Make ChannelMonitor always clonable
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index ce1ef9128f91efe8327f2f874daca511e7c6e4f1..1284553e74c4438876adfae913c2fc7519a57b69 100644 (file)
@@ -71,6 +71,15 @@ use crate::sync::{Mutex, LockTestExt};
 #[must_use]
 pub struct ChannelMonitorUpdate {
        pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
+       /// Historically, [`ChannelMonitor`]s didn't know their counterparty node id. However,
+       /// `ChannelManager` really wants to know it so that it can easily look up the corresponding
+       /// channel. For now, this results in a temporary map in `ChannelManager` to look up channels
+       /// by only the funding outpoint.
+       ///
+       /// To eventually remove that, we repeat the counterparty node id here so that we can upgrade
+       /// `ChannelMonitor`s to become aware of the counterparty node id if they were generated prior
+       /// to when it was stored directly in them.
+       pub(crate) counterparty_node_id: Option<PublicKey>,
        /// The sequence number of this update. Updates *must* be replayed in-order according to this
        /// sequence number (and updates may panic if they are not). The update_id values are strictly
        /// increasing and increase by one for each new update, with two exceptions specified below.
@@ -107,7 +116,9 @@ impl Writeable for ChannelMonitorUpdate {
                for update_step in self.updates.iter() {
                        update_step.write(w)?;
                }
-               write_tlv_fields!(w, {});
+               write_tlv_fields!(w, {
+                       (1, self.counterparty_node_id, option),
+               });
                Ok(())
        }
 }
@@ -122,8 +133,11 @@ impl Readable for ChannelMonitorUpdate {
                                updates.push(upd);
                        }
                }
-               read_tlv_fields!(r, {});
-               Ok(Self { update_id, updates })
+               let mut counterparty_node_id = None;
+               read_tlv_fields!(r, {
+                       (1, counterparty_node_id, option),
+               });
+               Ok(Self { update_id, counterparty_node_id, updates })
        }
 }
 
@@ -739,7 +753,7 @@ pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
        pub(super) inner: Mutex<ChannelMonitorImpl<Signer>>,
 }
 
-impl<Signer: WriteableEcdsaChannelSigner> Clone for ChannelMonitor<Signer> where Signer: Clone {
+impl<Signer: WriteableEcdsaChannelSigner> Clone for ChannelMonitor<Signer> {
        fn clone(&self) -> Self {
                let inner = self.inner.lock().unwrap().clone();
                ChannelMonitor::from_impl(inner)
@@ -1382,15 +1396,22 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
        /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
        /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
        /// have been registered.
-       pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
+       pub fn load_outputs_to_watch<F: Deref, L: Deref>(&self, filter: &F, logger: &L) 
+       where 
+               F::Target: chain::Filter, L::Target: Logger,
+       {
                let lock = self.inner.lock().unwrap();
+               let logger = WithChannelMonitor::from_impl(logger, &*lock);
+               log_trace!(&logger, "Registering funding outpoint {}", &lock.get_funding_txo().0);
                filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
                for (txid, outputs) in lock.get_outputs_to_watch().iter() {
                        for (index, script_pubkey) in outputs.iter() {
                                assert!(*index <= u16::max_value() as u32);
+                               let outpoint = OutPoint { txid: *txid, index: *index as u16 };
+                               log_trace!(logger, "Registering outpoint {} with the filter for monitoring spends", outpoint);
                                filter.register_output(WatchedOutput {
                                        block_hash: None,
-                                       outpoint: OutPoint { txid: *txid, index: *index as u16 },
+                                       outpoint,
                                        script_pubkey: script_pubkey.clone(),
                                });
                        }
@@ -2284,7 +2305,7 @@ macro_rules! fail_unbroadcast_htlcs {
                                                        // broadcastable commitment transaction has the HTLC in it, but it
                                                        // cannot currently change after channel initialization, so we don't
                                                        // need to here.
-                                                       let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
+                                                       let confirmed_htlcs_iter: &mut dyn Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
 
                                                        let mut matched_htlc = false;
                                                        for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
@@ -2659,18 +2680,59 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                }
        }
 
-       fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &WithChannelMonitor<L>)
-               where B::Target: BroadcasterInterface,
-                       L::Target: Logger,
-       {
-               let commit_txs = self.get_latest_holder_commitment_txn(logger);
-               let mut txs = vec![];
-               for tx in commit_txs.iter() {
-                       log_info!(logger, "Broadcasting local {}", log_tx!(tx));
-                       txs.push(tx);
-               }
-               broadcaster.broadcast_transactions(&txs);
+       fn generate_claimable_outpoints_and_watch_outputs(&mut self) -> (Vec<PackageTemplate>, Vec<TransactionOutputs>) {
+               let funding_outp = HolderFundingOutput::build(
+                       self.funding_redeemscript.clone(),
+                       self.channel_value_satoshis,
+                       self.onchain_tx_handler.channel_type_features().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(), self.best_block.height()
+               );
+               let mut claimable_outpoints = vec![commitment_package];
                self.pending_monitor_events.push(MonitorEvent::HolderForceClosed(self.funding_info.0));
+               // Although we aren't signing the transaction directly here, the transaction will be signed
+               // in the claim that is queued to OnchainTxHandler. We set holder_tx_signed here to reject
+               // new channel updates.
+               self.holder_tx_signed = true;
+               let mut watch_outputs = Vec::new();
+               // We can't broadcast our HTLC transactions while the commitment transaction is
+               // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
+               // `transactions_confirmed`.
+               if !self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
+                       // 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 unsigned_commitment_tx = self.onchain_tx_handler.get_unsigned_holder_commitment_tx();
+                       let new_outputs = self.get_broadcasted_holder_watch_outputs(
+                               &self.current_holder_commitment_tx, &unsigned_commitment_tx
+                       );
+                       if !new_outputs.is_empty() {
+                               watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
+                       }
+                       claimable_outpoints.append(&mut new_outpoints);
+               }
+               (claimable_outpoints, watch_outputs)
+       }
+
+       pub(crate) fn queue_latest_holder_commitment_txn_for_broadcast<B: Deref, F: Deref, L: Deref>(
+               &mut self, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &WithChannelMonitor<L>
+       )
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               let (claimable_outpoints, _) = self.generate_claimable_outpoints_and_watch_outputs();
+               self.onchain_tx_handler.update_claims_view_from_requests(
+                       claimable_outpoints, self.best_block.height(), self.best_block.height(), broadcaster,
+                       fee_estimator, logger
+               );
        }
 
        fn update_monitor<B: Deref, F: Deref, L: Deref>(
@@ -2690,6 +2752,15 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                        log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} change(s).",
                                log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
                }
+
+               if updates.counterparty_node_id.is_some() {
+                       if self.counterparty_node_id.is_none() {
+                               self.counterparty_node_id = updates.counterparty_node_id;
+                       } else {
+                               debug_assert_eq!(self.counterparty_node_id, updates.counterparty_node_id);
+                       }
+               }
+
                // ChannelMonitor updates may be applied after force close if we receive a preimage for a
                // broadcasted commitment transaction HTLC output that we'd like to claim on-chain. If this
                // is the case, we no longer have guaranteed access to the monitor's update ID, so we use a
@@ -2760,26 +2831,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                                        log_trace!(logger, "Avoiding commitment broadcast, already detected confirmed spend onchain");
                                                        continue;
                                                }
-                                               self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
-                                               // If the channel supports anchor outputs, we'll need to emit an external
-                                               // event to be consumed such that a child transaction is broadcast with a
-                                               // high enough feerate for the parent commitment transaction to confirm.
-                                               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
-                                                       let funding_output = HolderFundingOutput::build(
-                                                               self.funding_redeemscript.clone(), self.channel_value_satoshis,
-                                                               self.onchain_tx_handler.channel_type_features().clone(),
-                                                       );
-                                                       let best_block_height = self.best_block.height();
-                                                       let commitment_package = PackageTemplate::build_package(
-                                                               self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
-                                                               PackageSolvingData::HolderFundingOutput(funding_output),
-                                                               best_block_height, best_block_height
-                                                       );
-                                                       self.onchain_tx_handler.update_claims_view_from_requests(
-                                                               vec![commitment_package], best_block_height, best_block_height,
-                                                               broadcaster, &bounded_fee_estimator, logger,
-                                                       );
-                                               }
+                                               self.queue_latest_holder_commitment_txn_for_broadcast(broadcaster, &bounded_fee_estimator, logger);
                                        } else if !self.holder_tx_signed {
                                                log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
                                                log_error!(logger, "    in channel monitor for channel {}!", &self.funding_info.0.to_channel_id());
@@ -3356,6 +3408,58 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                }
        }
 
+       /// Cancels any existing pending claims for a commitment that previously confirmed and has now
+       /// been replaced by another.
+       pub fn cancel_prev_commitment_claims<L: Deref>(
+               &mut self, logger: &L, confirmed_commitment_txid: &Txid
+       ) where L::Target: Logger {
+               for (counterparty_commitment_txid, _) in &self.counterparty_commitment_txn_on_chain {
+                       // Cancel any pending claims for counterparty commitments we've seen confirm.
+                       if counterparty_commitment_txid == confirmed_commitment_txid {
+                               continue;
+                       }
+                       for (htlc, _) in self.counterparty_claimable_outpoints.get(counterparty_commitment_txid).unwrap_or(&vec![]) {
+                               log_trace!(logger, "Canceling claims for previously confirmed counterparty commitment {}",
+                                       counterparty_commitment_txid);
+                               let mut outpoint = BitcoinOutPoint { txid: *counterparty_commitment_txid, vout: 0 };
+                               if let Some(vout) = htlc.transaction_output_index {
+                                       outpoint.vout = vout;
+                                       self.onchain_tx_handler.abandon_claim(&outpoint);
+                               }
+                       }
+               }
+               if self.holder_tx_signed {
+                       // If we've signed, we may have broadcast either commitment (prev or current), and
+                       // attempted to claim from it immediately without waiting for a confirmation.
+                       if self.current_holder_commitment_tx.txid != *confirmed_commitment_txid {
+                               log_trace!(logger, "Canceling claims for previously broadcast holder commitment {}",
+                                       self.current_holder_commitment_tx.txid);
+                               let mut outpoint = BitcoinOutPoint { txid: self.current_holder_commitment_tx.txid, vout: 0 };
+                               for (htlc, _, _) in &self.current_holder_commitment_tx.htlc_outputs {
+                                       if let Some(vout) = htlc.transaction_output_index {
+                                               outpoint.vout = vout;
+                                               self.onchain_tx_handler.abandon_claim(&outpoint);
+                                       }
+                               }
+                       }
+                       if let Some(prev_holder_commitment_tx) = &self.prev_holder_signed_commitment_tx {
+                               if prev_holder_commitment_tx.txid != *confirmed_commitment_txid {
+                                       log_trace!(logger, "Canceling claims for previously broadcast holder commitment {}",
+                                               prev_holder_commitment_tx.txid);
+                                       let mut outpoint = BitcoinOutPoint { txid: prev_holder_commitment_tx.txid, vout: 0 };
+                                       for (htlc, _, _) in &prev_holder_commitment_tx.htlc_outputs {
+                                               if let Some(vout) = htlc.transaction_output_index {
+                                                       outpoint.vout = vout;
+                                                       self.onchain_tx_handler.abandon_claim(&outpoint);
+                                               }
+                                       }
+                               }
+                       }
+               } else {
+                       // No previous claim.
+               }
+       }
+
        fn get_latest_holder_commitment_txn<L: Deref>(
                &mut self, logger: &WithChannelMonitor<L>,
        ) -> Vec<Transaction> where L::Target: Logger {
@@ -3458,9 +3562,11 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 
                if height > self.best_block.height() {
                        self.best_block = BestBlock::new(block_hash, height);
+                       log_trace!(logger, "Connecting new block {} at height {}", block_hash, height);
                        self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, logger)
                } else if block_hash != self.best_block.block_hash() {
                        self.best_block = BestBlock::new(block_hash, height);
+                       log_trace!(logger, "Best block re-orged, replaced with new block {} at height {}", block_hash, height);
                        self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
                        self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
                        Vec::new()
@@ -3497,6 +3603,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                let mut claimable_outpoints = Vec::new();
                'tx_iter: for tx in &txn_matched {
                        let txid = tx.txid();
+                       log_trace!(logger, "Transaction {} confirmed in block {}", txid , block_hash);
                        // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
                        if Some(txid) == self.funding_spend_confirmed {
                                log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
@@ -3568,6 +3675,10 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                                        commitment_tx_to_counterparty_output,
                                                },
                                        });
+                                       // Now that we've detected a confirmed commitment transaction, attempt to cancel
+                                       // pending claims for any commitments that were previously confirmed such that
+                                       // we don't continue claiming inputs that no longer exist.
+                                       self.cancel_prev_commitment_claims(&logger, &txid);
                                }
                        }
                        if tx.input.len() >= 1 {
@@ -3633,29 +3744,9 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 
                let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
                if should_broadcast {
-                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.channel_type_features().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(), self.best_block.height());
-                       claimable_outpoints.push(commitment_package);
-                       self.pending_monitor_events.push(MonitorEvent::HolderForceClosed(self.funding_info.0));
-                       // Although we aren't signing the transaction directly here, the transaction will be signed
-                       // in the claim that is queued to OnchainTxHandler. We set holder_tx_signed here to reject
-                       // new channel updates.
-                       self.holder_tx_signed = true;
-                       // We can't broadcast our HTLC transactions while the commitment transaction is
-                       // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
-                       // `transactions_confirmed`.
-                       if !self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
-                               // 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 unsigned_commitment_tx = self.onchain_tx_handler.get_unsigned_holder_commitment_tx();
-                               let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &unsigned_commitment_tx);
-                               if !new_outputs.is_empty() {
-                                       watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
-                               }
-                               claimable_outpoints.append(&mut new_outpoints);
-                       }
+                       let (mut new_outpoints, mut new_outputs) = self.generate_claimable_outpoints_and_watch_outputs();
+                       claimable_outpoints.append(&mut new_outpoints);
+                       watch_outputs.append(&mut new_outputs);
                }
 
                // Find which on-chain events have reached their confirmation threshold.
@@ -4247,8 +4338,8 @@ where
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
 
-impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
-               for (BlockHash, ChannelMonitor<SP::EcdsaSigner>) {
+impl<'a, 'b, ES: EntropySource, Signer: WriteableEcdsaChannelSigner, SP: SignerProvider<EcdsaSigner=Signer>> ReadableArgs<(&'a ES, &'b SP)>
+               for (BlockHash, ChannelMonitor<Signer>) {
        fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
                macro_rules! unwrap_obj {
                        ($key: expr) => {
@@ -4717,7 +4808,7 @@ mod tests {
                                preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect()
                        }
                }
-               let dummy_sig = crate::util::crypto::sign(&secp_ctx,
+               let dummy_sig = crate::crypto::utils::sign(&secp_ctx,
                        &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(),
                        &SecretKey::from_slice(&[42; 32]).unwrap());