X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchannelmonitor.rs;h=cbb07305b1caa12b34a737721f1b09412450421b;hb=ba1349982ba28657c9e2d03a5b02c3ecc054b5cc;hp=9044eec63e4a3c5b4a23700647c571d38f51cb4e;hpb=23e233ba257c27b14d0d6167f1d87d9c1bf5e344;p=rust-lightning diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs index 9044eec6..cbb07305 100644 --- a/lightning/src/chain/channelmonitor.rs +++ b/lightning/src/chain/channelmonitor.rs @@ -69,34 +69,36 @@ use crate::sync::{Mutex, LockTestExt}; /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment /// transaction), a single update may reach upwards of 1 MiB in serialized size. -#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))] -#[derive(Clone)] +#[derive(Clone, PartialEq, Eq)] #[must_use] pub struct ChannelMonitorUpdate { pub(crate) updates: Vec, /// 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, with one exception specified below. + /// increasing and increase by one for each new update, with two exceptions specified below. /// /// This sequence number is also used to track up to which points updates which returned /// [`ChannelMonitorUpdateStatus::InProgress`] 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. + /// The only instances we allow where update_id values are not strictly increasing have a + /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that + /// will force close the channel by broadcasting the latest commitment transaction or + /// special post-force-close updates, like providing preimages necessary to claim outputs on the + /// broadcast commitment transaction. See its docs for more details. /// /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress 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. +/// The update ID used for a [`ChannelMonitorUpdate`] that is either: +/// +/// (1) attempting to force close the channel by broadcasting our latest commitment transaction or +/// (2) providing a preimage (after the channel has been force closed) from a forward link that +/// allows us to spend an HTLC output on this channel's (the backward link's) broadcasted +/// commitment transaction. +/// +/// No other [`ChannelMonitorUpdate`]s are allowed after force-close. pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX; impl Writeable for ChannelMonitorUpdate { @@ -488,13 +490,16 @@ impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, ); -#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))] -#[derive(Clone)] +#[derive(Clone, PartialEq, Eq)] pub(crate) enum ChannelMonitorUpdateStep { LatestHolderCommitmentTXInfo { commitment_tx: HolderCommitmentTransaction, + /// Note that LDK after 0.0.115 supports this only containing dust HTLCs (implying the + /// `Signature` field is never filled in). At that point, non-dust HTLCs are implied by the + /// HTLC fields in `commitment_tx` and the sources passed via `nondust_htlc_sources`. htlc_outputs: Vec<(HTLCOutputInCommitment, Option, Option)>, claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>, + nondust_htlc_sources: Vec, }, LatestCounterpartyCommitmentTXInfo { commitment_txid: Txid, @@ -539,6 +544,7 @@ impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep, (0, commitment_tx, required), (1, claimed_htlcs, vec_type), (2, htlc_outputs, vec_type), + (4, nondust_htlc_sources, optional_vec), }, (1, LatestCounterpartyCommitmentTXInfo) => { (0, commitment_txid, required), @@ -1180,7 +1186,7 @@ impl ChannelMonitor { &self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option, Option)>, ) -> Result<(), ()> { - self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new()).map_err(|_| ()) + self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new(), Vec::new()).map_err(|_| ()) } /// This is used to provide payment preimage(s) out-of-band during startup without updating the @@ -1201,17 +1207,6 @@ impl ChannelMonitor { payment_hash, payment_preimage, broadcaster, fee_estimator, logger) } - pub(crate) fn broadcast_latest_holder_commitment_txn( - &self, - broadcaster: &B, - logger: &L, - ) where - B::Target: BroadcasterInterface, - L::Target: Logger, - { - self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger); - } - /// Updates a ChannelMonitor on the basis of some new information provided by the Channel /// itself. /// @@ -2160,7 +2155,53 @@ impl ChannelMonitorImpl { /// is important that any clones of this channel monitor (including remote clones) by kept /// up-to-date as our holder commitment transaction is updated. /// Panics if set_on_holder_tx_csv has never been called. - fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option, Option)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)]) -> Result<(), &'static str> { + fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, mut htlc_outputs: Vec<(HTLCOutputInCommitment, Option, Option)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)], nondust_htlc_sources: Vec) -> Result<(), &'static str> { + if htlc_outputs.iter().any(|(_, s, _)| s.is_some()) { + // If we have non-dust HTLCs in htlc_outputs, ensure they match the HTLCs in the + // `holder_commitment_tx`. In the future, we'll no longer provide the redundant data + // and just pass in source data via `nondust_htlc_sources`. + debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.trust().htlcs().len()); + for (a, b) in htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).map(|(h, _, _)| h).zip(holder_commitment_tx.trust().htlcs().iter()) { + debug_assert_eq!(a, b); + } + debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.counterparty_htlc_sigs.len()); + for (a, b) in htlc_outputs.iter().filter_map(|(_, s, _)| s.as_ref()).zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) { + debug_assert_eq!(a, b); + } + debug_assert!(nondust_htlc_sources.is_empty()); + } else { + // If we don't have any non-dust HTLCs in htlc_outputs, assume they were all passed via + // `nondust_htlc_sources`, building up the final htlc_outputs by combining + // `nondust_htlc_sources` and the `holder_commitment_tx` + #[cfg(debug_assertions)] { + let mut prev = -1; + for htlc in holder_commitment_tx.trust().htlcs().iter() { + assert!(htlc.transaction_output_index.unwrap() as i32 > prev); + prev = htlc.transaction_output_index.unwrap() as i32; + } + } + debug_assert!(htlc_outputs.iter().all(|(htlc, _, _)| htlc.transaction_output_index.is_none())); + debug_assert!(htlc_outputs.iter().all(|(_, sig_opt, _)| sig_opt.is_none())); + debug_assert_eq!(holder_commitment_tx.trust().htlcs().len(), holder_commitment_tx.counterparty_htlc_sigs.len()); + + let mut sources_iter = nondust_htlc_sources.into_iter(); + + for (htlc, counterparty_sig) in holder_commitment_tx.trust().htlcs().iter() + .zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) + { + if htlc.offered { + let source = sources_iter.next().expect("Non-dust HTLC sources didn't match commitment tx"); + #[cfg(debug_assertions)] { + assert!(source.possibly_matches_output(htlc)); + } + htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), Some(source))); + } else { + htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), None)); + } + } + debug_assert!(sources_iter.next().is_none()); + } + let trusted_tx = holder_commitment_tx.trust(); let txid = trusted_tx.txid(); let tx_keys = trusted_tx.keys(); @@ -2265,14 +2306,22 @@ impl ChannelMonitorImpl { { log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.", log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len()); - // 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. + // 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. + // + // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still + // thinks the channel needs to have its commitment transaction broadcast, so we'll allow + // them as well. if updates.update_id == CLOSED_CHANNEL_UPDATE_ID { assert_eq!(updates.updates.len(), 1); match updates.updates[0] { - ChannelMonitorUpdateStep::PaymentPreimage { .. } => {}, + ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {}, + // We should have already seen a `ChannelForceClosed` update if we're trying to + // provide a preimage at this point. + ChannelMonitorUpdateStep::PaymentPreimage { .. } => + debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID), _ => { log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name()); panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"); @@ -2285,10 +2334,10 @@ impl ChannelMonitorImpl { let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator); for update in updates.updates.iter() { match update { - ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs } => { + ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs, nondust_htlc_sources } => { log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info"); if self.lockdown_from_offchain { panic!(); } - if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs) { + if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs, nondust_htlc_sources.clone()) { log_error!(logger, "Providing latest holder commitment transaction failed/was refused:"); log_error!(logger, " {}", e); ret = Err(()); @@ -2364,6 +2413,13 @@ impl ChannelMonitorImpl { }, } } + + // If the updates succeeded and we were in an already closed channel state, then there's no + // need to refuse any updates we expect to receive afer seeing a confirmed commitment. + if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id { + return Ok(()); + } + self.latest_update_id = updates.update_id; if ret.is_ok() && self.funding_spend_seen { @@ -3669,8 +3725,9 @@ where } } -impl chain::Confirm for (ChannelMonitor, T, F, L) +impl chain::Confirm for (M, T, F, L) where + M: Deref>, T::Target: BroadcasterInterface, F::Target: FeeEstimator, L::Target: Logger, @@ -4133,7 +4190,7 @@ mod tests { } } - macro_rules! preimages_slice_to_htlc_outputs { + macro_rules! preimages_slice_to_htlcs { ($preimages_slice: expr) => { { let mut res = Vec::new(); @@ -4144,21 +4201,20 @@ mod tests { cltv_expiry: 0, payment_hash: preimage.1.clone(), transaction_output_index: Some(idx as u32), - }, None)); + }, ())); } res } } } - macro_rules! preimages_to_holder_htlcs { + macro_rules! preimages_slice_to_htlc_outputs { ($preimages_slice: expr) => { - { - let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice); - let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect(); - res - } + preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect() } } + let dummy_sig = crate::util::crypto::sign(&secp_ctx, + &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(), + &SecretKey::from_slice(&[42; 32]).unwrap()); macro_rules! test_preimages_exist { ($preimages_slice: expr, $monitor: expr) => { @@ -4205,13 +4261,15 @@ mod tests { let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let best_block = BestBlock::from_network(Network::Testnet); let monitor = ChannelMonitor::new(Secp256k1::new(), keys, - Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(), - (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()), - &channel_parameters, - Script::new(), 46, 0, - HolderCommitmentTransaction::dummy(), best_block, dummy_key); - - monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap(); + Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(), + (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()), + &channel_parameters, Script::new(), 46, 0, HolderCommitmentTransaction::dummy(&mut Vec::new()), + best_block, dummy_key); + + let mut htlcs = preimages_slice_to_htlcs!(preimages[0..10]); + let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs); + monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(), + htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap(); monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()), preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger); monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()), @@ -4244,7 +4302,10 @@ mod tests { // Now update holder commitment tx info, pruning only element 18 as we still care about the // previous commitment tx's preimages too - monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap(); + let mut htlcs = preimages_slice_to_htlcs!(preimages[0..5]); + let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs); + monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(), + htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap(); secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); monitor.provide_secret(281474976710653, secret.clone()).unwrap(); assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12); @@ -4252,7 +4313,10 @@ mod tests { test_preimages_exist!(&preimages[18..20], monitor); // But if we do it again, we'll prune 5-10 - monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap(); + let mut htlcs = preimages_slice_to_htlcs!(preimages[0..3]); + let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs); + monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx, + htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap(); secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); monitor.provide_secret(281474976710652, secret.clone()).unwrap(); assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);