Merge pull request #1208 from TheBlueMatt/2021-12-less-force-close
[rust-lightning] / lightning-invoice / src / payment.rs
index 4099afbaa4c74b60e0427755f5dd0f42dbf9ab77..e785bb39264130a4895a25fd663e1b42560fd665 100644 (file)
 //! and payee using information provided by the payer and from the payee's [`Invoice`], when
 //! applicable.
 //!
+//! [`InvoicePayer`] is parameterized by a [`LockableScore`], which it uses for scoring failed and
+//! successful payment paths upon receiving [`Event::PaymentPathFailed`] and
+//! [`Event::PaymentPathSuccessful`] events, respectively.
+//!
 //! [`InvoicePayer`] is capable of retrying failed payments. It accomplishes this by implementing
 //! [`EventHandler`] which decorates a user-provided handler. It will intercept any
 //! [`Event::PaymentPathFailed`] events and retry the failed paths for a fixed number of total
 //! # use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 //! # use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
 //! # use lightning::ln::msgs::LightningError;
-//! # use lightning::routing;
+//! # use lightning::routing::scoring::Score;
 //! # use lightning::routing::network_graph::NodeId;
 //! # use lightning::routing::router::{Route, RouteHop, RouteParameters};
 //! # use lightning::util::events::{Event, EventHandler, EventsProvider};
 //! # use lightning::util::logger::{Logger, Record};
+//! # use lightning::util::ser::{Writeable, Writer};
 //! # use lightning_invoice::Invoice;
 //! # use lightning_invoice::payment::{InvoicePayer, Payer, RetryAttempts, Router};
 //! # use secp256k1::key::PublicKey;
 //! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
 //! # }
 //! #
-//! # struct FakeRouter {};
-//! # impl<S: routing::Score> Router<S> for FakeRouter {
+//! # struct FakeRouter {}
+//! # impl<S: Score> Router<S> for FakeRouter {
 //! #     fn find_route(
 //! #         &self, payer: &PublicKey, params: &RouteParameters, payment_hash: &PaymentHash,
 //! #         first_hops: Option<&[&ChannelDetails]>, scorer: &S
 //! #     ) -> Result<Route, LightningError> { unimplemented!() }
 //! # }
 //! #
-//! # struct FakeScorer {};
-//! # impl routing::Score for FakeScorer {
+//! # struct FakeScorer {}
+//! # impl Writeable for FakeScorer {
+//! #     fn write<W: Writer>(&self, w: &mut W) -> Result<(), std::io::Error> { unimplemented!(); }
+//! # }
+//! # impl Score for FakeScorer {
 //! #     fn channel_penalty_msat(
 //! #         &self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId
 //! #     ) -> u64 { 0 }
 //! #     fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+//! #     fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
 //! # }
 //! #
-//! # struct FakeLogger {};
+//! # struct FakeLogger {}
 //! # impl Logger for FakeLogger {
 //! #     fn log(&self, record: &Record) { unimplemented!() }
 //! # }
 //! let invoice_payer = InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
 //!
 //! let invoice = "...";
-//! let invoice = invoice.parse::<Invoice>().unwrap();
-//! invoice_payer.pay_invoice(&invoice).unwrap();
+//! if let Ok(invoice) = invoice.parse::<Invoice>() {
+//!     invoice_payer.pay_invoice(&invoice).unwrap();
 //!
 //! # let event_provider = FakeEventProvider {};
-//! loop {
-//!     event_provider.process_pending_events(&invoice_payer);
+//!     loop {
+//!         event_provider.process_pending_events(&invoice_payer);
+//!     }
 //! }
 //! # }
 //! ```
@@ -122,8 +132,7 @@ use bitcoin_hashes::sha256::Hash as Sha256;
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
 use lightning::ln::msgs::LightningError;
-use lightning::routing;
-use lightning::routing::{LockableScore, Score};
+use lightning::routing::scoring::{LockableScore, Score};
 use lightning::routing::router::{Payee, Route, RouteParameters};
 use lightning::util::events::{Event, EventHandler};
 use lightning::util::logger::Logger;
@@ -136,11 +145,15 @@ use std::sync::Mutex;
 use std::time::{Duration, SystemTime};
 
 /// A utility for paying [`Invoice`]s and sending spontaneous payments.
+///
+/// See [module-level documentation] for details.
+///
+/// [module-level documentation]: crate::payment
 pub struct InvoicePayer<P: Deref, R, S: Deref, L: Deref, E>
 where
        P::Target: Payer,
-       R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
-       S::Target: for <'a> routing::LockableScore<'a>,
+       R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
+       S::Target: for <'a> LockableScore<'a>,
        L::Target: Logger,
        E: EventHandler,
 {
@@ -177,7 +190,7 @@ pub trait Payer {
 }
 
 /// A trait defining behavior for routing an [`Invoice`] payment.
-pub trait Router<S: routing::Score> {
+pub trait Router<S: Score> {
        /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
        fn find_route(
                &self, payer: &PublicKey, params: &RouteParameters, payment_hash: &PaymentHash,
@@ -207,8 +220,8 @@ pub enum PaymentError {
 impl<P: Deref, R, S: Deref, L: Deref, E> InvoicePayer<P, R, S, L, E>
 where
        P::Target: Payer,
-       R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
-       S::Target: for <'a> routing::LockableScore<'a>,
+       R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
+       S::Target: for <'a> LockableScore<'a>,
        L::Target: Logger,
        E: EventHandler,
 {
@@ -441,8 +454,8 @@ fn has_expired(params: &RouteParameters) -> bool {
 impl<P: Deref, R, S: Deref, L: Deref, E> EventHandler for InvoicePayer<P, R, S, L, E>
 where
        P::Target: Payer,
-       R: for <'a> Router<<<S as Deref>::Target as routing::LockableScore<'a>>::Locked>,
-       S::Target: for <'a> routing::LockableScore<'a>,
+       R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
+       S::Target: for <'a> LockableScore<'a>,
        L::Target: Logger,
        E: EventHandler,
 {
@@ -470,6 +483,10 @@ where
 
                                if *all_paths_failed { self.payment_cache.lock().unwrap().remove(payment_hash); }
                        },
+                       Event::PaymentPathSuccessful { path, .. } => {
+                               let path = path.iter().collect::<Vec<_>>();
+                               self.scorer.lock().payment_path_successful(&path);
+                       },
                        Event::PaymentSent { payment_hash, .. } => {
                                let mut payment_cache = self.payment_cache.lock().unwrap();
                                let attempts = payment_cache
@@ -1124,7 +1141,9 @@ mod tests {
                        .expect_send(Amount::ForInvoice(final_value_msat))
                        .expect_send(Amount::OnRetry(final_value_msat / 2));
                let router = TestRouter {};
-               let scorer = RefCell::new(TestScorer::new().expect_channel_failure(short_channel_id.unwrap()));
+               let scorer = RefCell::new(TestScorer::new().expect(PaymentPath::Failure {
+                       path: path.clone(), short_channel_id: path[0].short_channel_id,
+               }));
                let logger = TestLogger::new();
                let invoice_payer =
                        InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
@@ -1143,6 +1162,39 @@ mod tests {
                invoice_payer.handle_event(&event);
        }
 
+       #[test]
+       fn scores_successful_channels() {
+               let event_handled = core::cell::RefCell::new(false);
+               let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
+
+               let payment_preimage = PaymentPreimage([1; 32]);
+               let invoice = invoice(payment_preimage);
+               let payment_hash = Some(PaymentHash(invoice.payment_hash().clone().into_inner()));
+               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
+               let route = TestRouter::route_for_value(final_value_msat);
+
+               // Expect that scorer is given short_channel_id upon handling the event.
+               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
+               let router = TestRouter {};
+               let scorer = RefCell::new(TestScorer::new()
+                       .expect(PaymentPath::Success { path: route.paths[0].clone() })
+                       .expect(PaymentPath::Success { path: route.paths[1].clone() })
+               );
+               let logger = TestLogger::new();
+               let invoice_payer =
+                       InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+
+               let payment_id = invoice_payer.pay_invoice(&invoice).unwrap();
+               let event = Event::PaymentPathSuccessful {
+                       payment_id, payment_hash, path: route.paths[0].clone()
+               };
+               invoice_payer.handle_event(&event);
+               let event = Event::PaymentPathSuccessful {
+                       payment_id, payment_hash, path: route.paths[1].clone()
+               };
+               invoice_payer.handle_event(&event);
+       }
+
        struct TestRouter;
 
        impl TestRouter {
@@ -1186,7 +1238,7 @@ mod tests {
                }
        }
 
-       impl<S: routing::Score> Router<S> for TestRouter {
+       impl<S: Score> Router<S> for TestRouter {
                fn find_route(
                        &self, _payer: &PublicKey, params: &RouteParameters, _payment_hash: &PaymentHash,
                        _first_hops: Option<&[&ChannelDetails]>, _scorer: &S
@@ -1199,7 +1251,7 @@ mod tests {
 
        struct FailingRouter;
 
-       impl<S: routing::Score> Router<S> for FailingRouter {
+       impl<S: Score> Router<S> for FailingRouter {
                fn find_route(
                        &self, _payer: &PublicKey, _params: &RouteParameters, _payment_hash: &PaymentHash,
                        _first_hops: Option<&[&ChannelDetails]>, _scorer: &S
@@ -1209,30 +1261,64 @@ mod tests {
        }
 
        struct TestScorer {
-               expectations: VecDeque<u64>,
+               expectations: Option<VecDeque<PaymentPath>>,
+       }
+
+       #[derive(Debug)]
+       enum PaymentPath {
+               Failure { path: Vec<RouteHop>, short_channel_id: u64 },
+               Success { path: Vec<RouteHop> },
        }
 
        impl TestScorer {
                fn new() -> Self {
                        Self {
-                               expectations: VecDeque::new(),
+                               expectations: None,
                        }
                }
 
-               fn expect_channel_failure(mut self, short_channel_id: u64) -> Self {
-                       self.expectations.push_back(short_channel_id);
+               fn expect(mut self, expectation: PaymentPath) -> Self {
+                       self.expectations.get_or_insert_with(|| VecDeque::new()).push_back(expectation);
                        self
                }
        }
 
-       impl routing::Score for TestScorer {
+       #[cfg(c_bindings)]
+       impl lightning::util::ser::Writeable for TestScorer {
+               fn write<W: lightning::util::ser::Writer>(&self, _: &mut W) -> Result<(), std::io::Error> { unreachable!(); }
+       }
+
+       impl Score for TestScorer {
                fn channel_penalty_msat(
                        &self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId
                ) -> u64 { 0 }
 
-               fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
-                       if let Some(expected_short_channel_id) = self.expectations.pop_front() {
-                               assert_eq!(short_channel_id, expected_short_channel_id);
+               fn payment_path_failed(&mut self, actual_path: &[&RouteHop], actual_short_channel_id: u64) {
+                       if let Some(expectations) = &mut self.expectations {
+                               match expectations.pop_front() {
+                                       Some(PaymentPath::Failure { path, short_channel_id }) => {
+                                               assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
+                                               assert_eq!(actual_short_channel_id, short_channel_id);
+                                       },
+                                       Some(PaymentPath::Success { path }) => {
+                                               panic!("Unexpected successful payment path: {:?}", path)
+                                       },
+                                       None => panic!("Unexpected payment_path_failed call: {:?}", actual_path),
+                               }
+                       }
+               }
+
+               fn payment_path_successful(&mut self, actual_path: &[&RouteHop]) {
+                       if let Some(expectations) = &mut self.expectations {
+                               match expectations.pop_front() {
+                                       Some(PaymentPath::Failure { path, .. }) => {
+                                               panic!("Unexpected payment path failure: {:?}", path)
+                                       },
+                                       Some(PaymentPath::Success { path }) => {
+                                               assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
+                                       },
+                                       None => panic!("Unexpected payment_path_successful call: {:?}", actual_path),
+                               }
                        }
                }
        }
@@ -1243,8 +1329,10 @@ mod tests {
                                return;
                        }
 
-                       if !self.expectations.is_empty() {
-                               panic!("Unsatisfied channel failure expectations: {:?}", self.expectations);
+                       if let Some(expectations) = &self.expectations {
+                               if !expectations.is_empty() {
+                                       panic!("Unsatisfied scorer expectations: {:?}", expectations);
+                               }
                        }
                }
        }
@@ -1364,7 +1452,7 @@ mod tests {
        // *** Full Featured Functional Tests with a Real ChannelManager ***
        struct ManualRouter(RefCell<VecDeque<Result<Route, LightningError>>>);
 
-       impl<S: routing::Score> Router<S> for ManualRouter {
+       impl<S: Score> Router<S> for ManualRouter {
                fn find_route(
                        &self, _payer: &PublicKey, _params: &RouteParameters, _payment_hash: &PaymentHash,
                        _first_hops: Option<&[&ChannelDetails]>, _scorer: &S