/// An update generated by the underlying Channel itself which contains some new information the
/// ChannelMonitor should be made aware of.
-#[cfg_attr(test, derive(PartialEq))]
+#[cfg_attr(any(test, feature = "_test_utils"), derive(PartialEq))]
#[derive(Clone)]
#[must_use]
pub struct ChannelMonitorUpdate {
pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
/// 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.
+ /// increasing and increase by one for each new update, with one exception specified below.
///
/// This sequence number is also used to track up to which points updates which returned
/// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
/// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
+ ///
+ /// The only instance where update_id values are not strictly increasing is the case where we
+ /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
+ /// its docs for more details.
+ ///
+ /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
pub update_id: u64,
}
+/// If:
+/// (1) a channel has been force closed and
+/// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
+/// this channel's (the backward link's) broadcasted commitment transaction
+/// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
+/// with the update providing said payment preimage. No other update types are allowed after
+/// force-close.
+pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
+
impl Writeable for ChannelMonitorUpdate {
fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
self.update_id.write(w)?;
}
/// An error enum representing a failure to persist a channel monitor update.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
pub enum ChannelMonitorUpdateErr {
/// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
/// our state failed, but is expected to succeed at some point in the future).
/// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
/// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
/// corrupted.
-/// Contains a human-readable error message.
+/// Contains a developer-readable error message.
#[derive(Debug)]
pub struct MonitorUpdateError(pub &'static str);
const SERIALIZATION_VERSION: u8 = 1;
const MIN_SERIALIZATION_VERSION: u8 = 1;
-#[cfg_attr(test, derive(PartialEq))]
+#[cfg_attr(any(test, feature = "_test_utils"), derive(PartialEq))]
#[derive(Clone)]
pub(crate) enum ChannelMonitorUpdateStep {
LatestHolderCommitmentTXInfo {
secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
}
-#[cfg(any(test, feature = "fuzztarget"))]
+#[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
/// Used only in testing and fuzztarget to check serialization roundtrips don't change the
/// underlying object
impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
/// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
/// returned block hash and the the current chain and then reconnecting blocks to get to the
/// best chain) upon deserializing the object!
- pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+ pub fn serialize_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
//TODO: We still write out all the serialization here manually instead of using the fancy
//serialization framework we have, we should migrate things over to it.
writer.write_all(&[SERIALIZATION_VERSION; 1])?;
/// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
/// commitment_tx_infos which contain the payment hash have been revoked.
- pub(crate) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
+ pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
+ where B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
}
/// itself.
///
/// panics if the given update is not the next update by update_id.
- pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
- where B::Target: BroadcasterInterface,
- L::Target: Logger,
+ pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
+ where B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
{
- if self.latest_update_id + 1 != updates.update_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 sentinel value instead.
+ if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+ match updates.updates[0] {
+ ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
+ _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
+ }
+ assert_eq!(updates.updates.len(), 1);
+ } else if self.latest_update_id + 1 != updates.update_id {
panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
}
- for update in updates.updates.drain(..) {
+ for update in updates.updates.iter() {
match update {
ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
+ log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
if self.lockdown_from_offchain { panic!(); }
- self.provide_latest_holder_commitment_tx_info(commitment_tx, htlc_outputs)?
+ self.provide_latest_holder_commitment_tx_info(commitment_tx.clone(), htlc_outputs.clone())?
+ },
+ ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } => {
+ log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
+ self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
+ },
+ ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
+ log_trace!(logger, "Updating ChannelMonitor with payment preimage");
+ self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
+ },
+ ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
+ log_trace!(logger, "Updating ChannelMonitor with commitment secret");
+ self.provide_secret(*idx, *secret)?
},
- ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
- self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
- ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
- self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
- ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
- self.provide_secret(idx, secret)?,
ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
+ log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
self.lockdown_from_offchain = true;
- if should_broadcast {
+ if *should_broadcast {
self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
} else {
log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
});
+ #[cfg(test)]
+ {
+ // If we see a transaction for which we registered outputs previously,
+ // make sure the registered scriptpubkey at the expected index match
+ // the actual transaction output one. We failed this case before #653.
+ for tx in &txn_matched {
+ if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
+ for idx_and_script in outputs.iter() {
+ assert!((idx_and_script.0 as usize) < tx.output.len());
+ assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
+ }
+ }
+ }
+ }
watch_outputs
}
if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
for (idx, _script_pubkey) in outputs.iter() {
if *idx == input.previous_output.vout {
+ #[cfg(test)]
+ {
+ // If the expected script is a known type, check that the witness
+ // appears to be spending the correct type (ie that the match would
+ // actually succeed in BIP 158/159-style filters).
+ if _script_pubkey.is_v0_p2wsh() {
+ assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
+ } else if _script_pubkey.is_v0_p2wpkh() {
+ assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
+ } else { panic!(); }
+ }
return true;
}
}
}
}
+/// `Persist` defines behavior for persisting channel monitors: this could mean
+/// writing once to disk, and/or uploading to one or more backup services.
+///
+/// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
+/// to disk/backups. And, on every update, you **must** persist either the
+/// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
+/// of situations such as revoking a transaction, then crashing before this
+/// revocation can be persisted, then unintentionally broadcasting a revoked
+/// transaction and losing money. This is a risk because previous channel states
+/// are toxic, so it's important that whatever channel state is persisted is
+/// kept up-to-date.
+pub trait Persist<Keys: ChannelKeys>: Send + Sync {
+ /// Persist a new channel's data. The data can be stored any way you want, but
+ /// the identifier provided by Rust-Lightning is the channel's outpoint (and
+ /// it is up to you to maintain a correct mapping between the outpoint and the
+ /// stored channel data). Note that you **must** persist every new monitor to
+ /// disk. See the `Persist` trait documentation for more details.
+ ///
+ /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
+ /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
+ ///
+ /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
+ /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
+ fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
+
+ /// Update one channel's data. The provided `ChannelMonitor` has already
+ /// applied the given update.
+ ///
+ /// Note that on every update, you **must** persist either the
+ /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
+ /// the `Persist` trait documentation for more details.
+ ///
+ /// If an implementer chooses to persist the updates only, they need to make
+ /// sure that all the updates are applied to the `ChannelMonitors` *before*
+ /// the set of channel monitors is given to the `ChannelManager`
+ /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
+ /// applying a monitor update to a monitor. If full `ChannelMonitors` are
+ /// persisted, then there is no need to persist individual updates.
+ ///
+ /// Note that there could be a performance tradeoff between persisting complete
+ /// channel monitors on every update vs. persisting only updates and applying
+ /// them in batches. The size of each monitor grows `O(number of state updates)`
+ /// whereas updates are small and `O(1)`.
+ ///
+ /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
+ /// [`ChannelMonitorUpdate::write`] for writing out an update, and
+ /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
+ ///
+ /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
+ /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
+ /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
+ /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
+ fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
+}
+
const MAX_ALLOC_SIZE: usize = 64*1024;
impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
use ln::chan_utils;
use ln::chan_utils::{HTLCOutputInCommitment, HolderCommitmentTransaction};
- use util::test_utils::TestLogger;
+ use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
use bitcoin::secp256k1::key::{SecretKey,PublicKey};
use bitcoin::secp256k1::Secp256k1;
- use std::sync::Arc;
+ use std::sync::{Arc, Mutex};
use chain::keysinterface::InMemoryChannelKeys;
#[test]
fn test_prune_preimages() {
let secp_ctx = Secp256k1::new();
let logger = Arc::new(TestLogger::new());
+ let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
+ let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
for &(ref preimage, ref hash) in preimages.iter() {
- monitor.provide_payment_preimage(hash, preimage);
+ monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
}
// Now provide a secret, pruning preimages 10-15
projects / rust-lightning / blobdiff