_ 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 {
 120                 payment_params,
 121                 final_value_msat: amount_msats,
 122         };
 123
 124         payer.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 125 }
 126
 127 /// Sends payment probes over all paths of a route that would be used to pay the given invoice.
 128 ///
 129 /// See [`ChannelManager::send_preflight_probes`] for more information.
 130 pub fn preflight_probe_invoice<C: AChannelManager>(
 131         invoice: &Bolt11Invoice, channelmanager: &C, liquidity_limit_multiplier: Option<u64>,
 132 ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbingError>
 133 {
 134         let amount_msat = if let Some(invoice_amount_msat) = invoice.amount_milli_satoshis() {
 135                 invoice_amount_msat
 136         } else {
 137                 return Err(ProbingError::Invoice("Failed to send probe as no amount was given in the invoice."));
 138         };
 139
 140         let mut payment_params = PaymentParameters::from_node_id(
 141                 invoice.recover_payee_pub_key(),
 142                 invoice.min_final_cltv_expiry_delta() as u32,
 143         )
 144         .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 145         .with_route_hints(invoice.route_hints())
 146         .unwrap();
 147
 148         if let Some(features) = invoice.features() {
 149                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 150         }
 151         let route_params = RouteParameters { payment_params, final_value_msat: amount_msat };
 152
 153         channelmanager.get_cm().send_preflight_probes(route_params, liquidity_limit_multiplier)
 154                 .map_err(ProbingError::Sending)
 155 }
 156
 157 /// Sends payment probes over all paths of a route that would be used to pay the given zero-value
 158 /// invoice using the given amount.
 159 ///
 160 /// See [`ChannelManager::send_preflight_probes`] for more information.
 161 pub fn preflight_probe_zero_value_invoice<C: AChannelManager>(
 162         invoice: &Bolt11Invoice, amount_msat: u64, channelmanager: &C,
 163         liquidity_limit_multiplier: Option<u64>,
 164 ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbingError>
 165 {
 166         if invoice.amount_milli_satoshis().is_some() {
 167                 return Err(ProbingError::Invoice("amount unexpected"));
 168         }
 169
 170         let mut payment_params = PaymentParameters::from_node_id(
 171                 invoice.recover_payee_pub_key(),
 172                 invoice.min_final_cltv_expiry_delta() as u32,
 173         )
 174         .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 175         .with_route_hints(invoice.route_hints())
 176         .unwrap();
 177
 178         if let Some(features) = invoice.features() {
 179                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 180         }
 181         let route_params = RouteParameters { payment_params, final_value_msat: amount_msat };
 182
 183         channelmanager.get_cm().send_preflight_probes(route_params, liquidity_limit_multiplier)
 184                 .map_err(ProbingError::Sending)
 185 }
 186
 187 fn expiry_time_from_unix_epoch(invoice: &Bolt11Invoice) -> Duration {
 188         invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 189 }
 190
 191 /// An error that may occur when making a payment.
 192 #[derive(Clone, Debug, PartialEq, Eq)]
 193 pub enum PaymentError {
 194         /// An error resulting from the provided [`Bolt11Invoice`] or payment hash.
 195         Invoice(&'static str),
 196         /// An error occurring when sending a payment.
 197         Sending(RetryableSendFailure),
 198 }
 199
 200 /// An error that may occur when sending a payment probe.
 201 #[derive(Clone, Debug, PartialEq, Eq)]
 202 pub enum ProbingError {
 203         /// An error resulting from the provided [`Bolt11Invoice`].
 204         Invoice(&'static str),
 205         /// An error occurring when sending a payment probe.
 206         Sending(ProbeSendFailure),
 207 }
 208
 209 /// A trait defining behavior of a [`Bolt11Invoice`] payer.
 210 ///
 211 /// Useful for unit testing internal methods.
 212 trait Payer {
 213         /// Sends a payment over the Lightning Network using the given [`Route`].
 214         ///
 215         /// [`Route`]: lightning::routing::router::Route
 216         fn send_payment(
 217                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 218                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 219         ) -> Result<(), PaymentError>;
 220 }
 221
 222 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>
 223 where
 224                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 225                 T::Target: BroadcasterInterface,
 226                 ES::Target: EntropySource,
 227                 NS::Target: NodeSigner,
 228                 SP::Target: SignerProvider,
 229                 F::Target: FeeEstimator,
 230                 R::Target: Router,
 231                 L::Target: Logger,
 232 {
 233         fn send_payment(
 234                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 235                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 236         ) -> Result<(), PaymentError> {
 237                 self.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 238                         .map_err(PaymentError::Sending)
 239         }
 240 }
 241
 242 #[cfg(test)]
 243 mod tests {
 244         use super::*;
 245         use crate::{InvoiceBuilder, Currency};
 246         use bitcoin_hashes::sha256::Hash as Sha256;
 247         use lightning::events::Event;
 248         use lightning::ln::msgs::ChannelMessageHandler;
 249         use lightning::ln::{PaymentPreimage, PaymentSecret};
 250         use lightning::ln::functional_test_utils::*;
 251         use secp256k1::{SecretKey, Secp256k1};
 252         use std::collections::VecDeque;
 253         use std::time::{SystemTime, Duration};
 254
 255         struct TestPayer {
 256                 expectations: core::cell::RefCell<VecDeque<Amount>>,
 257         }
 258
 259         impl TestPayer {
 260                 fn new() -> Self {
 261                         Self {
 262                                 expectations: core::cell::RefCell::new(VecDeque::new()),
 263                         }
 264                 }
 265
 266                 fn expect_send(self, value_msat: Amount) -> Self {
 267                         self.expectations.borrow_mut().push_back(value_msat);
 268                         self
 269                 }
 270
 271                 fn check_value_msats(&self, actual_value_msats: Amount) {
 272                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
 273                         if let Some(expected_value_msats) = expected_value_msats {
 274                                 assert_eq!(actual_value_msats, expected_value_msats);
 275                         } else {
 276                                 panic!("Unexpected amount: {:?}", actual_value_msats);
 277                         }
 278                 }
 279         }
 280
 281         #[derive(Clone, Debug, PartialEq, Eq)]
 282         struct Amount(u64); // msat
 283
 284         impl Payer for TestPayer {
 285                 fn send_payment(
 286                         &self, _payment_hash: PaymentHash, _recipient_onion: RecipientOnionFields,
 287                         _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
 288                 ) -> Result<(), PaymentError> {
 289                         self.check_value_msats(Amount(route_params.final_value_msat));
 290                         Ok(())
 291                 }
 292         }
 293
 294         impl Drop for TestPayer {
 295                 fn drop(&mut self) {
 296                         if std::thread::panicking() {
 297                                 return;
 298                         }
 299
 300                         if !self.expectations.borrow().is_empty() {
 301                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
 302                         }
 303                 }
 304         }
 305
 306         fn duration_since_epoch() -> Duration {
 307                 #[cfg(feature = "std")]
 308                 let duration_since_epoch =
 309                         SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 310                 #[cfg(not(feature = "std"))]
 311                 let duration_since_epoch = Duration::from_secs(1234567);
 312                 duration_since_epoch
 313         }
 314
 315         fn invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 316                 let payment_hash = Sha256::hash(&payment_preimage.0);
 317                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 318
 319                 InvoiceBuilder::new(Currency::Bitcoin)
 320                         .description("test".into())
 321                         .payment_hash(payment_hash)
 322                         .payment_secret(PaymentSecret([0; 32]))
 323                         .duration_since_epoch(duration_since_epoch())
 324                         .min_final_cltv_expiry_delta(144)
 325                         .amount_milli_satoshis(128)
 326                         .build_signed(|hash| {
 327                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 328                         })
 329                         .unwrap()
 330         }
 331
 332         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 333                 let payment_hash = Sha256::hash(&payment_preimage.0);
 334                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 335
 336                 InvoiceBuilder::new(Currency::Bitcoin)
 337                         .description("test".into())
 338                         .payment_hash(payment_hash)
 339                         .payment_secret(PaymentSecret([0; 32]))
 340                         .duration_since_epoch(duration_since_epoch())
 341                         .min_final_cltv_expiry_delta(144)
 342                         .build_signed(|hash| {
 343                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 344                         })
 345                 .unwrap()
 346         }
 347
 348         #[test]
 349         fn pays_invoice() {
 350                 let payment_id = PaymentId([42; 32]);
 351                 let payment_preimage = PaymentPreimage([1; 32]);
 352                 let invoice = invoice(payment_preimage);
 353                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 354
 355                 let payer = TestPayer::new().expect_send(Amount(final_value_msat));
 356                 pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 357         }
 358
 359         #[test]
 360         fn pays_zero_value_invoice() {
 361                 let payment_id = PaymentId([42; 32]);
 362                 let payment_preimage = PaymentPreimage([1; 32]);
 363                 let invoice = zero_value_invoice(payment_preimage);
 364                 let amt_msat = 10_000;
 365
 366                 let payer = TestPayer::new().expect_send(Amount(amt_msat));
 367                 pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 368         }
 369
 370         #[test]
 371         fn fails_paying_zero_value_invoice_with_amount() {
 372                 let chanmon_cfgs = create_chanmon_cfgs(1);
 373                 let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 374                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 375                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 376
 377                 let payment_preimage = PaymentPreimage([1; 32]);
 378                 let invoice = invoice(payment_preimage);
 379                 let amt_msat = 10_000;
 380
 381                 match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), nodes[0].node) {
 382                         Err(PaymentError::Invoice("amount unexpected")) => {},
 383                         _ => panic!()
 384                 }
 385         }
 386
 387         #[test]
 388         #[cfg(feature = "std")]
 389         fn payment_metadata_end_to_end() {
 390                 // Test that a payment metadata read from an invoice passed to `pay_invoice` makes it all
 391                 // the way out through the `PaymentClaimable` event.
 392                 let chanmon_cfgs = create_chanmon_cfgs(2);
 393                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 394                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 395                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 396                 create_announced_chan_between_nodes(&nodes, 0, 1);
 397
 398                 let payment_metadata = vec![42, 43, 44, 45, 46, 47, 48, 49, 42];
 399
 400                 let (payment_hash, payment_secret) =
 401                         nodes[1].node.create_inbound_payment(None, 7200, None).unwrap();
 402
 403                 let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 404                         .description("test".into())
 405                         .payment_hash(Sha256::from_slice(&payment_hash.0).unwrap())
 406                         .payment_secret(payment_secret)
 407                         .current_timestamp()
 408                         .min_final_cltv_expiry_delta(144)
 409                         .amount_milli_satoshis(50_000)
 410                         .payment_metadata(payment_metadata.clone())
 411                         .build_signed(|hash| {
 412                                 Secp256k1::new().sign_ecdsa_recoverable(hash,
 413                                         &nodes[1].keys_manager.backing.get_node_secret_key())
 414                         })
 415                         .unwrap();
 416
 417                 pay_invoice(&invoice, Retry::Attempts(0), nodes[0].node).unwrap();
 418                 check_added_monitors(&nodes[0], 1);
 419                 let send_event = SendEvent::from_node(&nodes[0]);
 420                 nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_event.msgs[0]);
 421                 commitment_signed_dance!(nodes[1], nodes[0], &send_event.commitment_msg, false);
 422
 423                 expect_pending_htlcs_forwardable!(nodes[1]);
 424
 425                 let mut events = nodes[1].node.get_and_clear_pending_events();
 426                 assert_eq!(events.len(), 1);
 427                 match events.pop().unwrap() {
 428                         Event::PaymentClaimable { onion_fields, .. } => {
 429                                 assert_eq!(Some(payment_metadata), onion_fields.unwrap().payment_metadata);
 430                         },
 431                         _ => panic!("Unexpected event")
 432                 }
 433         }
 434 }