use crate::attestation_verification::{ batch_verify_aggregated_attestations, batch_verify_unaggregated_attestations, Error as AttestationError, VerifiedAggregatedAttestation, VerifiedAttestation, VerifiedUnaggregatedAttestation, }; use crate::attester_cache::{AttesterCache, AttesterCacheKey}; use crate::beacon_proposer_cache::BeaconProposerCache; use crate::block_verification::{ check_block_is_finalized_descendant, check_block_relevancy, get_block_root, signature_verify_chain_segment, BlockError, FullyVerifiedBlock, GossipVerifiedBlock, IntoFullyVerifiedBlock, }; use crate::chain_config::ChainConfig; use crate::errors::{BeaconChainError as Error, BlockProductionError}; use crate::eth1_chain::{Eth1Chain, Eth1ChainBackend}; use crate::events::ServerSentEventHandler; use crate::head_tracker::HeadTracker; use crate::historical_blocks::HistoricalBlockError; use crate::migrate::BackgroundMigrator; use crate::naive_aggregation_pool::{ AggregatedAttestationMap, Error as NaiveAggregationError, NaiveAggregationPool, SyncContributionAggregateMap, }; use crate::observed_aggregates::{ Error as AttestationObservationError, ObservedAggregateAttestations, ObservedSyncContributions, }; use crate::observed_attesters::{ ObservedAggregators, ObservedAttesters, ObservedSyncAggregators, ObservedSyncContributors, }; use crate::observed_block_producers::ObservedBlockProducers; use crate::observed_operations::{ObservationOutcome, ObservedOperations}; use crate::persisted_beacon_chain::{PersistedBeaconChain, DUMMY_CANONICAL_HEAD_BLOCK_ROOT}; use crate::persisted_fork_choice::PersistedForkChoice; use crate::shuffling_cache::{BlockShufflingIds, ShufflingCache}; use crate::snapshot_cache::SnapshotCache; use crate::sync_committee_verification::{ Error as SyncCommitteeError, VerifiedSyncCommitteeMessage, VerifiedSyncContribution, }; use crate::timeout_rw_lock::TimeoutRwLock; use crate::validator_monitor::{ get_block_delay_ms, get_slot_delay_ms, timestamp_now, ValidatorMonitor, HISTORIC_EPOCHS as VALIDATOR_MONITOR_HISTORIC_EPOCHS, }; use crate::validator_pubkey_cache::ValidatorPubkeyCache; use crate::BeaconForkChoiceStore; use crate::BeaconSnapshot; use crate::{metrics, BeaconChainError}; use eth2::types::{EventKind, SseBlock, SseChainReorg, SseFinalizedCheckpoint, SseHead, SyncDuty}; use fork_choice::ForkChoice; use futures::channel::mpsc::Sender; use itertools::process_results; use itertools::Itertools; use operation_pool::{OperationPool, PersistedOperationPool}; use parking_lot::{Mutex, RwLock}; use safe_arith::SafeArith; use slasher::Slasher; use slog::{crit, debug, error, info, trace, warn, Logger}; use slot_clock::SlotClock; use state_processing::{ common::get_indexed_attestation, per_block_processing, per_block_processing::errors::AttestationValidationError, per_slot_processing, state_advance::{complete_state_advance, partial_state_advance}, BlockSignatureStrategy, SigVerifiedOp, }; use std::borrow::Cow; use std::cmp::Ordering; use std::collections::HashMap; use std::collections::HashSet; use std::io::prelude::*; use std::sync::Arc; use std::time::{Duration, Instant}; use store::iter::{BlockRootsIterator, ParentRootBlockIterator, StateRootsIterator}; use store::{Error as DBError, HotColdDB, KeyValueStore, KeyValueStoreOp, StoreItem, StoreOp}; use task_executor::ShutdownReason; use types::beacon_state::CloneConfig; use types::*; pub type ForkChoiceError = fork_choice::Error; /// The time-out before failure during an operation to take a read/write RwLock on the canonical /// head. pub const HEAD_LOCK_TIMEOUT: Duration = Duration::from_secs(1); /// The time-out before failure during an operation to take a read/write RwLock on the block /// processing cache. pub const BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1); /// The time-out before failure during an operation to take a read/write RwLock on the /// attestation cache. pub const ATTESTATION_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1); /// The time-out before failure during an operation to take a read/write RwLock on the /// validator pubkey cache. pub const VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1); // These keys are all zero because they get stored in different columns, see `DBColumn` type. pub const BEACON_CHAIN_DB_KEY: Hash256 = Hash256::zero(); pub const OP_POOL_DB_KEY: Hash256 = Hash256::zero(); pub const ETH1_CACHE_DB_KEY: Hash256 = Hash256::zero(); pub const FORK_CHOICE_DB_KEY: Hash256 = Hash256::zero(); /// Defines the behaviour when a block/block-root for a skipped slot is requested. pub enum WhenSlotSkipped { /// If the slot is a skip slot, return `None`. /// /// This is how the HTTP API behaves. None, /// If the slot it a skip slot, return the previous non-skipped block. /// /// This is generally how the specification behaves. Prev, } /// The result of a chain segment processing. pub enum ChainSegmentResult { /// Processing this chain segment finished successfully. Successful { imported_blocks: usize }, /// There was an error processing this chain segment. Before the error, some blocks could /// have been imported. Failed { imported_blocks: usize, error: BlockError, }, } /// The accepted clock drift for nodes gossiping blocks and attestations. See: /// /// https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/p2p-interface.md#configuration pub const MAXIMUM_GOSSIP_CLOCK_DISPARITY: Duration = Duration::from_millis(500); #[derive(Debug, PartialEq)] pub enum AttestationProcessingOutcome { Processed, EmptyAggregationBitfield, UnknownHeadBlock { beacon_block_root: Hash256, }, /// The attestation is attesting to a state that is later than itself. (Viz., attesting to the /// future). AttestsToFutureBlock { block: Slot, attestation: Slot, }, /// The slot is finalized, no need to import. FinalizedSlot { attestation: Slot, finalized: Slot, }, FutureEpoch { attestation_epoch: Epoch, current_epoch: Epoch, }, PastEpoch { attestation_epoch: Epoch, current_epoch: Epoch, }, BadTargetEpoch, UnknownTargetRoot(Hash256), InvalidSignature, NoCommitteeForSlotAndIndex { slot: Slot, index: CommitteeIndex, }, Invalid(AttestationValidationError), } /// Defines how a `BeaconState` should be "skipped" through skip-slots. pub enum StateSkipConfig { /// Calculate the state root during each skip slot, producing a fully-valid `BeaconState`. WithStateRoots, /// Don't calculate the state root at each slot, instead just use the zero hash. This is orders /// of magnitude faster, however it produces a partially invalid state. /// /// This state is useful for operations that don't use the state roots; e.g., for calculating /// the shuffling. WithoutStateRoots, } #[derive(Debug, PartialEq)] pub struct HeadInfo { pub slot: Slot, pub block_root: Hash256, pub state_root: Hash256, pub current_justified_checkpoint: types::Checkpoint, pub finalized_checkpoint: types::Checkpoint, pub fork: Fork, pub genesis_time: u64, pub genesis_validators_root: Hash256, pub proposer_shuffling_decision_root: Hash256, } pub trait BeaconChainTypes: Send + Sync + 'static { type HotStore: store::ItemStore; type ColdStore: store::ItemStore; type SlotClock: slot_clock::SlotClock; type Eth1Chain: Eth1ChainBackend; type EthSpec: types::EthSpec; } pub type BeaconForkChoice = ForkChoice< BeaconForkChoiceStore< ::EthSpec, ::HotStore, ::ColdStore, >, ::EthSpec, >; pub type BeaconStore = Arc< HotColdDB< ::EthSpec, ::HotStore, ::ColdStore, >, >; /// Represents the "Beacon Chain" component of Ethereum 2.0. Allows import of blocks and block /// operations and chooses a canonical head. pub struct BeaconChain { pub spec: ChainSpec, /// Configuration for `BeaconChain` runtime behaviour. pub config: ChainConfig, /// Persistent storage for blocks, states, etc. Typically an on-disk store, such as LevelDB. pub store: BeaconStore, /// Database migrator for running background maintenance on the store. pub store_migrator: BackgroundMigrator, /// Reports the current slot, typically based upon the system clock. pub slot_clock: T::SlotClock, /// Stores all operations (e.g., `Attestation`, `Deposit`, etc) that are candidates for /// inclusion in a block. pub op_pool: OperationPool, /// A pool of attestations dedicated to the "naive aggregation strategy" defined in the eth2 /// specs. /// /// This pool accepts `Attestation` objects that only have one aggregation bit set and provides /// a method to get an aggregated `Attestation` for some `AttestationData`. pub naive_aggregation_pool: RwLock>>, /// A pool of `SyncCommitteeContribution` dedicated to the "naive aggregation strategy" defined in the eth2 /// specs. /// /// This pool accepts `SyncCommitteeContribution` objects that only have one aggregation bit set and provides /// a method to get an aggregated `SyncCommitteeContribution` for some `SyncCommitteeContributionData`. pub naive_sync_aggregation_pool: RwLock>>, /// Contains a store of attestations which have been observed by the beacon chain. pub(crate) observed_attestations: RwLock>, /// Contains a store of sync contributions which have been observed by the beacon chain. pub(crate) observed_sync_contributions: RwLock>, /// Maintains a record of which validators have been seen to publish gossip attestations in /// recent epochs. pub observed_gossip_attesters: RwLock>, /// Maintains a record of which validators have been seen to have attestations included in /// blocks in recent epochs. pub observed_block_attesters: RwLock>, /// Maintains a record of which validators have been seen sending sync messages in recent epochs. pub(crate) observed_sync_contributors: RwLock>, /// Maintains a record of which validators have been seen to create `SignedAggregateAndProofs` /// in recent epochs. pub observed_aggregators: RwLock>, /// Maintains a record of which validators have been seen to create `SignedContributionAndProofs` /// in recent epochs. pub(crate) observed_sync_aggregators: RwLock>, /// Maintains a record of which validators have proposed blocks for each slot. pub(crate) observed_block_producers: RwLock>, /// Maintains a record of which validators have submitted voluntary exits. pub(crate) observed_voluntary_exits: Mutex>, /// Maintains a record of which validators we've seen proposer slashings for. pub(crate) observed_proposer_slashings: Mutex>, /// Maintains a record of which validators we've seen attester slashings for. pub(crate) observed_attester_slashings: Mutex, T::EthSpec>>, /// Provides information from the Ethereum 1 (PoW) chain. pub eth1_chain: Option>, /// Stores a "snapshot" of the chain at the time the head-of-the-chain block was received. pub(crate) canonical_head: TimeoutRwLock>, /// The root of the genesis block. pub genesis_block_root: Hash256, /// The root of the genesis state. pub genesis_state_root: Hash256, /// The root of the list of genesis validators, used during syncing. pub genesis_validators_root: Hash256, /// A state-machine that is updated with information from the network and chooses a canonical /// head block. pub fork_choice: RwLock>, /// A handler for events generated by the beacon chain. This is only initialized when the /// HTTP server is enabled. pub event_handler: Option>, /// Used to track the heads of the beacon chain. pub(crate) head_tracker: Arc, /// A cache dedicated to block processing. pub(crate) snapshot_cache: TimeoutRwLock>, /// Caches the attester shuffling for a given epoch and shuffling key root. pub(crate) shuffling_cache: TimeoutRwLock, /// Caches the beacon block proposer shuffling for a given epoch and shuffling key root. pub beacon_proposer_cache: Mutex, /// Caches a map of `validator_index -> validator_pubkey`. pub(crate) validator_pubkey_cache: TimeoutRwLock>, /// A cache used when producing attestations. pub(crate) attester_cache: Arc, /// A list of any hard-coded forks that have been disabled. pub disabled_forks: Vec, /// Sender given to tasks, so that if they encounter a state in which execution cannot /// continue they can request that everything shuts down. pub shutdown_sender: Sender, /// Logging to CLI, etc. pub(crate) log: Logger, /// Arbitrary bytes included in the blocks. pub(crate) graffiti: Graffiti, /// Optional slasher. pub slasher: Option>>, /// Provides monitoring of a set of explicitly defined validators. pub validator_monitor: RwLock>, } type BeaconBlockAndState = (BeaconBlock, BeaconState); impl BeaconChain { /// Persists the head tracker and fork choice. /// /// We do it atomically even though no guarantees need to be made about blocks from /// the head tracker also being present in fork choice. pub fn persist_head_and_fork_choice(&self) -> Result<(), Error> { let mut batch = vec![]; let _head_timer = metrics::start_timer(&metrics::PERSIST_HEAD); batch.push(self.persist_head_in_batch()); let _fork_choice_timer = metrics::start_timer(&metrics::PERSIST_FORK_CHOICE); batch.push(self.persist_fork_choice_in_batch()); self.store.hot_db.do_atomically(batch)?; Ok(()) } /// Return a `PersistedBeaconChain` representing the current head. pub fn make_persisted_head(&self) -> PersistedBeaconChain { PersistedBeaconChain { _canonical_head_block_root: DUMMY_CANONICAL_HEAD_BLOCK_ROOT, genesis_block_root: self.genesis_block_root, ssz_head_tracker: self.head_tracker.to_ssz_container(), } } /// Return a database operation for writing the beacon chain head to disk. pub fn persist_head_in_batch(&self) -> KeyValueStoreOp { self.make_persisted_head() .as_kv_store_op(BEACON_CHAIN_DB_KEY) } /// Return a database operation for writing fork choice to disk. pub fn persist_fork_choice_in_batch(&self) -> KeyValueStoreOp { let fork_choice = self.fork_choice.read(); let persisted_fork_choice = PersistedForkChoice { fork_choice: fork_choice.to_persisted(), fork_choice_store: fork_choice.fc_store().to_persisted(), }; persisted_fork_choice.as_kv_store_op(FORK_CHOICE_DB_KEY) } /// Load fork choice from disk, returning `None` if it isn't found. pub fn load_fork_choice(store: BeaconStore) -> Result>, Error> { let persisted_fork_choice = match store.get_item::(&FORK_CHOICE_DB_KEY)? { Some(fc) => fc, None => return Ok(None), }; let fc_store = BeaconForkChoiceStore::from_persisted(persisted_fork_choice.fork_choice_store, store)?; Ok(Some(ForkChoice::from_persisted( persisted_fork_choice.fork_choice, fc_store, )?)) } /// Persists `self.op_pool` to disk. /// /// ## Notes /// /// This operation is typically slow and causes a lot of allocations. It should be used /// sparingly. pub fn persist_op_pool(&self) -> Result<(), Error> { let _timer = metrics::start_timer(&metrics::PERSIST_OP_POOL); self.store.put_item( &OP_POOL_DB_KEY, &PersistedOperationPool::from_operation_pool(&self.op_pool), )?; Ok(()) } /// Persists `self.eth1_chain` and its caches to disk. pub fn persist_eth1_cache(&self) -> Result<(), Error> { let _timer = metrics::start_timer(&metrics::PERSIST_OP_POOL); if let Some(eth1_chain) = self.eth1_chain.as_ref() { self.store .put_item(Ð1_CACHE_DB_KEY, ð1_chain.as_ssz_container())?; } Ok(()) } /// Returns the slot _right now_ according to `self.slot_clock`. Returns `Err` if the slot is /// unavailable. /// /// The slot might be unavailable due to an error with the system clock, or if the present time /// is before genesis (i.e., a negative slot). pub fn slot(&self) -> Result { self.slot_clock.now().ok_or(Error::UnableToReadSlot) } /// Returns the epoch _right now_ according to `self.slot_clock`. Returns `Err` if the epoch is /// unavailable. /// /// The epoch might be unavailable due to an error with the system clock, or if the present time /// is before genesis (i.e., a negative epoch). pub fn epoch(&self) -> Result { self.slot() .map(|slot| slot.epoch(T::EthSpec::slots_per_epoch())) } /// Iterates across all `(block_root, slot)` pairs from `start_slot` /// to the head of the chain (inclusive). /// /// ## Notes /// /// - `slot` always increases by `1`. /// - Skipped slots contain the root of the closest prior /// non-skipped slot (identical to the way they are stored in `state.block_roots`). /// - Iterator returns `(Hash256, Slot)`. /// /// Will return a `BlockOutOfRange` error if the requested start slot is before the period of /// history for which we have blocks stored. See `get_oldest_block_slot`. pub fn forwards_iter_block_roots( &self, start_slot: Slot, ) -> Result>, Error> { let oldest_block_slot = self.store.get_oldest_block_slot(); if start_slot < oldest_block_slot { return Err(Error::HistoricalBlockError( HistoricalBlockError::BlockOutOfRange { slot: start_slot, oldest_block_slot, }, )); } let local_head = self.head()?; let iter = HotColdDB::forwards_block_roots_iterator( self.store.clone(), start_slot, local_head.beacon_state, local_head.beacon_block_root, &self.spec, )?; Ok(iter.map(|result| result.map_err(Into::into))) } /// Traverse backwards from `block_root` to find the block roots of its ancestors. /// /// ## Notes /// /// - `slot` always decreases by `1`. /// - Skipped slots contain the root of the closest prior /// non-skipped slot (identical to the way they are stored in `state.block_roots`) . /// - Iterator returns `(Hash256, Slot)`. /// - The provided `block_root` is included as the first item in the iterator. pub fn rev_iter_block_roots_from( &self, block_root: Hash256, ) -> Result>, Error> { let block = self .get_block(&block_root)? .ok_or(Error::MissingBeaconBlock(block_root))?; let state = self .get_state(&block.state_root(), Some(block.slot()))? .ok_or_else(|| Error::MissingBeaconState(block.state_root()))?; let iter = BlockRootsIterator::owned(self.store.clone(), state); Ok(std::iter::once(Ok((block_root, block.slot()))) .chain(iter) .map(|result| result.map_err(|e| e.into()))) } /// Iterate through the current chain to find the slot intersecting with the given beacon state. /// The maximum depth this will search is `SLOTS_PER_HISTORICAL_ROOT`, and if that depth is reached /// and no intersection is found, the finalized slot will be returned. pub fn find_reorg_slot( &self, new_state: &BeaconState, new_block_root: Hash256, ) -> Result { self.with_head(|snapshot| { let old_state = &snapshot.beacon_state; let old_block_root = snapshot.beacon_block_root; // The earliest slot for which the two chains may have a common history. let lowest_slot = std::cmp::min(new_state.slot(), old_state.slot()); // Create an iterator across `$state`, assuming that the block at `$state.slot` has the // block root of `$block_root`. // // The iterator will be skipped until the next value returns `lowest_slot`. // // This is a macro instead of a function or closure due to the complex types invloved // in all the iterator wrapping. macro_rules! aligned_roots_iter { ($state: ident, $block_root: ident) => { std::iter::once(Ok(($state.slot(), $block_root))) .chain($state.rev_iter_block_roots(&self.spec)) .skip_while(|result| { result .as_ref() .map_or(false, |(slot, _)| *slot > lowest_slot) }) }; } // Create iterators across old/new roots where iterators both start at the same slot. let mut new_roots = aligned_roots_iter!(new_state, new_block_root); let mut old_roots = aligned_roots_iter!(old_state, old_block_root); // Whilst *both* of the iterators are still returning values, try and find a common // ancestor between them. while let (Some(old), Some(new)) = (old_roots.next(), new_roots.next()) { let (old_slot, old_root) = old?; let (new_slot, new_root) = new?; // Sanity check to detect programming errors. if old_slot != new_slot { return Err(Error::InvalidReorgSlotIter { new_slot, old_slot }); } if old_root == new_root { // A common ancestor has been found. return Ok(old_slot); } } // If no common ancestor is found, declare that the re-org happened at the previous // finalized slot. // // Sometimes this will result in the return slot being *lower* than the actual reorg // slot. However, assuming we don't re-org through a finalized slot, it will never be // *higher*. // // We provide this potentially-inaccurate-but-safe information to avoid onerous // database reads during times of deep reorgs. Ok(old_state .finalized_checkpoint() .epoch .start_slot(T::EthSpec::slots_per_epoch())) }) } /// Iterates backwards across all `(state_root, slot)` pairs starting from /// an arbitrary `BeaconState` to the earliest reachable ancestor (may or may not be genesis). /// /// ## Notes /// /// - `slot` always decreases by `1`. /// - Iterator returns `(Hash256, Slot)`. /// - As this iterator starts at the `head` of the chain (viz., the best block), the first slot /// returned may be earlier than the wall-clock slot. pub fn rev_iter_state_roots_from<'a>( &self, state_root: Hash256, state: &'a BeaconState, ) -> impl Iterator> + 'a { std::iter::once(Ok((state_root, state.slot()))) .chain(StateRootsIterator::new(self.store.clone(), state)) .map(|result| result.map_err(Into::into)) } /// Iterates across all `(state_root, slot)` pairs from `start_slot` /// to the head of the chain (inclusive). /// /// ## Notes /// /// - `slot` always increases by `1`. /// - Iterator returns `(Hash256, Slot)`. pub fn forwards_iter_state_roots( &self, start_slot: Slot, ) -> Result>, Error> { let local_head = self.head()?; let iter = HotColdDB::forwards_state_roots_iterator( self.store.clone(), start_slot, local_head.beacon_state_root(), local_head.beacon_state, &self.spec, )?; Ok(iter.map(|result| result.map_err(Into::into))) } /// Returns the block at the given slot, if any. Only returns blocks in the canonical chain. /// /// Use the `skips` parameter to define the behaviour when `request_slot` is a skipped slot. /// /// ## Errors /// /// May return a database error. pub fn block_at_slot( &self, request_slot: Slot, skips: WhenSlotSkipped, ) -> Result>, Error> { let root = self.block_root_at_slot(request_slot, skips)?; if let Some(block_root) = root { Ok(self.store.get_block(&block_root)?) } else { Ok(None) } } /// Returns the state root at the given slot, if any. Only returns state roots in the canonical chain. /// /// ## Errors /// /// May return a database error. pub fn state_root_at_slot(&self, request_slot: Slot) -> Result, Error> { if request_slot > self.slot()? { return Ok(None); } else if request_slot == self.spec.genesis_slot { return Ok(Some(self.genesis_state_root)); } // Check limits w.r.t historic state bounds. let (historic_lower_limit, historic_upper_limit) = self.store.get_historic_state_limits(); if request_slot > historic_lower_limit && request_slot < historic_upper_limit { return Ok(None); } // Try an optimized path of reading the root directly from the head state. let fast_lookup: Option = self.with_head(|head| { if head.beacon_block.slot() <= request_slot { // Return the head state root if all slots between the request and the head are skipped. Ok(Some(head.beacon_state_root())) } else if let Ok(root) = head.beacon_state.get_state_root(request_slot) { // Return the root if it's easily accessible from the head state. Ok(Some(*root)) } else { // Fast lookup is not possible. Ok::<_, Error>(None) } })?; if let Some(root) = fast_lookup { return Ok(Some(root)); } process_results(self.forwards_iter_state_roots(request_slot)?, |mut iter| { if let Some((root, slot)) = iter.next() { if slot == request_slot { Ok(Some(root)) } else { // Sanity check. Err(Error::InconsistentForwardsIter { request_slot, slot }) } } else { Ok(None) } })? } /// Returns the block root at the given slot, if any. Only returns roots in the canonical chain. /// /// ## Notes /// /// - Use the `skips` parameter to define the behaviour when `request_slot` is a skipped slot. /// - Returns `Ok(None)` for any slot higher than the current wall-clock slot, or less than /// the oldest known block slot. pub fn block_root_at_slot( &self, request_slot: Slot, skips: WhenSlotSkipped, ) -> Result, Error> { match skips { WhenSlotSkipped::None => self.block_root_at_slot_skips_none(request_slot), WhenSlotSkipped::Prev => self.block_root_at_slot_skips_prev(request_slot), } .or_else(|e| match e { Error::HistoricalBlockError(_) => Ok(None), e => Err(e), }) } /// Returns the block root at the given slot, if any. Only returns roots in the canonical chain. /// /// ## Notes /// /// - Returns `Ok(None)` if the given `Slot` was skipped. /// - Returns `Ok(None)` for any slot higher than the current wall-clock slot. /// /// ## Errors /// /// May return a database error. fn block_root_at_slot_skips_none(&self, request_slot: Slot) -> Result, Error> { if request_slot > self.slot()? { return Ok(None); } else if request_slot == self.spec.genesis_slot { return Ok(Some(self.genesis_block_root)); } let prev_slot = request_slot.saturating_sub(1_u64); // Try an optimized path of reading the root directly from the head state. let fast_lookup: Option> = self.with_head(|head| { let state = &head.beacon_state; // Try find the root for the `request_slot`. let request_root_opt = match state.slot().cmp(&request_slot) { // It's always a skip slot if the head is less than the request slot, return early. Ordering::Less => return Ok(Some(None)), // The request slot is the head slot. Ordering::Equal => Some(head.beacon_block_root), // Try find the request slot in the state. Ordering::Greater => state.get_block_root(request_slot).ok().copied(), }; if let Some(request_root) = request_root_opt { if let Ok(prev_root) = state.get_block_root(prev_slot) { return Ok(Some((*prev_root != request_root).then(|| request_root))); } } // Fast lookup is not possible. Ok::<_, Error>(None) })?; if let Some(root_opt) = fast_lookup { return Ok(root_opt); } if let Some(((prev_root, _), (curr_root, curr_slot))) = process_results(self.forwards_iter_block_roots(prev_slot)?, |iter| { iter.tuple_windows().next() })? { // Sanity check. if curr_slot != request_slot { return Err(Error::InconsistentForwardsIter { request_slot, slot: curr_slot, }); } Ok((curr_root != prev_root).then(|| curr_root)) } else { Ok(None) } } /// Returns the block root at the given slot, if any. Only returns roots in the canonical chain. /// /// ## Notes /// /// - Returns the root at the previous non-skipped slot if the given `Slot` was skipped. /// - Returns `Ok(None)` for any slot higher than the current wall-clock slot. /// /// ## Errors /// /// May return a database error. fn block_root_at_slot_skips_prev(&self, request_slot: Slot) -> Result, Error> { if request_slot > self.slot()? { return Ok(None); } else if request_slot == self.spec.genesis_slot { return Ok(Some(self.genesis_block_root)); } // Try an optimized path of reading the root directly from the head state. let fast_lookup: Option = self.with_head(|head| { if head.beacon_block.slot() <= request_slot { // Return the head root if all slots between the request and the head are skipped. Ok(Some(head.beacon_block_root)) } else if let Ok(root) = head.beacon_state.get_block_root(request_slot) { // Return the root if it's easily accessible from the head state. Ok(Some(*root)) } else { // Fast lookup is not possible. Ok::<_, Error>(None) } })?; if let Some(root) = fast_lookup { return Ok(Some(root)); } process_results(self.forwards_iter_block_roots(request_slot)?, |mut iter| { if let Some((root, slot)) = iter.next() { if slot == request_slot { Ok(Some(root)) } else { // Sanity check. Err(Error::InconsistentForwardsIter { request_slot, slot }) } } else { Ok(None) } })? } /// Returns the block at the given root, if any. /// /// ## Errors /// /// May return a database error. pub fn get_block( &self, block_root: &Hash256, ) -> Result>, Error> { Ok(self.store.get_block(block_root)?) } /// Returns the state at the given root, if any. /// /// ## Errors /// /// May return a database error. pub fn get_state( &self, state_root: &Hash256, slot: Option, ) -> Result>, Error> { Ok(self.store.get_state(state_root, slot)?) } /// Returns a `Checkpoint` representing the head block and state. Contains the "best block"; /// the head of the canonical `BeaconChain`. /// /// It is important to note that the `beacon_state` returned may not match the present slot. It /// is the state as it was when the head block was received, which could be some slots prior to /// now. pub fn head(&self) -> Result, Error> { self.with_head(|head| Ok(head.clone_with(CloneConfig::committee_caches_only()))) } /// Apply a function to the canonical head without cloning it. pub fn with_head( &self, f: impl FnOnce(&BeaconSnapshot) -> Result, ) -> Result where E: From, { let head_lock = self .canonical_head .try_read_for(HEAD_LOCK_TIMEOUT) .ok_or(Error::CanonicalHeadLockTimeout)?; f(&head_lock) } /// Returns the beacon block root at the head of the canonical chain. /// /// See `Self::head` for more information. pub fn head_beacon_block_root(&self) -> Result { self.with_head(|s| Ok(s.beacon_block_root)) } /// Returns the beacon block at the head of the canonical chain. /// /// See `Self::head` for more information. pub fn head_beacon_block(&self) -> Result, Error> { self.with_head(|s| Ok(s.beacon_block.clone())) } /// Returns the beacon state at the head of the canonical chain. /// /// See `Self::head` for more information. pub fn head_beacon_state(&self) -> Result, Error> { self.with_head(|s| { Ok(s.beacon_state .clone_with(CloneConfig::committee_caches_only())) }) } /// Return the sync committee at `slot + 1` from the canonical chain. /// /// This is useful when dealing with sync committee messages, because messages are signed /// and broadcast one slot prior to the slot of the sync committee (which is relevant at /// sync committee period boundaries). pub fn sync_committee_at_next_slot( &self, slot: Slot, ) -> Result>, Error> { let epoch = slot.safe_add(1)?.epoch(T::EthSpec::slots_per_epoch()); self.sync_committee_at_epoch(epoch) } /// Return the sync committee at `epoch` from the canonical chain. pub fn sync_committee_at_epoch( &self, epoch: Epoch, ) -> Result>, Error> { // Try to read a committee from the head. This will work most of the time, but will fail // for faraway committees, or if there are skipped slots at the transition to Altair. let spec = &self.spec; let committee_from_head = self.with_head( |head| match head.beacon_state.get_built_sync_committee(epoch, spec) { Ok(committee) => Ok(Some(committee.clone())), Err(BeaconStateError::SyncCommitteeNotKnown { .. }) | Err(BeaconStateError::IncorrectStateVariant) => Ok(None), Err(e) => Err(Error::from(e)), }, )?; if let Some(committee) = committee_from_head { Ok(committee) } else { // Slow path: load a state (or advance the head). let sync_committee_period = epoch.sync_committee_period(spec)?; let committee = self .state_for_sync_committee_period(sync_committee_period)? .get_built_sync_committee(epoch, spec)? .clone(); Ok(committee) } } /// Load a state suitable for determining the sync committee for the given period. /// /// Specifically, the state at the start of the *previous* sync committee period. /// /// This is sufficient for historical duties, and efficient in the case where the head /// is lagging the current period and we need duties for the next period (because we only /// have to transition the head to start of the current period). /// /// We also need to ensure that the load slot is after the Altair fork. /// /// **WARNING**: the state returned will have dummy state roots. It should only be used /// for its sync committees (determining duties, etc). pub fn state_for_sync_committee_period( &self, sync_committee_period: u64, ) -> Result, Error> { let altair_fork_epoch = self .spec .altair_fork_epoch .ok_or(Error::AltairForkDisabled)?; let load_slot = std::cmp::max( self.spec.epochs_per_sync_committee_period * sync_committee_period.saturating_sub(1), altair_fork_epoch, ) .start_slot(T::EthSpec::slots_per_epoch()); self.state_at_slot(load_slot, StateSkipConfig::WithoutStateRoots) } /// Returns info representing the head block and state. /// /// A summarized version of `Self::head` that involves less cloning. pub fn head_info(&self) -> Result { self.with_head(|head| { let proposer_shuffling_decision_root = head .beacon_state .proposer_shuffling_decision_root(head.beacon_block_root)?; Ok(HeadInfo { slot: head.beacon_block.slot(), block_root: head.beacon_block_root, state_root: head.beacon_state_root(), current_justified_checkpoint: head.beacon_state.current_justified_checkpoint(), finalized_checkpoint: head.beacon_state.finalized_checkpoint(), fork: head.beacon_state.fork(), genesis_time: head.beacon_state.genesis_time(), genesis_validators_root: head.beacon_state.genesis_validators_root(), proposer_shuffling_decision_root, }) }) } /// Returns the current heads of the `BeaconChain`. For the canonical head, see `Self::head`. /// /// Returns `(block_root, block_slot)`. pub fn heads(&self) -> Vec<(Hash256, Slot)> { self.head_tracker.heads() } pub fn knows_head(&self, block_hash: &SignedBeaconBlockHash) -> bool { self.head_tracker.contains_head((*block_hash).into()) } /// Returns the `BeaconState` at the given slot. /// /// Returns `None` when the state is not found in the database or there is an error skipping /// to a future state. pub fn state_at_slot( &self, slot: Slot, config: StateSkipConfig, ) -> Result, Error> { let head_state = self.head()?.beacon_state; match slot.cmp(&head_state.slot()) { Ordering::Equal => Ok(head_state), Ordering::Greater => { if slot > head_state.slot() + T::EthSpec::slots_per_epoch() { warn!( self.log, "Skipping more than an epoch"; "head_slot" => head_state.slot(), "request_slot" => slot ) } let start_slot = head_state.slot(); let task_start = Instant::now(); let max_task_runtime = Duration::from_secs(self.spec.seconds_per_slot); let head_state_slot = head_state.slot(); let mut state = head_state; let skip_state_root = match config { StateSkipConfig::WithStateRoots => None, StateSkipConfig::WithoutStateRoots => Some(Hash256::zero()), }; while state.slot() < slot { // Do not allow and forward state skip that takes longer than the maximum task duration. // // This is a protection against nodes doing too much work when they're not synced // to a chain. if task_start + max_task_runtime < Instant::now() { return Err(Error::StateSkipTooLarge { start_slot, requested_slot: slot, max_task_runtime, }); } // Note: supplying some `state_root` when it is known would be a cheap and easy // optimization. match per_slot_processing(&mut state, skip_state_root, &self.spec) { Ok(_) => (), Err(e) => { warn!( self.log, "Unable to load state at slot"; "error" => ?e, "head_slot" => head_state_slot, "requested_slot" => slot ); return Err(Error::NoStateForSlot(slot)); } }; } Ok(state) } Ordering::Less => { let state_root = process_results(self.forwards_iter_state_roots(slot)?, |iter| { iter.take_while(|(_, current_slot)| *current_slot >= slot) .find(|(_, current_slot)| *current_slot == slot) .map(|(root, _slot)| root) })? .ok_or(Error::NoStateForSlot(slot))?; Ok(self .get_state(&state_root, Some(slot))? .ok_or(Error::NoStateForSlot(slot))?) } } } /// Returns the `BeaconState` the current slot (viz., `self.slot()`). /// /// - A reference to the head state (note: this keeps a read lock on the head, try to use /// sparingly). /// - The head state, but with skipped slots (for states later than the head). /// /// Returns `None` when there is an error skipping to a future state or the slot clock cannot /// be read. pub fn wall_clock_state(&self) -> Result, Error> { self.state_at_slot(self.slot()?, StateSkipConfig::WithStateRoots) } /// Returns the slot of the highest block in the canonical chain. pub fn best_slot(&self) -> Result { self.canonical_head .try_read_for(HEAD_LOCK_TIMEOUT) .map(|head| head.beacon_block.slot()) .ok_or(Error::CanonicalHeadLockTimeout) } /// Returns the validator index (if any) for the given public key. /// /// ## Notes /// /// This query uses the `validator_pubkey_cache` which contains _all_ validators ever seen, /// even if those validators aren't included in the head state. It is important to remember /// that just because a validator exists here, it doesn't necessarily exist in all /// `BeaconStates`. /// /// ## Errors /// /// May return an error if acquiring a read-lock on the `validator_pubkey_cache` times out. pub fn validator_index(&self, pubkey: &PublicKeyBytes) -> Result, Error> { let pubkey_cache = self .validator_pubkey_cache .try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)?; Ok(pubkey_cache.get_index(pubkey)) } /// Return the validator indices of all public keys fetched from an iterator. /// /// If any public key doesn't belong to a known validator then an error will be returned. /// We could consider relaxing this by returning `Vec>` in future. pub fn validator_indices<'a>( &self, validator_pubkeys: impl Iterator, ) -> Result, Error> { let pubkey_cache = self .validator_pubkey_cache .try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)?; validator_pubkeys .map(|pubkey| { pubkey_cache .get_index(pubkey) .map(|id| id as u64) .ok_or(Error::ValidatorPubkeyUnknown(*pubkey)) }) .collect() } /// Returns the validator pubkey (if any) for the given validator index. /// /// ## Notes /// /// This query uses the `validator_pubkey_cache` which contains _all_ validators ever seen, /// even if those validators aren't included in the head state. It is important to remember /// that just because a validator exists here, it doesn't necessarily exist in all /// `BeaconStates`. /// /// ## Errors /// /// May return an error if acquiring a read-lock on the `validator_pubkey_cache` times out. pub fn validator_pubkey(&self, validator_index: usize) -> Result, Error> { let pubkey_cache = self .validator_pubkey_cache .try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)?; Ok(pubkey_cache.get(validator_index).cloned()) } /// As per `Self::validator_pubkey`, but returns `PublicKeyBytes`. pub fn validator_pubkey_bytes( &self, validator_index: usize, ) -> Result, Error> { let pubkey_cache = self .validator_pubkey_cache .try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)?; Ok(pubkey_cache.get_pubkey_bytes(validator_index).copied()) } /// As per `Self::validator_pubkey_bytes` but will resolve multiple indices at once to avoid /// bouncing the read-lock on the pubkey cache. /// /// Returns a map that may have a length less than `validator_indices.len()` if some indices /// were unable to be resolved. pub fn validator_pubkey_bytes_many( &self, validator_indices: &[usize], ) -> Result, Error> { let pubkey_cache = self .validator_pubkey_cache .try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)?; let mut map = HashMap::with_capacity(validator_indices.len()); for &validator_index in validator_indices { if let Some(pubkey) = pubkey_cache.get_pubkey_bytes(validator_index) { map.insert(validator_index, *pubkey); } } Ok(map) } /// Returns the block canonical root of the current canonical chain at a given slot, starting from the given state. /// /// Returns `None` if the given slot doesn't exist in the chain. pub fn root_at_slot_from_state( &self, target_slot: Slot, beacon_block_root: Hash256, state: &BeaconState, ) -> Result, Error> { let iter = BlockRootsIterator::new(self.store.clone(), state); let iter_with_head = std::iter::once(Ok((beacon_block_root, state.slot()))) .chain(iter) .map(|result| result.map_err(|e| e.into())); process_results(iter_with_head, |mut iter| { iter.find(|(_, slot)| *slot == target_slot) .map(|(root, _)| root) }) } /// Returns the attestation duties for the given validator indices using the shuffling cache. /// /// An error may be returned if `head_block_root` is a finalized block, this function is only /// designed for operations at the head of the chain. /// /// The returned `Vec` will have the same length as `validator_indices`, any /// non-existing/inactive validators will have `None` values. /// /// ## Notes /// /// This function will try to use the shuffling cache to return the value. If the value is not /// in the shuffling cache, it will be added. Care should be taken not to wash out the /// shuffling cache with historical/useless values. pub fn validator_attestation_duties( &self, validator_indices: &[u64], epoch: Epoch, head_block_root: Hash256, ) -> Result<(Vec>, Hash256), Error> { self.with_committee_cache(head_block_root, epoch, |committee_cache, dependent_root| { let duties = validator_indices .iter() .map(|validator_index| { let validator_index = *validator_index as usize; committee_cache.get_attestation_duties(validator_index) }) .collect(); Ok((duties, dependent_root)) }) } /// Returns an aggregated `Attestation`, if any, that has a matching `attestation.data`. /// /// The attestation will be obtained from `self.naive_aggregation_pool`. pub fn get_aggregated_attestation( &self, data: &AttestationData, ) -> Option> { self.naive_aggregation_pool.read().get(data) } /// Returns an aggregated `Attestation`, if any, that has a matching /// `attestation.data.tree_hash_root()`. /// /// The attestation will be obtained from `self.naive_aggregation_pool`. pub fn get_aggregated_attestation_by_slot_and_root( &self, slot: Slot, attestation_data_root: &Hash256, ) -> Option> { self.naive_aggregation_pool .read() .get_by_slot_and_root(slot, attestation_data_root) } /// Return an aggregated `SyncCommitteeContribution` matching the given `root`. pub fn get_aggregated_sync_committee_contribution( &self, sync_contribution_data: &SyncContributionData, ) -> Option> { self.naive_sync_aggregation_pool .read() .get(sync_contribution_data) } /// Produce an unaggregated `Attestation` that is valid for the given `slot` and `index`. /// /// The produced `Attestation` will not be valid until it has been signed by exactly one /// validator that is in the committee for `slot` and `index` in the canonical chain. /// /// Always attests to the canonical chain. /// /// ## Errors /// /// May return an error if the `request_slot` is too far behind the head state. pub fn produce_unaggregated_attestation( &self, request_slot: Slot, request_index: CommitteeIndex, ) -> Result, Error> { let _total_timer = metrics::start_timer(&metrics::ATTESTATION_PRODUCTION_SECONDS); let slots_per_epoch = T::EthSpec::slots_per_epoch(); let request_epoch = request_slot.epoch(slots_per_epoch); /* * Phase 1/2: * * Take a short-lived read-lock on the head and copy the necessary information from it. * * It is important that this first phase is as quick as possible; creating contention for * the head-lock is not desirable. */ let head_state_slot; let beacon_block_root; let beacon_state_root; let target; let current_epoch_attesting_info: Option<(Checkpoint, usize)>; let attester_cache_key; let head_timer = metrics::start_timer(&metrics::ATTESTATION_PRODUCTION_HEAD_SCRAPE_SECONDS); if let Some(head) = self.canonical_head.try_read_for(HEAD_LOCK_TIMEOUT) { let head_state = &head.beacon_state; head_state_slot = head_state.slot(); // There is no value in producing an attestation to a block that is pre-finalization and // it is likely to cause expensive and pointless reads to the freezer database. Exit // early if this is the case. let finalized_slot = head_state .finalized_checkpoint() .epoch .start_slot(slots_per_epoch); if request_slot < finalized_slot { return Err(Error::AttestingToFinalizedSlot { finalized_slot, request_slot, }); } // This function will eventually fail when trying to access a slot which is // out-of-bounds of `state.block_roots`. This explicit error is intended to provide a // clearer message to the user than an ambiguous `SlotOutOfBounds` error. let slots_per_historical_root = T::EthSpec::slots_per_historical_root() as u64; let lowest_permissible_slot = head_state.slot().saturating_sub(slots_per_historical_root); if request_slot < lowest_permissible_slot { return Err(Error::AttestingToAncientSlot { lowest_permissible_slot, request_slot, }); } if request_slot >= head_state.slot() { // When attesting to the head slot or later, always use the head of the chain. beacon_block_root = head.beacon_block_root; beacon_state_root = head.beacon_state_root(); } else { // Permit attesting to slots *prior* to the current head. This is desirable when // the VC and BN are out-of-sync due to time issues or overloading. beacon_block_root = *head_state.get_block_root(request_slot)?; beacon_state_root = *head_state.get_state_root(request_slot)?; }; let target_slot = request_epoch.start_slot(T::EthSpec::slots_per_epoch()); let target_root = if head_state.slot() <= target_slot { // If the state is earlier than the target slot then the target *must* be the head // block root. beacon_block_root } else { *head_state.get_block_root(target_slot)? }; target = Checkpoint { epoch: request_epoch, root: target_root, }; current_epoch_attesting_info = if head_state.current_epoch() == request_epoch { // When the head state is in the same epoch as the request, all the information // required to attest is available on the head state. Some(( head_state.current_justified_checkpoint(), head_state .get_beacon_committee(request_slot, request_index)? .committee .len(), )) } else { // If the head state is in a *different* epoch to the request, more work is required // to determine the justified checkpoint and committee length. None }; // Determine the key for `self.attester_cache`, in case it is required later in this // routine. attester_cache_key = AttesterCacheKey::new(request_epoch, head_state, beacon_block_root)?; } else { return Err(Error::CanonicalHeadLockTimeout); } drop(head_timer); /* * Phase 2/2: * * If the justified checkpoint and committee length from the head are suitable for this * attestation, use them. If not, try the attester cache. If the cache misses, load a state * from disk and prime the cache with it. */ let cache_timer = metrics::start_timer(&metrics::ATTESTATION_PRODUCTION_CACHE_INTERACTION_SECONDS); let (justified_checkpoint, committee_len) = if let Some((justified_checkpoint, committee_len)) = current_epoch_attesting_info { // The head state is in the same epoch as the attestation, so there is no more // required information. (justified_checkpoint, committee_len) } else if let Some(cached_values) = self.attester_cache.get::( &attester_cache_key, request_slot, request_index, &self.spec, )? { // The suitable values were already cached. Return them. cached_values } else { debug!( self.log, "Attester cache miss"; "beacon_block_root" => ?beacon_block_root, "head_state_slot" => %head_state_slot, "request_slot" => %request_slot, ); // Neither the head state, nor the attester cache was able to produce the required // information to attest in this epoch. So, load a `BeaconState` from disk and use // it to fulfil the request (and prime the cache to avoid this next time). let _cache_build_timer = metrics::start_timer(&metrics::ATTESTATION_PRODUCTION_CACHE_PRIME_SECONDS); self.attester_cache.load_and_cache_state( beacon_state_root, attester_cache_key, request_slot, request_index, self, )? }; drop(cache_timer); Ok(Attestation { aggregation_bits: BitList::with_capacity(committee_len)?, data: AttestationData { slot: request_slot, index: request_index, beacon_block_root, source: justified_checkpoint, target, }, signature: AggregateSignature::empty(), }) } /// Produces an "unaggregated" attestation for the given `slot` and `index` that attests to /// `beacon_block_root`. The provided `state` should match the `block.state_root` for the /// `block` identified by `beacon_block_root`. /// /// The attestation doesn't _really_ have anything about it that makes it unaggregated per say, /// however this function is only required in the context of forming an unaggregated /// attestation. It would be an (undetectable) violation of the protocol to create a /// `SignedAggregateAndProof` based upon the output of this function. pub fn produce_unaggregated_attestation_for_block( &self, slot: Slot, index: CommitteeIndex, beacon_block_root: Hash256, mut state: Cow>, state_root: Hash256, ) -> Result, Error> { let epoch = slot.epoch(T::EthSpec::slots_per_epoch()); if state.slot() > slot { return Err(Error::CannotAttestToFutureState); } else if state.current_epoch() < epoch { let mut_state = state.to_mut(); // Only perform a "partial" state advance since we do not require the state roots to be // accurate. partial_state_advance( mut_state, Some(state_root), epoch.start_slot(T::EthSpec::slots_per_epoch()), &self.spec, )?; mut_state.build_committee_cache(RelativeEpoch::Current, &self.spec)?; } let committee_len = state.get_beacon_committee(slot, index)?.committee.len(); let target_slot = epoch.start_slot(T::EthSpec::slots_per_epoch()); let target_root = if state.slot() <= target_slot { beacon_block_root } else { *state.get_block_root(target_slot)? }; Ok(Attestation { aggregation_bits: BitList::with_capacity(committee_len)?, data: AttestationData { slot, index, beacon_block_root, source: state.current_justified_checkpoint(), target: Checkpoint { epoch, root: target_root, }, }, signature: AggregateSignature::empty(), }) } /// Performs the same validation as `Self::verify_unaggregated_attestation_for_gossip`, but for /// multiple attestations using batch BLS verification. Batch verification can provide /// significant CPU-time savings compared to individual verification. pub fn batch_verify_unaggregated_attestations_for_gossip<'a, I>( &self, attestations: I, ) -> Result< Vec, AttestationError>>, AttestationError, > where I: Iterator, Option)> + ExactSizeIterator, { batch_verify_unaggregated_attestations(attestations, self) } /// Accepts some `Attestation` from the network and attempts to verify it, returning `Ok(_)` if /// it is valid to be (re)broadcast on the gossip network. /// /// The attestation must be "unaggregated", that is it must have exactly one /// aggregation bit set. pub fn verify_unaggregated_attestation_for_gossip<'a>( &self, unaggregated_attestation: &'a Attestation, subnet_id: Option, ) -> Result, AttestationError> { metrics::inc_counter(&metrics::UNAGGREGATED_ATTESTATION_PROCESSING_REQUESTS); let _timer = metrics::start_timer(&metrics::UNAGGREGATED_ATTESTATION_GOSSIP_VERIFICATION_TIMES); VerifiedUnaggregatedAttestation::verify(unaggregated_attestation, subnet_id, self).map( |v| { // This method is called for API and gossip attestations, so this covers all unaggregated attestation events if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_attestation_subscribers() { event_handler.register(EventKind::Attestation(v.attestation().clone())); } } metrics::inc_counter(&metrics::UNAGGREGATED_ATTESTATION_PROCESSING_SUCCESSES); v }, ) } /// Performs the same validation as `Self::verify_aggregated_attestation_for_gossip`, but for /// multiple attestations using batch BLS verification. Batch verification can provide /// significant CPU-time savings compared to individual verification. pub fn batch_verify_aggregated_attestations_for_gossip<'a, I>( &self, aggregates: I, ) -> Result, AttestationError>>, AttestationError> where I: Iterator> + ExactSizeIterator, { batch_verify_aggregated_attestations(aggregates, self) } /// Accepts some `SignedAggregateAndProof` from the network and attempts to verify it, /// returning `Ok(_)` if it is valid to be (re)broadcast on the gossip network. pub fn verify_aggregated_attestation_for_gossip<'a>( &self, signed_aggregate: &'a SignedAggregateAndProof, ) -> Result, AttestationError> { metrics::inc_counter(&metrics::AGGREGATED_ATTESTATION_PROCESSING_REQUESTS); let _timer = metrics::start_timer(&metrics::AGGREGATED_ATTESTATION_GOSSIP_VERIFICATION_TIMES); VerifiedAggregatedAttestation::verify(signed_aggregate, self).map(|v| { // This method is called for API and gossip attestations, so this covers all aggregated attestation events if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_attestation_subscribers() { event_handler.register(EventKind::Attestation(v.attestation().clone())); } } metrics::inc_counter(&metrics::AGGREGATED_ATTESTATION_PROCESSING_SUCCESSES); v }) } /// Accepts some `SyncCommitteeMessage` from the network and attempts to verify it, returning `Ok(_)` if /// it is valid to be (re)broadcast on the gossip network. pub fn verify_sync_committee_message_for_gossip( &self, sync_message: SyncCommitteeMessage, subnet_id: SyncSubnetId, ) -> Result { metrics::inc_counter(&metrics::SYNC_MESSAGE_PROCESSING_REQUESTS); let _timer = metrics::start_timer(&metrics::SYNC_MESSAGE_GOSSIP_VERIFICATION_TIMES); VerifiedSyncCommitteeMessage::verify(sync_message, subnet_id, self).map(|v| { metrics::inc_counter(&metrics::SYNC_MESSAGE_PROCESSING_SUCCESSES); v }) } /// Accepts some `SignedContributionAndProof` from the network and attempts to verify it, /// returning `Ok(_)` if it is valid to be (re)broadcast on the gossip network. pub fn verify_sync_contribution_for_gossip( &self, sync_contribution: SignedContributionAndProof, ) -> Result, SyncCommitteeError> { metrics::inc_counter(&metrics::SYNC_CONTRIBUTION_PROCESSING_REQUESTS); let _timer = metrics::start_timer(&metrics::SYNC_CONTRIBUTION_GOSSIP_VERIFICATION_TIMES); VerifiedSyncContribution::verify(sync_contribution, self).map(|v| { if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_contribution_subscribers() { event_handler.register(EventKind::ContributionAndProof(Box::new( v.aggregate().clone(), ))); } } metrics::inc_counter(&metrics::SYNC_CONTRIBUTION_PROCESSING_SUCCESSES); v }) } /// Accepts some attestation-type object and attempts to verify it in the context of fork /// choice. If it is valid it is applied to `self.fork_choice`. /// /// Common items that implement `VerifiedAttestation`: /// /// - `VerifiedUnaggregatedAttestation` /// - `VerifiedAggregatedAttestation` pub fn apply_attestation_to_fork_choice( &self, verified: &impl VerifiedAttestation, ) -> Result<(), Error> { let _timer = metrics::start_timer(&metrics::FORK_CHOICE_PROCESS_ATTESTATION_TIMES); self.fork_choice .write() .on_attestation(self.slot()?, verified.indexed_attestation()) .map_err(Into::into) } /// Accepts an `VerifiedUnaggregatedAttestation` and attempts to apply it to the "naive /// aggregation pool". /// /// The naive aggregation pool is used by local validators to produce /// `SignedAggregateAndProof`. /// /// If the attestation is too old (low slot) to be included in the pool it is simply dropped /// and no error is returned. pub fn add_to_naive_aggregation_pool( &self, unaggregated_attestation: &impl VerifiedAttestation, ) -> Result<(), AttestationError> { let _timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_APPLY_TO_AGG_POOL); let attestation = unaggregated_attestation.attestation(); match self.naive_aggregation_pool.write().insert(attestation) { Ok(outcome) => trace!( self.log, "Stored unaggregated attestation"; "outcome" => ?outcome, "index" => attestation.data.index, "slot" => attestation.data.slot.as_u64(), ), Err(NaiveAggregationError::SlotTooLow { slot, lowest_permissible_slot, }) => { trace!( self.log, "Refused to store unaggregated attestation"; "lowest_permissible_slot" => lowest_permissible_slot.as_u64(), "slot" => slot.as_u64(), ); } Err(e) => { error!( self.log, "Failed to store unaggregated attestation"; "error" => ?e, "index" => attestation.data.index, "slot" => attestation.data.slot.as_u64(), ); return Err(Error::from(e).into()); } }; Ok(()) } /// Accepts a `VerifiedSyncCommitteeMessage` and attempts to apply it to the "naive /// aggregation pool". /// /// The naive aggregation pool is used by local validators to produce /// `SignedContributionAndProof`. /// /// If the sync message is too old (low slot) to be included in the pool it is simply dropped /// and no error is returned. pub fn add_to_naive_sync_aggregation_pool( &self, verified_sync_committee_message: VerifiedSyncCommitteeMessage, ) -> Result { let sync_message = verified_sync_committee_message.sync_message(); let positions_by_subnet_id: &HashMap> = verified_sync_committee_message.subnet_positions(); for (subnet_id, positions) in positions_by_subnet_id.iter() { for position in positions { let _timer = metrics::start_timer(&metrics::SYNC_CONTRIBUTION_PROCESSING_APPLY_TO_AGG_POOL); let contribution = SyncCommitteeContribution::from_message( sync_message, subnet_id.into(), *position, )?; match self .naive_sync_aggregation_pool .write() .insert(&contribution) { Ok(outcome) => trace!( self.log, "Stored unaggregated sync committee message"; "outcome" => ?outcome, "index" => sync_message.validator_index, "slot" => sync_message.slot.as_u64(), ), Err(NaiveAggregationError::SlotTooLow { slot, lowest_permissible_slot, }) => { trace!( self.log, "Refused to store unaggregated sync committee message"; "lowest_permissible_slot" => lowest_permissible_slot.as_u64(), "slot" => slot.as_u64(), ); } Err(e) => { error!( self.log, "Failed to store unaggregated sync committee message"; "error" => ?e, "index" => sync_message.validator_index, "slot" => sync_message.slot.as_u64(), ); return Err(Error::from(e).into()); } }; } } Ok(verified_sync_committee_message) } /// Accepts a `VerifiedAttestation` and attempts to apply it to `self.op_pool`. /// /// The op pool is used by local block producers to pack blocks with operations. pub fn add_to_block_inclusion_pool( &self, verified_attestation: &impl VerifiedAttestation, ) -> Result<(), AttestationError> { let _timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_APPLY_TO_OP_POOL); // If there's no eth1 chain then it's impossible to produce blocks and therefore // useless to put things in the op pool. if self.eth1_chain.is_some() { let fork = self.with_head(|head| Ok::<_, AttestationError>(head.beacon_state.fork()))?; self.op_pool .insert_attestation( // TODO: address this clone. verified_attestation.attestation().clone(), &fork, self.genesis_validators_root, &self.spec, ) .map_err(Error::from)?; } Ok(()) } /// Accepts a `VerifiedSyncContribution` and attempts to apply it to `self.op_pool`. /// /// The op pool is used by local block producers to pack blocks with operations. pub fn add_contribution_to_block_inclusion_pool( &self, contribution: VerifiedSyncContribution, ) -> Result<(), SyncCommitteeError> { let _timer = metrics::start_timer(&metrics::SYNC_CONTRIBUTION_PROCESSING_APPLY_TO_OP_POOL); // If there's no eth1 chain then it's impossible to produce blocks and therefore // useless to put things in the op pool. if self.eth1_chain.is_some() { self.op_pool .insert_sync_contribution(contribution.contribution()) .map_err(Error::from)?; } Ok(()) } /// Filter an attestation from the op pool for shuffling compatibility. /// /// Use the provided `filter_cache` map to memoize results. pub fn filter_op_pool_attestation( &self, filter_cache: &mut HashMap<(Hash256, Epoch), bool>, att: &Attestation, state: &BeaconState, ) -> bool { *filter_cache .entry((att.data.beacon_block_root, att.data.target.epoch)) .or_insert_with(|| { self.shuffling_is_compatible( &att.data.beacon_block_root, att.data.target.epoch, state, ) }) } /// Check that the shuffling at `block_root` is equal to one of the shufflings of `state`. /// /// The `target_epoch` argument determines which shuffling to check compatibility with, it /// should be equal to the current or previous epoch of `state`, or else `false` will be /// returned. /// /// The compatibility check is designed to be fast: we check that the block that /// determined the RANDAO mix for the `target_epoch` matches the ancestor of the block /// identified by `block_root` (at that slot). pub fn shuffling_is_compatible( &self, block_root: &Hash256, target_epoch: Epoch, state: &BeaconState, ) -> bool { let slots_per_epoch = T::EthSpec::slots_per_epoch(); let shuffling_lookahead = 1 + self.spec.min_seed_lookahead.as_u64(); // Shuffling can't have changed if we're in the first few epochs if state.current_epoch() < shuffling_lookahead { return true; } // Otherwise the shuffling is determined by the block at the end of the target epoch // minus the shuffling lookahead (usually 2). We call this the "pivot". let pivot_slot = if target_epoch == state.previous_epoch() || target_epoch == state.current_epoch() { (target_epoch - shuffling_lookahead).end_slot(slots_per_epoch) } else { return false; }; let state_pivot_block_root = match state.get_block_root(pivot_slot) { Ok(root) => *root, Err(e) => { warn!( &self.log, "Missing pivot block root for attestation"; "slot" => pivot_slot, "error" => ?e, ); return false; } }; // Use fork choice's view of the block DAG to quickly evaluate whether the attestation's // pivot block is the same as the current state's pivot block. If it is, then the // attestation's shuffling is the same as the current state's. // To account for skipped slots, find the first block at *or before* the pivot slot. let fork_choice_lock = self.fork_choice.read(); let pivot_block_root = fork_choice_lock .proto_array() .core_proto_array() .iter_block_roots(block_root) .find(|(_, slot)| *slot <= pivot_slot) .map(|(block_root, _)| block_root); drop(fork_choice_lock); match pivot_block_root { Some(root) => root == state_pivot_block_root, None => { debug!( &self.log, "Discarding attestation because of missing ancestor"; "pivot_slot" => pivot_slot.as_u64(), "block_root" => ?block_root, ); false } } } /// Verify a voluntary exit before allowing it to propagate on the gossip network. pub fn verify_voluntary_exit_for_gossip( &self, exit: SignedVoluntaryExit, ) -> Result, Error> { // NOTE: this could be more efficient if it avoided cloning the head state let wall_clock_state = self.wall_clock_state()?; Ok(self .observed_voluntary_exits .lock() .verify_and_observe(exit, &wall_clock_state, &self.spec) .map(|exit| { // this method is called for both API and gossip exits, so this covers all exit events if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_exit_subscribers() { if let ObservationOutcome::New(exit) = exit.clone() { event_handler.register(EventKind::VoluntaryExit(exit.into_inner())); } } } exit })?) } /// Accept a pre-verified exit and queue it for inclusion in an appropriate block. pub fn import_voluntary_exit(&self, exit: SigVerifiedOp) { if self.eth1_chain.is_some() { self.op_pool.insert_voluntary_exit(exit) } } /// Verify a proposer slashing before allowing it to propagate on the gossip network. pub fn verify_proposer_slashing_for_gossip( &self, proposer_slashing: ProposerSlashing, ) -> Result, Error> { let wall_clock_state = self.wall_clock_state()?; Ok(self.observed_proposer_slashings.lock().verify_and_observe( proposer_slashing, &wall_clock_state, &self.spec, )?) } /// Accept some proposer slashing and queue it for inclusion in an appropriate block. pub fn import_proposer_slashing(&self, proposer_slashing: SigVerifiedOp) { if self.eth1_chain.is_some() { self.op_pool.insert_proposer_slashing(proposer_slashing) } } /// Verify an attester slashing before allowing it to propagate on the gossip network. pub fn verify_attester_slashing_for_gossip( &self, attester_slashing: AttesterSlashing, ) -> Result>, Error> { let wall_clock_state = self.wall_clock_state()?; Ok(self.observed_attester_slashings.lock().verify_and_observe( attester_slashing, &wall_clock_state, &self.spec, )?) } /// Accept some attester slashing and queue it for inclusion in an appropriate block. pub fn import_attester_slashing( &self, attester_slashing: SigVerifiedOp>, ) -> Result<(), Error> { if self.eth1_chain.is_some() { self.op_pool .insert_attester_slashing(attester_slashing, self.head_info()?.fork) } Ok(()) } /// Attempt to obtain sync committee duties from the head. pub fn sync_committee_duties_from_head( &self, epoch: Epoch, validator_indices: &[u64], ) -> Result>, Error> { self.with_head(move |head| { head.beacon_state .get_sync_committee_duties(epoch, validator_indices, &self.spec) .map_err(Error::SyncDutiesError) }) } /// Attempt to verify and import a chain of blocks to `self`. /// /// The provided blocks _must_ each reference the previous block via `block.parent_root` (i.e., /// be a chain). An error will be returned if this is not the case. /// /// This operation is not atomic; if one of the blocks in the chain is invalid then some prior /// blocks might be imported. /// /// This method is generally much more efficient than importing each block using /// `Self::process_block`. pub fn process_chain_segment( &self, chain_segment: Vec>, ) -> ChainSegmentResult { let mut filtered_chain_segment = Vec::with_capacity(chain_segment.len()); let mut imported_blocks = 0; // Produce a list of the parent root and slot of the child of each block. // // E.g., `children[0] == (chain_segment[1].parent_root(), chain_segment[1].slot())` let children = chain_segment .iter() .skip(1) .map(|block| (block.parent_root(), block.slot())) .collect::>(); for (i, block) in chain_segment.into_iter().enumerate() { // Ensure the block is the correct structure for the fork at `block.slot()`. if let Err(e) = block.fork_name(&self.spec) { return ChainSegmentResult::Failed { imported_blocks, error: BlockError::InconsistentFork(e), }; } let block_root = get_block_root(&block); if let Some((child_parent_root, child_slot)) = children.get(i) { // If this block has a child in this chain segment, ensure that its parent root matches // the root of this block. // // Without this check it would be possible to have a block verified using the // incorrect shuffling. That would be bad, mmkay. if block_root != *child_parent_root { return ChainSegmentResult::Failed { imported_blocks, error: BlockError::NonLinearParentRoots, }; } // Ensure that the slots are strictly increasing throughout the chain segment. if *child_slot <= block.slot() { return ChainSegmentResult::Failed { imported_blocks, error: BlockError::NonLinearSlots, }; } } match check_block_relevancy(&block, Some(block_root), self) { // If the block is relevant, add it to the filtered chain segment. Ok(_) => filtered_chain_segment.push((block_root, block)), // If the block is already known, simply ignore this block. Err(BlockError::BlockIsAlreadyKnown) => continue, // If the block is the genesis block, simply ignore this block. Err(BlockError::GenesisBlock) => continue, // If the block is is for a finalized slot, simply ignore this block. // // The block is either: // // 1. In the canonical finalized chain. // 2. In some non-canonical chain at a slot that has been finalized already. // // In the case of (1), there's no need to re-import and later blocks in this // segement might be useful. // // In the case of (2), skipping the block is valid since we should never import it. // However, we will potentially get a `ParentUnknown` on a later block. The sync // protocol will need to ensure this is handled gracefully. Err(BlockError::WouldRevertFinalizedSlot { .. }) => continue, // The block has a known parent that does not descend from the finalized block. // There is no need to process this block or any children. Err(BlockError::NotFinalizedDescendant { block_parent_root }) => { return ChainSegmentResult::Failed { imported_blocks, error: BlockError::NotFinalizedDescendant { block_parent_root }, }; } // If there was an error whilst determining if the block was invalid, return that // error. Err(BlockError::BeaconChainError(e)) => { return ChainSegmentResult::Failed { imported_blocks, error: BlockError::BeaconChainError(e), }; } // If the block was decided to be irrelevant for any other reason, don't include // this block or any of it's children in the filtered chain segment. _ => break, } } while let Some((_root, block)) = filtered_chain_segment.first() { // Determine the epoch of the first block in the remaining segment. let start_epoch = block.slot().epoch(T::EthSpec::slots_per_epoch()); // The `last_index` indicates the position of the last block that is in the current // epoch of `start_epoch`. let last_index = filtered_chain_segment .iter() .position(|(_root, block)| { block.slot().epoch(T::EthSpec::slots_per_epoch()) > start_epoch }) .unwrap_or_else(|| filtered_chain_segment.len()); // Split off the first section blocks that are all either within the current epoch of // the first block. These blocks can all be signature-verified with the same // `BeaconState`. let mut blocks = filtered_chain_segment.split_off(last_index); std::mem::swap(&mut blocks, &mut filtered_chain_segment); // Verify the signature of the blocks, returning early if the signature is invalid. let signature_verified_blocks = match signature_verify_chain_segment(blocks, self) { Ok(blocks) => blocks, Err(error) => { return ChainSegmentResult::Failed { imported_blocks, error, }; } }; // Import the blocks into the chain. for signature_verified_block in signature_verified_blocks { match self.process_block(signature_verified_block) { Ok(_) => imported_blocks += 1, Err(error) => { return ChainSegmentResult::Failed { imported_blocks, error, }; } } } } ChainSegmentResult::Successful { imported_blocks } } /// Returns `Ok(GossipVerifiedBlock)` if the supplied `block` should be forwarded onto the /// gossip network. The block is not imported into the chain, it is just partially verified. /// /// The returned `GossipVerifiedBlock` should be provided to `Self::process_block` immediately /// after it is returned, unless some other circumstance decides it should not be imported at /// all. /// /// ## Errors /// /// Returns an `Err` if the given block was invalid, or an error was encountered during pub fn verify_block_for_gossip( &self, block: SignedBeaconBlock, ) -> Result, BlockError> { let slot = block.slot(); let graffiti_string = block.message().body().graffiti().as_utf8_lossy(); match GossipVerifiedBlock::new(block, self) { Ok(verified) => { debug!( self.log, "Successfully processed gossip block"; "graffiti" => graffiti_string, "slot" => slot, "root" => ?verified.block_root(), ); Ok(verified) } Err(e) => { debug!( self.log, "Rejected gossip block"; "error" => e.to_string(), "graffiti" => graffiti_string, "slot" => slot, ); Err(e) } } } /// Returns `Ok(block_root)` if the given `unverified_block` was successfully verified and /// imported into the chain. /// /// Items that implement `IntoFullyVerifiedBlock` include: /// /// - `SignedBeaconBlock` /// - `GossipVerifiedBlock` /// /// ## Errors /// /// Returns an `Err` if the given block was invalid, or an error was encountered during /// verification. pub fn process_block>( &self, unverified_block: B, ) -> Result> { // Start the Prometheus timer. let _full_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_TIMES); // Increment the Prometheus counter for block processing requests. metrics::inc_counter(&metrics::BLOCK_PROCESSING_REQUESTS); // Clone the block so we can provide it to the event handler. let block = unverified_block.block().clone(); // A small closure to group the verification and import errors. let import_block = |unverified_block: B| -> Result> { let fully_verified = unverified_block.into_fully_verified_block(self)?; self.import_block(fully_verified) }; // Verify and import the block. match import_block(unverified_block) { // The block was successfully verified and imported. Yay. Ok(block_root) => { trace!( self.log, "Beacon block imported"; "block_root" => ?block_root, "block_slot" => %block.slot(), ); // Increment the Prometheus counter for block processing successes. metrics::inc_counter(&metrics::BLOCK_PROCESSING_SUCCESSES); Ok(block_root) } // There was an error whilst attempting to verify and import the block. The block might // be partially verified or partially imported. Err(BlockError::BeaconChainError(e)) => { crit!( self.log, "Beacon block processing error"; "error" => ?e, ); Err(BlockError::BeaconChainError(e)) } // The block failed verification. Err(other) => { trace!( self.log, "Beacon block rejected"; "reason" => other.to_string(), ); Err(other) } } } /// Accepts a fully-verified block and imports it into the chain without performing any /// additional verification. /// /// An error is returned if the block was unable to be imported. It may be partially imported /// (i.e., this function is not atomic). fn import_block( &self, fully_verified_block: FullyVerifiedBlock, ) -> Result> { let signed_block = fully_verified_block.block; let block_root = fully_verified_block.block_root; let mut state = fully_verified_block.state; let current_slot = self.slot()?; let current_epoch = current_slot.epoch(T::EthSpec::slots_per_epoch()); let mut ops = fully_verified_block.confirmation_db_batch; let attestation_observation_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_ATTESTATION_OBSERVATION); // Iterate through the attestations in the block and register them as an "observed // attestation". This will stop us from propagating them on the gossip network. for a in signed_block.message().body().attestations() { match self.observed_attestations.write().observe_item(a, None) { // If the observation was successful or if the slot for the attestation was too // low, continue. // // We ignore `SlotTooLow` since this will be very common whilst syncing. Ok(_) | Err(AttestationObservationError::SlotTooLow { .. }) => {} Err(e) => return Err(BlockError::BeaconChainError(e.into())), } } metrics::stop_timer(attestation_observation_timer); // If a slasher is configured, provide the attestations from the block. if let Some(slasher) = self.slasher.as_ref() { for attestation in signed_block.message().body().attestations() { let committee = state.get_beacon_committee(attestation.data.slot, attestation.data.index)?; let indexed_attestation = get_indexed_attestation(committee.committee, attestation) .map_err(|e| BlockError::BeaconChainError(e.into()))?; slasher.accept_attestation(indexed_attestation); } } // If there are new validators in this block, update our pubkey cache. // // We perform this _before_ adding the block to fork choice because the pubkey cache is // used by attestation processing which will only process an attestation if the block is // known to fork choice. This ordering ensure that the pubkey cache is always up-to-date. self.validator_pubkey_cache .try_write_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT) .ok_or(Error::ValidatorPubkeyCacheLockTimeout)? .import_new_pubkeys(&state)?; // For the current and next epoch of this state, ensure we have the shuffling from this // block in our cache. for relative_epoch in &[RelativeEpoch::Current, RelativeEpoch::Next] { let shuffling_id = AttestationShufflingId::new(block_root, &state, *relative_epoch)?; let shuffling_is_cached = self .shuffling_cache .try_read_for(ATTESTATION_CACHE_LOCK_TIMEOUT) .ok_or(Error::AttestationCacheLockTimeout)? .contains(&shuffling_id); if !shuffling_is_cached { state.build_committee_cache(*relative_epoch, &self.spec)?; let committee_cache = state.committee_cache(*relative_epoch)?; self.shuffling_cache .try_write_for(ATTESTATION_CACHE_LOCK_TIMEOUT) .ok_or(Error::AttestationCacheLockTimeout)? .insert(shuffling_id, committee_cache); } } // Apply the state to the attester cache, only if it is from the previous epoch or later. // // In a perfect scenario there should be no need to add previous-epoch states to the cache. // However, latency between the VC and the BN might cause the VC to produce attestations at // a previous slot. if state.current_epoch().saturating_add(1_u64) >= current_epoch { self.attester_cache .maybe_cache_state(&state, block_root, &self.spec) .map_err(BeaconChainError::from)?; } let mut fork_choice = self.fork_choice.write(); // Do not import a block that doesn't descend from the finalized root. let signed_block = check_block_is_finalized_descendant::(signed_block, &fork_choice, &self.store)?; let (block, block_signature) = signed_block.clone().deconstruct(); // compare the existing finalized checkpoint with the incoming block's finalized checkpoint let old_finalized_checkpoint = fork_choice.finalized_checkpoint(); let new_finalized_checkpoint = state.finalized_checkpoint(); // Only perform the weak subjectivity check if it was configured. if let Some(wss_checkpoint) = self.config.weak_subjectivity_checkpoint { // This ensures we only perform the check once. if (old_finalized_checkpoint.epoch < wss_checkpoint.epoch) && (wss_checkpoint.epoch <= new_finalized_checkpoint.epoch) { if let Err(e) = self.verify_weak_subjectivity_checkpoint(wss_checkpoint, block_root, &state) { let mut shutdown_sender = self.shutdown_sender(); crit!( self.log, "Weak subjectivity checkpoint verification failed while importing block!"; "block_root" => ?block_root, "parent_root" => ?block.parent_root(), "old_finalized_epoch" => ?old_finalized_checkpoint.epoch, "new_finalized_epoch" => ?new_finalized_checkpoint.epoch, "weak_subjectivity_epoch" => ?wss_checkpoint.epoch, "error" => ?e, ); crit!(self.log, "You must use the `--purge-db` flag to clear the database and restart sync. You may be on a hostile network."); shutdown_sender .try_send(ShutdownReason::Failure( "Weak subjectivity checkpoint verification failed. Provided block root is not a checkpoint." )) .map_err(|err| BlockError::BeaconChainError(BeaconChainError::WeakSubjectivtyShutdownError(err)))?; return Err(BlockError::WeakSubjectivityConflict); } } } // Register the new block with the fork choice service. { let _fork_choice_block_timer = metrics::start_timer(&metrics::FORK_CHOICE_PROCESS_BLOCK_TIMES); fork_choice .on_block(current_slot, &block, block_root, &state) .map_err(|e| BlockError::BeaconChainError(e.into()))?; } // Allow the validator monitor to learn about a new valid state. self.validator_monitor .write() .process_valid_state(current_slot.epoch(T::EthSpec::slots_per_epoch()), &state); let validator_monitor = self.validator_monitor.read(); // Register each attestation in the block with the fork choice service. for attestation in block.body().attestations() { let _fork_choice_attestation_timer = metrics::start_timer(&metrics::FORK_CHOICE_PROCESS_ATTESTATION_TIMES); let attestation_target_epoch = attestation.data.target.epoch; let committee = state.get_beacon_committee(attestation.data.slot, attestation.data.index)?; let indexed_attestation = get_indexed_attestation(committee.committee, attestation) .map_err(|e| BlockError::BeaconChainError(e.into()))?; match fork_choice.on_attestation(current_slot, &indexed_attestation) { Ok(()) => Ok(()), // Ignore invalid attestations whilst importing attestations from a block. The // block might be very old and therefore the attestations useless to fork choice. Err(ForkChoiceError::InvalidAttestation(_)) => Ok(()), Err(e) => Err(BlockError::BeaconChainError(e.into())), }?; // To avoid slowing down sync, only register attestations for the // `observed_block_attesters` if they are from the previous epoch or later. if attestation_target_epoch + 1 >= current_epoch { let mut observed_block_attesters = self.observed_block_attesters.write(); for &validator_index in &indexed_attestation.attesting_indices { if let Err(e) = observed_block_attesters .observe_validator(attestation_target_epoch, validator_index as usize) { debug!( self.log, "Failed to register observed block attester"; "error" => ?e, "epoch" => attestation_target_epoch, "validator_index" => validator_index, ) } } } // Only register this with the validator monitor when the block is sufficiently close to // the current slot. if VALIDATOR_MONITOR_HISTORIC_EPOCHS as u64 * T::EthSpec::slots_per_epoch() + block.slot().as_u64() >= current_slot.as_u64() { validator_monitor.register_attestation_in_block( &indexed_attestation, block.to_ref(), &self.spec, ); } } // Register sync aggregate with validator monitor if let Some(sync_aggregate) = block.body().sync_aggregate() { // `SyncCommittee` for the sync_aggregate should correspond to the duty slot let duty_epoch = block.slot().epoch(T::EthSpec::slots_per_epoch()); let sync_committee = self.sync_committee_at_epoch(duty_epoch)?; let participant_pubkeys = sync_committee .pubkeys .iter() .zip(sync_aggregate.sync_committee_bits.iter()) .filter_map(|(pubkey, bit)| bit.then(|| pubkey)) .collect::>(); validator_monitor.register_sync_aggregate_in_block( block.slot(), block.parent_root(), participant_pubkeys, ); } for exit in block.body().voluntary_exits() { validator_monitor.register_block_voluntary_exit(&exit.message) } for slashing in block.body().attester_slashings() { validator_monitor.register_block_attester_slashing(slashing) } for slashing in block.body().proposer_slashings() { validator_monitor.register_block_proposer_slashing(slashing) } drop(validator_monitor); // Only present some metrics for blocks from the previous epoch or later. // // This helps avoid noise in the metrics during sync. if block.slot().epoch(T::EthSpec::slots_per_epoch()) + 1 >= self.epoch()? { metrics::observe( &metrics::OPERATIONS_PER_BLOCK_ATTESTATION, block.body().attestations().len() as f64, ); if let Some(sync_aggregate) = block.body().sync_aggregate() { metrics::set_gauge( &metrics::BLOCK_SYNC_AGGREGATE_SET_BITS, sync_aggregate.num_set_bits() as i64, ); } } let db_write_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_DB_WRITE); // Store the block and its state, and execute the confirmation batch for the intermediate // states, which will delete their temporary flags. // If the write fails, revert fork choice to the version from disk, else we can // end up with blocks in fork choice that are missing from disk. // See https://github.com/sigp/lighthouse/issues/2028 ops.push(StoreOp::PutBlock(block_root, Box::new(signed_block))); ops.push(StoreOp::PutState(block.state_root(), &state)); let txn_lock = self.store.hot_db.begin_rw_transaction(); if let Err(e) = self.store.do_atomically(ops) { error!( self.log, "Database write failed!"; "msg" => "Restoring fork choice from disk", "error" => ?e, ); match Self::load_fork_choice(self.store.clone())? { Some(persisted_fork_choice) => { *fork_choice = persisted_fork_choice; } None => { crit!( self.log, "No stored fork choice found to restore from"; "warning" => "The database is likely corrupt now, consider --purge-db" ); } } return Err(e.into()); } drop(txn_lock); // The fork choice write-lock is dropped *after* the on-disk database has been updated. // This prevents inconsistency between the two at the expense of concurrency. drop(fork_choice); // Log metrics to track the delay between when the block was made and when we imported it. // // We're declaring the block "imported" at this point, since fork choice and the DB know // about it. metrics::observe_duration( &metrics::BEACON_BLOCK_IMPORTED_SLOT_START_DELAY_TIME, get_block_delay_ms(timestamp_now(), block.to_ref(), &self.slot_clock), ); let parent_root = block.parent_root(); let slot = block.slot(); let signed_block = SignedBeaconBlock::from_block(block, block_signature); self.snapshot_cache .try_write_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT) .ok_or(Error::SnapshotCacheLockTimeout) .map(|mut snapshot_cache| { snapshot_cache.insert( BeaconSnapshot { beacon_state: state, beacon_block: signed_block, beacon_block_root: block_root, }, None, ) }) .unwrap_or_else(|e| { error!( self.log, "Failed to insert snapshot"; "error" => ?e, "task" => "process block" ); }); self.head_tracker .register_block(block_root, parent_root, slot); // Send an event to the `events` endpoint after fully processing the block. if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_block_subscribers() { event_handler.register(EventKind::Block(SseBlock { slot, block: block_root, })); } } metrics::stop_timer(db_write_timer); metrics::inc_counter(&metrics::BLOCK_PROCESSING_SUCCESSES); Ok(block_root) } /// Produce a new block at the given `slot`. /// /// The produced block will not be inherently valid, it must be signed by a block producer. /// Block signing is out of the scope of this function and should be done by a separate program. pub fn produce_block( &self, randao_reveal: Signature, slot: Slot, validator_graffiti: Option, ) -> Result, BlockProductionError> { metrics::inc_counter(&metrics::BLOCK_PRODUCTION_REQUESTS); let _complete_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_TIMES); // Producing a block requires the tree hash cache, so clone a full state corresponding to // the head from the snapshot cache. Unfortunately we can't move the snapshot out of the // cache (which would be fast), because we need to re-process the block after it has been // signed. If we miss the cache or we're producing a block that conflicts with the head, // fall back to getting the head from `slot - 1`. let state_load_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_STATE_LOAD_TIMES); let head_info = self .head_info() .map_err(BlockProductionError::UnableToGetHeadInfo)?; let (state, state_root_opt) = if head_info.slot < slot { // Normal case: proposing a block atop the current head. Use the snapshot cache. if let Some(pre_state) = self .snapshot_cache .try_read_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT) .and_then(|snapshot_cache| { snapshot_cache.get_state_for_block_production(head_info.block_root) }) { (pre_state.pre_state, pre_state.state_root) } else { warn!( self.log, "Block production cache miss"; "message" => "this block is more likely to be orphaned", "slot" => slot, ); let state = self .state_at_slot(slot - 1, StateSkipConfig::WithStateRoots) .map_err(|_| BlockProductionError::UnableToProduceAtSlot(slot))?; (state, None) } } else { warn!( self.log, "Producing block that conflicts with head"; "message" => "this block is more likely to be orphaned", "slot" => slot, ); let state = self .state_at_slot(slot - 1, StateSkipConfig::WithStateRoots) .map_err(|_| BlockProductionError::UnableToProduceAtSlot(slot))?; (state, None) }; drop(state_load_timer); self.produce_block_on_state( state, state_root_opt, slot, randao_reveal, validator_graffiti, ) } /// Produce a block for some `slot` upon the given `state`. /// /// Typically the `self.produce_block()` function should be used, instead of calling this /// function directly. This function is useful for purposefully creating forks or blocks at /// non-current slots. /// /// If required, the given state will be advanced to the given `produce_at_slot`, then a block /// will be produced at that slot height. /// /// The provided `state_root_opt` should only ever be set to `Some` if the contained value is /// equal to the root of `state`. Providing this value will serve as an optimization to avoid /// performing a tree hash in some scenarios. pub fn produce_block_on_state( &self, mut state: BeaconState, state_root_opt: Option, produce_at_slot: Slot, randao_reveal: Signature, validator_graffiti: Option, ) -> Result, BlockProductionError> { let eth1_chain = self .eth1_chain .as_ref() .ok_or(BlockProductionError::NoEth1ChainConnection)?; // It is invalid to try to produce a block using a state from a future slot. if state.slot() > produce_at_slot { return Err(BlockProductionError::StateSlotTooHigh { produce_at_slot, state_slot: state.slot(), }); } let slot_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_SLOT_PROCESS_TIMES); // Ensure the state has performed a complete transition into the required slot. complete_state_advance(&mut state, state_root_opt, produce_at_slot, &self.spec)?; drop(slot_timer); state.build_committee_cache(RelativeEpoch::Current, &self.spec)?; let parent_root = if state.slot() > 0 { *state .get_block_root(state.slot() - 1) .map_err(|_| BlockProductionError::UnableToGetBlockRootFromState)? } else { state.latest_block_header().canonical_root() }; let (proposer_slashings, attester_slashings) = self.op_pool.get_slashings(&state); let eth1_data = eth1_chain.eth1_data_for_block_production(&state, &self.spec)?; let deposits = eth1_chain .deposits_for_block_inclusion(&state, ð1_data, &self.spec)? .into(); // Iterate through the naive aggregation pool and ensure all the attestations from there // are included in the operation pool. let unagg_import_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_UNAGGREGATED_TIMES); for attestation in self.naive_aggregation_pool.read().iter() { if let Err(e) = self.op_pool.insert_attestation( attestation.clone(), &state.fork(), state.genesis_validators_root(), &self.spec, ) { // Don't stop block production if there's an error, just create a log. error!( self.log, "Attestation did not transfer to op pool"; "reason" => ?e ); } } drop(unagg_import_timer); // Override the beacon node's graffiti with graffiti from the validator, if present. let graffiti = match validator_graffiti { Some(graffiti) => graffiti, None => self.graffiti, }; let attestation_packing_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_ATTESTATION_TIMES); let mut prev_filter_cache = HashMap::new(); let prev_attestation_filter = |att: &&Attestation| { self.filter_op_pool_attestation(&mut prev_filter_cache, *att, &state) }; let mut curr_filter_cache = HashMap::new(); let curr_attestation_filter = |att: &&Attestation| { self.filter_op_pool_attestation(&mut curr_filter_cache, *att, &state) }; let attestations = self .op_pool .get_attestations( &state, prev_attestation_filter, curr_attestation_filter, &self.spec, ) .map_err(BlockProductionError::OpPoolError)? .into(); drop(attestation_packing_timer); let slot = state.slot(); let proposer_index = state.get_beacon_proposer_index(state.slot(), &self.spec)? as u64; let voluntary_exits = self.op_pool.get_voluntary_exits(&state, &self.spec).into(); // Closure to fetch a sync aggregate in cases where it is required. let get_sync_aggregate = || -> Result, BlockProductionError> { Ok(self .op_pool .get_sync_aggregate(&state) .map_err(BlockProductionError::OpPoolError)? .unwrap_or_else(|| { warn!( self.log, "Producing block with no sync contributions"; "slot" => state.slot(), ); SyncAggregate::new() })) }; let inner_block = match state { BeaconState::Base(_) => BeaconBlock::Base(BeaconBlockBase { slot, proposer_index, parent_root, state_root: Hash256::zero(), body: BeaconBlockBodyBase { randao_reveal, eth1_data, graffiti, proposer_slashings: proposer_slashings.into(), attester_slashings: attester_slashings.into(), attestations, deposits, voluntary_exits, }, }), BeaconState::Altair(_) => { let sync_aggregate = get_sync_aggregate()?; BeaconBlock::Altair(BeaconBlockAltair { slot, proposer_index, parent_root, state_root: Hash256::zero(), body: BeaconBlockBodyAltair { randao_reveal, eth1_data, graffiti, proposer_slashings: proposer_slashings.into(), attester_slashings: attester_slashings.into(), attestations, deposits, voluntary_exits, sync_aggregate, }, }) } }; let block = SignedBeaconBlock::from_block( inner_block, // The block is not signed here, that is the task of a validator client. Signature::empty(), ); let process_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_PROCESS_TIMES); per_block_processing( &mut state, &block, None, BlockSignatureStrategy::NoVerification, &self.spec, )?; drop(process_timer); let state_root_timer = metrics::start_timer(&metrics::BLOCK_PRODUCTION_STATE_ROOT_TIMES); let state_root = state.update_tree_hash_cache()?; drop(state_root_timer); let (mut block, _) = block.deconstruct(); *block.state_root_mut() = state_root; metrics::inc_counter(&metrics::BLOCK_PRODUCTION_SUCCESSES); trace!( self.log, "Produced beacon block"; "parent" => %block.parent_root(), "attestations" => block.body().attestations().len(), "slot" => block.slot() ); Ok((block, state)) } /// Execute the fork choice algorithm and enthrone the result as the canonical head. pub fn fork_choice(&self) -> Result<(), Error> { metrics::inc_counter(&metrics::FORK_CHOICE_REQUESTS); let _timer = metrics::start_timer(&metrics::FORK_CHOICE_TIMES); let result = self.fork_choice_internal(); if result.is_err() { metrics::inc_counter(&metrics::FORK_CHOICE_ERRORS); } result } fn fork_choice_internal(&self) -> Result<(), Error> { // Determine the root of the block that is the head of the chain. let beacon_block_root = self.fork_choice.write().get_head(self.slot()?)?; let current_head = self.head_info()?; let old_finalized_checkpoint = current_head.finalized_checkpoint; if beacon_block_root == current_head.block_root { return Ok(()); } let lag_timer = metrics::start_timer(&metrics::FORK_CHOICE_SET_HEAD_LAG_TIMES); // At this point we know that the new head block is not the same as the previous one metrics::inc_counter(&metrics::FORK_CHOICE_CHANGED_HEAD); // Try and obtain the snapshot for `beacon_block_root` from the snapshot cache, falling // back to a database read if that fails. let new_head = self .snapshot_cache .try_read_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT) .and_then(|snapshot_cache| { snapshot_cache.get_cloned(beacon_block_root, CloneConfig::committee_caches_only()) }) .map::, _>(Ok) .unwrap_or_else(|| { let beacon_block = self .get_block(&beacon_block_root)? .ok_or(Error::MissingBeaconBlock(beacon_block_root))?; let beacon_state_root = beacon_block.state_root(); let beacon_state: BeaconState = self .get_state(&beacon_state_root, Some(beacon_block.slot()))? .ok_or(Error::MissingBeaconState(beacon_state_root))?; Ok(BeaconSnapshot { beacon_block, beacon_block_root, beacon_state, }) }) .and_then(|mut snapshot| { // Regardless of where we got the state from, attempt to build the committee // caches. snapshot .beacon_state .build_all_committee_caches(&self.spec) .map_err(Into::into) .map(|()| snapshot) })?; // Attempt to detect if the new head is not on the same chain as the previous block // (i.e., a re-org). // // Note: this will declare a re-org if we skip `SLOTS_PER_HISTORICAL_ROOT` blocks // between calls to fork choice without swapping between chains. This seems like an // extreme-enough scenario that a warning is fine. let is_reorg = new_head .beacon_state .get_block_root(current_head.slot) .map_or(true, |root| *root != current_head.block_root); let mut reorg_distance = Slot::new(0); if is_reorg { match self.find_reorg_slot(&new_head.beacon_state, new_head.beacon_block_root) { Ok(slot) => reorg_distance = current_head.slot.saturating_sub(slot), Err(e) => { warn!( self.log, "Could not find re-org depth"; "error" => format!("{:?}", e), ); } } metrics::inc_counter(&metrics::FORK_CHOICE_REORG_COUNT); warn!( self.log, "Beacon chain re-org"; "previous_head" => %current_head.block_root, "previous_slot" => current_head.slot, "new_head_parent" => %new_head.beacon_block.parent_root(), "new_head" => %beacon_block_root, "new_slot" => new_head.beacon_block.slot(), "reorg_distance" => reorg_distance, ); } else { debug!( self.log, "Head beacon block"; "justified_root" => %new_head.beacon_state.current_justified_checkpoint().root, "justified_epoch" => new_head.beacon_state.current_justified_checkpoint().epoch, "finalized_root" => %new_head.beacon_state.finalized_checkpoint().root, "finalized_epoch" => new_head.beacon_state.finalized_checkpoint().epoch, "root" => %beacon_block_root, "slot" => new_head.beacon_block.slot(), ); }; let new_finalized_checkpoint = new_head.beacon_state.finalized_checkpoint(); // It is an error to try to update to a head with a lesser finalized epoch. if new_finalized_checkpoint.epoch < old_finalized_checkpoint.epoch { return Err(Error::RevertedFinalizedEpoch { previous_epoch: old_finalized_checkpoint.epoch, new_epoch: new_finalized_checkpoint.epoch, }); } let is_epoch_transition = current_head.slot.epoch(T::EthSpec::slots_per_epoch()) < new_head .beacon_state .slot() .epoch(T::EthSpec::slots_per_epoch()); let update_head_timer = metrics::start_timer(&metrics::UPDATE_HEAD_TIMES); // These fields are used for server-sent events let state_root = new_head.beacon_state_root(); let head_slot = new_head.beacon_state.slot(); let target_epoch_start_slot = new_head .beacon_state .current_epoch() .start_slot(T::EthSpec::slots_per_epoch()); let prev_target_epoch_start_slot = new_head .beacon_state .previous_epoch() .start_slot(T::EthSpec::slots_per_epoch()); let head_proposer_index = new_head.beacon_block.message().proposer_index(); drop(lag_timer); // Update the snapshot that stores the head of the chain at the time it received the // block. *self .canonical_head .try_write_for(HEAD_LOCK_TIMEOUT) .ok_or(Error::CanonicalHeadLockTimeout)? = new_head; metrics::stop_timer(update_head_timer); let block_delay = get_slot_delay_ms(timestamp_now(), head_slot, &self.slot_clock); // Observe the delay between the start of the slot and when we set the block as head. metrics::observe_duration( &metrics::BEACON_BLOCK_HEAD_SLOT_START_DELAY_TIME, block_delay, ); // If the block was enshrined as head too late for attestations to be created for it, log a // debug warning and increment a metric. // // Don't create this log if the block was > 4 slots old, this helps prevent noise during // sync. if block_delay >= self.slot_clock.unagg_attestation_production_delay() && block_delay < self.slot_clock.slot_duration() * 4 { metrics::inc_counter(&metrics::BEACON_BLOCK_HEAD_SLOT_START_DELAY_EXCEEDED_TOTAL); debug!( self.log, "Delayed head block"; "block_root" => ?beacon_block_root, "proposer_index" => head_proposer_index, "slot" => head_slot, "block_delay" => ?block_delay, ); } self.snapshot_cache .try_write_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT) .map(|mut snapshot_cache| { snapshot_cache.update_head(beacon_block_root); }) .unwrap_or_else(|| { error!( self.log, "Failed to obtain cache write lock"; "lock" => "snapshot_cache", "task" => "update head" ); }); if is_epoch_transition || is_reorg { self.persist_head_and_fork_choice()?; self.op_pool.prune_attestations(self.epoch()?); } if new_finalized_checkpoint.epoch != old_finalized_checkpoint.epoch { // Due to race conditions, it's technically possible that the head we load here is // different to the one earlier in this function. // // Since the head can't move backwards in terms of finalized epoch, we can only load a // head with a *later* finalized state. There is no harm in this. let head = self .canonical_head .try_read_for(HEAD_LOCK_TIMEOUT) .ok_or(Error::CanonicalHeadLockTimeout)?; // State root of the finalized state on the epoch boundary, NOT the state // of the finalized block. We need to use an iterator in case the state is beyond // the reach of the new head's `state_roots` array. let new_finalized_slot = head .beacon_state .finalized_checkpoint() .epoch .start_slot(T::EthSpec::slots_per_epoch()); let new_finalized_state_root = process_results( StateRootsIterator::new(self.store.clone(), &head.beacon_state), |mut iter| { iter.find_map(|(state_root, slot)| { if slot == new_finalized_slot { Some(state_root) } else { None } }) }, )? .ok_or(Error::MissingFinalizedStateRoot(new_finalized_slot))?; self.after_finalization(&head.beacon_state, new_finalized_state_root)?; } // Register a server-sent event if necessary if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_head_subscribers() { if let Ok(Some(current_duty_dependent_root)) = self.block_root_at_slot(target_epoch_start_slot - 1, WhenSlotSkipped::Prev) { if let Ok(Some(previous_duty_dependent_root)) = self .block_root_at_slot(prev_target_epoch_start_slot - 1, WhenSlotSkipped::Prev) { event_handler.register(EventKind::Head(SseHead { slot: head_slot, block: beacon_block_root, state: state_root, current_duty_dependent_root, previous_duty_dependent_root, epoch_transition: is_epoch_transition, })); } else { warn!( self.log, "Unable to find previous target root, cannot register head event" ); } } else { warn!( self.log, "Unable to find current target root, cannot register head event" ); } } if is_reorg && event_handler.has_reorg_subscribers() { event_handler.register(EventKind::ChainReorg(SseChainReorg { slot: head_slot, depth: reorg_distance.as_u64(), old_head_block: current_head.block_root, old_head_state: current_head.state_root, new_head_block: beacon_block_root, new_head_state: state_root, epoch: head_slot.epoch(T::EthSpec::slots_per_epoch()), })); } } Ok(()) } /// This function takes a configured weak subjectivity `Checkpoint` and the latest finalized `Checkpoint`. /// If the weak subjectivity checkpoint and finalized checkpoint share the same epoch, we compare /// roots. If we the weak subjectivity checkpoint is from an older epoch, we iterate back through /// roots in the canonical chain until we reach the finalized checkpoint from the correct epoch, and /// compare roots. This must called on startup and during verification of any block which causes a finality /// change affecting the weak subjectivity checkpoint. pub fn verify_weak_subjectivity_checkpoint( &self, wss_checkpoint: Checkpoint, beacon_block_root: Hash256, state: &BeaconState, ) -> Result<(), BeaconChainError> { let finalized_checkpoint = state.finalized_checkpoint(); info!(self.log, "Verifying the configured weak subjectivity checkpoint"; "weak_subjectivity_epoch" => wss_checkpoint.epoch, "weak_subjectivity_root" => ?wss_checkpoint.root); // If epochs match, simply compare roots. if wss_checkpoint.epoch == finalized_checkpoint.epoch && wss_checkpoint.root != finalized_checkpoint.root { crit!( self.log, "Root found at the specified checkpoint differs"; "weak_subjectivity_root" => ?wss_checkpoint.root, "finalized_checkpoint_root" => ?finalized_checkpoint.root ); return Err(BeaconChainError::WeakSubjectivtyVerificationFailure); } else if wss_checkpoint.epoch < finalized_checkpoint.epoch { let slot = wss_checkpoint .epoch .start_slot(T::EthSpec::slots_per_epoch()); // Iterate backwards through block roots from the given state. If first slot of the epoch is a skip-slot, // this will return the root of the closest prior non-skipped slot. match self.root_at_slot_from_state(slot, beacon_block_root, state)? { Some(root) => { if root != wss_checkpoint.root { crit!( self.log, "Root found at the specified checkpoint differs"; "weak_subjectivity_root" => ?wss_checkpoint.root, "finalized_checkpoint_root" => ?finalized_checkpoint.root ); return Err(BeaconChainError::WeakSubjectivtyVerificationFailure); } } None => { crit!(self.log, "The root at the start slot of the given epoch could not be found"; "wss_checkpoint_slot" => ?slot); return Err(BeaconChainError::WeakSubjectivtyVerificationFailure); } } } Ok(()) } /// Called by the timer on every slot. /// /// Performs slot-based pruning. pub fn per_slot_task(&self) { trace!(self.log, "Running beacon chain per slot tasks"); if let Some(slot) = self.slot_clock.now() { self.naive_aggregation_pool.write().prune(slot); } } /// Called after `self` has had a new block finalized. /// /// Performs pruning and finality-based optimizations. fn after_finalization( &self, head_state: &BeaconState, new_finalized_state_root: Hash256, ) -> Result<(), Error> { self.fork_choice.write().prune()?; let new_finalized_checkpoint = head_state.finalized_checkpoint(); self.observed_block_producers.write().prune( new_finalized_checkpoint .epoch .start_slot(T::EthSpec::slots_per_epoch()), ); self.snapshot_cache .try_write_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT) .map(|mut snapshot_cache| { snapshot_cache.prune(new_finalized_checkpoint.epoch); }) .unwrap_or_else(|| { error!( self.log, "Failed to obtain cache write lock"; "lock" => "snapshot_cache", "task" => "prune" ); }); self.op_pool.prune_all(head_state, self.epoch()?); self.store_migrator.process_finalization( new_finalized_state_root.into(), new_finalized_checkpoint, self.head_tracker.clone(), )?; self.attester_cache .prune_below(new_finalized_checkpoint.epoch); if let Some(event_handler) = self.event_handler.as_ref() { if event_handler.has_finalized_subscribers() { event_handler.register(EventKind::FinalizedCheckpoint(SseFinalizedCheckpoint { epoch: new_finalized_checkpoint.epoch, block: new_finalized_checkpoint.root, state: new_finalized_state_root, })); } } Ok(()) } /// Runs the `map_fn` with the committee cache for `shuffling_epoch` from the chain with head /// `head_block_root`. The `map_fn` will be supplied two values: /// /// - `&CommitteeCache`: the committee cache that serves the given parameters. /// - `Hash256`: the "shuffling decision root" which uniquely identifies the `CommitteeCache`. /// /// It's not necessary that `head_block_root` matches our current view of the chain, it can be /// any block that is: /// /// - Known to us. /// - The finalized block or a descendant of the finalized block. /// /// It would be quite common for attestation verification operations to use a `head_block_root` /// that differs from our view of the head. /// /// ## Important /// /// This function is **not** suitable for determining proposer duties (only attester duties). /// /// ## Notes /// /// This function exists in this odd "map" pattern because efficiently obtaining a committee /// can be complex. It might involve reading straight from the `beacon_chain.shuffling_cache` /// or it might involve reading it from a state from the DB. Due to the complexities of /// `RwLock`s on the shuffling cache, a simple `Cow` isn't suitable here. /// /// If the committee for `(head_block_root, shuffling_epoch)` isn't found in the /// `shuffling_cache`, we will read a state from disk and then update the `shuffling_cache`. pub(crate) fn with_committee_cache( &self, head_block_root: Hash256, shuffling_epoch: Epoch, map_fn: F, ) -> Result where F: Fn(&CommitteeCache, Hash256) -> Result, { let head_block = self .fork_choice .read() .get_block(&head_block_root) .ok_or(Error::MissingBeaconBlock(head_block_root))?; let shuffling_id = BlockShufflingIds { current: head_block.current_epoch_shuffling_id.clone(), next: head_block.next_epoch_shuffling_id.clone(), block_root: head_block.root, } .id_for_epoch(shuffling_epoch) .ok_or_else(|| Error::InvalidShufflingId { shuffling_epoch, head_block_epoch: head_block.slot.epoch(T::EthSpec::slots_per_epoch()), })?; // Obtain the shuffling cache, timing how long we wait. let cache_wait_timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_SHUFFLING_CACHE_WAIT_TIMES); let mut shuffling_cache = self .shuffling_cache .try_write_for(ATTESTATION_CACHE_LOCK_TIMEOUT) .ok_or(Error::AttestationCacheLockTimeout)?; metrics::stop_timer(cache_wait_timer); if let Some(committee_cache) = shuffling_cache.get(&shuffling_id) { map_fn(committee_cache, shuffling_id.shuffling_decision_block) } else { // Drop the shuffling cache to avoid holding the lock for any longer than // required. drop(shuffling_cache); debug!( self.log, "Committee cache miss"; "shuffling_id" => ?shuffling_epoch, "head_block_root" => head_block_root.to_string(), ); let state_read_timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_STATE_READ_TIMES); // If the head of the chain can serve this request, use it. // // This code is a little awkward because we need to ensure that the head we read and // the head we copy is identical. Taking one lock to read the head values and another // to copy the head is liable to race-conditions. let head_state_opt = self.with_head(|head| { if head.beacon_block_root == head_block_root { Ok(Some(( head.beacon_state .clone_with(CloneConfig::committee_caches_only()), head.beacon_state_root(), ))) } else { Ok::<_, Error>(None) } })?; // If the head state is useful for this request, use it. Otherwise, read a state from // disk. let (mut state, state_root) = if let Some((state, state_root)) = head_state_opt { (state, state_root) } else { let state_root = head_block.state_root; let state = self .store .get_inconsistent_state_for_attestation_verification_only( &state_root, Some(head_block.slot), )? .ok_or(Error::MissingBeaconState(head_block.state_root))?; (state, state_root) }; /* * IMPORTANT * * Since it's possible that * `Store::get_inconsistent_state_for_attestation_verification_only` was used to obtain * the state, we cannot rely upon the following fields: * * - `state.state_roots` * - `state.block_roots` * * These fields should not be used for the rest of this function. */ metrics::stop_timer(state_read_timer); let state_skip_timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_STATE_SKIP_TIMES); // If the state is in an earlier epoch, advance it. If it's from a later epoch, reject // it. if state.current_epoch() + 1 < shuffling_epoch { // Since there's a one-epoch look-ahead on the attester shuffling, it suffices to // only advance into the slot prior to the `shuffling_epoch`. let target_slot = shuffling_epoch .saturating_sub(1_u64) .start_slot(T::EthSpec::slots_per_epoch()); // Advance the state into the required slot, using the "partial" method since the state // roots are not relevant for the shuffling. partial_state_advance(&mut state, Some(state_root), target_slot, &self.spec)?; } else if state.current_epoch() > shuffling_epoch { return Err(Error::InvalidStateForShuffling { state_epoch: state.current_epoch(), shuffling_epoch, }); } metrics::stop_timer(state_skip_timer); let committee_building_timer = metrics::start_timer(&metrics::ATTESTATION_PROCESSING_COMMITTEE_BUILDING_TIMES); let relative_epoch = RelativeEpoch::from_epoch(state.current_epoch(), shuffling_epoch) .map_err(Error::IncorrectStateForAttestation)?; state.build_committee_cache(relative_epoch, &self.spec)?; let committee_cache = state.committee_cache(relative_epoch)?; let shuffling_decision_block = shuffling_id.shuffling_decision_block; self.shuffling_cache .try_write_for(ATTESTATION_CACHE_LOCK_TIMEOUT) .ok_or(Error::AttestationCacheLockTimeout)? .insert(shuffling_id, committee_cache); metrics::stop_timer(committee_building_timer); map_fn(committee_cache, shuffling_decision_block) } } /// Dumps the entire canonical chain, from the head to genesis to a vector for analysis. /// /// This could be a very expensive operation and should only be done in testing/analysis /// activities. pub fn chain_dump(&self) -> Result>, Error> { let mut dump = vec![]; let mut last_slot = BeaconSnapshot { beacon_block: self.head()?.beacon_block, beacon_block_root: self.head()?.beacon_block_root, beacon_state: self.head()?.beacon_state, }; dump.push(last_slot.clone()); loop { let beacon_block_root = last_slot.beacon_block.parent_root(); if beacon_block_root == Hash256::zero() { break; // Genesis has been reached. } let beacon_block = self.store.get_block(&beacon_block_root)?.ok_or_else(|| { Error::DBInconsistent(format!("Missing block {}", beacon_block_root)) })?; let beacon_state_root = beacon_block.state_root(); let beacon_state = self .store .get_state(&beacon_state_root, Some(beacon_block.slot()))? .ok_or_else(|| { Error::DBInconsistent(format!("Missing state {:?}", beacon_state_root)) })?; let slot = BeaconSnapshot { beacon_block, beacon_block_root, beacon_state, }; dump.push(slot.clone()); last_slot = slot; } dump.reverse(); Ok(dump) } /// Gets the current `EnrForkId`. pub fn enr_fork_id(&self) -> EnrForkId { // If we are unable to read the slot clock we assume that it is prior to genesis and // therefore use the genesis slot. let slot = self.slot().unwrap_or(self.spec.genesis_slot); self.spec .enr_fork_id::(slot, self.genesis_validators_root) } /// Calculates the `Duration` to the next fork if it exists and returns it /// with it's corresponding `ForkName`. pub fn duration_to_next_fork(&self) -> Option<(ForkName, Duration)> { // If we are unable to read the slot clock we assume that it is prior to genesis and // therefore use the genesis slot. let slot = self.slot().unwrap_or(self.spec.genesis_slot); let (fork_name, epoch) = self.spec.next_fork_epoch::(slot)?; self.slot_clock .duration_to_slot(epoch.start_slot(T::EthSpec::slots_per_epoch())) .map(|duration| (fork_name, duration)) } pub fn dump_as_dot(&self, output: &mut W) { let canonical_head_hash = self .canonical_head .try_read_for(HEAD_LOCK_TIMEOUT) .ok_or(Error::CanonicalHeadLockTimeout) .unwrap() .beacon_block_root; let mut visited: HashSet = HashSet::new(); let mut finalized_blocks: HashSet = HashSet::new(); let mut justified_blocks: HashSet = HashSet::new(); let genesis_block_hash = Hash256::zero(); writeln!(output, "digraph beacon {{").unwrap(); writeln!(output, "\t_{:?}[label=\"zero\"];", genesis_block_hash).unwrap(); // Canonical head needs to be processed first as otherwise finalized blocks aren't detected // properly. let heads = { let mut heads = self.heads(); let canonical_head_index = heads .iter() .position(|(block_hash, _)| *block_hash == canonical_head_hash) .unwrap(); let (canonical_head_hash, canonical_head_slot) = heads.swap_remove(canonical_head_index); heads.insert(0, (canonical_head_hash, canonical_head_slot)); heads }; for (head_hash, _head_slot) in heads { for maybe_pair in ParentRootBlockIterator::new(&*self.store, head_hash) { let (block_hash, signed_beacon_block) = maybe_pair.unwrap(); if visited.contains(&block_hash) { break; } visited.insert(block_hash); if signed_beacon_block.slot() % T::EthSpec::slots_per_epoch() == 0 { let block = self.get_block(&block_hash).unwrap().unwrap(); let state = self .get_state(&block.state_root(), Some(block.slot())) .unwrap() .unwrap(); finalized_blocks.insert(state.finalized_checkpoint().root); justified_blocks.insert(state.current_justified_checkpoint().root); justified_blocks.insert(state.previous_justified_checkpoint().root); } if block_hash == canonical_head_hash { writeln!( output, "\t_{:?}[label=\"{} ({})\" shape=box3d];", block_hash, block_hash, signed_beacon_block.slot() ) .unwrap(); } else if finalized_blocks.contains(&block_hash) { writeln!( output, "\t_{:?}[label=\"{} ({})\" shape=Msquare];", block_hash, block_hash, signed_beacon_block.slot() ) .unwrap(); } else if justified_blocks.contains(&block_hash) { writeln!( output, "\t_{:?}[label=\"{} ({})\" shape=cds];", block_hash, block_hash, signed_beacon_block.slot() ) .unwrap(); } else { writeln!( output, "\t_{:?}[label=\"{} ({})\" shape=box];", block_hash, block_hash, signed_beacon_block.slot() ) .unwrap(); } writeln!( output, "\t_{:?} -> _{:?};", block_hash, signed_beacon_block.parent_root() ) .unwrap(); } } writeln!(output, "}}").unwrap(); } /// Get a channel to request shutting down. pub fn shutdown_sender(&self) -> Sender { self.shutdown_sender.clone() } // Used for debugging #[allow(dead_code)] pub fn dump_dot_file(&self, file_name: &str) { let mut file = std::fs::File::create(file_name).unwrap(); self.dump_as_dot(&mut file); } /// Checks if attestations have been seen from the given `validator_index` at the /// given `epoch`. pub fn validator_seen_at_epoch(&self, validator_index: usize, epoch: Epoch) -> bool { // It's necessary to assign these checks to intermediate variables to avoid a deadlock. // // See: https://github.com/sigp/lighthouse/pull/2230#discussion_r620013993 let gossip_attested = self .observed_gossip_attesters .read() .index_seen_at_epoch(validator_index, epoch); let block_attested = self .observed_block_attesters .read() .index_seen_at_epoch(validator_index, epoch); let aggregated = self .observed_aggregators .read() .index_seen_at_epoch(validator_index, epoch); let produced_block = self .observed_block_producers .read() .index_seen_at_epoch(validator_index as u64, epoch); gossip_attested || block_attested || aggregated || produced_block } } impl Drop for BeaconChain { fn drop(&mut self) { let drop = || -> Result<(), Error> { self.persist_head_and_fork_choice()?; self.persist_op_pool()?; self.persist_eth1_cache() }; if let Err(e) = drop() { error!( self.log, "Failed to persist on BeaconChain drop"; "error" => ?e ) } else { info!( self.log, "Saved beacon chain to disk"; ) } } } impl From for Error { fn from(e: DBError) -> Error { Error::DBError(e) } } impl From for Error { fn from(e: ForkChoiceError) -> Error { Error::ForkChoiceError(e) } } impl From for Error { fn from(e: BeaconStateError) -> Error { Error::BeaconStateError(e) } } impl ChainSegmentResult { pub fn into_block_error(self) -> Result<(), BlockError> { match self { ChainSegmentResult::Failed { error, .. } => Err(error), ChainSegmentResult::Successful { .. } => Ok(()), } } }