Fail channel if we can't sign a new commitment tx during HTLC claim

[rust-lightning] / lightning / src / chain / channelmonitor.rs

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 4aef7852ba138b19c97939d1fbf2bebd5679d1e3..42c3e13a34feeff236a1b19712470808f0b19f69 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -37,9 +37,9 @@ use ln::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
 use ln::chan_utils;
 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
-use ln::channelmanager::{BestBlock, HTLCSource};
+use ln::channelmanager::HTLCSource;
 use chain;
-use chain::WatchedOutput;
+use chain::{BestBlock, WatchedOutput};
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
@@ -114,7 +114,7 @@ impl Readable for ChannelMonitorUpdate {
 }
 
 /// An error enum representing a failure to persist a channel monitor update.
-#[derive(Clone, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum ChannelMonitorUpdateErr {
        /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
        /// our state failed, but is expected to succeed at some point in the future).
@@ -1189,6 +1189,12 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                txids.dedup();
                txids
        }
+
+       /// Gets the latest best block which was connected either via the [`chain::Listen`] or
+       /// [`chain::Confirm`] interfaces.
+       pub fn current_best_block(&self) -> BestBlock {
+               self.inner.lock().unwrap().best_block.clone()
+       }
 }
 
 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
@@ -1353,10 +1359,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
                // holder commitment transactions.
                if self.broadcasted_holder_revokable_script.is_some() {
-                       let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, 0);
+                       // Assume that the broadcasted commitment transaction confirmed in the current best
+                       // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
+                       // transactions.
+                       let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
                        self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
                        if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
-                               let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, 0);
+                               let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
                                self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
                        }
                }
@@ -1724,7 +1733,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        // Returns (1) `PackageTemplate`s that can be given to the OnChainTxHandler, so that the handler can
        // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
        // script so we can detect whether a holder transaction has been seen on-chain.
-       fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
+       fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
                let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
 
                let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
@@ -1743,7 +1752,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                };
                                                HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
                                        };
-                               let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), height, false, height);
+                               let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
                                claim_requests.push(htlc_package);
                        }
                }
@@ -2043,6 +2052,9 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(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
+                       // assuming it gets confirmed in the next block. Sadly, we have code which considers
+                       // "not yet confirmed" things as discardable, so we cannot do that here.
                        let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
                        let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
                        if !new_outputs.is_empty() {
@@ -2821,11 +2833,11 @@ mod tests {
        use bitcoin::hash_types::Txid;
        use bitcoin::network::constants::Network;
        use hex;
+       use chain::BestBlock;
        use chain::channelmonitor::ChannelMonitor;
        use chain::package::{WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC, WEIGHT_REVOKED_OUTPUT};
        use chain::transaction::OutPoint;
        use ln::{PaymentPreimage, PaymentHash};
-       use ln::channelmanager::BestBlock;
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
        use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};