use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
use bitcoin::secp256k1;
-use ln::msgs::DecodeError;
-use ln::PaymentPreimage;
-use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
-use chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
-use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
-use chain::keysinterface::{Sign, KeysInterface};
-use chain::package::PackageTemplate;
-use util::logger::Logger;
-use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter};
-use util::byte_utils;
-
-use io;
-use prelude::*;
+use crate::ln::msgs::DecodeError;
+use crate::ln::PaymentPreimage;
+#[cfg(anchors)]
+use crate::ln::chan_utils;
+use crate::ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
+#[cfg(anchors)]
+use crate::chain::chaininterface::ConfirmationTarget;
+use crate::chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
+use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
+use crate::chain::keysinterface::{Sign, KeysInterface};
+#[cfg(anchors)]
+use crate::chain::package::PackageSolvingData;
+use crate::chain::package::PackageTemplate;
+use crate::util::logger::Logger;
+use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter};
+use crate::util::byte_utils;
+
+use crate::io;
+use crate::prelude::*;
use alloc::collections::BTreeMap;
use core::cmp;
use core::ops::Deref;
use core::mem::replace;
+#[cfg(anchors)]
+use core::mem::swap;
use bitcoin::hashes::Hash;
const MAX_ALLOC_SIZE: usize = 64*1024;
}
}
+// 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
/// do RBF bumping if possible.
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.
- fn generate_claim_tx<F: Deref, L: Deref>(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(Option<u32>, u64, Transaction)>
+ #[cfg(anchors)]
+ pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<ClaimEvent> {
+ let mut ret = HashMap::new();
+ swap(&mut ret, &mut self.pending_claim_events);
+ ret.into_iter().map(|(_, event)| event).collect::<Vec<_>>()
+ }
+
+ /// 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,
{
- if cached_request.outpoints().len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
+ let request_outpoints = cached_request.outpoints();
+ if request_outpoints.is_empty() {
+ // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
+ // packages cannot be aggregated and will never be split, so we cannot end up with an
+ // empty claim.
+ debug_assert!(cached_request.is_malleable());
+ return None;
+ }
+ // If we've seen transaction inclusion in the chain for all outpoints in our request, we
+ // don't need to continue generating more claims. We'll keep tracking the request to fully
+ // remove it once it reaches the confirmation threshold, or to generate a new claim if the
+ // transaction is reorged out.
+ let mut all_inputs_have_confirmed_spend = true;
+ for outpoint in &request_outpoints {
+ if let Some(first_claim_txid_height) = self.claimable_outpoints.get(outpoint) {
+ // We check for outpoint spends within claims individually rather than as a set
+ // since requests can have outpoints split off.
+ if !self.onchain_events_awaiting_threshold_conf.iter()
+ .any(|event_entry| if let OnchainEvent::Claim { claim_request } = event_entry.event {
+ first_claim_txid_height.0 == claim_request
+ } else {
+ // The onchain event is not a claim, keep seeking until we find one.
+ false
+ })
+ {
+ // Either we had no `OnchainEvent::Claim`, or we did but none matched the
+ // outpoint's registered spend.
+ all_inputs_have_confirmed_spend = false;
+ }
+ } else {
+ // The request's outpoint spend does not exist yet.
+ all_inputs_have_confirmed_spend = false;
+ }
+ }
+ if all_inputs_have_confirmed_spend {
+ return None;
+ }
// Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
// didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
cached_request.compute_package_output(predicted_weight, self.destination_script.dust_value().to_sat(), fee_estimator, logger) {
assert!(new_feerate != 0);
- let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap();
+ let transaction = cached_request.finalize_malleable_package(self, output_value, self.destination_script.clone(), logger).unwrap();
log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate);
assert!(predicted_weight >= transaction.weight());
- return Some((new_timer, new_feerate, transaction))
+ 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_package(self, 0, self.destination_script.clone(), logger) {
- return Some((None, 0, 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
}
// Generate claim transactions and track them to bump if necessary at
// height timer expiration (i.e in how many blocks we're going to take action).
for mut req in preprocessed_requests {
- if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(cur_height, &req, &*fee_estimator, &*logger) {
+ if let Some((new_timer, new_feerate, claim)) = self.generate_claim(cur_height, &req, &*fee_estimator, &*logger) {
req.set_timer(new_timer);
req.set_feerate(new_feerate);
- let txid = tx.txid();
+ let txid = match claim {
+ OnchainClaim::Tx(tx) => {
+ log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
+ 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);
self.claimable_outpoints.insert(k.clone(), (txid, conf_height));
}
self.pending_claim_requests.insert(txid, req);
- log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
- broadcaster.broadcast_transaction(&tx);
}
}
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);
}
}
},
// Build, bump and rebroadcast tx accordingly
log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
for (first_claim_txid, request) in bump_candidates.iter() {
- if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(cur_height, &request, &*fee_estimator, &*logger) {
- log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
- broadcaster.broadcast_transaction(&bump_tx);
+ if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(cur_height, &request, &*fee_estimator, &*logger) {
+ match bump_claim {
+ OnchainClaim::Tx(bump_tx) => {
+ 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);
request.set_feerate(new_feerate);
self.onchain_events_awaiting_threshold_conf.push(entry);
}
}
- for (_, request) in bump_candidates.iter_mut() {
- if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, fee_estimator, &&*logger) {
+ 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);
+ match bump_claim {
+ OnchainClaim::Tx(bump_tx) => {
+ 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);
+ },
+ }
}
}
for (ancestor_claim_txid, request) in bump_candidates.drain() {
projects / rust-lightning / blobdiff