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