if let Some(transaction_output_index) = htlc.transaction_output_index {
if let &Some((ref their_sig, ref our_sig)) = sigs {
if htlc.offered {
+ log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions");
let mut htlc_timeout_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
res.push(htlc_timeout_tx);
} else {
if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
+ log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions");
let mut htlc_success_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
// weren't yet included in our commitment transaction(s).
if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
if local_tx.txid == commitment_txid {
+ log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
match self.key_storage {
Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
}
if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
if local_tx.txid == commitment_txid {
+ log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
match self.key_storage {
Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
}
pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
- // TODO: We need to consider HTLCs which weren't included in latest local commitment
- // transaction (or in any of the latest two local commitment transactions). This probably
- // needs to use the same logic as the revoked-tx-announe logic - checking the last two
- // remote commitment transactions. This probably has implications for what data we need to
- // store in local commitment transactions.
+ // We need to consider all HTLCs which are:
+ // * in any unrevoked remote commitment transaction, as they could broadcast said
+ // transactions and we'd end up in a race, or
+ // * are in our latest local commitment transaction, as this is the thing we will
+ // broadcast if we go on-chain.
// Note that we consider HTLCs which were below dust threshold here - while they don't
// strictly imply that we need to fail the channel, we need to go ahead and fail them back
// to the source, and if we don't fail the channel we will have to ensure that the next
// updates that peer sends us are update_fails, failing the channel if not. It's probably
// easier to just fail the channel as this case should be rare enough anyway.
+ macro_rules! scan_commitment {
+ ($htlcs: expr, $local_tx: expr) => {
+ for ref htlc in $htlcs {
+ // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
+ // chain with enough room to claim the HTLC without our counterparty being able to
+ // time out the HTLC first.
+ // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
+ // concern is being able to claim the corresponding inbound HTLC (on another
+ // channel) before it expires. In fact, we don't even really care if our
+ // counterparty here claims such an outbound HTLC after it expired as long as we
+ // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
+ // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
+ // we give ourselves a few blocks of headroom after expiration before going
+ // on-chain for an expired HTLC.
+ // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
+ // from us until we've reached the point where we go on-chain with the
+ // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
+ // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
+ // aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
+ // inbound_cltv == height + CLTV_CLAIM_BUFFER
+ // outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFER <= inbound_cltv - CLTV_CLAIM_BUFFER
+ // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= inbound_cltv - outbound_cltv
+ // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= CLTV_EXPIRY_DELTA
+ let htlc_outbound = $local_tx == htlc.offered;
+ if ( htlc_outbound && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
+ (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
+ log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
+ return true;
+ }
+ }
+ }
+ }
+
if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
- for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
- // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
- // chain with enough room to claim the HTLC without our counterparty being able to
- // time out the HTLC first.
- // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
- // concern is being able to claim the corresponding inbound HTLC (on another
- // channel) before it expires. In fact, we don't even really care if our
- // counterparty here claims such an outbound HTLC after it expired as long as we
- // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
- // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
- // we give ourselves a few blocks of headroom after expiration before going
- // on-chain for an expired HTLC.
- // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
- // from us until we've reached the point where we go on-chain with the
- // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
- // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
- // aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
- // inbound_cltv == height + CLTV_CLAIM_BUFFER
- // outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFER <= inbound_cltv - CLTV_CLAIM_BUFFER
- // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= inbound_cltv - outbound_cltv
- // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= CLTV_EXPIRY_DELTA
- if ( htlc.offered && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
- (!htlc.offered && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
- return true;
+ scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
+ }
+
+ if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
+ if let &Some(ref txid) = current_remote_commitment_txid {
+ if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
+ scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
+ }
+ }
+ if let &Some(ref txid) = prev_remote_commitment_txid {
+ if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
+ scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
}
}
}
+
false
}
projects / rust-lightning / blobdiff