//! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
//! building, tracking, bumping and notifications functions.
+#[cfg(anchors)]
+use bitcoin::PackedLockTime;
use bitcoin::blockdata::transaction::Transaction;
use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
use bitcoin::blockdata::script::Script;
use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
use bitcoin::secp256k1;
-use crate::chain::keysinterface::{ChannelSigner, EntropySource, SignerProvider};
+use crate::sign::{ChannelSigner, EntropySource, SignerProvider};
use crate::ln::msgs::DecodeError;
use crate::ln::PaymentPreimage;
#[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::WriteableEcdsaChannelSigner;
+use crate::sign::WriteableEcdsaChannelSigner;
#[cfg(anchors)]
use crate::chain::package::PackageSolvingData;
use crate::chain::package::PackageTemplate;
BumpHTLC {
target_feerate_sat_per_1000_weight: u32,
htlcs: Vec<ExternalHTLCClaim>,
+ tx_lock_time: PackedLockTime,
},
}
events.into_iter().map(|(_, event)| event).collect()
}
+ /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
+ /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
+ /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
+ /// invoking this every 30 seconds, or lower if running in an environment with spotty
+ /// connections, like on mobile.
+ pub(crate) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
+ &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
+ logger: &L,
+ )
+ where
+ B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
+ for (package_id, request) in self.pending_claim_requests.iter() {
+ let inputs = request.outpoints();
+ log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
+ bump_requests.push((*package_id, request.clone()));
+ }
+ for (package_id, request) in bump_requests {
+ self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
+ .map(|(_, new_feerate, claim)| {
+ let mut bumped_feerate = false;
+ if let Some(mut_request) = self.pending_claim_requests.get_mut(&package_id) {
+ bumped_feerate = request.previous_feerate() > new_feerate;
+ mut_request.set_feerate(new_feerate);
+ }
+ match claim {
+ OnchainClaim::Tx(tx) => {
+ let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
+ log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
+ broadcaster.broadcast_transaction(&tx);
+ },
+ #[cfg(anchors)]
+ OnchainClaim::Event(event) => {
+ let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
+ log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
+ request.outpoints());
+ #[cfg(debug_assertions)] {
+ debug_assert!(request.requires_external_funding());
+ let num_existing = self.pending_claim_events.iter()
+ .filter(|entry| entry.0 == package_id).count();
+ assert!(num_existing == 0 || num_existing == 1);
+ }
+ self.pending_claim_events.retain(|event| event.0 != package_id);
+ self.pending_claim_events.push((package_id, event));
+ }
+ }
+ });
+ }
+ }
+
/// 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
///
/// 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,
+ fn generate_claim<F: Deref, L: Deref>(
+ &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
+ fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
+ ) -> Option<(u32, u64, OnchainClaim)>
+ where
+ F::Target: FeeEstimator,
+ L::Target: Logger,
{
let request_outpoints = cached_request.outpoints();
if request_outpoints.is_empty() {
// 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).
- let new_timer = Some(cached_request.get_height_timer(cur_height));
+ let new_timer = cached_request.get_height_timer(cur_height);
if cached_request.is_malleable() {
#[cfg(anchors)]
{ // Attributes are not allowed on if expressions on our current MSRV of 1.41.
if cached_request.requires_external_funding() {
- let target_feerate_sat_per_1000_weight = cached_request
- .compute_package_feerate(fee_estimator, ConfirmationTarget::HighPriority);
+ let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
+ fee_estimator, ConfirmationTarget::HighPriority, force_feerate_bump
+ );
if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
return Some((
new_timer,
OnchainClaim::Event(ClaimEvent::BumpHTLC {
target_feerate_sat_per_1000_weight,
htlcs,
+ tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)),
}),
));
} else {
let predicted_weight = cached_request.package_weight(&self.destination_script);
if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
- predicted_weight, self.destination_script.dust_value().to_sat(), fee_estimator, logger,
+ predicted_weight, self.destination_script.dust_value().to_sat(),
+ force_feerate_bump, fee_estimator, logger,
) {
assert!(new_feerate != 0);
- 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);
+ let transaction = cached_request.finalize_malleable_package(
+ cur_height, self, output_value, self.destination_script.clone(), logger
+ ).unwrap();
+ log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
assert!(predicted_weight >= transaction.weight());
return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
}
None => return None,
};
if !cached_request.requires_external_funding() {
- return Some((None, 0, OnchainClaim::Tx(tx)));
+ return Some((new_timer, 0, OnchainClaim::Tx(tx)));
}
#[cfg(anchors)]
return inputs.find_map(|input| match input {
// 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);
+ .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
Some((
new_timer,
package_target_feerate_sat_per_1000_weight as u64,
// 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()))),
+ None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
}
},
_ => {
preprocessed_requests.push(req);
}
- // Claim everything up to and including cur_height + 1
- let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 2));
+ // Claim everything up to and including `cur_height`
+ let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
preprocessed_requests.append(&mut entry);
// 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, claim)) = self.generate_claim(cur_height, &req, &*fee_estimator, &*logger) {
+ if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
+ cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
+ ) {
req.set_timer(new_timer);
req.set_feerate(new_feerate);
let package_id = match claim {
// Check if any pending claim request must be rescheduled
for (package_id, request) in self.pending_claim_requests.iter() {
- if let Some(h) = request.timer() {
- if cur_height >= h {
- bump_candidates.insert(*package_id, request.clone());
- }
+ if cur_height >= request.timer() {
+ bump_candidates.insert(*package_id, request.clone());
}
}
// Build, bump and rebroadcast tx accordingly
log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
for (package_id, request) in bump_candidates.iter() {
- if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(cur_height, &request, &*fee_estimator, &*logger) {
+ if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
+ cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
+ ) {
match bump_claim {
OnchainClaim::Tx(bump_tx) => {
log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
}
}
for ((_package_id, _), ref mut request) in bump_candidates.iter_mut() {
- if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(height, &request, fee_estimator, &&*logger) {
+ // `height` is the height being disconnected, so our `current_height` is 1 lower.
+ let current_height = height - 1;
+ if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
+ current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger
+ ) {
request.set_timer(new_timer);
request.set_feerate(new_feerate);
match bump_claim {
projects / rust-lightning / blobdiff