# beacon_chain # Copyright (c) 2018-2024 Status Research & Development GmbH # Licensed and distributed under either of # * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT). # * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0). # at your option. This file may not be copied, modified, or distributed except according to those terms. {.push raises: [].} import chronicles, chronos, web3/[primitives, engine_api_types], ../spec/datatypes/base, ../consensus_object_pools/[blockchain_dag, block_quarantine, attestation_pool], ../el/el_manager, ../beacon_clock, ./common_tools from ../el/engine_api_conversions import asBlockHash from ../spec/beaconstate import get_expected_withdrawals, has_eth1_withdrawal_credential from ../spec/datatypes/capella import Withdrawal from ../spec/eth2_apis/dynamic_fee_recipients import DynamicFeeRecipientsStore, getDynamicFeeRecipient from ../validators/keystore_management import KeymanagerHost, getPerValidatorDefaultFeeRecipient, getSuggestedFeeRecipient, getSuggestedGasLimit from ../validators/action_tracker import ActionTracker, getNextProposalSlot logScope: topics = "cman" type ConsensusManager* = object expectedSlot: Slot expectedBlockReceived: Future[bool].Raising([CancelledError]) # Validated & Verified # ---------------------------------------------------------------- dag*: ChainDAGRef attestationPool*: ref AttestationPool # Missing info # ---------------------------------------------------------------- quarantine*: ref Quarantine # Execution layer integration # ---------------------------------------------------------------- elManager*: ELManager # Allow determination of whether there's an upcoming proposal # ---------------------------------------------------------------- actionTracker*: ActionTracker # Allow determination of preferred fee recipient during proposals # ---------------------------------------------------------------- dynamicFeeRecipientsStore: ref DynamicFeeRecipientsStore validatorsDir: string defaultFeeRecipient: Opt[Eth1Address] defaultGasLimit: uint64 # Tracking last proposal forkchoiceUpdated payload information # ---------------------------------------------------------------- optimisticHead: tuple[bid: BlockId, execution_block_hash: Eth2Digest] # Initialization # ------------------------------------------------------------------------------ func new*(T: type ConsensusManager, dag: ChainDAGRef, attestationPool: ref AttestationPool, quarantine: ref Quarantine, elManager: ELManager, actionTracker: ActionTracker, dynamicFeeRecipientsStore: ref DynamicFeeRecipientsStore, validatorsDir: string, defaultFeeRecipient: Opt[Eth1Address], defaultGasLimit: uint64 ): ref ConsensusManager = (ref ConsensusManager)( dag: dag, attestationPool: attestationPool, quarantine: quarantine, elManager: elManager, actionTracker: actionTracker, dynamicFeeRecipientsStore: dynamicFeeRecipientsStore, validatorsDir: validatorsDir, defaultFeeRecipient: defaultFeeRecipient, defaultGasLimit: defaultGasLimit ) # Consensus Management # ----------------------------------------------------------------------------------- proc checkExpectedBlock(self: var ConsensusManager) = if self.expectedBlockReceived == nil: return if self.dag.head.slot < self.expectedSlot: return self.expectedBlockReceived.complete(true) self.expectedBlockReceived = nil # Don't keep completed futures around! proc expectBlock*(self: var ConsensusManager, expectedSlot: Slot): Future[bool] {.async: (raises: [CancelledError], raw: true).} = ## Return a future that will complete when a head is selected whose slot is ## equal or greater than the given slot, or a new expectation is created if self.expectedBlockReceived != nil: # Reset the old future to not leave it hanging.. an alternative would be to # cancel it, but it doesn't make any practical difference for now self.expectedBlockReceived.complete(false) let fut = newFuture[bool]("ConsensusManager.expectBlock") self.expectedSlot = expectedSlot self.expectedBlockReceived = fut # It might happen that by the time we're expecting a block, it might have # already been processed! self.checkExpectedBlock() return fut func shouldSyncOptimistically*( optimisticSlot, dagSlot, wallSlot: Slot): bool = ## Determine whether an optimistic execution block hash should be reported ## to the EL client instead of the current head as determined by fork choice. # Check whether optimistic head is sufficiently ahead of DAG const minProgress = 8 * SLOTS_PER_EPOCH # Set arbitrarily if optimisticSlot < dagSlot or optimisticSlot - dagSlot < minProgress: return false # Check whether optimistic head has synced sufficiently close to wall slot const maxAge = 2 * SLOTS_PER_EPOCH # Set arbitrarily if optimisticSlot < max(wallSlot, maxAge.Slot) - maxAge: return false true func shouldSyncOptimistically*(self: ConsensusManager, wallSlot: Slot): bool = if self.optimisticHead.execution_block_hash.isZero: return false shouldSyncOptimistically( optimisticSlot = self.optimisticHead.bid.slot, dagSlot = getStateField(self.dag.headState, slot), wallSlot = wallSlot) func optimisticHead*(self: ConsensusManager): BlockId = self.optimisticHead.bid func optimisticExecutionBlockHash*(self: ConsensusManager): Eth2Digest = self.optimisticHead.execution_block_hash func setOptimisticHead*( self: var ConsensusManager, bid: BlockId, execution_block_hash: Eth2Digest) = self.optimisticHead = (bid: bid, execution_block_hash: execution_block_hash) proc updateExecutionClientHead*( self: ref ConsensusManager, newHead: BeaconHead ): Future[Opt[void]] {.async: (raises: [CancelledError]).} = let headExecutionBlockHash = self.dag.loadExecutionBlockHash(newHead.blck).valueOr: # `BlockRef` are only created for blocks that have passed # execution block hash validation, either explicitly in # `block_processor.storeBlock`, or implicitly, e.g., through # checkpoint sync. With checkpoint sync, the checkpoint block # is initially not available, so if there is a reorg to it, # this may be triggered. Such a reorg could happen if the first # imported chain is completely invalid (after the checkpoint block) # and is subsequently pruned, in which case checkpoint block is head. # Because execution block hash validation has already passed, # we can treat this as `SYNCING`. warn "Failed to load head execution block hash", head = newHead.blck return Opt[void].ok() if headExecutionBlockHash.isZero: # Blocks without execution payloads can't be optimistic. self.dag.markBlockVerified(newHead.blck) return Opt[void].ok() template callForkchoiceUpdated(attributes: untyped): auto = await self.elManager.forkchoiceUpdated( headBlockHash = headExecutionBlockHash, safeBlockHash = newHead.safeExecutionBlockHash, finalizedBlockHash = newHead.finalizedExecutionBlockHash, payloadAttributes = Opt.none attributes) # Can't use dag.head here because it hasn't been updated yet let consensusFork = self.dag.cfg.consensusForkAtEpoch(newHead.blck.bid.slot.epoch) (payloadExecutionStatus, _) = withConsensusFork(consensusFork): when consensusFork >= ConsensusFork.Bellatrix: callForkchoiceUpdated(consensusFork.PayloadAttributes) else: callForkchoiceUpdated(PayloadAttributesV1) case payloadExecutionStatus of PayloadExecutionStatus.valid: self.dag.markBlockVerified(newHead.blck) of PayloadExecutionStatus.invalid, PayloadExecutionStatus.invalid_block_hash: self.attestationPool[].forkChoice.mark_root_invalid(newHead.blck.root) self.quarantine[].addUnviable(newHead.blck.root) return Opt.none(void) of PayloadExecutionStatus.accepted, PayloadExecutionStatus.syncing: # Don't do anything. Either newHead.blck.executionValid was already false, # in which case it'd be superfluous to set it to false again, or the block # was marked as `VALID` in the `newPayload` path already, in which case it # is fine to keep it as valid here. Conceptually, were this to be lines of # code, it'd be something like # if newHead.blck.executionValid: # do nothing because of latter case # else: # do nothing because it's a no-op # So, either way, do nothing. discard return Opt[void].ok() func getKnownValidatorsForBlsChangeTracking( self: ConsensusManager, newHead: BlockRef): seq[ValidatorIndex] = # Ensure that large nodes won't be overloaded by a nice-to-have, but # inessential cosmetic feature. const MAX_CHECKED_INDICES = 64 if newHead.bid.slot.epoch >= self.dag.cfg.CAPELLA_FORK_EPOCH: var res = newSeqOfCap[ValidatorIndex](min( len(self.actionTracker.knownValidators), MAX_CHECKED_INDICES)) for vi in self.actionTracker.knownValidators.keys(): res.add vi if res.len >= MAX_CHECKED_INDICES: break res else: # It is not possible for any BLS to execution changes, for any validator, # to have been yet processed. # https://github.com/nim-lang/Nim/issues/19802 (static(@[])) proc updateHead*(self: var ConsensusManager, newHead: BlockRef) = ## Trigger fork choice and update the DAG with the new head block ## This does not automatically prune the DAG after finalization ## `pruneFinalized` must be called for pruning. # Store the new head in the chain DAG - this may cause epochs to be # justified and finalized self.dag.updateHead( newHead, self.quarantine[], self.getKnownValidatorsForBlsChangeTracking(newHead)) self.checkExpectedBlock() proc updateHead*(self: var ConsensusManager, wallSlot: Slot) = ## Trigger fork choice and update the DAG with the new head block ## This does not automatically prune the DAG after finalization ## `pruneFinalized` must be called for pruning. # Grab the new head according to our latest attestation data let newHead = self.attestationPool[].selectOptimisticHead( wallSlot.start_beacon_time).valueOr: warn "Head selection failed, using previous head", head = shortLog(self.dag.head), wallSlot return executionBlockHash = self.dag.loadExecutionBlockHash(newHead.blck) if executionBlockHash.isSome and executionBlockHash.unsafeGet.isZero: # Blocks without execution payloads can't be optimistic. self.dag.markBlockVerified(newHead.blck) self.updateHead(newHead.blck) func isSynced(dag: ChainDAGRef, wallSlot: Slot): bool = # This is a tweaked version of the beacon_validators isSynced. TODO, refactor # that one so this becomes the default version, with the same information to # work with. For the head slot, use the DAG head regardless of what head the # proposer forkchoiceUpdated is using, because by the beacon_validators might # be ready to actually propose, it's going to do so from the DAG head. Given # the defaultSyncHorizon, it will start triggering in time so that potential # discrepancies between the head here, and the head the DAG has (which might # not yet be updated) won't be visible. if dag.head.slot + defaultSyncHorizon < wallSlot: false else: dag.head.executionValid proc checkNextProposer( dag: ChainDAGRef, actionTracker: ActionTracker, dynamicFeeRecipientsStore: ref DynamicFeeRecipientsStore, wallSlot: Slot): Opt[(ValidatorIndex, ValidatorPubKey)] = let nextWallSlot = wallSlot + 1 # Avoid long rewinds during syncing, when it's not going to propose. Though # this is preparing for a proposal on `nextWallSlot`, it can't possibly yet # be on said slot, so still check just `wallSlot`. if not dag.isSynced(wallSlot): return Opt.none((ValidatorIndex, ValidatorPubKey)) let proposer = ? dag.getProposer(dag.head, nextWallSlot) if actionTracker.getNextProposalSlot(wallSlot) != nextWallSlot and dynamicFeeRecipientsStore[].getDynamicFeeRecipient( proposer, nextWallSlot.epoch).isNone: return Opt.none((ValidatorIndex, ValidatorPubKey)) let proposerKey = dag.validatorKey(proposer).get().toPubKey Opt.some((proposer, proposerKey)) proc checkNextProposer*(self: ref ConsensusManager, wallSlot: Slot): Opt[(ValidatorIndex, ValidatorPubKey)] = self.dag.checkNextProposer( self.actionTracker, self.dynamicFeeRecipientsStore, wallSlot) proc getFeeRecipient*( self: ConsensusManager, pubkey: ValidatorPubKey, validatorIdx: Opt[ValidatorIndex], epoch: Epoch): Eth1Address = let validator = if validatorIdx.isSome(): withState(self.dag.headState): if validatorIdx.get < forkyState.data.validators.lenu64: Opt.some forkyState.data.validators.item(validatorIdx.get) else: Opt.none Validator else: Opt.none Validator getFeeRecipient(self.dynamicFeeRecipientsStore, pubkey, validatorIdx, validator, self.defaultFeeRecipient, self.validatorsDir, epoch) proc getGasLimit*(self: ConsensusManager, pubkey: ValidatorPubKey): uint64 = getGasLimit(self.validatorsDir, self.defaultGasLimit, pubkey) proc runProposalForkchoiceUpdated*( self: ref ConsensusManager, wallSlot: Slot): Future[Opt[void]] {.async: (raises: [CancelledError]).} = let nextWallSlot = wallSlot + 1 (validatorIndex, nextProposer) = self.checkNextProposer(wallSlot).valueOr: return err() debug "runProposalForkchoiceUpdated: expected to be proposing next slot", nextWallSlot, validatorIndex, nextProposer # In Capella and later, computing correct withdrawals would mean creating a # proposal state. Instead, only do that at proposal time. if nextWallSlot.is_epoch: debug "runProposalForkchoiceUpdated: not running early fcU for epoch-aligned proposal slot", nextWallSlot, validatorIndex, nextProposer return err() # Approximately lines up with validator_duties version. Used optimistically/ # opportunistically, so mismatches are fine if not too frequent. let timestamp = withState(self.dag.headState): compute_timestamp_at_slot(forkyState.data, nextWallSlot) # If the current head block still forms the basis of the eventual proposal # state, then its `get_randao_mix` will remain unchanged as well, as it is # constant until the next block. randomData = withState(self.dag.headState): get_randao_mix(forkyState.data, get_current_epoch(forkyState.data)).data feeRecipient = self[].getFeeRecipient( nextProposer, Opt.some(validatorIndex), nextWallSlot.epoch) beaconHead = self.attestationPool[].getBeaconHead(self.dag.head) headBlockHash = ? self.dag.loadExecutionBlockHash(beaconHead.blck) if headBlockHash.isZero: return err() let safeBlockHash = beaconHead.safeExecutionBlockHash withState(self.dag.headState): template callForkchoiceUpdated(fcPayloadAttributes: auto) = let (status, _) = await self.elManager.forkchoiceUpdated( headBlockHash, safeBlockHash, beaconHead.finalizedExecutionBlockHash, payloadAttributes = Opt.some fcPayloadAttributes) debug "Fork-choice updated for proposal", status static: doAssert high(ConsensusFork) == ConsensusFork.Electra when consensusFork >= ConsensusFork.Deneb: # https://github.com/ethereum/execution-apis/blob/90a46e9137c89d58e818e62fa33a0347bba50085/src/engine/prague.md # does not define any new forkchoiceUpdated, so reuse V3 from Dencun callForkchoiceUpdated(PayloadAttributesV3( timestamp: Quantity timestamp, prevRandao: FixedBytes[32] randomData, suggestedFeeRecipient: feeRecipient, withdrawals: toEngineWithdrawals get_expected_withdrawals(forkyState.data), parentBeaconBlockRoot: beaconHead.blck.bid.root.asBlockHash)) elif consensusFork >= ConsensusFork.Capella: callForkchoiceUpdated(PayloadAttributesV2( timestamp: Quantity timestamp, prevRandao: FixedBytes[32] randomData, suggestedFeeRecipient: feeRecipient, withdrawals: toEngineWithdrawals get_expected_withdrawals(forkyState.data))) else: callForkchoiceUpdated(PayloadAttributesV1( timestamp: Quantity timestamp, prevRandao: FixedBytes[32] randomData, suggestedFeeRecipient: feeRecipient)) ok() proc updateHeadWithExecution*( self: ref ConsensusManager, initialNewHead: BeaconHead, getBeaconTimeFn: GetBeaconTimeFn) {.async: (raises: [CancelledError]).} = ## Trigger fork choice and update the DAG with the new head block ## This does not automatically prune the DAG after finalization ## `pruneFinalized` must be called for pruning. # Grab the new head according to our latest attestation data try: # Ensure dag.updateHead has most current information var attempts = 0 newHead = initialNewHead while (await self.updateExecutionClientHead(newHead)).isErr: # This proc is called on every new block; guarantee timely return inc attempts const maxAttempts = 5 if attempts >= maxAttempts: warn "updateHeadWithExecution: too many attempts to recover from invalid payload", attempts, maxAttempts, newHead, initialNewHead break # Select new head for next attempt let wallTime = getBeaconTimeFn() nextHead = self.attestationPool[].selectOptimisticHead(wallTime).valueOr: warn "Head selection failed after invalid block, using previous head", newHead, wallSlot = wallTime.slotOrZero break warn "updateHeadWithExecution: attempting to recover from invalid payload", attempts, maxAttempts, newHead, initialNewHead, nextHead newHead = nextHead # Store the new head in the chain DAG - this may cause epochs to be # justified and finalized self.dag.updateHead( newHead.blck, self.quarantine[], self[].getKnownValidatorsForBlsChangeTracking(newHead.blck)) # If this node should propose next slot, start preparing payload. Both # fcUs are useful: the updateExecutionClientHead(newHead) call updates # the head state (including optimistic status) that self.dagUpdateHead # needs while runProposalForkchoiceUpdated requires RANDAO information # from the head state corresponding to the `newHead` block, which only # self.dag.updateHead(...) sets up. discard await self.runProposalForkchoiceUpdated(getBeaconTimeFn().slotOrZero) self[].checkExpectedBlock() except CatchableError as exc: debug "updateHeadWithExecution error", error = exc.msg proc pruneStateCachesAndForkChoice*(self: var ConsensusManager) = ## Prune unneeded and invalidated data after finalization ## - the DAG state checkpoints ## - the DAG EpochRef ## - the attestation pool/fork choice # Cleanup DAG & fork choice if we have a finalized head if self.dag.needStateCachesAndForkChoicePruning(): self.dag.pruneStateCachesDAG() self.attestationPool[].prune()