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