//! future, as well as generate and broadcast funding transactions handle payment preimages and a
//! few other things.
-use chain::keysinterface::SpendableOutputDescriptor;
-use ln::msgs;
-use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
-use routing::network_graph::NetworkUpdate;
-use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
+use crate::chain::keysinterface::SpendableOutputDescriptor;
+#[cfg(anchors)]
+use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment};
+use crate::ln::channelmanager::{InterceptId, PaymentId};
+use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
+use crate::ln::features::ChannelTypeFeatures;
+use crate::ln::msgs;
+use crate::ln::msgs::DecodeError;
+use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
+use crate::routing::gossip::NetworkUpdate;
+use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, WithoutLength, OptionDeserWrapper};
+use crate::routing::router::{RouteHop, RouteParameters};
+use bitcoin::{PackedLockTime, Transaction};
+#[cfg(anchors)]
+use bitcoin::{OutPoint, Txid, TxIn, TxOut, Witness};
use bitcoin::blockdata::script::Script;
-
-use bitcoin::secp256k1::key::PublicKey;
-
-use io;
-use prelude::*;
+use bitcoin::hashes::Hash;
+use bitcoin::hashes::sha256::Hash as Sha256;
+use bitcoin::secp256k1::PublicKey;
+#[cfg(anchors)]
+use bitcoin::secp256k1::{self, Secp256k1};
+#[cfg(anchors)]
+use bitcoin::secp256k1::ecdsa::Signature;
+use crate::io;
+use crate::prelude::*;
use core::time::Duration;
use core::ops::Deref;
+use crate::sync::Arc;
/// 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.
/// [`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,
- /// This is the `user_payment_id` which was provided to
- /// [`ChannelManager::create_inbound_payment_for_hash`] or
- /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
- /// simply copied here. It may be used to correlate PaymentReceived events with invoice
- /// metadata stored elsewhere.
- ///
- /// [`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
- user_payment_id: u64,
},
/// 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,
+ },
+ /// We couldn't forward to the outgoing scid. An example would be attempting to send a duplicate
+ /// intercept HTLC.
+ InvalidForward {
+ /// 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),
+ },
+ (1, InvalidForward) => {
+ (0, requested_forward_scid, required),
+ },
+ (2, UnknownNextHop) => {
+ (0, requested_forward_scid, required),
+ },
+ (4, FailedPayment) => {
+ (0, payment_hash, required),
+ },
+);
+
+#[cfg(anchors)]
+/// A descriptor used to sign for a commitment transaction's anchor output.
+#[derive(Clone, Debug)]
+pub struct AnchorDescriptor {
+ /// A unique identifier used along with `channel_value_satoshis` to re-derive the
+ /// [`InMemorySigner`] required to sign `input`.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ pub channel_keys_id: [u8; 32],
+ /// The value in satoshis of the channel we're attempting to spend the anchor output of. This is
+ /// used along with `channel_keys_id` to re-derive the [`InMemorySigner`] required to sign
+ /// `input`.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ pub channel_value_satoshis: u64,
+ /// The transaction input's outpoint corresponding to the commitment transaction's anchor
+ /// output.
+ pub outpoint: OutPoint,
+}
+
+#[cfg(anchors)]
+/// A descriptor used to sign for a commitment transaction's HTLC output.
+#[derive(Clone, Debug)]
+pub struct HTLCDescriptor {
+ /// A unique identifier used along with `channel_value_satoshis` to re-derive the
+ /// [`InMemorySigner`] required to sign `input`.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ pub channel_keys_id: [u8; 32],
+ /// The value in satoshis of the channel we're attempting to spend the anchor output of. This is
+ /// used along with `channel_keys_id` to re-derive the [`InMemorySigner`] required to sign
+ /// `input`.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ pub channel_value_satoshis: u64,
+ /// The necessary channel parameters that need to be provided to the re-derived
+ /// [`InMemorySigner`] through [`BaseSign::provide_channel_parameters`].
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ /// [`BaseSign::provide_channel_parameters`]: crate::chain::keysinterface::BaseSign::provide_channel_parameters
+ pub channel_parameters: ChannelTransactionParameters,
+ /// The txid of the commitment transaction in which the HTLC output lives.
+ pub commitment_txid: Txid,
+ /// The number of the commitment transaction in which the HTLC output lives.
+ pub per_commitment_number: u64,
+ /// The details of the HTLC as it appears in the commitment transaction.
+ pub htlc: HTLCOutputInCommitment,
+ /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be
+ /// taken.
+ pub preimage: Option<PaymentPreimage>,
+ /// The counterparty's signature required to spend the HTLC output.
+ pub counterparty_sig: Signature
+}
+
+#[cfg(anchors)]
+impl HTLCDescriptor {
+ /// Returns the unsigned transaction input spending the HTLC output in the commitment
+ /// transaction.
+ pub fn unsigned_tx_input(&self) -> TxIn {
+ chan_utils::build_htlc_input(&self.commitment_txid, &self.htlc, true /* opt_anchors */)
+ }
+
+ /// Returns the delayed output created as a result of spending the HTLC output in the commitment
+ /// transaction.
+ pub fn tx_output<C: secp256k1::Signing + secp256k1::Verification>(
+ &self, per_commitment_point: &PublicKey, secp: &Secp256k1<C>
+ ) -> TxOut {
+ let channel_params = self.channel_parameters.as_holder_broadcastable();
+ let broadcaster_keys = channel_params.broadcaster_pubkeys();
+ let counterparty_keys = channel_params.countersignatory_pubkeys();
+ let broadcaster_delayed_key = chan_utils::derive_public_key(
+ secp, per_commitment_point, &broadcaster_keys.delayed_payment_basepoint
+ );
+ let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
+ secp, per_commitment_point, &counterparty_keys.revocation_basepoint
+ );
+ chan_utils::build_htlc_output(
+ 0 /* feerate_per_kw */, channel_params.contest_delay(), &self.htlc, true /* opt_anchors */,
+ false /* use_non_zero_fee_anchors */, &broadcaster_delayed_key, &counterparty_revocation_key
+ )
+ }
+
+ /// Returns the witness script of the HTLC output in the commitment transaction.
+ pub fn witness_script<C: secp256k1::Signing + secp256k1::Verification>(
+ &self, per_commitment_point: &PublicKey, secp: &Secp256k1<C>
+ ) -> Script {
+ let channel_params = self.channel_parameters.as_holder_broadcastable();
+ let broadcaster_keys = channel_params.broadcaster_pubkeys();
+ let counterparty_keys = channel_params.countersignatory_pubkeys();
+ let broadcaster_htlc_key = chan_utils::derive_public_key(
+ secp, per_commitment_point, &broadcaster_keys.htlc_basepoint
+ );
+ let counterparty_htlc_key = chan_utils::derive_public_key(
+ secp, per_commitment_point, &counterparty_keys.htlc_basepoint
+ );
+ let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
+ secp, per_commitment_point, &counterparty_keys.revocation_basepoint
+ );
+ chan_utils::get_htlc_redeemscript_with_explicit_keys(
+ &self.htlc, true /* opt_anchors */, &broadcaster_htlc_key, &counterparty_htlc_key,
+ &counterparty_revocation_key,
+ )
+ }
+
+ /// Returns the fully signed witness required to spend the HTLC output in the commitment
+ /// transaction.
+ pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness {
+ chan_utils::build_htlc_input_witness(
+ signature, &self.counterparty_sig, &self.preimage, witness_script, true /* opt_anchors */
+ )
+ }
+}
+
+#[cfg(anchors)]
+/// Represents the different types of transactions, originating from LDK, to be bumped.
+#[derive(Clone, Debug)]
+pub enum BumpTransactionEvent {
+ /// Indicates that a channel featuring anchor outputs is to be closed by broadcasting the local
+ /// commitment transaction. Since commitment transactions have a static feerate pre-agreed upon,
+ /// they may need additional fees to be attached through a child transaction using the popular
+ /// [Child-Pays-For-Parent](https://bitcoinops.org/en/topics/cpfp) fee bumping technique. This
+ /// child transaction must include the anchor input described within `anchor_descriptor` along
+ /// with additional inputs to meet the target feerate. Failure to meet the target feerate
+ /// decreases the confirmation odds of the transaction package (which includes the commitment
+ /// and child anchor transactions), possibly resulting in a loss of funds. Once the transaction
+ /// is constructed, it must be fully signed for and broadcast by the consumer of the event
+ /// along with the `commitment_tx` enclosed. Note that the `commitment_tx` must always be
+ /// broadcast first, as the child anchor transaction depends on it.
+ ///
+ /// The consumer should be able to sign for any of the additional inputs included within the
+ /// child anchor transaction. To sign its anchor input, an [`InMemorySigner`] should be
+ /// re-derived through [`KeysManager::derive_channel_keys`] with the help of
+ /// [`AnchorDescriptor::channel_keys_id`] and [`AnchorDescriptor::channel_value_satoshis`]. The
+ /// anchor input signature can be computed with [`BaseSign::sign_holder_anchor_input`],
+ /// which can then be provided to [`build_anchor_input_witness`] along with the `funding_pubkey`
+ /// to obtain the full witness required to spend.
+ ///
+ /// It is possible to receive more than one instance of this event if a valid child anchor
+ /// transaction is never broadcast or is but not with a sufficient fee to be mined. Care should
+ /// be taken by the consumer of the event to ensure any future iterations of the child anchor
+ /// transaction adhere to the [Replace-By-Fee
+ /// rules](https://github.com/bitcoin/bitcoin/blob/master/doc/policy/mempool-replacements.md)
+ /// for fee bumps to be accepted into the mempool, and eventually the chain. As the frequency of
+ /// these events is not user-controlled, users may ignore/drop the event if they are no longer
+ /// able to commit external confirmed funds to the child anchor transaction.
+ ///
+ /// The set of `pending_htlcs` on the commitment transaction to be broadcast can be inspected to
+ /// determine whether a significant portion of the channel's funds are allocated to HTLCs,
+ /// enabling users to make their own decisions regarding the importance of the commitment
+ /// transaction's confirmation. Note that this is not required, but simply exists as an option
+ /// for users to override LDK's behavior. On commitments with no HTLCs (indicated by those with
+ /// an empty `pending_htlcs`), confirmation of the commitment transaction can be considered to
+ /// be not urgent.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ /// [`KeysManager::derive_channel_keys`]: crate::chain::keysinterface::KeysManager::derive_channel_keys
+ /// [`BaseSign::sign_holder_anchor_input`]: crate::chain::keysinterface::BaseSign::sign_holder_anchor_input
+ /// [`build_anchor_input_witness`]: crate::ln::chan_utils::build_anchor_input_witness
+ ChannelClose {
+ /// The target feerate that the transaction package, which consists of the commitment
+ /// transaction and the to-be-crafted child anchor transaction, must meet.
+ package_target_feerate_sat_per_1000_weight: u32,
+ /// The channel's commitment transaction to bump the fee of. This transaction should be
+ /// broadcast along with the anchor transaction constructed as a result of consuming this
+ /// event.
+ commitment_tx: Transaction,
+ /// The absolute fee in satoshis of the commitment transaction. This can be used along the
+ /// with weight of the commitment transaction to determine its feerate.
+ commitment_tx_fee_satoshis: u64,
+ /// The descriptor to sign the anchor input of the anchor transaction constructed as a
+ /// result of consuming this event.
+ anchor_descriptor: AnchorDescriptor,
+ /// The set of pending HTLCs on the commitment transaction that need to be resolved once the
+ /// commitment transaction confirms.
+ pending_htlcs: Vec<HTLCOutputInCommitment>,
+ },
+ /// Indicates that a channel featuring anchor outputs has unilaterally closed on-chain by a
+ /// holder commitment transaction and its HTLC(s) need to be resolved on-chain. With the
+ /// zero-HTLC-transaction-fee variant of anchor outputs, the pre-signed HTLC
+ /// transactions have a zero fee, thus requiring additional inputs and/or outputs to be attached
+ /// for a timely confirmation within the chain. These additional inputs and/or outputs must be
+ /// appended to the resulting HTLC transaction to meet the target feerate. Failure to meet the
+ /// target feerate decreases the confirmation odds of the transaction, possibly resulting in a
+ /// loss of funds. Once the transaction meets the target feerate, it must be signed for and
+ /// broadcast by the consumer of the event.
+ ///
+ /// The consumer should be able to sign for any of the non-HTLC inputs added to the resulting
+ /// HTLC transaction. To sign HTLC inputs, an [`InMemorySigner`] should be re-derived through
+ /// [`KeysManager::derive_channel_keys`] with the help of `channel_keys_id` and
+ /// `channel_value_satoshis`. Each HTLC input's signature can be computed with
+ /// [`BaseSign::sign_holder_htlc_transaction`], which can then be provided to
+ /// [`HTLCDescriptor::tx_input_witness`] to obtain the fully signed witness required to spend.
+ ///
+ /// It is possible to receive more than one instance of this event if a valid HTLC transaction
+ /// is never broadcast or is but not with a sufficient fee to be mined. Care should be taken by
+ /// the consumer of the event to ensure any future iterations of the HTLC transaction adhere to
+ /// the [Replace-By-Fee
+ /// rules](https://github.com/bitcoin/bitcoin/blob/master/doc/policy/mempool-replacements.md)
+ /// for fee bumps to be accepted into the mempool, and eventually the chain. As the frequency of
+ /// these events is not user-controlled, users may ignore/drop the event if either they are no
+ /// longer able to commit external confirmed funds to the HTLC transaction or the fee committed
+ /// to the HTLC transaction is greater in value than the HTLCs being claimed.
+ ///
+ /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
+ /// [`KeysManager::derive_channel_keys`]: crate::chain::keysinterface::KeysManager::derive_channel_keys
+ /// [`BaseSign::sign_holder_htlc_transaction`]: crate::chain::keysinterface::BaseSign::sign_holder_htlc_transaction
+ /// [`HTLCDescriptor::tx_input_witness`]: HTLCDescriptor::tx_input_witness
+ HTLCResolution {
+ target_feerate_sat_per_1000_weight: u32,
+ htlc_descriptors: Vec<HTLCDescriptor>,
+ },
+}
+
+/// Will be used in [`Event::HTLCIntercepted`] to identify the next hop in the HTLC's path.
+/// Currently only used in serialization for the sake of maintaining compatibility. More variants
+/// will be added for general-purpose HTLC forward intercepts as well as trampoline forward
+/// intercepts in upcoming work.
+enum InterceptNextHop {
+ FakeScid {
+ requested_next_hop_scid: u64,
+ },
+}
+
+impl_writeable_tlv_based_enum!(InterceptNextHop,
+ (0, FakeScid) => {
+ (0, requested_next_hop_scid, required),
+ };
+);
+
/// 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
#[derive(Clone, Debug)]
pub enum Event {
/// Used to indicate that the client should generate a funding transaction with the given
- /// parameters and then call ChannelManager::funding_transaction_generated.
- /// Generated in ChannelManager message handling.
+ /// parameters and then call [`ChannelManager::funding_transaction_generated`].
+ /// Generated in [`ChannelManager`] message handling.
/// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
/// counterparty can steal your funds!
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
FundingGenerationReady {
/// The random channel_id we picked which you'll need to pass into
- /// ChannelManager::funding_transaction_generated.
+ /// [`ChannelManager::funding_transaction_generated`].
+ ///
+ /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
temporary_channel_id: [u8; 32],
+ /// The counterparty's node_id, which you'll need to pass back into
+ /// [`ChannelManager::funding_transaction_generated`].
+ ///
+ /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
+ counterparty_node_id: PublicKey,
/// The value, in satoshis, that the output should have.
channel_value_satoshis: u64,
/// The script which should be used in the transaction output.
output_script: Script,
- /// The value passed in to ChannelManager::create_channel
- user_channel_id: u64,
+ /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or a
+ /// random value for an inbound channel. This may be zero for objects serialized with LDK
+ /// versions prior to 0.0.113.
+ ///
+ /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+ user_channel_id: u128,
},
- /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
- /// ChannelManager::claim_funds to get it....
- /// Note that if the preimage is not known or the amount paid is incorrect, you should call
- /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
+ /// Indicates that we've been offered a payment and it needs to be claimed via calling
+ /// [`ChannelManager::claim_funds`] with the preimage given in [`PaymentPurpose`].
+ ///
+ /// Note that if the preimage is not known, you should call
+ /// [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
/// network congestion.
- /// The amount paid should be considered 'incorrect' when it is less than or more than twice
- /// the amount expected.
- /// If you fail to call either ChannelManager::claim_funds or
- /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
+ /// If you fail to call either [`ChannelManager::claim_funds`] or
+ /// [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
/// automatically failed.
- PaymentReceived {
- /// The hash for which the preimage should be handed to the ChannelManager.
+ ///
+ /// # Note
+ /// LDK will not stop an inbound payment from being paid multiple times, so multiple
+ /// `PaymentClaimable` events may be generated for the same payment.
+ ///
+ /// # Note
+ /// This event used to be called `PaymentReceived` in LDK versions 0.0.112 and earlier.
+ ///
+ /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
+ PaymentClaimable {
+ /// The node that will receive the payment after it has been claimed.
+ /// This is useful to identify payments received via [phantom nodes].
+ /// This field will always be filled in when the event was generated by LDK versions
+ /// 0.0.113 and above.
+ ///
+ /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
+ receiver_node_id: Option<PublicKey>,
+ /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
+ /// not stop you from registering duplicate payment hashes for inbound payments.
payment_hash: PaymentHash,
- /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
- /// compare this to the expected value before accepting the payment (as otherwise you are
- /// providing proof-of-payment for less than the value you expected!).
- amt: u64,
+ /// The value, in thousandths of a satoshi, that this payment is for.
+ amount_msat: u64,
/// Information for claiming this received payment, based on whether the purpose of the
/// payment is to pay an invoice or to send a spontaneous payment.
purpose: PaymentPurpose,
+ /// The `channel_id` indicating over which channel we received the payment.
+ via_channel_id: Option<[u8; 32]>,
+ /// The `user_channel_id` indicating over which channel we received the payment.
+ via_user_channel_id: Option<u128>,
},
- /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
+ /// Indicates a payment has been claimed and we've received money!
+ ///
+ /// This most likely occurs when [`ChannelManager::claim_funds`] has been called in response
+ /// to an [`Event::PaymentClaimable`]. However, if we previously crashed during a
+ /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
+ /// [`Event::PaymentClaimable`] event.
+ ///
+ /// # Note
+ /// LDK will not stop an inbound payment from being paid multiple times, so multiple
+ /// `PaymentClaimable` events may be generated for the same payment. If you then call
+ /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentClaimable`] you may get
+ /// multiple `PaymentClaimed` events.
+ ///
+ /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ PaymentClaimed {
+ /// The node that received the payment.
+ /// This is useful to identify payments which were received via [phantom nodes].
+ /// This field will always be filled in when the event was generated by LDK versions
+ /// 0.0.113 and above.
+ ///
+ /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
+ receiver_node_id: Option<PublicKey>,
+ /// The payment hash of the claimed payment. Note that LDK will not stop you from
+ /// registering duplicate payment hashes for inbound payments.
+ payment_hash: PaymentHash,
+ /// The value, in thousandths of a satoshi, that this payment is for.
+ amount_msat: u64,
+ /// The purpose of the claimed payment, i.e. whether the payment was for an invoice or a
+ /// spontaneous payment.
+ purpose: PaymentPurpose,
+ },
+ /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
/// and we got back the payment preimage for it).
+ ///
+ /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
+ /// event. In this situation, you SHOULD treat this payment as having succeeded.
PaymentSent {
+ /// The id returned by [`ChannelManager::send_payment`] and used with
+ /// [`ChannelManager::retry_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
+ payment_id: Option<PaymentId>,
/// The preimage to the hash given to ChannelManager::send_payment.
/// Note that this serves as a payment receipt, if you wish to have such a thing, you must
/// store it somehow!
payment_preimage: PaymentPreimage,
+ /// The hash that was given to [`ChannelManager::send_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ payment_hash: PaymentHash,
+ /// The total fee which was spent at intermediate hops in this payment, across all paths.
+ ///
+ /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
+ /// overpayment to the recipient node.
+ ///
+ /// If the recipient or an intermediate node misbehaves and gives us free money, this may
+ /// overstate the amount paid, though this is unlikely.
+ ///
+ /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
+ fee_paid_msat: Option<u64>,
},
- /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
- /// something. You may wish to retry with a different route.
+ /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
+ /// provide failure information for each MPP part in the payment.
+ ///
+ /// This event is provided once there are no further pending HTLCs for the payment and the
+ /// payment is no longer retryable due to [`ChannelManager::abandon_payment`] having been
+ /// called for the corresponding payment.
+ ///
+ /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
PaymentFailed {
- /// The hash which was given to ChannelManager::send_payment.
+ /// The id returned by [`ChannelManager::send_payment`] and used with
+ /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
+ /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
+ payment_id: PaymentId,
+ /// The hash that was given to [`ChannelManager::send_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ payment_hash: PaymentHash,
+ },
+ /// Indicates that a path for an outbound payment was successful.
+ ///
+ /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
+ /// [`Event::PaymentSent`] for obtaining the payment preimage.
+ PaymentPathSuccessful {
+ /// The id returned by [`ChannelManager::send_payment`] and used with
+ /// [`ChannelManager::retry_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
+ payment_id: PaymentId,
+ /// The hash that was given to [`ChannelManager::send_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ payment_hash: Option<PaymentHash>,
+ /// 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>,
+ },
+ /// Indicates an outbound HTLC we sent failed. Probably some intermediary node dropped
+ /// something. You may wish to retry with a different route.
+ ///
+ /// If you have given up retrying this payment and wish to fail it, you MUST call
+ /// [`ChannelManager::abandon_payment`] at least once for a given [`PaymentId`] or memory
+ /// related to payment tracking will leak.
+ ///
+ /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
+ /// [`Event::PaymentFailed`] and [`all_paths_failed`].
+ ///
+ /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
+ /// [`all_paths_failed`]: Self::PaymentPathFailed::all_paths_failed
+ PaymentPathFailed {
+ /// The id returned by [`ChannelManager::send_payment`] and used with
+ /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
+ /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
+ payment_id: Option<PaymentId>,
+ /// The hash that was given to [`ChannelManager::send_payment`].
+ ///
+ /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
payment_hash: PaymentHash,
/// Indicates the payment was rejected for some reason by the recipient. This implies that
/// the payment has failed, not just the route in question. If this is not set, you may
/// retry the payment via a different route.
- rejected_by_dest: bool,
+ payment_failed_permanently: bool,
/// Any failure information conveyed via the Onion return packet by a node along the failed
/// payment route.
///
/// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
- /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
+ /// account the update.
///
- /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
- /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
+ /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
network_update: Option<NetworkUpdate>,
+ /// For both single-path and multi-path payments, this is set if all paths of the payment have
+ /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
+ /// larger MPP payment were still in flight when this event was generated.
+ ///
+ /// Note that if you are retrying individual MPP parts, using this value to determine if a
+ /// payment has fully failed is race-y. Because multiple failures can happen prior to events
+ /// being processed, you may retry in response to a first failure, with a second failure
+ /// (with `all_paths_failed` set) still pending. Then, when the second failure is processed
+ /// you will see `all_paths_failed` set even though the retry of the first failure still
+ /// has an associated in-flight HTLC. See (1) for an example of such a failure.
+ ///
+ /// If you wish to retry individual MPP parts and learn when a payment has failed, you must
+ /// call [`ChannelManager::abandon_payment`] and wait for a [`Event::PaymentFailed`] event.
+ ///
+ /// (1) <https://github.com/lightningdevkit/rust-lightning/issues/1164>
+ ///
+ /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
+ all_paths_failed: bool,
+ /// The payment path that failed.
+ path: Vec<RouteHop>,
+ /// 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
+ /// may not refer to a channel in the public network graph. These aliases may also collide
+ /// with channels in the public network graph.
+ ///
+ /// If this is `Some`, then the corresponding channel should be avoided when the payment is
+ /// retried. May be `None` for older [`Event`] serializations.
+ short_channel_id: Option<u64>,
+ /// Parameters needed to compute a new [`Route`] when retrying the failed payment path.
+ ///
+ /// See [`find_route`] for details.
+ ///
+ /// [`Route`]: crate::routing::router::Route
+ /// [`find_route`]: crate::routing::router::find_route
+ retry: Option<RouteParameters>,
#[cfg(test)]
error_code: Option<u16>,
#[cfg(test)]
error_data: Option<Vec<u8>>,
},
- /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
- /// time in the future.
+ /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
+ ProbeSuccessful {
+ /// The id returned by [`ChannelManager::send_probe`].
+ ///
+ /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
+ payment_id: PaymentId,
+ /// The hash generated by [`ChannelManager::send_probe`].
+ ///
+ /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
+ payment_hash: PaymentHash,
+ /// The payment path that was successful.
+ path: Vec<RouteHop>,
+ },
+ /// Indicates that a probe payment we sent failed at an intermediary node on the path.
+ ProbeFailed {
+ /// The id returned by [`ChannelManager::send_probe`].
+ ///
+ /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
+ payment_id: PaymentId,
+ /// The hash generated by [`ChannelManager::send_probe`].
+ ///
+ /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
+ payment_hash: PaymentHash,
+ /// The payment path that failed.
+ path: Vec<RouteHop>,
+ /// 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
+ /// may not refer to a channel in the public network graph. These aliases may also collide
+ /// with channels in the public network graph.
+ short_channel_id: Option<u64>,
+ },
+ /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
+ /// a time in the future.
+ ///
+ /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
PendingHTLCsForwardable {
/// The minimum amount of time that should be waited prior to calling
/// process_pending_htlc_forwards. To increase the effort required to correlate payments,
/// now + 5*time_forwardable).
time_forwardable: Duration,
},
+ /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
+ /// you've encoded an intercept scid in the receiver's invoice route hints using
+ /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
+ ///
+ /// [`ChannelManager::forward_intercepted_htlc`] or
+ /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
+ /// their docs for more information.
+ ///
+ /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+ /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
+ /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
+ /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
+ HTLCIntercepted {
+ /// An id to help LDK identify which HTLC is being forwarded or failed.
+ intercept_id: InterceptId,
+ /// The fake scid that was programmed as the next hop's scid, generated using
+ /// [`ChannelManager::get_intercept_scid`].
+ ///
+ /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+ requested_next_hop_scid: u64,
+ /// The payment hash used for this HTLC.
+ payment_hash: PaymentHash,
+ /// How many msats were received on the inbound edge of this HTLC.
+ inbound_amount_msat: u64,
+ /// How many msats the payer intended to route to the next node. Depending on the reason you are
+ /// intercepting this payment, you might take a fee by forwarding less than this amount.
+ ///
+ /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
+ /// check that whatever fee you want has been included here or subtract it as required. Further,
+ /// LDK will not stop you from forwarding more than you received.
+ expected_outbound_amount_msat: u64,
+ },
/// Used to indicate that an output which you should know how to spend was confirmed on chain
/// and is now spendable.
/// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
/// This event is generated when a payment has been successfully forwarded through us and a
/// forwarding fee earned.
PaymentForwarded {
+ /// The incoming channel between the previous node and us. This is only `None` for events
+ /// generated or serialized by versions prior to 0.0.107.
+ prev_channel_id: Option<[u8; 32]>,
+ /// The outgoing channel between the next node and us. This is only `None` for events
+ /// generated or serialized by versions prior to 0.0.107.
+ next_channel_id: Option<[u8; 32]>,
/// The fee, in milli-satoshis, which was earned as a result of the payment.
///
/// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
/// transaction.
claim_from_onchain_tx: bool,
},
+ /// Used to indicate that a channel with the given `channel_id` is ready to
+ /// be used. This event is emitted either when the funding transaction has been confirmed
+ /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
+ /// establishment.
+ ChannelReady {
+ /// The channel_id of the channel that is ready.
+ channel_id: [u8; 32],
+ /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
+ /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
+ /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
+ /// `user_channel_id` will be randomized for an inbound channel.
+ ///
+ /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+ user_channel_id: u128,
+ /// The node_id of the channel counterparty.
+ counterparty_node_id: PublicKey,
+ /// The features that this channel will operate with.
+ channel_type: ChannelTypeFeatures,
+ },
+ /// Used to indicate that a previously opened channel with the given `channel_id` is in the
+ /// process of closure.
+ ChannelClosed {
+ /// The channel_id of the channel which has been closed. Note that on-chain transactions
+ /// resolving the channel are likely still awaiting confirmation.
+ channel_id: [u8; 32],
+ /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
+ /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
+ /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
+ /// `user_channel_id` will be randomized for inbound channels.
+ /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
+ /// zero for objects serialized with LDK versions prior to 0.0.102.
+ ///
+ /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+ user_channel_id: u128,
+ /// The reason the channel was closed.
+ reason: ClosureReason
+ },
+ /// Used to indicate to the user that they can abandon the funding transaction and recycle the
+ /// inputs for another purpose.
+ DiscardFunding {
+ /// The channel_id of the channel which has been closed.
+ channel_id: [u8; 32],
+ /// The full transaction received from the user
+ transaction: Transaction
+ },
+ /// Indicates a request to open a new channel by a peer.
+ ///
+ /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
+ /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
+ ///
+ /// The event is only triggered when a new open channel request is received and the
+ /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
+ ///
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
+ /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+ OpenChannelRequest {
+ /// The temporary channel ID of the channel requested to be opened.
+ ///
+ /// When responding to the request, the `temporary_channel_id` should be passed
+ /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
+ /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
+ ///
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
+ temporary_channel_id: [u8; 32],
+ /// The node_id of the counterparty requesting to open the channel.
+ ///
+ /// When responding to the request, the `counterparty_node_id` should be passed
+ /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
+ /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
+ /// request.
+ ///
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
+ counterparty_node_id: PublicKey,
+ /// The channel value of the requested channel.
+ funding_satoshis: u64,
+ /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
+ push_msat: u64,
+ /// The features that this channel will operate with. If you reject the channel, a
+ /// well-behaved counterparty may automatically re-attempt the channel with a new set of
+ /// feature flags.
+ ///
+ /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
+ /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
+ /// 0.0.106.
+ ///
+ /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
+ /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
+ /// 0.0.107. Channels setting this type also need to get manually accepted via
+ /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
+ /// or will be rejected otherwise.
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ channel_type: ChannelTypeFeatures,
+ },
+ /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
+ /// forward it.
+ ///
+ /// Some scenarios where this event may be sent include:
+ /// * Insufficient capacity in the outbound channel
+ /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
+ /// * When an unknown SCID is requested for forwarding a payment.
+ /// * Claiming an amount for an MPP payment that exceeds the HTLC total
+ /// * The HTLC has timed out
+ ///
+ /// This event, however, does not get generated if an HTLC fails to meet the forwarding
+ /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
+ HTLCHandlingFailed {
+ /// The channel over which the HTLC was received.
+ prev_channel_id: [u8; 32],
+ /// Destination of the HTLC that failed to be processed.
+ failed_next_destination: HTLCDestination,
+ },
+ #[cfg(anchors)]
+ /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
+ /// requires confirmed external funds to be readily available to spend.
+ ///
+ /// LDK does not currently generate this event. It is limited to the scope of channels with
+ /// anchor outputs, which will be introduced in a future release.
+ BumpTransaction(BumpTransactionEvent),
}
impl Writeable for Event {
// We never write out FundingGenerationReady events as, upon disconnection, peers
// drop any channels which have not yet exchanged funding_signed.
},
- &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
+ &Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id } => {
1u8.write(writer)?;
let mut payment_secret = None;
- let mut user_payment_id = None;
let payment_preimage;
match &purpose {
- PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
+ PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
payment_secret = Some(secret);
payment_preimage = *preimage;
- user_payment_id = Some(id);
},
PaymentPurpose::SpontaneousPayment(preimage) => {
payment_preimage = Some(*preimage);
}
write_tlv_fields!(writer, {
(0, payment_hash, required),
+ (1, receiver_node_id, option),
(2, payment_secret, option),
- (4, amt, required),
- (6, user_payment_id, option),
+ (3, via_channel_id, option),
+ (4, amount_msat, required),
+ (5, via_user_channel_id, option),
+ (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
(8, payment_preimage, option),
});
},
- &Event::PaymentSent { ref payment_preimage } => {
+ &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
2u8.write(writer)?;
write_tlv_fields!(writer, {
(0, payment_preimage, required),
+ (1, payment_hash, required),
+ (3, payment_id, option),
+ (5, fee_paid_msat, option),
});
},
- &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, ref network_update,
+ &Event::PaymentPathFailed {
+ ref payment_id, ref payment_hash, ref payment_failed_permanently, ref network_update,
+ ref all_paths_failed, ref path, ref short_channel_id, ref retry,
#[cfg(test)]
ref error_code,
#[cfg(test)]
write_tlv_fields!(writer, {
(0, payment_hash, required),
(1, network_update, option),
- (2, rejected_by_dest, required),
+ (2, payment_failed_permanently, required),
+ (3, all_paths_failed, required),
+ (5, *path, vec_type),
+ (7, short_channel_id, option),
+ (9, retry, option),
+ (11, payment_id, option),
});
},
&Event::PendingHTLCsForwardable { time_forwardable: _ } => {
&Event::SpendableOutputs { ref outputs } => {
5u8.write(writer)?;
write_tlv_fields!(writer, {
- (0, VecWriteWrapper(outputs), required),
+ (0, WithoutLength(outputs), required),
});
},
- &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
+ &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
+ 6u8.write(writer)?;
+ let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
+ write_tlv_fields!(writer, {
+ (0, intercept_id, required),
+ (2, intercept_scid, required),
+ (4, payment_hash, required),
+ (6, inbound_amount_msat, required),
+ (8, expected_outbound_amount_msat, required),
+ });
+ }
+ &Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id } => {
7u8.write(writer)?;
write_tlv_fields!(writer, {
(0, fee_earned_msat, option),
+ (1, prev_channel_id, option),
(2, claim_from_onchain_tx, required),
+ (3, next_channel_id, option),
});
},
+ &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
+ 9u8.write(writer)?;
+ // `user_channel_id` used to be a single u64 value. In order to remain backwards
+ // compatible with versions prior to 0.0.113, the u128 is serialized as two
+ // separate u64 values.
+ let user_channel_id_low = *user_channel_id as u64;
+ let user_channel_id_high = (*user_channel_id >> 64) as u64;
+ write_tlv_fields!(writer, {
+ (0, channel_id, required),
+ (1, user_channel_id_low, required),
+ (2, reason, required),
+ (3, user_channel_id_high, required),
+ });
+ },
+ &Event::DiscardFunding { ref channel_id, ref transaction } => {
+ 11u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, channel_id, required),
+ (2, transaction, required)
+ })
+ },
+ &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
+ 13u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_id, required),
+ (2, payment_hash, option),
+ (4, *path, vec_type)
+ })
+ },
+ &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
+ 15u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
+ })
+ },
+ &Event::OpenChannelRequest { .. } => {
+ 17u8.write(writer)?;
+ // We never write the OpenChannelRequest events as, upon disconnection, peers
+ // drop any channels which have not yet exchanged funding_signed.
+ },
+ &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
+ 19u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_hash, required),
+ (1, receiver_node_id, option),
+ (2, purpose, required),
+ (4, amount_msat, required),
+ });
+ },
+ &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
+ 21u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
+ (4, *path, vec_type)
+ })
+ },
+ &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
+ 23u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
+ (4, *path, vec_type),
+ (6, short_channel_id, option),
+ })
+ },
+ &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
+ 25u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, prev_channel_id, required),
+ (2, failed_next_destination, required),
+ })
+ },
+ #[cfg(anchors)]
+ &Event::BumpTransaction(ref event)=> {
+ 27u8.write(writer)?;
+ match event {
+ // We never write the ChannelClose|HTLCResolution events as they'll be replayed
+ // upon restarting anyway if they remain unresolved.
+ BumpTransactionEvent::ChannelClose { .. } => {}
+ BumpTransactionEvent::HTLCResolution { .. } => {}
+ }
+ write_tlv_fields!(writer, {}); // Write a length field for forwards compat
+ }
+ &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
+ 29u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, channel_id, required),
+ (2, user_channel_id, required),
+ (4, counterparty_node_id, required),
+ (6, channel_type, required),
+ });
+ },
+ // Note that, going forward, all new events must only write data inside of
+ // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
+ // data via `write_tlv_fields`.
}
Ok(())
}
impl MaybeReadable for Event {
fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
match Readable::read(reader)? {
+ // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
+ // unlike all other events, thus we return immediately here.
0u8 => Ok(None),
1u8 => {
let f = || {
let mut payment_hash = PaymentHash([0; 32]);
let mut payment_preimage = None;
let mut payment_secret = None;
- let mut amt = 0;
- let mut user_payment_id = None;
+ let mut amount_msat = 0;
+ let mut receiver_node_id = None;
+ let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
+ let mut via_channel_id = None;
+ let mut via_user_channel_id = None;
read_tlv_fields!(reader, {
(0, payment_hash, required),
+ (1, receiver_node_id, option),
(2, payment_secret, option),
- (4, amt, required),
- (6, user_payment_id, option),
+ (3, via_channel_id, option),
+ (4, amount_msat, required),
+ (5, via_user_channel_id, option),
+ (6, _user_payment_id, option),
(8, payment_preimage, option),
});
let purpose = match payment_secret {
Some(secret) => PaymentPurpose::InvoicePayment {
payment_preimage,
- payment_secret: secret,
- user_payment_id: if let Some(id) = user_payment_id {
- id
- } else { return Err(msgs::DecodeError::InvalidValue) }
+ payment_secret: secret
},
None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
None => return Err(msgs::DecodeError::InvalidValue),
};
- Ok(Some(Event::PaymentReceived {
+ Ok(Some(Event::PaymentClaimable {
+ receiver_node_id,
payment_hash,
- amt,
+ amount_msat,
purpose,
+ via_channel_id,
+ via_user_channel_id,
}))
};
f()
2u8 => {
let f = || {
let mut payment_preimage = PaymentPreimage([0; 32]);
+ let mut payment_hash = None;
+ let mut payment_id = None;
+ let mut fee_paid_msat = None;
read_tlv_fields!(reader, {
(0, payment_preimage, required),
+ (1, payment_hash, option),
+ (3, payment_id, option),
+ (5, fee_paid_msat, option),
});
+ if payment_hash.is_none() {
+ payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
+ }
Ok(Some(Event::PaymentSent {
+ payment_id,
payment_preimage,
+ payment_hash: payment_hash.unwrap(),
+ fee_paid_msat,
}))
};
f()
#[cfg(test)]
let error_data = Readable::read(reader)?;
let mut payment_hash = PaymentHash([0; 32]);
- let mut rejected_by_dest = false;
+ let mut payment_failed_permanently = false;
let mut network_update = None;
+ let mut all_paths_failed = Some(true);
+ let mut path: Option<Vec<RouteHop>> = Some(vec![]);
+ let mut short_channel_id = None;
+ let mut retry = None;
+ let mut payment_id = None;
read_tlv_fields!(reader, {
(0, payment_hash, required),
(1, network_update, ignorable),
- (2, rejected_by_dest, required),
+ (2, payment_failed_permanently, required),
+ (3, all_paths_failed, option),
+ (5, path, vec_type),
+ (7, short_channel_id, option),
+ (9, retry, option),
+ (11, payment_id, option),
});
- Ok(Some(Event::PaymentFailed {
+ Ok(Some(Event::PaymentPathFailed {
+ payment_id,
payment_hash,
- rejected_by_dest,
+ payment_failed_permanently,
network_update,
+ all_paths_failed: all_paths_failed.unwrap(),
+ path: path.unwrap(),
+ short_channel_id,
+ retry,
#[cfg(test)]
error_code,
#[cfg(test)]
4u8 => Ok(None),
5u8 => {
let f = || {
- let mut outputs = VecReadWrapper(Vec::new());
+ let mut outputs = WithoutLength(Vec::new());
read_tlv_fields!(reader, {
(0, outputs, required),
});
};
f()
},
+ 6u8 => {
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut intercept_id = InterceptId([0; 32]);
+ let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
+ let mut inbound_amount_msat = 0;
+ let mut expected_outbound_amount_msat = 0;
+ read_tlv_fields!(reader, {
+ (0, intercept_id, required),
+ (2, requested_next_hop_scid, required),
+ (4, payment_hash, required),
+ (6, inbound_amount_msat, required),
+ (8, expected_outbound_amount_msat, required),
+ });
+ let next_scid = match requested_next_hop_scid {
+ InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
+ };
+ Ok(Some(Event::HTLCIntercepted {
+ payment_hash,
+ requested_next_hop_scid: next_scid,
+ inbound_amount_msat,
+ expected_outbound_amount_msat,
+ intercept_id,
+ }))
+ },
7u8 => {
let f = || {
let mut fee_earned_msat = None;
+ let mut prev_channel_id = None;
let mut claim_from_onchain_tx = false;
+ let mut next_channel_id = None;
read_tlv_fields!(reader, {
(0, fee_earned_msat, option),
+ (1, prev_channel_id, option),
(2, claim_from_onchain_tx, required),
+ (3, next_channel_id, option),
+ });
+ Ok(Some(Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id }))
+ };
+ f()
+ },
+ 9u8 => {
+ let f = || {
+ let mut channel_id = [0; 32];
+ let mut reason = None;
+ let mut user_channel_id_low_opt: Option<u64> = None;
+ let mut user_channel_id_high_opt: Option<u64> = None;
+ read_tlv_fields!(reader, {
+ (0, channel_id, required),
+ (1, user_channel_id_low_opt, option),
+ (2, reason, ignorable),
+ (3, user_channel_id_high_opt, option),
+ });
+ if reason.is_none() { return Ok(None); }
+
+ // `user_channel_id` used to be a single u64 value. In order to remain
+ // backwards compatible with versions prior to 0.0.113, the u128 is serialized
+ // as two separate u64 values.
+ let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
+ ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
+
+ Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: reason.unwrap() }))
+ };
+ f()
+ },
+ 11u8 => {
+ let f = || {
+ let mut channel_id = [0; 32];
+ let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
+ read_tlv_fields!(reader, {
+ (0, channel_id, required),
+ (2, transaction, required),
+ });
+ Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
+ };
+ f()
+ },
+ 13u8 => {
+ let f = || {
+ let mut payment_id = PaymentId([0; 32]);
+ let mut payment_hash = None;
+ let mut path: Option<Vec<RouteHop>> = Some(vec![]);
+ read_tlv_fields!(reader, {
+ (0, payment_id, required),
+ (2, payment_hash, option),
+ (4, path, vec_type),
+ });
+ Ok(Some(Event::PaymentPathSuccessful {
+ payment_id,
+ payment_hash,
+ path: path.unwrap(),
+ }))
+ };
+ f()
+ },
+ 15u8 => {
+ let f = || {
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut payment_id = PaymentId([0; 32]);
+ read_tlv_fields!(reader, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
});
- Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
+ Ok(Some(Event::PaymentFailed {
+ payment_id,
+ payment_hash,
+ }))
+ };
+ f()
+ },
+ 17u8 => {
+ // Value 17 is used for `Event::OpenChannelRequest`.
+ Ok(None)
+ },
+ 19u8 => {
+ let f = || {
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut purpose = None;
+ let mut amount_msat = 0;
+ let mut receiver_node_id = None;
+ read_tlv_fields!(reader, {
+ (0, payment_hash, required),
+ (1, receiver_node_id, option),
+ (2, purpose, ignorable),
+ (4, amount_msat, required),
+ });
+ if purpose.is_none() { return Ok(None); }
+ Ok(Some(Event::PaymentClaimed {
+ receiver_node_id,
+ payment_hash,
+ purpose: purpose.unwrap(),
+ amount_msat,
+ }))
+ };
+ f()
+ },
+ 21u8 => {
+ let f = || {
+ let mut payment_id = PaymentId([0; 32]);
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut path: Option<Vec<RouteHop>> = Some(vec![]);
+ read_tlv_fields!(reader, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
+ (4, path, vec_type),
+ });
+ Ok(Some(Event::ProbeSuccessful {
+ payment_id,
+ payment_hash,
+ path: path.unwrap(),
+ }))
+ };
+ f()
+ },
+ 23u8 => {
+ let f = || {
+ let mut payment_id = PaymentId([0; 32]);
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut path: Option<Vec<RouteHop>> = Some(vec![]);
+ let mut short_channel_id = None;
+ read_tlv_fields!(reader, {
+ (0, payment_id, required),
+ (2, payment_hash, required),
+ (4, path, vec_type),
+ (6, short_channel_id, option),
+ });
+ Ok(Some(Event::ProbeFailed {
+ payment_id,
+ payment_hash,
+ path: path.unwrap(),
+ short_channel_id,
+ }))
+ };
+ f()
+ },
+ 25u8 => {
+ let f = || {
+ let mut prev_channel_id = [0; 32];
+ let mut failed_next_destination_opt = None;
+ read_tlv_fields!(reader, {
+ (0, prev_channel_id, required),
+ (2, failed_next_destination_opt, ignorable),
+ });
+ if let Some(failed_next_destination) = failed_next_destination_opt {
+ Ok(Some(Event::HTLCHandlingFailed {
+ prev_channel_id,
+ failed_next_destination,
+ }))
+ } else {
+ // If we fail to read a `failed_next_destination` assume it's because
+ // `MaybeReadable::read` returned `Ok(None)`, though it's also possible we
+ // were simply missing the field.
+ Ok(None)
+ }
+ };
+ f()
+ },
+ 27u8 => Ok(None),
+ 29u8 => {
+ let f = || {
+ let mut channel_id = [0; 32];
+ let mut user_channel_id: u128 = 0;
+ let mut counterparty_node_id = OptionDeserWrapper(None);
+ let mut channel_type = OptionDeserWrapper(None);
+ read_tlv_fields!(reader, {
+ (0, channel_id, required),
+ (2, user_channel_id, required),
+ (4, counterparty_node_id, required),
+ (6, channel_type, required),
+ });
+
+ Ok(Some(Event::ChannelReady {
+ channel_id,
+ user_channel_id,
+ counterparty_node_id: counterparty_node_id.0.unwrap(),
+ channel_type: channel_type.0.unwrap()
+ }))
};
f()
},
// Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
- x if x % 2 == 1 => Ok(None),
+ // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
+ // reads.
+ x if x % 2 == 1 => {
+ // If the event is of unknown type, assume it was written with `write_tlv_fields`,
+ // which prefixes the whole thing with a length BigSize. Because the event is
+ // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
+ // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
+ // exactly the number of bytes specified, ignoring them entirely.
+ let tlv_len: BigSize = Readable::read(reader)?;
+ FixedLengthReader::new(reader, tlv_len.0)
+ .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
+ Ok(None)
+ },
_ => Err(msgs::DecodeError::InvalidValue)
}
}
/// The message which should be sent.
msg: msgs::FundingSigned,
},
- /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
- SendFundingLocked {
+ /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
+ SendChannelReady {
/// The node_id of the node which should receive these message(s)
node_id: PublicKey,
- /// The funding_locked message which should be sent.
- msg: msgs::FundingLocked,
+ /// The channel_ready message which should be sent.
+ msg: msgs::ChannelReady,
},
/// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
SendAnnouncementSignatures {
/// The message which should be sent.
msg: msgs::ChannelReestablish,
},
+ /// Used to send a channel_announcement and channel_update to a specific peer, likely on
+ /// initial connection to ensure our peers know about our channels.
+ SendChannelAnnouncement {
+ /// The node_id of the node which should receive this message
+ node_id: PublicKey,
+ /// The channel_announcement which should be sent.
+ msg: msgs::ChannelAnnouncement,
+ /// The followup channel_update which should be sent.
+ update_msg: msgs::ChannelUpdate,
+ },
/// Used to indicate that a channel_announcement and channel_update should be broadcast to all
/// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
///
- /// Note that after doing so, you very likely (unless you did so very recently) want to call
- /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
- /// This ensures that any nodes which see our channel_announcement also have a relevant
+ /// Note that after doing so, you very likely (unless you did so very recently) want to
+ /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
+ /// ensures that any nodes which see our channel_announcement also have a relevant
/// node_announcement, including relevant feature flags which may be important for routing
/// through or to us.
+ ///
+ /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
BroadcastChannelAnnouncement {
/// The channel_announcement which should be sent.
msg: msgs::ChannelAnnouncement,
/// The followup channel_update which should be sent.
update_msg: msgs::ChannelUpdate,
},
- /// Used to indicate that a node_announcement should be broadcast to all peers.
- BroadcastNodeAnnouncement {
- /// The node_announcement which should be sent.
- msg: msgs::NodeAnnouncement,
- },
/// Used to indicate that a channel_update should be broadcast to all peers.
BroadcastChannelUpdate {
/// The channel_update which should be sent.
node_id: PublicKey,
/// The reply_channel_range which should be sent.
msg: msgs::ReplyChannelRange,
- }
+ },
+ /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
+ /// enable receiving gossip messages from the peer.
+ SendGossipTimestampFilter {
+ /// The node_id of this message recipient
+ node_id: PublicKey,
+ /// The gossip_timestamp_filter which should be sent.
+ msg: msgs::GossipTimestampFilter,
+ },
}
/// A trait indicating an object may generate message send events
fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
}
+/// A trait indicating an object may generate onion messages to send
+pub trait OnionMessageProvider {
+ /// Gets the next pending onion message for the peer with the given node id.
+ fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
+}
+
/// A trait indicating an object may generate events.
///
/// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
///
-/// # Requirements
+/// Implementations of this trait may also feature an async version of event handling, as shown with
+/// [`ChannelManager::process_pending_events_async`] and
+/// [`ChainMonitor::process_pending_events_async`].
///
-/// See [`process_pending_events`] for requirements around event processing.
+/// # Requirements
///
/// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
-/// event since the last invocation. The handler must either act upon the event immediately
-/// or preserve it for later handling.
+/// event since the last invocation.
+///
+/// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
+/// and replay any unhandled events on startup. An [`Event`] is considered handled when
+/// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
+/// relevant changes to disk *before* returning.
+///
+/// Further, because an application may crash between an [`Event`] being handled and the
+/// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
+/// effect, [`Event`]s may be replayed.
///
/// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
/// consult the provider's documentation on the implication of processing events and how a handler
/// [`handle_event`]: EventHandler::handle_event
/// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
/// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
+/// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
+/// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
pub trait EventsProvider {
/// Processes any events generated since the last call using the given event handler.
///
- /// Subsequent calls must only process new events. However, handlers must be capable of handling
- /// duplicate events across process restarts. This may occur if the provider was recovered from
- /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
+ /// See the trait-level documentation for requirements.
fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
}
/// A trait implemented for objects handling events from [`EventsProvider`].
+///
+/// An async variation also exists for implementations of [`EventsProvider`] that support async
+/// event handling. The async event handler should satisfy the generic bounds: `F:
+/// core::future::Future, H: Fn(Event) -> F`.
pub trait EventHandler {
/// Handles the given [`Event`].
///
/// See [`EventsProvider`] for details that must be considered when implementing this method.
- fn handle_event(&self, event: &Event);
+ fn handle_event(&self, event: Event);
}
-impl<F> EventHandler for F where F: Fn(&Event) {
- fn handle_event(&self, event: &Event) {
+impl<F> EventHandler for F where F: Fn(Event) {
+ fn handle_event(&self, event: Event) {
self(event)
}
}
+
+impl<T: EventHandler> EventHandler for Arc<T> {
+ fn handle_event(&self, event: Event) {
+ self.deref().handle_event(event)
+ }
+}