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