Replace Vec<RouteHop> with new Path struct
[rust-lightning] / lightning / src / events / mod.rs
index 18d2929178f7f1b7a6b44c3c926d2e8a42c62d6f..dc066b1e78e228eeb9766e647c0fd65241a37d5e 100644 (file)
@@ -30,7 +30,7 @@ use crate::routing::gossip::NetworkUpdate;
 use crate::util::errors::APIError;
 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, RequiredWrapper, UpgradableRequired, WithoutLength};
 use crate::util::string::UntrustedString;
-use crate::routing::router::{RouteHop, RouteParameters};
+use crate::routing::router::{Path, RouteHop, RouteParameters};
 
 use bitcoin::{PackedLockTime, Transaction, OutPoint};
 #[cfg(anchors)]
@@ -232,8 +232,11 @@ pub enum HTLCDestination {
        ///
        /// Some of the reasons may include:
        /// * HTLC Timeouts
-       /// * Expected MPP amount has already been reached
-       /// * Claimable amount does not match expected amount
+       /// * Excess HTLCs for a payment that we have already fully received, over-paying for the
+       ///   payment,
+       /// * The counterparty node modified the HTLC in transit,
+       /// * A probing attack where an intermediary node is trying to detect if we are the ultimate
+       ///   recipient for a payment.
        FailedPayment {
                /// The payment hash of the payment we attempted to process.
                payment_hash: PaymentHash
@@ -272,6 +275,43 @@ impl_writeable_tlv_based_enum!(InterceptNextHop,
        };
 );
 
+/// The reason the payment failed. Used in [`Event::PaymentFailed`].
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum PaymentFailureReason {
+       /// The intended recipient rejected our payment.
+       RecipientRejected,
+       /// The user chose to abandon this payment by calling [`ChannelManager::abandon_payment`].
+       ///
+       /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
+       UserAbandoned,
+       /// We exhausted all of our retry attempts while trying to send the payment, or we
+       /// exhausted the [`Retry::Timeout`] if the user set one. If at any point a retry
+       /// attempt failed while being forwarded along the path, an [`Event::PaymentPathFailed`] will
+       /// have come before this.
+       ///
+       /// [`Retry::Timeout`]: crate::ln::channelmanager::Retry::Timeout
+       RetriesExhausted,
+       /// The payment expired while retrying, based on the provided
+       /// [`PaymentParameters::expiry_time`].
+       ///
+       /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
+       PaymentExpired,
+       /// We failed to find a route while retrying the payment.
+       RouteNotFound,
+       /// This error should generally never happen. This likely means that there is a problem with
+       /// your router.
+       UnexpectedError,
+}
+
+impl_writeable_tlv_based_enum!(PaymentFailureReason,
+       (0, RecipientRejected) => {},
+       (2, UserAbandoned) => {},
+       (4, RetriesExhausted) => {},
+       (6, PaymentExpired) => {},
+       (8, RouteNotFound) => {},
+       (10, UnexpectedError) => {}, ;
+);
+
 /// An Event which you should probably take some action in response to.
 ///
 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
@@ -443,6 +483,9 @@ pub enum Event {
                ///
                /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
                payment_hash: PaymentHash,
+               /// The reason the payment failed. This is only `None` for events generated or serialized
+               /// by versions prior to 0.0.115.
+               reason: Option<PaymentFailureReason>,
        },
        /// Indicates that a path for an outbound payment was successful.
        ///
@@ -460,7 +503,7 @@ pub enum Event {
                /// The payment path that was successful.
                ///
                /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
-               path: Vec<RouteHop>,
+               path: Path,
        },
        /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
        /// handle the HTLC.
@@ -492,7 +535,7 @@ pub enum Event {
                /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
                failure: PathFailure,
                /// The payment path that failed.
-               path: Vec<RouteHop>,
+               path: Path,
                /// The channel responsible for the failed payment path.
                ///
                /// Note that for route hints or for the first hop in a path this may be an SCID alias and
@@ -518,7 +561,7 @@ pub enum Event {
                /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
                payment_hash: PaymentHash,
                /// The payment path that was successful.
-               path: Vec<RouteHop>,
+               path: Path,
        },
        /// Indicates that a probe payment we sent failed at an intermediary node on the path.
        ProbeFailed {
@@ -531,7 +574,7 @@ pub enum Event {
                /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
                payment_hash: PaymentHash,
                /// The payment path that failed.
-               path: Vec<RouteHop>,
+               path: Path,
                /// The channel responsible for the failed probe.
                ///
                /// Note that for route hints or for the first hop in a path this may be an SCID alias and
@@ -841,7 +884,7 @@ impl Writeable for Event {
                                        (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
                                        (2, payment_failed_permanently, required),
                                        (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
-                                       (5, *path, vec_type),
+                                       (5, path.hops, vec_type),
                                        (7, short_channel_id, option),
                                        (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
                                        (11, payment_id, option),
@@ -909,13 +952,14 @@ impl Writeable for Event {
                                write_tlv_fields!(writer, {
                                        (0, payment_id, required),
                                        (2, payment_hash, option),
-                                       (4, *path, vec_type)
+                                       (4, path.hops, vec_type),
                                })
                        },
-                       &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
+                       &Event::PaymentFailed { ref payment_id, ref payment_hash, ref reason } => {
                                15u8.write(writer)?;
                                write_tlv_fields!(writer, {
                                        (0, payment_id, required),
+                                       (1, reason, option),
                                        (2, payment_hash, required),
                                })
                        },
@@ -938,7 +982,7 @@ impl Writeable for Event {
                                write_tlv_fields!(writer, {
                                        (0, payment_id, required),
                                        (2, payment_hash, required),
-                                       (4, *path, vec_type)
+                                       (4, path.hops, vec_type),
                                })
                        },
                        &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
@@ -946,7 +990,7 @@ impl Writeable for Event {
                                write_tlv_fields!(writer, {
                                        (0, payment_id, required),
                                        (2, payment_hash, required),
-                                       (4, *path, vec_type),
+                                       (4, path.hops, vec_type),
                                        (6, short_channel_id, option),
                                })
                        },
@@ -1097,7 +1141,7 @@ impl MaybeReadable for Event {
                                                payment_hash,
                                                payment_failed_permanently,
                                                failure,
-                                               path: path.unwrap(),
+                                               path: Path { hops: path.unwrap() },
                                                short_channel_id,
                                                #[cfg(test)]
                                                error_code,
@@ -1211,7 +1255,7 @@ impl MaybeReadable for Event {
                                        Ok(Some(Event::PaymentPathSuccessful {
                                                payment_id,
                                                payment_hash,
-                                               path: path.unwrap(),
+                                               path: Path { hops: path.unwrap() },
                                        }))
                                };
                                f()
@@ -1220,13 +1264,16 @@ impl MaybeReadable for Event {
                                let f = || {
                                        let mut payment_hash = PaymentHash([0; 32]);
                                        let mut payment_id = PaymentId([0; 32]);
+                                       let mut reason = None;
                                        read_tlv_fields!(reader, {
                                                (0, payment_id, required),
+                                               (1, reason, upgradable_option),
                                                (2, payment_hash, required),
                                        });
                                        Ok(Some(Event::PaymentFailed {
                                                payment_id,
                                                payment_hash,
+                                               reason,
                                        }))
                                };
                                f()
@@ -1269,7 +1316,7 @@ impl MaybeReadable for Event {
                                        Ok(Some(Event::ProbeSuccessful {
                                                payment_id,
                                                payment_hash,
-                                               path: path.unwrap(),
+                                               path: Path { hops: path.unwrap() },
                                        }))
                                };
                                f()
@@ -1289,7 +1336,7 @@ impl MaybeReadable for Event {
                                        Ok(Some(Event::ProbeFailed {
                                                payment_id,
                                                payment_hash,
-                                               path: path.unwrap(),
+                                               path: Path { hops: path.unwrap() },
                                                short_channel_id,
                                        }))
                                };