Collect all lightning std::sync imports under crate::sync
[rust-lightning] / lightning / src / chain / chainmonitor.rs
index eb17b469a0365df2de4464ef313cc243441b6767..12bfebbc4aeee8941b6ad4734cd1f539f8816360 100644 (file)
 //! servicing [`ChannelMonitor`] updates from the client.
 
 use bitcoin::blockdata::block::{Block, BlockHeader};
+use bitcoin::hash_types::Txid;
 
 use chain;
-use chain::Filter;
+use chain::{Filter, WatchedOutput};
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::channelmonitor;
-use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, Persist};
+use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, Persist, TransactionOutputs};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::Sign;
 use util::logger::Logger;
 use util::events;
-use util::events::Event;
+use util::events::EventHandler;
 
-use std::collections::{HashMap, hash_map};
-use std::sync::RwLock;
-use std::ops::Deref;
+use prelude::*;
+use sync::RwLock;
+use core::ops::Deref;
 
 /// An implementation of [`chain::Watch`] for monitoring channels.
 ///
@@ -73,7 +74,7 @@ where C::Target: chain::Filter,
            P::Target: channelmonitor::Persist<ChannelSigner>,
 {
        /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
-       /// of a channel and reacting accordingly based on transactions in the connected block. See
+       /// of a channel and reacting accordingly based on transactions in the given chain data. See
        /// [`ChannelMonitor::block_connected`] for details. Any HTLCs that were resolved on chain will
        /// be returned by [`chain::Watch::release_pending_monitor_events`].
        ///
@@ -81,28 +82,43 @@ where C::Target: chain::Filter,
        /// calls must not exclude any transactions matching the new outputs nor any in-block
        /// descendants of such transactions. It is not necessary to re-fetch the block to obtain
        /// updated `txdata`.
-       pub fn block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+       fn process_chain_data<FN>(&self, header: &BlockHeader, txdata: &TransactionData, process: FN)
+       where
+               FN: Fn(&ChannelMonitor<ChannelSigner>, &TransactionData) -> Vec<TransactionOutputs>
+       {
+               let mut dependent_txdata = Vec::new();
                let monitors = self.monitors.read().unwrap();
                for monitor in monitors.values() {
-                       let mut txn_outputs = monitor.block_connected(header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
+                       let mut txn_outputs = process(monitor, txdata);
 
+                       // Register any new outputs with the chain source for filtering, storing any dependent
+                       // transactions from within the block that previously had not been included in txdata.
                        if let Some(ref chain_source) = self.chain_source {
-                               for (txid, outputs) in txn_outputs.drain(..) {
-                                       for (idx, output) in outputs.iter() {
-                                               chain_source.register_output(&OutPoint { txid, index: *idx as u16 }, &output.script_pubkey);
+                               let block_hash = header.block_hash();
+                               for (txid, mut outputs) in txn_outputs.drain(..) {
+                                       for (idx, output) in outputs.drain(..) {
+                                               // Register any new outputs with the chain source for filtering and recurse
+                                               // if it indicates that there are dependent transactions within the block
+                                               // that had not been previously included in txdata.
+                                               let output = WatchedOutput {
+                                                       block_hash: Some(block_hash),
+                                                       outpoint: OutPoint { txid, index: idx as u16 },
+                                                       script_pubkey: output.script_pubkey,
+                                               };
+                                               if let Some(tx) = chain_source.register_output(output) {
+                                                       dependent_txdata.push(tx);
+                                               }
                                        }
                                }
                        }
                }
-       }
 
-       /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
-       /// of a channel based on the disconnected block. See [`ChannelMonitor::block_disconnected`] for
-       /// details.
-       pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
-               let monitors = self.monitors.read().unwrap();
-               for monitor in monitors.values() {
-                       monitor.block_disconnected(header, disconnected_height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
+               // Recursively call for any dependent transactions that were identified by the chain source.
+               if !dependent_txdata.is_empty() {
+                       dependent_txdata.sort_unstable_by_key(|(index, _tx)| *index);
+                       dependent_txdata.dedup_by_key(|(index, _tx)| *index);
+                       let txdata: Vec<_> = dependent_txdata.iter().map(|(index, tx)| (*index, tx)).collect();
+                       self.process_chain_data(header, &txdata, process);
                }
        }
 
@@ -123,12 +139,20 @@ where C::Target: chain::Filter,
                        persister,
                }
        }
+
+       #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
+       pub fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
+               use util::events::EventsProvider;
+               let events = core::cell::RefCell::new(Vec::new());
+               let event_handler = |event| events.borrow_mut().push(event);
+               self.process_pending_events(&event_handler);
+               events.into_inner()
+       }
 }
 
-impl<ChannelSigner: Sign, C: Deref + Send + Sync, T: Deref + Send + Sync, F: Deref + Send + Sync, L: Deref + Send + Sync, P: Deref + Send + Sync>
+impl<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
 chain::Listen for ChainMonitor<ChannelSigner, C, T, F, L, P>
 where
-       ChannelSigner: Sign,
        C::Target: chain::Filter,
        T::Target: BroadcasterInterface,
        F::Target: FeeEstimator,
@@ -136,16 +160,70 @@ where
        P::Target: channelmonitor::Persist<ChannelSigner>,
 {
        fn block_connected(&self, block: &Block, height: u32) {
+               let header = &block.header;
                let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
-               ChainMonitor::block_connected(self, &block.header, &txdata, height);
+               self.process_chain_data(header, &txdata, |monitor, txdata| {
+                       monitor.block_connected(
+                               header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
+               });
        }
 
        fn block_disconnected(&self, header: &BlockHeader, height: u32) {
-               ChainMonitor::block_disconnected(self, header, height);
+               let monitors = self.monitors.read().unwrap();
+               for monitor in monitors.values() {
+                       monitor.block_disconnected(
+                               header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
+               }
        }
 }
 
-impl<ChannelSigner: Sign, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, P: Deref + Sync + Send>
+impl<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
+chain::Confirm for ChainMonitor<ChannelSigner, C, T, F, L, P>
+where
+       C::Target: chain::Filter,
+       T::Target: BroadcasterInterface,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+       P::Target: channelmonitor::Persist<ChannelSigner>,
+{
+       fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+               self.process_chain_data(header, txdata, |monitor, txdata| {
+                       monitor.transactions_confirmed(
+                               header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
+               });
+       }
+
+       fn transaction_unconfirmed(&self, txid: &Txid) {
+               let monitors = self.monitors.read().unwrap();
+               for monitor in monitors.values() {
+                       monitor.transaction_unconfirmed(txid, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
+               }
+       }
+
+       fn best_block_updated(&self, header: &BlockHeader, height: u32) {
+               self.process_chain_data(header, &[], |monitor, txdata| {
+                       // While in practice there shouldn't be any recursive calls when given empty txdata,
+                       // it's still possible if a chain::Filter implementation returns a transaction.
+                       debug_assert!(txdata.is_empty());
+                       monitor.best_block_updated(
+                               header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
+               });
+       }
+
+       fn get_relevant_txids(&self) -> Vec<Txid> {
+               let mut txids = Vec::new();
+               let monitors = self.monitors.read().unwrap();
+               for monitor in monitors.values() {
+                       txids.append(&mut monitor.get_relevant_txids());
+               }
+
+               txids.sort_unstable();
+               txids.dedup();
+               txids
+       }
+}
+
+impl<ChannelSigner: Sign, C: Deref , T: Deref , F: Deref , L: Deref , P: Deref >
 chain::Watch<ChannelSigner> for ChainMonitor<ChannelSigner, C, T, F, L, P>
 where C::Target: chain::Filter,
            T::Target: BroadcasterInterface,
@@ -237,11 +315,71 @@ impl<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> even
              L::Target: Logger,
              P::Target: channelmonitor::Persist<ChannelSigner>,
 {
-       fn get_and_clear_pending_events(&self) -> Vec<Event> {
+       /// Processes [`SpendableOutputs`] events produced from each [`ChannelMonitor`] upon maturity.
+       ///
+       /// An [`EventHandler`] may safely call back to the provider, though this shouldn't be needed in
+       /// order to handle these events.
+       ///
+       /// [`SpendableOutputs`]: events::Event::SpendableOutputs
+       fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {
                let mut pending_events = Vec::new();
                for monitor in self.monitors.read().unwrap().values() {
                        pending_events.append(&mut monitor.get_and_clear_pending_events());
                }
-               pending_events
+               for event in pending_events.drain(..) {
+                       handler.handle_event(event);
+               }
+       }
+}
+
+#[cfg(test)]
+mod tests {
+       use ::{check_added_monitors, get_local_commitment_txn};
+       use ln::features::InitFeatures;
+       use ln::functional_test_utils::*;
+       use util::events::MessageSendEventsProvider;
+       use util::test_utils::{OnRegisterOutput, TxOutReference};
+
+       /// Tests that in-block dependent transactions are processed by `block_connected` when not
+       /// included in `txdata` but returned by [`chain::Filter::register_output`]. For instance,
+       /// a (non-anchor) commitment transaction's HTLC output may be spent in the same block as the
+       /// commitment transaction itself. An Electrum client may filter the commitment transaction but
+       /// needs to return the HTLC transaction so it can be processed.
+       #[test]
+       fn connect_block_checks_dependent_transactions() {
+               let chanmon_cfgs = create_chanmon_cfgs(2);
+               let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+               let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+               let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+               let channel = create_announced_chan_between_nodes(
+                       &nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+               // Send a payment, saving nodes[0]'s revoked commitment and HTLC-Timeout transactions.
+               let (commitment_tx, htlc_tx) = {
+                       let payment_preimage = route_payment(&nodes[0], &vec!(&nodes[1])[..], 5_000_000).0;
+                       let mut txn = get_local_commitment_txn!(nodes[0], channel.2);
+                       claim_payment(&nodes[0], &vec!(&nodes[1])[..], payment_preimage);
+
+                       assert_eq!(txn.len(), 2);
+                       (txn.remove(0), txn.remove(0))
+               };
+
+               // Set expectations on nodes[1]'s chain source to return dependent transactions.
+               let htlc_output = TxOutReference(commitment_tx.clone(), 0);
+               let to_local_output = TxOutReference(commitment_tx.clone(), 1);
+               let htlc_timeout_output = TxOutReference(htlc_tx.clone(), 0);
+               nodes[1].chain_source
+                       .expect(OnRegisterOutput { with: htlc_output, returns: Some((1, htlc_tx)) })
+                       .expect(OnRegisterOutput { with: to_local_output, returns: None })
+                       .expect(OnRegisterOutput { with: htlc_timeout_output, returns: None });
+
+               // Notify nodes[1] that nodes[0]'s revoked commitment transaction was mined. The chain
+               // source should return the dependent HTLC transaction when the HTLC output is registered.
+               mine_transaction(&nodes[1], &commitment_tx);
+
+               // Clean up so uninteresting assertions don't fail.
+               check_added_monitors!(nodes[1], 1);
+               nodes[1].node.get_and_clear_pending_msg_events();
+               nodes[1].node.get_and_clear_pending_events();
        }
 }