use ln::msgs::DecodeError;
use ln::PaymentPreimage;
+#[cfg(anchors)]
+use ln::chan_utils;
use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
+#[cfg(anchors)]
+use chain::chaininterface::ConfirmationTarget;
use chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
use chain::keysinterface::{Sign, KeysInterface};
+#[cfg(anchors)]
+use chain::package::PackageSolvingData;
use chain::package::PackageTemplate;
use util::logger::Logger;
use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter};
}
}
+// Represents the different types of claims for which events are yielded externally to satisfy said
+// claims.
+#[cfg(anchors)]
+pub(crate) enum ClaimEvent {
+ /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
+ /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
+ BumpCommitment {
+ package_target_feerate_sat_per_1000_weight: u32,
+ commitment_tx: Transaction,
+ anchor_output_idx: u32,
+ },
+}
+
/// Represents the different ways an output can be claimed (i.e., spent to an address under our
/// control) onchain.
pub(crate) enum OnchainClaim {
/// A finalized transaction pending confirmation spending the output to claim.
Tx(Transaction),
+ #[cfg(anchors)]
+ /// An event yielded externally to signal additional inputs must be added to a transaction
+ /// pending confirmation spending the output to claim.
+ Event(ClaimEvent),
}
/// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
pub(crate) pending_claim_requests: HashMap<Txid, PackageTemplate>,
#[cfg(not(test))]
pending_claim_requests: HashMap<Txid, PackageTemplate>,
+ #[cfg(anchors)]
+ pending_claim_events: HashMap<Txid, ClaimEvent>,
// Used to link outpoints claimed in a connected block to a pending claim request.
// Key is outpoint than monitor parsing has detected we have keys/scripts to claim
locktimed_packages,
pending_claim_requests,
onchain_events_awaiting_threshold_conf,
+ #[cfg(anchors)]
+ pending_claim_events: HashMap::new(),
secp_ctx,
})
}
claimable_outpoints: HashMap::new(),
locktimed_packages: BTreeMap::new(),
onchain_events_awaiting_threshold_conf: Vec::new(),
+ #[cfg(anchors)]
+ pending_claim_events: HashMap::new(),
secp_ctx,
}
self.holder_commitment.to_broadcaster_value_sat()
}
- /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
- /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
- /// Panics if there are signing errors, because signing operations in reaction to on-chain events
- /// are not expected to fail, and if they do, we may lose funds.
+ /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
+ /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
+ /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
+ /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
+ /// Child-Pay-For-Parent.
+ ///
+ /// Panics if there are signing errors, because signing operations in reaction to on-chain
+ /// events are not expected to fail, and if they do, we may lose funds.
fn generate_claim<F: Deref, L: Deref>(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(Option<u32>, u64, OnchainClaim)>
where F::Target: FeeEstimator,
L::Target: Logger,
return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)))
}
} else {
- // Note: Currently, amounts of holder outputs spending witnesses aren't used
- // as we can't malleate spending package to increase their feerate. This
- // should change with the remaining anchor output patchset.
- if let Some(transaction) = cached_request.finalize_untractable_package(self, logger) {
- return Some((None, 0, OnchainClaim::Tx(transaction)));
+ // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
+ // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
+ // which require external funding.
+ #[cfg(not(anchors))]
+ let inputs = cached_request.inputs();
+ #[cfg(anchors)]
+ let mut inputs = cached_request.inputs();
+ debug_assert_eq!(inputs.len(), 1);
+ let tx = match cached_request.finalize_untractable_package(self, logger) {
+ Some(tx) => tx,
+ None => return None,
+ };
+ if !cached_request.requires_external_funding() {
+ return Some((None, 0, OnchainClaim::Tx(tx)));
}
+ #[cfg(anchors)]
+ return inputs.find_map(|input| match input {
+ // Commitment inputs with anchors support are the only untractable inputs supported
+ // thus far that require external funding.
+ PackageSolvingData::HolderFundingOutput(..) => {
+ debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
+ "Holder commitment transaction mismatch");
+ // We'll locate an anchor output we can spend within the commitment transaction.
+ let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
+ match chan_utils::get_anchor_output(&tx, funding_pubkey) {
+ // An anchor output was found, so we should yield a funding event externally.
+ Some((idx, _)) => {
+ // TODO: Use a lower confirmation target when both our and the
+ // counterparty's latest commitment don't have any HTLCs present.
+ let conf_target = ConfirmationTarget::HighPriority;
+ let package_target_feerate_sat_per_1000_weight = cached_request
+ .compute_package_feerate(fee_estimator, conf_target);
+ Some((
+ new_timer,
+ package_target_feerate_sat_per_1000_weight as u64,
+ OnchainClaim::Event(ClaimEvent::BumpCommitment {
+ package_target_feerate_sat_per_1000_weight,
+ commitment_tx: tx.clone(),
+ anchor_output_idx: idx,
+ }),
+ ))
+ },
+ // An anchor output was not found. There's nothing we can do other than
+ // attempt to broadcast the transaction with its current fee rate and hope
+ // it confirms. This is essentially the same behavior as a commitment
+ // transaction without anchor outputs.
+ None => Some((None, 0, OnchainClaim::Tx(tx.clone()))),
+ }
+ },
+ _ => {
+ debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
+ None
+ },
+ });
}
None
}
broadcaster.broadcast_transaction(&tx);
tx.txid()
},
+ #[cfg(anchors)]
+ OnchainClaim::Event(claim_event) => {
+ log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
+ let txid = match claim_event {
+ ClaimEvent::BumpCommitment { ref commitment_tx, .. } => commitment_tx.txid(),
+ };
+ self.pending_claim_events.insert(txid, claim_event);
+ txid
+ },
};
for k in req.outpoints() {
log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
for outpoint in request.outpoints() {
log_debug!(logger, "Removing claim tracking for {} due to maturation of claim tx {}.", outpoint, claim_request);
self.claimable_outpoints.remove(&outpoint);
+ #[cfg(anchors)]
+ self.pending_claim_events.remove(&claim_request);
}
}
},
log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
broadcaster.broadcast_transaction(&bump_tx);
},
+ #[cfg(anchors)]
+ OnchainClaim::Event(claim_event) => {
+ log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
+ self.pending_claim_events.insert(*first_claim_txid, claim_event);
+ },
}
if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) {
request.set_timer(new_timer);
self.onchain_events_awaiting_threshold_conf.push(entry);
}
}
- for (_, request) in bump_candidates.iter_mut() {
+ for (_first_claim_txid_height, request) in bump_candidates.iter_mut() {
if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(height, &request, fee_estimator, &&*logger) {
request.set_timer(new_timer);
request.set_feerate(new_feerate);
log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
broadcaster.broadcast_transaction(&bump_tx);
},
+ #[cfg(anchors)]
+ OnchainClaim::Event(claim_event) => {
+ log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
+ self.pending_claim_events.insert(_first_claim_txid_height.0, claim_event);
+ },
}
}
}
use io;
use prelude::*;
use core::cmp;
+#[cfg(anchors)]
+use core::convert::TryInto;
use core::mem;
use core::ops::Deref;
use bitcoin::{PackedLockTime, Sequence, Witness};
pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
self.inputs.iter().map(|(o, _)| o).collect()
}
+ pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
+ self.inputs.iter().map(|(_, i)| i)
+ }
pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
match self.malleability {
PackageMalleability::Malleable => {
}
/// Gets the amount of all outptus being spent by this package, only valid for malleable
/// packages.
- fn package_amount(&self) -> u64 {
+ pub(crate) fn package_amount(&self) -> u64 {
let mut amounts = 0;
for (_, outp) in self.inputs.iter() {
amounts += outp.amount();
inputs_weight + witnesses_weight + transaction_weight + output_weight
}
pub(crate) fn finalize_malleable_package<L: Deref, Signer: Sign>(
- &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L,
+ &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L
) -> Option<Transaction> where L::Target: Logger {
debug_assert!(self.is_malleable());
let mut bumped_tx = Transaction {
}
None
}
+
+ #[cfg(anchors)]
+ /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
+ /// and the new feerate is below it, we'll use a 25% increase of the previous feerate instead of
+ /// the new one.
+ pub(crate) fn compute_package_feerate<F: Deref>(
+ &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
+ ) -> u32 where F::Target: FeeEstimator {
+ let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
+ if self.feerate_previous != 0 {
+ // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
+ if feerate_estimate as u64 > self.feerate_previous {
+ feerate_estimate
+ } else {
+ // ...else just increase the previous feerate by 25% (because that's a nice number)
+ (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
+ }
+ } else {
+ feerate_estimate
+ }
+ }
+
+ /// Determines whether a package contains an input which must have additional external inputs
+ /// attached to help the spending transaction reach confirmation.
+ pub(crate) fn requires_external_funding(&self) -> bool {
+ self.inputs.iter().find(|input| match input.1 {
+ PackageSolvingData::HolderFundingOutput(ref outp) => outp.opt_anchors(),
+ _ => false,
+ }).is_some()
+ }
+
pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
let malleability = match input_solving_data {
- PackageSolvingData::RevokedOutput(..) => { PackageMalleability::Malleable },
- PackageSolvingData::RevokedHTLCOutput(..) => { PackageMalleability::Malleable },
- PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { PackageMalleability::Malleable },
- PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { PackageMalleability::Malleable },
- PackageSolvingData::HolderHTLCOutput(..) => { PackageMalleability::Untractable },
- PackageSolvingData::HolderFundingOutput(..) => { PackageMalleability::Untractable },
+ PackageSolvingData::RevokedOutput(..) => PackageMalleability::Malleable,
+ PackageSolvingData::RevokedHTLCOutput(..) => PackageMalleability::Malleable,
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => PackageMalleability::Malleable,
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => PackageMalleability::Malleable,
+ PackageSolvingData::HolderHTLCOutput(..) => PackageMalleability::Untractable,
+ PackageSolvingData::HolderFundingOutput(..) => PackageMalleability::Untractable,
};
let mut inputs = Vec::with_capacity(1);
inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
projects / rust-lightning / commitdiff