/// A monitor event containing an HTLCUpdate.
HTLCEvent(HTLCUpdate),
- /// A monitor event that the Channel's commitment transaction was broadcasted.
- CommitmentTxBroadcasted(OutPoint),
+ /// A monitor event that the Channel's commitment transaction was confirmed.
+ CommitmentTxConfirmed(OutPoint),
}
/// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
/// with at worst this delay, so we are not only using this value as a mercy for them but also
/// us as a safeguard to delay with enough time.
pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
-/// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
-/// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
+/// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
+/// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
+/// losing money.
+///
+/// Note that this is a library-wide security assumption. If a reorg deeper than this number of
+/// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
+/// by a [`ChannelMonitor`] may be incorrect.
// We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
// It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
},
);
+/// Details about the balance(s) available for spending once the channel appears on chain.
+///
+/// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
+/// be provided.
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[cfg_attr(test, derive(PartialOrd, Ord))]
+pub enum Balance {
+ /// The channel is not yet closed (or the commitment or closing transaction has not yet
+ /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
+ /// force-closed now.
+ ClaimableOnChannelClose {
+ /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
+ /// required to do so.
+ claimable_amount_satoshis: u64,
+ },
+ /// The channel has been closed, and the given balance is ours but awaiting confirmations until
+ /// we consider it spendable.
+ ClaimableAwaitingConfirmations {
+ /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
+ /// were spent in broadcasting the transaction.
+ claimable_amount_satoshis: u64,
+ /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
+ /// amount.
+ confirmation_height: u32,
+ },
+ /// The channel has been closed, and the given balance should be ours but awaiting spending
+ /// transaction confirmation. If the spending transaction does not confirm in time, it is
+ /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
+ ///
+ /// Once the spending transaction confirms, before it has reached enough confirmations to be
+ /// considered safe from chain reorganizations, the balance will instead be provided via
+ /// [`Balance::ClaimableAwaitingConfirmations`].
+ ContentiousClaimable {
+ /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
+ /// required to do so.
+ claimable_amount_satoshis: u64,
+ /// The height at which the counterparty may be able to claim the balance if we have not
+ /// done so.
+ timeout_height: u32,
+ },
+ /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
+ /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
+ /// likely to be claimed by our counterparty before we do.
+ MaybeClaimableHTLCAwaitingTimeout {
+ /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
+ /// required to do so.
+ claimable_amount_satoshis: u64,
+ /// The height at which we will be able to claim the balance if our counterparty has not
+ /// done so.
+ claimable_height: u32,
+ },
+}
+
/// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
#[derive(PartialEq)]
struct IrrevocablyResolvedHTLC {
0u8.write(writer)?;
upd.write(writer)?;
},
- MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
+ MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?
}
}
pub fn current_best_block(&self) -> BestBlock {
self.inner.lock().unwrap().best_block.clone()
}
+
+ /// Gets the balances in this channel which are either claimable by us if we were to
+ /// force-close the channel now or which are claimable on-chain (possibly awaiting
+ /// confirmation).
+ ///
+ /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
+ /// included here until an [`Event::SpendableOutputs`] event has been generated for the
+ /// balance, or until our counterparty has claimed the balance and accrued several
+ /// confirmations on the claim transaction.
+ ///
+ /// Note that the balances available when you or your counterparty have broadcasted revoked
+ /// state(s) may not be fully captured here.
+ // TODO, fix that ^
+ ///
+ /// See [`Balance`] for additional details on the types of claimable balances which
+ /// may be returned here and their meanings.
+ pub fn get_claimable_balances(&self) -> Vec<Balance> {
+ let mut res = Vec::new();
+ let us = self.inner.lock().unwrap();
+
+ let mut confirmed_txid = us.funding_spend_confirmed;
+ let mut pending_commitment_tx_conf_thresh = None;
+ let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+ if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
+ Some((event.txid, event.confirmation_threshold()))
+ } else { None }
+ });
+ if let Some((txid, conf_thresh)) = funding_spend_pending {
+ debug_assert!(us.funding_spend_confirmed.is_none(),
+ "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
+ confirmed_txid = Some(txid);
+ pending_commitment_tx_conf_thresh = Some(conf_thresh);
+ }
+
+ macro_rules! walk_htlcs {
+ ($holder_commitment: expr, $htlc_iter: expr) => {
+ for htlc in $htlc_iter {
+ if let Some(htlc_input_idx) = htlc.transaction_output_index {
+ if us.htlcs_resolved_on_chain.iter().any(|v| v.input_idx == htlc_input_idx) {
+ assert!(us.funding_spend_confirmed.is_some());
+ } else if htlc.offered == $holder_commitment {
+ // If the payment was outbound, check if there's an HTLCUpdate
+ // indicating we have spent this HTLC with a timeout, claiming it back
+ // and awaiting confirmations on it.
+ let htlc_update_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+ if let OnchainEvent::HTLCUpdate { input_idx: Some(input_idx), .. } = event.event {
+ if input_idx == htlc_input_idx { Some(event.confirmation_threshold()) } else { None }
+ } else { None }
+ });
+ if let Some(conf_thresh) = htlc_update_pending {
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: htlc.amount_msat / 1000,
+ confirmation_height: conf_thresh,
+ });
+ } else {
+ res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
+ claimable_amount_satoshis: htlc.amount_msat / 1000,
+ claimable_height: htlc.cltv_expiry,
+ });
+ }
+ } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
+ // Otherwise (the payment was inbound), only expose it as claimable if
+ // we know the preimage.
+ // Note that if there is a pending claim, but it did not use the
+ // preimage, we lost funds to our counterparty! We will then continue
+ // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
+ let htlc_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+ if let OnchainEvent::HTLCSpendConfirmation { input_idx, preimage, .. } = event.event {
+ if input_idx == htlc_input_idx {
+ Some((event.confirmation_threshold(), preimage.is_some()))
+ } else { None }
+ } else { None }
+ });
+ if let Some((conf_thresh, true)) = htlc_spend_pending {
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: htlc.amount_msat / 1000,
+ confirmation_height: conf_thresh,
+ });
+ } else {
+ res.push(Balance::ContentiousClaimable {
+ claimable_amount_satoshis: htlc.amount_msat / 1000,
+ timeout_height: htlc.cltv_expiry,
+ });
+ }
+ }
+ }
+ }
+ }
+ }
+
+ if let Some(txid) = confirmed_txid {
+ let mut found_commitment_tx = false;
+ if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
+ walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().map(|(a, _)| a));
+ if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
+ if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+ if let OnchainEvent::MaturingOutput {
+ descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
+ } = &event.event {
+ Some(descriptor.output.value)
+ } else { None }
+ }) {
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: value,
+ confirmation_height: conf_thresh,
+ });
+ } else {
+ // If a counterparty commitment transaction is awaiting confirmation, we
+ // should either have a StaticPaymentOutput MaturingOutput event awaiting
+ // confirmation with the same height or have never met our dust amount.
+ }
+ }
+ found_commitment_tx = true;
+ } else if txid == us.current_holder_commitment_tx.txid {
+ walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
+ if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
+ confirmation_height: conf_thresh,
+ });
+ }
+ found_commitment_tx = true;
+ } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
+ if txid == prev_commitment.txid {
+ walk_htlcs!(true, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
+ if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: prev_commitment.to_self_value_sat,
+ confirmation_height: conf_thresh,
+ });
+ }
+ found_commitment_tx = true;
+ }
+ }
+ if !found_commitment_tx {
+ if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
+ // We blindly assume this is a cooperative close transaction here, and that
+ // neither us nor our counterparty misbehaved. At worst we've under-estimated
+ // the amount we can claim as we'll punish a misbehaving counterparty.
+ res.push(Balance::ClaimableAwaitingConfirmations {
+ claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
+ confirmation_height: conf_thresh,
+ });
+ }
+ }
+ // TODO: Add logic to provide claimable balances for counterparty broadcasting revoked
+ // outputs.
+ } else {
+ let mut claimable_inbound_htlc_value_sat = 0;
+ for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
+ if htlc.transaction_output_index.is_none() { continue; }
+ if htlc.offered {
+ res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
+ claimable_amount_satoshis: htlc.amount_msat / 1000,
+ claimable_height: htlc.cltv_expiry,
+ });
+ } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
+ claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
+ }
+ }
+ res.push(Balance::ClaimableOnChannelClose {
+ claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
+ });
+ }
+
+ res
+ }
}
/// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
log_info!(logger, "Broadcasting local {}", log_tx!(tx));
broadcaster.broadcast_transaction(tx);
}
- self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
+ self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
}
pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
} else if !self.holder_tx_signed {
log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
} else {
- // If we generated a MonitorEvent::CommitmentTxBroadcasted, the ChannelManager
+ // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
// will still give us a ChannelForceClosed event with !should_broadcast, but we
// shouldn't print the scary warning above.
log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), false, self.best_block.height());
claimable_outpoints.push(commitment_package);
- self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
+ self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
self.holder_tx_signed = true;
// Because we're broadcasting a commitment transaction, we should construct the package
// we've already failed the HTLC as the commitment transaction
// which was broadcasted was revoked. In that case, we should
// spend the HTLC output here immediately, and expose that fact
- // as a ClaimableBalance, something which we do not yet do.
+ // as a Balance, something which we do not yet do.
// TODO: Track the above as claimable!
}
continue 'outer_loop;
for _ in 0..pending_monitor_events_len {
let ev = match <u8 as Readable>::read(reader)? {
0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
- 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
+ 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
_ => return Err(DecodeError::InvalidValue)
};
pending_monitor_events.push(ev);
projects / rust-lightning / blobdiff