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events.rs
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// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.
//! Events are returned from various bits in the library which indicate some action must be taken
//! by the client.
//!
//! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
//! future, as well as generate and broadcast funding transactions handle payment preimages and a
//! few other things.
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::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.
#[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,
},
/// 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
/// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
/// written as it makes no sense to respond to it after reconnecting to peers).
#[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.
/// 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`]: 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 `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 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`] or [`ChannelManager::fail_htlc_backwards_with_reason`]
/// to free up resources for this HTLC and avoid network congestion.
/// If you fail to call either [`ChannelManager::claim_funds`], [`ChannelManager::fail_htlc_backwards`],
/// or [`ChannelManager::fail_htlc_backwards_with_reason`] within the HTLC's timeout, the HTLC will be
/// automatically failed.
///
/// # 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
/// [`ChannelManager::fail_htlc_backwards_with_reason`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards_with_reason
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.
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 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 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 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.
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.
///
/// [`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>>,
},
/// 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,
/// you should wait a random amount of time in roughly the range (now + time_forwardable,
/// 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
/// counterparty spending them due to some kind of timeout. Thus, you need to store them
/// somewhere and spend them when you create on-chain transactions.
SpendableOutputs {
/// The outputs which you should store as spendable by you.
outputs: Vec<SpendableOutputDescriptor>,
},
/// 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
/// was pending, the amount the next hop claimed will have been rounded down to the nearest
/// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
/// claimed the full value in millisatoshis from the source. In this case,
/// `claim_from_onchain_tx` will be set.
///
/// If the channel which sent us the payment has been force-closed, we will claim the funds
/// via an on-chain transaction. In that case we do not yet know the on-chain transaction
/// fees which we will spend and will instead set this to `None`. It is possible duplicate
/// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
/// `None`.
fee_earned_msat: Option<u64>,
/// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
/// 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 {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
match self {
&Event::FundingGenerationReady { .. } => {
0u8.write(writer)?;
// We never write out FundingGenerationReady events as, upon disconnection, peers
// drop any channels which have not yet exchanged funding_signed.
},
&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 payment_preimage;
match &purpose {
PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
payment_secret = Some(secret);
payment_preimage = *preimage;
},
PaymentPurpose::SpontaneousPayment(preimage) => {
payment_preimage = Some(*preimage);
}
}
write_tlv_fields!(writer, {
(0, payment_hash, required),
(1, receiver_node_id, option),
(2, payment_secret, 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_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::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)]
ref error_data,
} => {
3u8.write(writer)?;
#[cfg(test)]