X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchainmonitor.rs;h=12bfebbc4aeee8941b6ad4734cd1f539f8816360;hb=002a5db5b07fd317545d3aa4f1a217cd40b608e2;hp=179d0edb55fd7942eda7b819d16c57f53989fbd8;hpb=f35a5ce659a17d95270518ad7cb0f9b2aa997b4a;p=rust-lightning diff --git a/lightning/src/chain/chainmonitor.rs b/lightning/src/chain/chainmonitor.rs index 179d0edb..12bfebbc 100644 --- a/lightning/src/chain/chainmonitor.rs +++ b/lightning/src/chain/chainmonitor.rs @@ -13,37 +13,33 @@ //! update [`ChannelMonitor`]s accordingly. If any on-chain events need further processing, it will //! make those available as [`MonitorEvent`]s to be consumed. //! -//! `ChainMonitor` is parameterized by an optional chain source, which must implement the +//! [`ChainMonitor`] is parameterized by an optional chain source, which must implement the //! [`chain::Filter`] trait. This provides a mechanism to signal new relevant outputs back to light //! clients, such that transactions spending those outputs are included in block data. //! -//! `ChainMonitor` may be used directly to monitor channels locally or as a part of a distributed -//! setup to monitor channels remotely. In the latter case, a custom `chain::Watch` implementation +//! [`ChainMonitor`] may be used directly to monitor channels locally or as a part of a distributed +//! setup to monitor channels remotely. In the latter case, a custom [`chain::Watch`] implementation //! would be responsible for routing each update to a remote server and for retrieving monitor -//! events. The remote server would make use of `ChainMonitor` for block processing and for -//! servicing `ChannelMonitor` updates from the client. -//! -//! [`ChainMonitor`]: struct.ChainMonitor.html -//! [`chain::Filter`]: ../trait.Filter.html -//! [`chain::Watch`]: ../trait.Watch.html -//! [`ChannelMonitor`]: ../channelmonitor/struct.ChannelMonitor.html -//! [`MonitorEvent`]: ../channelmonitor/enum.MonitorEvent.html +//! events. The remote server would make use of [`ChainMonitor`] for block processing and for +//! servicing [`ChannelMonitor`] updates from the client. -use bitcoin::blockdata::block::BlockHeader; +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::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, MonitorUpdateError}; +use chain::channelmonitor; +use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, Persist, TransactionOutputs}; use chain::transaction::{OutPoint, TransactionData}; -use chain::keysinterface::ChannelKeys; +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::Mutex; -use std::ops::Deref; +use prelude::*; +use sync::RwLock; +use core::ops::Deref; /// An implementation of [`chain::Watch`] for monitoring channels. /// @@ -52,31 +48,33 @@ use std::ops::Deref; /// or used independently to monitor channels remotely. See the [module-level documentation] for /// details. /// -/// [`chain::Watch`]: ../trait.Watch.html -/// [`ChannelManager`]: ../../ln/channelmanager/struct.ChannelManager.html -/// [module-level documentation]: index.html -pub struct ChainMonitor +/// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager +/// [module-level documentation]: crate::chain::chainmonitor +pub struct ChainMonitor where C::Target: chain::Filter, T::Target: BroadcasterInterface, F::Target: FeeEstimator, L::Target: Logger, + P::Target: channelmonitor::Persist, { /// The monitors - pub monitors: Mutex>>, + pub monitors: RwLock>>, chain_source: Option, broadcaster: T, logger: L, - fee_estimator: F + fee_estimator: F, + persister: P, } -impl ChainMonitor - where C::Target: chain::Filter, - T::Target: BroadcasterInterface, - F::Target: FeeEstimator, - L::Target: Logger, +impl ChainMonitor +where C::Target: chain::Filter, + T::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + P::Target: channelmonitor::Persist, { /// 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`]. /// @@ -84,34 +82,43 @@ impl ChainMonit /// 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`. - /// - /// [`ChannelMonitor::block_connected`]: ../channelmonitor/struct.ChannelMonitor.html#method.block_connected - /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events - /// [`chain::Filter`]: ../trait.Filter.html - pub fn block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) { - let mut monitors = self.monitors.lock().unwrap(); - for monitor in monitors.values_mut() { - let mut txn_outputs = monitor.block_connected(header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger); + fn process_chain_data(&self, header: &BlockHeader, txdata: &TransactionData, process: FN) + where + FN: Fn(&ChannelMonitor, &TransactionData) -> Vec + { + let mut dependent_txdata = Vec::new(); + let monitors = self.monitors.read().unwrap(); + for monitor in monitors.values() { + 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().enumerate() { - 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. - /// - /// [`ChannelMonitor::block_disconnected`]: ../channelmonitor/struct.ChannelMonitor.html#method.block_disconnected - pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) { - let mut monitors = self.monitors.lock().unwrap(); - for monitor in monitors.values_mut() { - 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); } } @@ -122,101 +129,257 @@ impl ChainMonit /// pre-filter blocks or only fetch blocks matching a compact filter. Otherwise, clients may /// always need to fetch full blocks absent another means for determining which blocks contain /// transactions relevant to the watched channels. - /// - /// [`chain::Filter`]: ../trait.Filter.html - pub fn new(chain_source: Option, broadcaster: T, logger: L, feeest: F) -> Self { + pub fn new(chain_source: Option, broadcaster: T, logger: L, feeest: F, persister: P) -> Self { Self { - monitors: Mutex::new(HashMap::new()), + monitors: RwLock::new(HashMap::new()), chain_source, broadcaster, logger, fee_estimator: feeest, + persister, } } + #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))] + pub fn get_and_clear_pending_events(&self) -> Vec { + 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 +chain::Listen for ChainMonitor +where + C::Target: chain::Filter, + T::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + P::Target: channelmonitor::Persist, +{ + fn block_connected(&self, block: &Block, height: u32) { + let header = &block.header; + let txdata: Vec<_> = block.txdata.iter().enumerate().collect(); + 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) { + let monitors = self.monitors.read().unwrap(); + for monitor in monitors.values() { + monitor.block_disconnected( + header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger); + } + } +} + +impl +chain::Confirm for ChainMonitor +where + C::Target: chain::Filter, + T::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + P::Target: channelmonitor::Persist, +{ + 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 { + 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 +chain::Watch for ChainMonitor +where C::Target: chain::Filter, + T::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + P::Target: channelmonitor::Persist, +{ /// Adds the monitor that watches the channel referred to by the given outpoint. /// /// Calls back to [`chain::Filter`] with the funding transaction and outputs to watch. /// - /// [`chain::Filter`]: ../trait.Filter.html - fn add_monitor(&self, outpoint: OutPoint, monitor: ChannelMonitor) -> Result<(), MonitorUpdateError> { - let mut monitors = self.monitors.lock().unwrap(); - let entry = match monitors.entry(outpoint) { - hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given outpoint is already present")), + /// Note that we persist the given `ChannelMonitor` while holding the `ChainMonitor` + /// monitors lock. + fn watch_channel(&self, funding_outpoint: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> { + let mut monitors = self.monitors.write().unwrap(); + let entry = match monitors.entry(funding_outpoint) { + hash_map::Entry::Occupied(_) => { + log_error!(self.logger, "Failed to add new channel data: channel monitor for given outpoint is already present"); + return Err(ChannelMonitorUpdateErr::PermanentFailure)}, hash_map::Entry::Vacant(e) => e, }; + if let Err(e) = self.persister.persist_new_channel(funding_outpoint, &monitor) { + log_error!(self.logger, "Failed to persist new channel data"); + return Err(e); + } { let funding_txo = monitor.get_funding_txo(); log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..])); if let Some(ref chain_source) = self.chain_source { - chain_source.register_tx(&funding_txo.0.txid, &funding_txo.1); - for (txid, outputs) in monitor.get_outputs_to_watch().iter() { - for (idx, script_pubkey) in outputs.iter().enumerate() { - chain_source.register_output(&OutPoint { txid: *txid, index: idx as u16 }, &script_pubkey); - } - } + monitor.load_outputs_to_watch(chain_source); } } entry.insert(monitor); Ok(()) } - /// Updates the monitor that watches the channel referred to by the given outpoint. - fn update_monitor(&self, outpoint: OutPoint, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> { - let mut monitors = self.monitors.lock().unwrap(); - match monitors.get_mut(&outpoint) { - Some(orig_monitor) => { - log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor)); - orig_monitor.update_monitor(update, &self.broadcaster, &self.logger) - }, - None => Err(MonitorUpdateError("No such monitor registered")) - } - } -} - -impl chain::Watch for ChainMonitor - where C::Target: chain::Filter, - T::Target: BroadcasterInterface, - F::Target: FeeEstimator, - L::Target: Logger, -{ - type Keys = ChanSigner; - - fn watch_channel(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> { - match self.add_monitor(funding_txo, monitor) { - Ok(_) => Ok(()), - Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure), - } - } - + /// Note that we persist the given `ChannelMonitor` update while holding the + /// `ChainMonitor` monitors lock. fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> { - match self.update_monitor(funding_txo, update) { - Ok(_) => Ok(()), - Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure), + // Update the monitor that watches the channel referred to by the given outpoint. + let monitors = self.monitors.read().unwrap(); + match monitors.get(&funding_txo) { + None => { + log_error!(self.logger, "Failed to update channel monitor: no such monitor registered"); + + // We should never ever trigger this from within ChannelManager. Technically a + // user could use this object with some proxying in between which makes this + // possible, but in tests and fuzzing, this should be a panic. + #[cfg(any(test, feature = "fuzztarget"))] + panic!("ChannelManager generated a channel update for a channel that was not yet registered!"); + #[cfg(not(any(test, feature = "fuzztarget")))] + Err(ChannelMonitorUpdateErr::PermanentFailure) + }, + Some(monitor) => { + log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(monitor)); + let update_res = monitor.update_monitor(&update, &self.broadcaster, &self.fee_estimator, &self.logger); + if let Err(e) = &update_res { + log_error!(self.logger, "Failed to update channel monitor: {:?}", e); + } + // Even if updating the monitor returns an error, the monitor's state will + // still be changed. So, persist the updated monitor despite the error. + let persist_res = self.persister.update_persisted_channel(funding_txo, &update, monitor); + if let Err(ref e) = persist_res { + log_error!(self.logger, "Failed to persist channel monitor update: {:?}", e); + } + if update_res.is_err() { + Err(ChannelMonitorUpdateErr::PermanentFailure) + } else { + persist_res + } + } } } fn release_pending_monitor_events(&self) -> Vec { let mut pending_monitor_events = Vec::new(); - for chan in self.monitors.lock().unwrap().values_mut() { - pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events()); + for monitor in self.monitors.read().unwrap().values() { + pending_monitor_events.append(&mut monitor.get_and_clear_pending_monitor_events()); } pending_monitor_events } } -impl events::EventsProvider for ChainMonitor +impl events::EventsProvider for ChainMonitor where C::Target: chain::Filter, T::Target: BroadcasterInterface, F::Target: FeeEstimator, L::Target: Logger, + P::Target: channelmonitor::Persist, { - fn get_and_clear_pending_events(&self) -> Vec { + /// 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(&self, handler: H) where H::Target: EventHandler { let mut pending_events = Vec::new(); - for chan in self.monitors.lock().unwrap().values_mut() { - pending_events.append(&mut chan.get_and_clear_pending_events()); + for monitor in self.monitors.read().unwrap().values() { + pending_events.append(&mut monitor.get_and_clear_pending_events()); + } + for event in pending_events.drain(..) { + handler.handle_event(event); } - pending_events + } +} + +#[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(); } }