Support spontaneous payment retries in ChannelManager
[rust-lightning] / lightning / src / ln / channelmanager.rs
index db326a2ecb5880ce5f5fe0636f6799c47d9d38ab..1b8d03a87a023dcbcaef334a76e9310c8d519cbd 100644 (file)
@@ -45,7 +45,7 @@ use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, No
 #[cfg(any(feature = "_test_utils", test))]
 use crate::ln::features::InvoiceFeatures;
 use crate::routing::gossip::NetworkGraph;
-use crate::routing::router::{DefaultRouter, InFlightHtlcs, PaymentParameters, Route, RouteHop, RoutePath, Router};
+use crate::routing::router::{DefaultRouter, InFlightHtlcs, PaymentParameters, Route, RouteHop, RouteParameters, RoutePath, Router};
 use crate::routing::scoring::ProbabilisticScorer;
 use crate::ln::msgs;
 use crate::ln::onion_utils;
@@ -53,9 +53,9 @@ use crate::ln::onion_utils::HTLCFailReason;
 use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError, MAX_VALUE_MSAT};
 #[cfg(test)]
 use crate::ln::outbound_payment;
-use crate::ln::outbound_payment::{OutboundPayments, PendingOutboundPayment};
+use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, Retry};
 use crate::ln::wire::Encode;
-use crate::chain::keysinterface::{EntropySource, KeysManager, NodeSigner, Recipient, Sign, SignerProvider};
+use crate::chain::keysinterface::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, ChannelSigner};
 use crate::util::config::{UserConfig, ChannelConfig};
 use crate::util::events::{Event, EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
 use crate::util::events;
@@ -245,6 +245,10 @@ pub(crate) enum HTLCSource {
                first_hop_htlc_msat: u64,
                payment_id: PaymentId,
                payment_secret: Option<PaymentSecret>,
+               /// Note that this is now "deprecated" - we write it for forwards (and read it for
+               /// backwards) compatibility reasons, but prefer to use the data in the
+               /// [`super::outbound_payment`] module, which stores per-payment data once instead of in
+               /// each HTLC.
                payment_params: Option<PaymentParameters>,
        },
 }
@@ -289,6 +293,25 @@ struct ReceiveError {
        msg: &'static str,
 }
 
+/// This enum is used to specify which error data to send to peers when failing back an HTLC
+/// using [`ChannelManager::fail_htlc_backwards_with_reason`].
+///
+/// For more info on failure codes, see <https://github.com/lightning/bolts/blob/master/04-onion-routing.md#failure-messages>.
+#[derive(Clone, Copy)]
+pub enum FailureCode {
+       /// We had a temporary error processing the payment. Useful if no other error codes fit
+       /// and you want to indicate that the payer may want to retry.
+       TemporaryNodeFailure             = 0x2000 | 2,
+       /// We have a required feature which was not in this onion. For example, you may require
+       /// some additional metadata that was not provided with this payment.
+       RequiredNodeFeatureMissing       = 0x4000 | 0x2000 | 3,
+       /// You may wish to use this when a `payment_preimage` is unknown, or the CLTV expiry of
+       /// the HTLC is too close to the current block height for safe handling.
+       /// Using this failure code in [`ChannelManager::fail_htlc_backwards_with_reason`] is
+       /// equivalent to calling [`ChannelManager::fail_htlc_backwards`].
+       IncorrectOrUnknownPaymentDetails = 0x4000 | 15,
+}
+
 type ShutdownResult = (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash, PublicKey, [u8; 32])>);
 
 /// Error type returned across the peer_state mutex boundary. When an Err is generated for a
@@ -388,7 +411,7 @@ impl MsgHandleErrInternal {
 /// Event::PendingHTLCsForwardable for the API guidelines indicating how long should be waited).
 /// This provides some limited amount of privacy. Ideally this would range from somewhere like one
 /// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
-const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
+pub(super) const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
 
 /// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
 /// be sent in the order they appear in the return value, however sometimes the order needs to be
@@ -452,7 +475,7 @@ pub(crate) enum MonitorUpdateCompletionAction {
 }
 
 /// State we hold per-peer.
-pub(super) struct PeerState<Signer: Sign> {
+pub(super) struct PeerState<Signer: ChannelSigner> {
        /// `temporary_channel_id` or `channel_id` -> `channel`.
        ///
        /// Holds all channels where the peer is the counterparty. Once a channel has been assigned a
@@ -2447,6 +2470,18 @@ where
                                self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
+       /// Similar to [`ChannelManager::send_payment`], but will automatically find a route based on
+       /// `route_params` and retry failed payment paths based on `retry_strategy`.
+       pub fn send_payment_with_retry(&self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<(), PaymentSendFailure> {
+               let best_block_height = self.best_block.read().unwrap().height();
+               self.pending_outbound_payments
+                       .send_payment(payment_hash, payment_secret, payment_id, retry_strategy, route_params,
+                               &self.router, self.list_usable_channels(), self.compute_inflight_htlcs(),
+                               &self.entropy_source, &self.node_signer, best_block_height, &self.logger,
+                               |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                               self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+       }
+
        #[cfg(test)]
        fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
@@ -2458,7 +2493,7 @@ where
        #[cfg(test)]
        pub(crate) fn test_add_new_pending_payment(&self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId, route: &Route) -> Result<Vec<[u8; 32]>, PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
-               self.pending_outbound_payments.test_add_new_pending_payment(payment_hash, payment_secret, payment_id, route, &self.entropy_source, best_block_height)
+               self.pending_outbound_payments.test_add_new_pending_payment(payment_hash, payment_secret, payment_id, route, None, &self.entropy_source, best_block_height)
        }
 
 
@@ -2523,7 +2558,21 @@ where
        /// [`send_payment`]: Self::send_payment
        pub fn send_spontaneous_payment(&self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId) -> Result<PaymentHash, PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
-               self.pending_outbound_payments.send_spontaneous_payment(route, payment_preimage, payment_id, &self.entropy_source, &self.node_signer, best_block_height,
+               self.pending_outbound_payments.send_spontaneous_payment_with_route(
+                       route, payment_preimage, payment_id, &self.entropy_source, &self.node_signer,
+                       best_block_height,
+                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+       }
+
+       /// Similar to [`ChannelManager::send_spontaneous_payment`], but will automatically find a route
+       /// based on `route_params` and retry failed payment paths based on `retry_strategy`.
+       pub fn send_spontaneous_payment_with_retry(&self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<PaymentHash, PaymentSendFailure> {
+               let best_block_height = self.best_block.read().unwrap().height();
+               self.pending_outbound_payments.send_spontaneous_payment(payment_preimage, payment_id,
+                       retry_strategy, route_params, &self.router, self.list_usable_channels(),
+                       self.compute_inflight_htlcs(),  &self.entropy_source, &self.node_signer, best_block_height,
+                       &self.logger,
                        |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
                        self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
@@ -3261,6 +3310,12 @@ where
                        }
                }
 
+               let best_block_height = self.best_block.read().unwrap().height();
+               self.pending_outbound_payments.check_retry_payments(&self.router, || self.list_usable_channels(),
+                       || self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer, best_block_height, &self.logger,
+                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv));
+
                for (htlc_source, payment_hash, failure_reason, destination) in failed_forwards.drain(..) {
                        self.fail_htlc_backwards_internal(&htlc_source, &payment_hash, &failure_reason, destination);
                }
@@ -3483,21 +3538,40 @@ where
        /// [`events::Event::PaymentClaimed`] events even for payments you intend to fail, especially on
        /// startup during which time claims that were in-progress at shutdown may be replayed.
        pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash) {
+               self.fail_htlc_backwards_with_reason(payment_hash, &FailureCode::IncorrectOrUnknownPaymentDetails);
+       }
+
+       /// This is a variant of [`ChannelManager::fail_htlc_backwards`] that allows you to specify the
+       /// reason for the failure.
+       ///
+       /// See [`FailureCode`] for valid failure codes.
+       pub fn fail_htlc_backwards_with_reason(&self, payment_hash: &PaymentHash, failure_code: &FailureCode) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
                let removed_source = self.claimable_payments.lock().unwrap().claimable_htlcs.remove(payment_hash);
                if let Some((_, mut sources)) = removed_source {
                        for htlc in sources.drain(..) {
-                               let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
-                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               let reason = self.get_htlc_fail_reason_from_failure_code(failure_code, &htlc);
                                let source = HTLCSource::PreviousHopData(htlc.prev_hop);
-                               let reason = HTLCFailReason::reason(0x4000 | 15, htlc_msat_height_data);
                                let receiver = HTLCDestination::FailedPayment { payment_hash: *payment_hash };
                                self.fail_htlc_backwards_internal(&source, &payment_hash, &reason, receiver);
                        }
                }
        }
 
+       /// Gets error data to form an [`HTLCFailReason`] given a [`FailureCode`] and [`ClaimableHTLC`].
+       fn get_htlc_fail_reason_from_failure_code(&self, failure_code: &FailureCode, htlc: &ClaimableHTLC) -> HTLCFailReason {
+               match failure_code {
+                       FailureCode::TemporaryNodeFailure => HTLCFailReason::from_failure_code(*failure_code as u16),
+                       FailureCode::RequiredNodeFeatureMissing => HTLCFailReason::from_failure_code(*failure_code as u16),
+                       FailureCode::IncorrectOrUnknownPaymentDetails => {
+                               let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
+                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               HTLCFailReason::reason(*failure_code as u16, htlc_msat_height_data)
+                       }
+               }
+       }
+
        /// Gets an HTLC onion failure code and error data for an `UPDATE` error, given the error code
        /// that we want to return and a channel.
        ///
@@ -5730,8 +5804,8 @@ where
                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                        let peer_state = &mut *peer_state_lock;
                        for chan in peer_state.channel_by_id.values() {
-                               if let (Some(funding_txo), block_hash) = (chan.get_funding_txo(), chan.get_funding_tx_confirmed_in()) {
-                                       res.push((funding_txo.txid, block_hash));
+                               if let (Some(funding_txo), Some(block_hash)) = (chan.get_funding_txo(), chan.get_funding_tx_confirmed_in()) {
+                                       res.push((funding_txo.txid, Some(block_hash)));
                                }
                        }
                }
@@ -7301,9 +7375,13 @@ where
                                                                hash_map::Entry::Vacant(entry) => {
                                                                        let path_fee = path.get_path_fees();
                                                                        entry.insert(PendingOutboundPayment::Retryable {
+                                                                               retry_strategy: None,
+                                                                               attempts: PaymentAttempts::new(),
+                                                                               payment_params: None,
                                                                                session_privs: [session_priv_bytes].iter().map(|a| *a).collect(),
                                                                                payment_hash: htlc.payment_hash,
                                                                                payment_secret,
+                                                                               keysend_preimage: None, // only used for retries, and we'll never retry on startup
                                                                                pending_amt_msat: path_amt,
                                                                                pending_fee_msat: Some(path_fee),
                                                                                total_msat: path_amt,
@@ -7812,7 +7890,7 @@ mod tests {
 
                // Next, attempt a keysend payment and make sure it fails.
                let route_params = RouteParameters {
-                       payment_params: PaymentParameters::for_keysend(expected_route.last().unwrap().node.get_our_node_id()),
+                       payment_params: PaymentParameters::for_keysend(expected_route.last().unwrap().node.get_our_node_id(), TEST_FINAL_CLTV),
                        final_value_msat: 100_000,
                        final_cltv_expiry_delta: TEST_FINAL_CLTV,
                };
@@ -7905,7 +7983,7 @@ mod tests {
 
                let _chan = create_chan_between_nodes(&nodes[0], &nodes[1]);
                let route_params = RouteParameters {
-                       payment_params: PaymentParameters::for_keysend(payee_pubkey),
+                       payment_params: PaymentParameters::for_keysend(payee_pubkey, 40),
                        final_value_msat: 10_000,
                        final_cltv_expiry_delta: 40,
                };
@@ -7950,7 +8028,7 @@ mod tests {
 
                let _chan = create_chan_between_nodes(&nodes[0], &nodes[1]);
                let route_params = RouteParameters {
-                       payment_params: PaymentParameters::for_keysend(payee_pubkey),
+                       payment_params: PaymentParameters::for_keysend(payee_pubkey, 40),
                        final_value_msat: 10_000,
                        final_cltv_expiry_delta: 40,
                };
@@ -8515,7 +8593,7 @@ pub mod bench {
                macro_rules! send_payment {
                        ($node_a: expr, $node_b: expr) => {
                                let usable_channels = $node_a.list_usable_channels();
-                               let payment_params = PaymentParameters::from_node_id($node_b.get_our_node_id())
+                               let payment_params = PaymentParameters::from_node_id($node_b.get_our_node_id(), TEST_FINAL_CLTV)
                                        .with_features($node_b.invoice_features());
                                let scorer = test_utils::TestScorer::with_penalty(0);
                                let seed = [3u8; 32];