Drop all HTML-relative links since rustdoc now supports resolution
[rust-lightning] / lightning / src / chain / chainmonitor.rs
index 469837f07ed6cf8f790bd4abe2315ed3d7f43b49..eb17b469a0365df2de4464ef313cc243441b6767 100644 (file)
 //! 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 chain;
 use chain::Filter;
@@ -37,13 +31,13 @@ use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::channelmonitor;
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, Persist};
 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 std::collections::{HashMap, hash_map};
-use std::sync::Mutex;
+use std::sync::RwLock;
 use std::ops::Deref;
 
 /// An implementation of [`chain::Watch`] for monitoring channels.
@@ -53,18 +47,17 @@ 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<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
+/// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+/// [module-level documentation]: crate::chain::chainmonitor
+pub struct ChainMonitor<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
        where C::Target: chain::Filter,
         T::Target: BroadcasterInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
-        P::Target: channelmonitor::Persist<ChanSigner>,
+        P::Target: channelmonitor::Persist<ChannelSigner>,
 {
        /// The monitors
-       pub monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
+       pub monitors: RwLock<HashMap<OutPoint, ChannelMonitor<ChannelSigner>>>,
        chain_source: Option<C>,
        broadcaster: T,
        logger: L,
@@ -72,12 +65,12 @@ pub struct ChainMonitor<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L
        persister: P,
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> ChainMonitor<ChanSigner, C, T, F, L, P>
+impl<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> 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<ChanSigner>,
+           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
@@ -88,13 +81,9 @@ 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`.
-       ///
-       /// [`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 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);
 
                        if let Some(ref chain_source) = self.chain_source {
@@ -110,11 +99,9 @@ where C::Target: chain::Filter,
        /// 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() {
+               let monitors = self.monitors.read().unwrap();
+               for monitor in monitors.values() {
                        monitor.block_disconnected(header, disconnected_height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
                }
        }
@@ -126,11 +113,9 @@ where C::Target: chain::Filter,
        /// 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<C>, broadcaster: T, logger: L, feeest: F, persister: P) -> Self {
                Self {
-                       monitors: Mutex::new(HashMap::new()),
+                       monitors: RwLock::new(HashMap::new()),
                        chain_source,
                        broadcaster,
                        logger,
@@ -140,25 +125,42 @@ where C::Target: chain::Filter,
        }
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, P: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, C, T, F, L, P>
+impl<ChannelSigner: Sign, C: Deref + Send + Sync, T: Deref + Send + Sync, F: Deref + Send + Sync, L: Deref + Send + Sync, P: Deref + Send + Sync>
+chain::Listen for ChainMonitor<ChannelSigner, C, T, F, L, P>
+where
+       ChannelSigner: Sign,
+       C::Target: chain::Filter,
+       T::Target: BroadcasterInterface,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+       P::Target: channelmonitor::Persist<ChannelSigner>,
+{
+       fn block_connected(&self, block: &Block, height: u32) {
+               let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
+               ChainMonitor::block_connected(self, &block.header, &txdata, height);
+       }
+
+       fn block_disconnected(&self, header: &BlockHeader, height: u32) {
+               ChainMonitor::block_disconnected(self, header, height);
+       }
+}
+
+impl<ChannelSigner: Sign, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, P: Deref + Sync + Send>
+chain::Watch<ChannelSigner> 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<ChanSigner>,
+           P::Target: channelmonitor::Persist<ChannelSigner>,
 {
-       type Keys = ChanSigner;
-
        /// 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.
        ///
        /// Note that we persist the given `ChannelMonitor` while holding the `ChainMonitor`
        /// monitors lock.
-       ///
-       /// [`chain::Filter`]: ../trait.Filter.html
-       fn watch_channel(&self, funding_outpoint: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
-               let mut monitors = self.monitors.lock().unwrap();
+       fn watch_channel(&self, funding_outpoint: OutPoint, monitor: ChannelMonitor<ChannelSigner>) -> 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");
@@ -174,12 +176,7 @@ where C::Target: chain::Filter,
                        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() {
-                                               chain_source.register_output(&OutPoint { txid: *txid, index: *idx as u16 }, script_pubkey);
-                                       }
-                               }
+                               monitor.load_outputs_to_watch(chain_source);
                        }
                }
                entry.insert(monitor);
@@ -190,21 +187,28 @@ where C::Target: chain::Filter,
        /// `ChainMonitor` monitors lock.
        fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
                // Update the monitor that watches the channel referred to by the given outpoint.
-               let mut monitors = self.monitors.lock().unwrap();
-               match monitors.get_mut(&funding_txo) {
+               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(orig_monitor) => {
-                               log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
-                               let update_res = orig_monitor.update_monitor(&update, &self.broadcaster, &self.logger);
+                       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, orig_monitor);
+                               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);
                                }
@@ -219,24 +223,24 @@ where C::Target: chain::Filter,
 
        fn release_pending_monitor_events(&self) -> Vec<MonitorEvent> {
                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<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> events::EventsProvider for ChainMonitor<ChanSigner, C, T, F, L, P>
+impl<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> events::EventsProvider 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<ChanSigner>,
+             P::Target: channelmonitor::Persist<ChannelSigner>,
 {
        fn get_and_clear_pending_events(&self) -> Vec<Event> {
                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());
                }
                pending_events
        }