  84
  85 /// Pays the given zero-value [`Bolt11Invoice`] using the given amount and custom idempotency key,
  86 /// retrying if needed based on [`Retry`].
  87 ///
  88 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
  89 /// payment completes or fails, no idempotency guarantees are made.
  90 ///
  91 /// You should ensure that the [`Bolt11Invoice::payment_hash`] is unique and the same
  92 /// [`PaymentHash`] has never been paid before.
  93 ///
  94 /// See [`pay_zero_value_invoice`] for a variant which uses the [`PaymentHash`] for the
  95 /// idempotency token.
  96 pub fn pay_zero_value_invoice_with_id<C: Deref>(
  97         invoice: &Bolt11Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
  98         channelmanager: C
  99 ) -> Result<(), PaymentError>
 100 where C::Target: AChannelManager,
 101 {
 102         if invoice.amount_milli_satoshis().is_some() {
 103                 Err(PaymentError::Invoice("amount unexpected"))
 104         } else {
 105                 pay_invoice_using_amount(invoice, amount_msats, payment_id, retry_strategy,
 106                         channelmanager.get_cm())
 107         }
 108 }
 109
 110 fn pay_invoice_using_amount<P: Deref>(
 111         invoice: &Bolt11Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
 112         payer: P
 113 ) -> Result<(), PaymentError> where P::Target: Payer {
 114         let payment_hash = PaymentHash((*invoice.payment_hash()).into_inner());
 115         let mut recipient_onion = RecipientOnionFields::secret_only(*invoice.payment_secret());
 116         recipient_onion.payment_metadata = invoice.payment_metadata().map(|v| v.clone());
 117         let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
 118                 invoice.min_final_cltv_expiry_delta() as u32)
 119                 .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 120                 .with_route_hints(invoice.route_hints()).unwrap();
 121         if let Some(features) = invoice.features() {
 122                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 123         }
 124         let route_params = RouteParameters::from_payment_params_and_value(payment_params, amount_msats);
 125
 126         payer.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 127 }
 128
 129 /// Sends payment probes over all paths of a route that would be used to pay the given invoice.
 130 ///
 131 /// See [`ChannelManager::send_preflight_probes`] for more information.
 132 pub fn preflight_probe_invoice<C: Deref>(
 133         invoice: &Bolt11Invoice, channelmanager: C, liquidity_limit_multiplier: Option<u64>,
 134 ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbingError>
 135 where C::Target: AChannelManager,
 136 {
 137         let amount_msat = if let Some(invoice_amount_msat) = invoice.amount_milli_satoshis() {
 138                 invoice_amount_msat
 139         } else {
 140                 return Err(ProbingError::Invoice("Failed to send probe as no amount was given in the invoice."));
 141         };
 142
 143         let mut payment_params = PaymentParameters::from_node_id(
 144                 invoice.recover_payee_pub_key(),
 145                 invoice.min_final_cltv_expiry_delta() as u32,
 146         )
 147         .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 148         .with_route_hints(invoice.route_hints())
 149         .unwrap();
 150
 151         if let Some(features) = invoice.features() {
 152                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 153         }
 154         let route_params = RouteParameters::from_payment_params_and_value(payment_params, amount_msat);
 155
 156         channelmanager.get_cm().send_preflight_probes(route_params, liquidity_limit_multiplier)
 157                 .map_err(ProbingError::Sending)
 158 }
 159
 160 /// Sends payment probes over all paths of a route that would be used to pay the given zero-value
 161 /// invoice using the given amount.
 162 ///
 163 /// See [`ChannelManager::send_preflight_probes`] for more information.
 164 pub fn preflight_probe_zero_value_invoice<C: Deref>(
 165         invoice: &Bolt11Invoice, amount_msat: u64, channelmanager: C,
 166         liquidity_limit_multiplier: Option<u64>,
 167 ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbingError>
 168 where C::Target: AChannelManager,
 169 {
 170         if invoice.amount_milli_satoshis().is_some() {
 171                 return Err(ProbingError::Invoice("amount unexpected"));
 172         }
 173
 174         let mut payment_params = PaymentParameters::from_node_id(
 175                 invoice.recover_payee_pub_key(),
 176                 invoice.min_final_cltv_expiry_delta() as u32,
 177         )
 178         .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 179         .with_route_hints(invoice.route_hints())
 180         .unwrap();
 181
 182         if let Some(features) = invoice.features() {
 183                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 184         }
 185         let route_params = RouteParameters::from_payment_params_and_value(payment_params, amount_msat);
 186
 187         channelmanager.get_cm().send_preflight_probes(route_params, liquidity_limit_multiplier)
 188                 .map_err(ProbingError::Sending)
 189 }
 190
 191 fn expiry_time_from_unix_epoch(invoice: &Bolt11Invoice) -> Duration {
 192         invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 193 }
 194
 195 /// An error that may occur when making a payment.
 196 #[derive(Clone, Debug, PartialEq, Eq)]
 197 pub enum PaymentError {
 198         /// An error resulting from the provided [`Bolt11Invoice`] or payment hash.
 199         Invoice(&'static str),
 200         /// An error occurring when sending a payment.
 201         Sending(RetryableSendFailure),
 202 }
 203
 204 /// An error that may occur when sending a payment probe.
 205 #[derive(Clone, Debug, PartialEq, Eq)]
 206 pub enum ProbingError {
 207         /// An error resulting from the provided [`Bolt11Invoice`].
 208         Invoice(&'static str),
 209         /// An error occurring when sending a payment probe.
 210         Sending(ProbeSendFailure),
 211 }
 212
 213 /// A trait defining behavior of a [`Bolt11Invoice`] payer.
 214 ///
 215 /// Useful for unit testing internal methods.
 216 trait Payer {
 217         /// Sends a payment over the Lightning Network using the given [`Route`].
 218         ///
 219         /// [`Route`]: lightning::routing::router::Route
 220         fn send_payment(
 221                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 222                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 223         ) -> Result<(), PaymentError>;
 224 }
 225
 226 impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> Payer for ChannelManager<M, T, ES, NS, SP, F, R, L>
 227 where
 228                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 229                 T::Target: BroadcasterInterface,
 230                 ES::Target: EntropySource,
 231                 NS::Target: NodeSigner,
 232                 SP::Target: SignerProvider,
 233                 F::Target: FeeEstimator,
 234                 R::Target: Router,
 235                 L::Target: Logger,
 236 {
 237         fn send_payment(
 238                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 239                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 240         ) -> Result<(), PaymentError> {
 241                 self.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 242                         .map_err(PaymentError::Sending)
 243         }
 244 }
 245
 246 #[cfg(test)]
 247 mod tests {
 248         use super::*;
 249         use crate::{InvoiceBuilder, Currency};
 250         use bitcoin_hashes::sha256::Hash as Sha256;
 251         use lightning::events::Event;
 252         use lightning::ln::msgs::ChannelMessageHandler;
 253         use lightning::ln::{PaymentPreimage, PaymentSecret};
 254         use lightning::ln::functional_test_utils::*;
 255         use secp256k1::{SecretKey, Secp256k1};
 256         use std::collections::VecDeque;
 257         use std::time::{SystemTime, Duration};
 258
 259         struct TestPayer {
 260                 expectations: core::cell::RefCell<VecDeque<Amount>>,
 261         }
 262
 263         impl TestPayer {
 264                 fn new() -> Self {
 265                         Self {
 266                                 expectations: core::cell::RefCell::new(VecDeque::new()),
 267                         }
 268                 }
 269
 270                 fn expect_send(self, value_msat: Amount) -> Self {
 271                         self.expectations.borrow_mut().push_back(value_msat);
 272                         self
 273                 }
 274
 275                 fn check_value_msats(&self, actual_value_msats: Amount) {
 276                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
 277                         if let Some(expected_value_msats) = expected_value_msats {
 278                                 assert_eq!(actual_value_msats, expected_value_msats);
 279                         } else {
 280                                 panic!("Unexpected amount: {:?}", actual_value_msats);
 281                         }
 282                 }
 283         }
 284
 285         #[derive(Clone, Debug, PartialEq, Eq)]
 286         struct Amount(u64); // msat
 287
 288         impl Payer for TestPayer {
 289                 fn send_payment(
 290                         &self, _payment_hash: PaymentHash, _recipient_onion: RecipientOnionFields,
 291                         _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
 292                 ) -> Result<(), PaymentError> {
 293                         self.check_value_msats(Amount(route_params.final_value_msat));
 294                         Ok(())
 295                 }
 296         }
 297
 298         impl Drop for TestPayer {
 299                 fn drop(&mut self) {
 300                         if std::thread::panicking() {
 301                                 return;
 302                         }
 303
 304                         if !self.expectations.borrow().is_empty() {
 305                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
 306                         }
 307                 }
 308         }
 309
 310         fn duration_since_epoch() -> Duration {
 311                 #[cfg(feature = "std")]
 312                 let duration_since_epoch =
 313                         SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 314                 #[cfg(not(feature = "std"))]
 315                 let duration_since_epoch = Duration::from_secs(1234567);
 316                 duration_since_epoch
 317         }
 318
 319         fn invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 320                 let payment_hash = Sha256::hash(&payment_preimage.0);
 321                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 322
 323                 InvoiceBuilder::new(Currency::Bitcoin)
 324                         .description("test".into())
 325                         .payment_hash(payment_hash)
 326                         .payment_secret(PaymentSecret([0; 32]))
 327                         .duration_since_epoch(duration_since_epoch())
 328                         .min_final_cltv_expiry_delta(144)
 329                         .amount_milli_satoshis(128)
 330                         .build_signed(|hash| {
 331                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 332                         })
 333                         .unwrap()
 334         }
 335
 336         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 337                 let payment_hash = Sha256::hash(&payment_preimage.0);
 338                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 339
 340                 InvoiceBuilder::new(Currency::Bitcoin)
 341                         .description("test".into())
 342                         .payment_hash(payment_hash)
 343                         .payment_secret(PaymentSecret([0; 32]))
 344                         .duration_since_epoch(duration_since_epoch())
 345                         .min_final_cltv_expiry_delta(144)
 346                         .build_signed(|hash| {
 347                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 348                         })
 349                 .unwrap()
 350         }
 351
 352         #[test]
 353         fn pays_invoice() {
 354                 let payment_id = PaymentId([42; 32]);
 355                 let payment_preimage = PaymentPreimage([1; 32]);
 356                 let invoice = invoice(payment_preimage);
 357                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 358
 359                 let payer = TestPayer::new().expect_send(Amount(final_value_msat));
 360                 pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 361         }
 362
 363         #[test]
 364         fn pays_zero_value_invoice() {
 365                 let payment_id = PaymentId([42; 32]);
 366                 let payment_preimage = PaymentPreimage([1; 32]);
 367                 let invoice = zero_value_invoice(payment_preimage);
 368                 let amt_msat = 10_000;
 369
 370                 let payer = TestPayer::new().expect_send(Amount(amt_msat));
 371                 pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 372         }
 373
 374         #[test]
 375         fn fails_paying_zero_value_invoice_with_amount() {
 376                 let chanmon_cfgs = create_chanmon_cfgs(1);
 377                 let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 378                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 379                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 380
 381                 let payment_preimage = PaymentPreimage([1; 32]);
 382                 let invoice = invoice(payment_preimage);
 383                 let amt_msat = 10_000;
 384
 385                 match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), nodes[0].node) {
 386                         Err(PaymentError::Invoice("amount unexpected")) => {},
 387                         _ => panic!()
 388                 }
 389         }
 390
 391         #[test]
 392         #[cfg(feature = "std")]
 393         fn payment_metadata_end_to_end() {
 394                 // Test that a payment metadata read from an invoice passed to `pay_invoice` makes it all
 395                 // the way out through the `PaymentClaimable` event.
 396                 let chanmon_cfgs = create_chanmon_cfgs(2);
 397                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 398                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 399                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 400                 create_announced_chan_between_nodes(&nodes, 0, 1);
 401
 402                 let payment_metadata = vec![42, 43, 44, 45, 46, 47, 48, 49, 42];
 403
 404                 let (payment_hash, payment_secret) =
 405                         nodes[1].node.create_inbound_payment(None, 7200, None).unwrap();
 406
 407                 let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 408                         .description("test".into())
 409                         .payment_hash(Sha256::from_slice(&payment_hash.0).unwrap())
 410                         .payment_secret(payment_secret)
 411                         .current_timestamp()
 412                         .min_final_cltv_expiry_delta(144)
 413                         .amount_milli_satoshis(50_000)
 414                         .payment_metadata(payment_metadata.clone())
 415                         .build_signed(|hash| {
 416                                 Secp256k1::new().sign_ecdsa_recoverable(hash,
 417                                         &nodes[1].keys_manager.backing.get_node_secret_key())
 418                         })
 419                         .unwrap();
 420
 421                 pay_invoice(&invoice, Retry::Attempts(0), nodes[0].node).unwrap();
 422                 check_added_monitors(&nodes[0], 1);
 423                 let send_event = SendEvent::from_node(&nodes[0]);
 424                 nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_event.msgs[0]);
 425                 commitment_signed_dance!(nodes[1], nodes[0], &send_event.commitment_msg, false);
 426
 427                 expect_pending_htlcs_forwardable!(nodes[1]);
 428
 429                 let mut events = nodes[1].node.get_and_clear_pending_events();
 430                 assert_eq!(events.len(), 1);
 431                 match events.pop().unwrap() {
 432                         Event::PaymentClaimable { onion_fields, .. } => {
 433                                 assert_eq!(Some(payment_metadata), onion_fields.unwrap().payment_metadata);
 434                         },
 435                         _ => panic!("Unexpected event")
 436                 }
 437         }
 438 }