+/// Some information provided on receipt of payment depends on whether the payment received is a
+/// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
+#[derive(Clone, Debug)]
+pub enum PaymentPurpose {
+ /// Information for receiving a payment that we generated an invoice for.
+ InvoicePayment {
+ /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
+ /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
+ /// [`ChannelManager::claim_funds`].
+ ///
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ payment_preimage: Option<PaymentPreimage>,
+ /// The "payment secret". This authenticates the sender to the recipient, preventing a
+ /// number of deanonymization attacks during the routing process.
+ /// It is provided here for your reference, however its accuracy is enforced directly by
+ /// [`ChannelManager`] using the values you previously provided to
+ /// [`ChannelManager::create_inbound_payment`] or
+ /// [`ChannelManager::create_inbound_payment_for_hash`].
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
+ payment_secret: PaymentSecret,
+ },
+ /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
+ /// (the payee) providing a preimage.
+ SpontaneousPayment(PaymentPreimage),
+}
+
+impl_writeable_tlv_based_enum!(PaymentPurpose,
+ (0, InvoicePayment) => {
+ (0, payment_preimage, option),
+ (2, payment_secret, required),
+ };
+ (2, SpontaneousPayment)
+);
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+/// The reason the channel was closed. See individual variants more details.
+pub enum ClosureReason {
+ /// Closure generated from receiving a peer error message.
+ ///
+ /// Our counterparty may have broadcasted their latest commitment state, and we have
+ /// as well.
+ CounterpartyForceClosed {
+ /// The error which the peer sent us.
+ ///
+ /// The string should be sanitized before it is used (e.g emitted to logs
+ /// or printed to stdout). Otherwise, a well crafted error message may exploit
+ /// a security vulnerability in the terminal emulator or the logging subsystem.
+ peer_msg: String,
+ },
+ /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
+ ///
+ /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
+ HolderForceClosed,
+ /// The channel was closed after negotiating a cooperative close and we've now broadcasted
+ /// the cooperative close transaction. Note the shutdown may have been initiated by us.
+ //TODO: split between CounterpartyInitiated/LocallyInitiated
+ CooperativeClosure,
+ /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
+ /// commitment transaction came from our counterparty, but it may also have come from
+ /// a copy of our own `ChannelMonitor`.
+ CommitmentTxConfirmed,
+ /// The funding transaction failed to confirm in a timely manner on an inbound channel.
+ FundingTimedOut,
+ /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
+ ProcessingError {
+ /// A developer-readable error message which we generated.
+ err: String,
+ },
+ /// The peer disconnected prior to funding completing. In this case the spec mandates that we
+ /// forget the channel entirely - we can attempt again if the peer reconnects.
+ ///
+ /// This includes cases where we restarted prior to funding completion, including prior to the
+ /// initial [`ChannelMonitor`] persistence completing.
+ ///
+ /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
+ /// peer because of mutual incompatibility between us and our channel counterparty.
+ ///
+ /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
+ DisconnectedPeer,
+ /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
+ /// the [`ChannelManager`] deserialized.
+ ///
+ /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ OutdatedChannelManager
+}
+
+impl core::fmt::Display for ClosureReason {
+ fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
+ f.write_str("Channel closed because ")?;
+ match self {
+ ClosureReason::CounterpartyForceClosed { peer_msg } => {
+ f.write_str("counterparty force-closed with message ")?;
+ f.write_str(&peer_msg)
+ },
+ ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
+ ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
+ ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
+ ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
+ ClosureReason::ProcessingError { err } => {
+ f.write_str("of an exception: ")?;
+ f.write_str(&err)
+ },
+ ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
+ ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
+ }
+ }
+}
+
+impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
+ (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
+ (1, FundingTimedOut) => {},
+ (2, HolderForceClosed) => {},
+ (6, CommitmentTxConfirmed) => {},
+ (4, CooperativeClosure) => {},
+ (8, ProcessingError) => { (1, err, required) },
+ (10, DisconnectedPeer) => {},
+ (12, OutdatedChannelManager) => {},
+);
+
+/// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum HTLCDestination {
+ /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
+ /// there is insufficient capacity in our outbound channel.
+ NextHopChannel {
+ /// The `node_id` of the next node. For backwards compatibility, this field is
+ /// marked as optional, versions prior to 0.0.110 may not always be able to provide
+ /// counterparty node information.
+ node_id: Option<PublicKey>,
+ /// The outgoing `channel_id` between us and the next node.
+ channel_id: [u8; 32],
+ },
+ /// Scenario where we are unsure of the next node to forward the HTLC to.
+ UnknownNextHop {
+ /// Short channel id we are requesting to forward an HTLC to.
+ requested_forward_scid: u64,
+ },
+ /// Failure scenario where an HTLC may have been forwarded to be intended for us,
+ /// but is invalid for some reason, so we reject it.
+ ///
+ /// Some of the reasons may include:
+ /// * HTLC Timeouts
+ /// * Expected MPP amount to claim does not equal HTLC total
+ /// * Claimable amount does not match expected amount
+ FailedPayment {
+ /// The payment hash of the payment we attempted to process.
+ payment_hash: PaymentHash
+ },
+}
+
+impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
+ (0, NextHopChannel) => {
+ (0, node_id, required),
+ (2, channel_id, required),
+ },
+ (2, UnknownNextHop) => {
+ (0, requested_forward_scid, required),
+ },
+ (4, FailedPayment) => {
+ (0, payment_hash, required),
+ }
+);