use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HolderCommitmentTransaction, HTLCType};
use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
-use chain;
-use chain::Filter;
use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
use chain::transaction::{OutPoint, TransactionData};
use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
use util::logger::Logger;
use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
-use util::{byte_utils, events};
+use util::byte_utils;
use util::events::Event;
use std::collections::{HashMap, HashSet, hash_map};
-use std::sync::Mutex;
use std::{cmp, mem};
use std::ops::Deref;
use std::io::Error;
}
impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
-/// An implementation of [`chain::Watch`] for monitoring channels.
-///
-/// Connected and disconnected blocks must be provided to `ChainMonitor` as documented by
-/// [`chain::Watch`]. May be used in conjunction with [`ChannelManager`] to monitor channels locally
-/// or used independently to monitor channels remotely.
-///
-/// [`chain::Watch`]: ../trait.Watch.html
-/// [`ChannelManager`]: ../../ln/channelmanager/struct.ChannelManager.html
-pub struct ChainMonitor<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref>
- where C::Target: chain::Filter,
- T::Target: BroadcasterInterface,
- F::Target: FeeEstimator,
- L::Target: Logger,
-{
- /// The monitors
- pub monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
- chain_source: Option<C>,
- broadcaster: T,
- logger: L,
- fee_estimator: F
-}
-
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, C, T, F, L>
- where C::Target: chain::Filter,
- T::Target: BroadcasterInterface,
- F::Target: FeeEstimator,
- L::Target: Logger,
-{
- /// 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
- /// [`ChannelMonitor::block_connected`] for details. Any HTLCs that were resolved on chain will
- /// be returned by [`chain::Watch::release_pending_monitor_events`].
- ///
- /// Calls back to [`chain::Filter`] if any monitor indicated new outputs to watch, returning
- /// `true` if so. Subsequent 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`]: 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) -> bool {
- let mut has_new_outputs_to_watch = false;
- {
- 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);
- has_new_outputs_to_watch |= !txn_outputs.is_empty();
-
- 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);
- }
- }
- }
- }
- }
- has_new_outputs_to_watch
- }
-
- /// 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`]: 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);
- }
- }
-
- /// Creates a new `ChainMonitor` used to watch on-chain activity pertaining to channels.
- ///
- /// When an optional chain source implementing [`chain::Filter`] is provided, the chain monitor
- /// will call back to it indicating transactions and outputs of interest. This allows clients to
- /// 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) -> Self {
- Self {
- monitors: Mutex::new(HashMap::new()),
- chain_source,
- broadcaster,
- logger,
- fee_estimator: feeest,
- }
- }
-
- /// 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<ChanSigner>) -> 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")),
- hash_map::Entry::Vacant(e) => 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);
- }
- }
- }
- }
- 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<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, C, T, F, L>
- 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<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
- match self.add_monitor(funding_txo, monitor) {
- Ok(_) => Ok(()),
- Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
- }
- }
-
- fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
- match self.update_monitor(funding_txo, update) {
- Ok(_) => Ok(()),
- Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
- }
- }
-
- 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());
- }
- pending_monitor_events
- }
-}
-
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> events::EventsProvider for ChainMonitor<ChanSigner, C, T, F, L>
- where C::Target: chain::Filter,
- T::Target: BroadcasterInterface,
- F::Target: FeeEstimator,
- L::Target: Logger,
-{
- 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());
- }
- pending_events
- }
-}
-
/// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
/// instead claiming it in its own individual transaction.
pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
///
/// (C-not exported) because we have no HashMap bindings
pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
- &self.outputs_to_watch
- }
-
- /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
- /// Generally useful when deserializing as during normal operation the return values of
- /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
- /// that the get_funding_txo outpoint and transaction must also be monitored for!).
- ///
- /// (C-not exported) as there is no practical way to track lifetimes of returned values.
- pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
- let mut res = Vec::with_capacity(self.counterparty_commitment_txn_on_chain.len() * 2);
- for (ref txid, &(_, ref outputs)) in self.counterparty_commitment_txn_on_chain.iter() {
- for (idx, output) in outputs.iter().enumerate() {
- res.push(((*txid).clone(), idx as u32, output));
+ // If we've detected a counterparty commitment tx on chain, we must include it in the set
+ // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
+ // its trivial to do, double-check that here.
+ for (txid, &(_, ref outputs)) in self.counterparty_commitment_txn_on_chain.iter() {
+ let watched_outputs = self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
+ assert_eq!(watched_outputs.len(), outputs.len());
+ for (watched, output) in watched_outputs.iter().zip(outputs.iter()) {
+ assert_eq!(watched, output);
}
}
- res
+ &self.outputs_to_watch
}
/// Get the list of HTLCs who's status has been updated on chain. This should be called by