nimbus-eth2/beacon_chain/consensus_object_pools/block_clearance.nim

409 lines
16 KiB
Nim

# beacon_chain
# Copyright (c) 2018-2022 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.
when (NimMajor, NimMinor) < (1, 4):
{.push raises: [Defect].}
else:
{.push raises: [].}
import
chronicles,
stew/[assign2, results],
../spec/[
beaconstate, forks, signatures, signatures_batch,
state_transition, state_transition_epoch],
"."/[block_dag, blockchain_dag, blockchain_dag_light_client]
export results, signatures_batch, block_dag, blockchain_dag
# Clearance
# ---------------------------------------------
#
# This module is in charge of making the
# "quarantined" network blocks
# pass the firewall and be stored in the chain DAG
logScope:
topics = "clearance"
proc addResolvedHeadBlock(
dag: ChainDAGRef,
state: var ForkedHashedBeaconState,
trustedBlock: ForkyTrustedSignedBeaconBlock,
blockVerified: bool,
parent: BlockRef, cache: var StateCache,
onBlockAdded: OnPhase0BlockAdded | OnAltairBlockAdded | OnBellatrixBlockAdded,
stateDataDur, sigVerifyDur, stateVerifyDur: Duration
): BlockRef =
doAssert state.matches_block_slot(
trustedBlock.root, trustedBlock.message.slot),
"Given state must have the new block applied"
let
blockRoot = trustedBlock.root
blockRef = BlockRef.init(blockRoot, trustedBlock.message)
startTick = Moment.now()
link(parent, blockRef)
dag.forkBlocks.incl(KeyedBlockRef.init(blockRef))
# Resolved blocks should be stored in database
dag.putBlock(trustedBlock)
let putBlockTick = Moment.now()
var foundHead: bool
for head in dag.heads.mitems():
if head.isAncestorOf(blockRef):
head = blockRef
foundHead = true
break
if not foundHead:
dag.heads.add(blockRef)
# Regardless of the chain we're on, the deposits come in the same order so
# as soon as we import a block, we'll also update the shared public key
# cache
dag.updateValidatorKeys(getStateField(state, validators).asSeq())
# Getting epochRef with the state will potentially create a new EpochRef
let
epochRef = dag.getEpochRef(state, cache)
epochRefTick = Moment.now()
debug "Block resolved",
blockRoot = shortLog(blockRoot),
blck = shortLog(trustedBlock.message),
blockVerified,
heads = dag.heads.len(),
stateDataDur, sigVerifyDur, stateVerifyDur,
putBlockDur = putBlockTick - startTick,
epochRefDur = epochRefTick - putBlockTick
# Update light client data
dag.processNewBlockForLightClient(state, trustedBlock, parent.bid)
# Pre-heat the shuffling cache with the shuffling caused by this block - this
# is useful for attestation duty lookahead, REST API queries and attestation
# validation of untaken forks (in case of instability / multiple heads)
if dag.findShufflingRef(blockRef.bid, blockRef.slot.epoch + 1).isNone:
dag.putShufflingRef(
ShufflingRef.init(state, cache, blockRef.slot.epoch + 1))
if not blockVerified:
dag.optimisticRoots.incl blockRoot
# Notify others of the new block before processing the quarantine, such that
# notifications for parents happens before those of the children
if onBlockAdded != nil:
var unrealized: FinalityCheckpoints
if enableTestFeatures in dag.updateFlags:
unrealized = withState(state):
when stateFork >= BeaconStateFork.Altair:
forkyState.data.compute_unrealized_finality()
else:
forkyState.data.compute_unrealized_finality(cache)
onBlockAdded(blockRef, trustedBlock, epochRef, unrealized)
if not(isNil(dag.onBlockAdded)):
dag.onBlockAdded(ForkedTrustedSignedBeaconBlock.init(trustedBlock))
blockRef
proc checkStateTransition(
dag: ChainDAGRef, signedBlock: ForkySigVerifiedSignedBeaconBlock,
cache: var StateCache): Result[void, BlockError] =
## Ensure block can be applied on a state
func restore(v: var ForkedHashedBeaconState) =
assign(dag.clearanceState, dag.headState)
let res = state_transition_block(
dag.cfg, dag.clearanceState, signedBlock,
cache, dag.updateFlags, restore)
if res.isErr():
info "Invalid block",
blockRoot = shortLog(signedBlock.root),
blck = shortLog(signedBlock.message),
error = res.error()
err(BlockError.Invalid)
else:
ok()
proc advanceClearanceState*(dag: ChainDAGRef) =
# When the chain is synced, the most likely block to be produced is the block
# right after head - we can exploit this assumption and advance the state
# to that slot before the block arrives, thus allowing us to do the expensive
# epoch transition ahead of time.
# Notably, we use the clearance state here because that's where the block will
# first be seen - later, this state will be copied to the head state!
let advanced = withState(dag.clearanceState):
forkyState.data.slot > forkyState.data.latest_block_header.slot
if not advanced:
let next = getStateField(dag.clearanceState, slot) + 1
let startTick = Moment.now()
var
cache = StateCache()
info = ForkedEpochInfo()
dag.advanceSlots(dag.clearanceState, next, true, cache, info)
debug "Prepared clearance state for next block",
next, updateStateDur = Moment.now() - startTick
proc addHeadBlock*(
dag: ChainDAGRef, verifier: var BatchVerifier,
signedBlock: ForkySignedBeaconBlock,
blockVerified: bool,
onBlockAdded: OnPhase0BlockAdded | OnAltairBlockAdded |
OnBellatrixBlockAdded
): Result[BlockRef, BlockError] =
## Try adding a block to the chain, verifying first that it passes the state
## transition function and contains correct cryptographic signature.
##
## Cryptographic checks can be skipped by adding skipBlsValidation to
## dag.updateFlags
logScope:
blockRoot = shortLog(signedBlock.root)
blck = shortLog(signedBlock.message)
signature = shortLog(signedBlock.signature)
template blck(): untyped = signedBlock.message # shortcuts without copy
template blockRoot(): untyped = signedBlock.root
# If the block we get is older than what we finalized already, we drop it.
# One way this can happen is that we start request a block and finalization
# happens in the meantime - the block we requested will then be stale
# by the time it gets here.
if blck.slot <= dag.finalizedHead.slot:
let existing = dag.getBlockIdAtSlot(blck.slot)
# The exact slot match ensures we reject blocks that were orphaned in
# the finalized chain
if existing.isSome:
if existing.get().bid.slot == blck.slot and
existing.get().bid.root == blockRoot:
debug "Duplicate block"
return err(BlockError.Duplicate)
# Block is older than finalized, but different from the block in our
# canonical history: it must be from an unviable branch
debug "Block from unviable fork",
existing = shortLog(existing.get()),
finalizedHead = shortLog(dag.finalizedHead),
tail = shortLog(dag.tail)
return err(BlockError.UnviableFork)
# Check non-finalized blocks as well
if dag.containsForkBlock(blockRoot):
return err(BlockError.Duplicate)
let parent = dag.getBlockRef(blck.parent_root).valueOr:
# There are two cases where the parent won't be found: we don't have it or
# it has been finalized already, and as a result the branch the new block
# is on is no longer a viable fork candidate - we can't tell which is which
# at this stage, but we can check if we've seen the parent block previously
# and thus prevent requests for it to be downloaded again.
let parentId = dag.getBlockId(blck.parent_root)
if parentId.isSome():
debug "Block unviable due to pre-finalized-checkpoint parent",
parentId = parentId.get()
return err(BlockError.UnviableFork)
debug "Block parent unknown or finalized already", parentId
return err(BlockError.MissingParent)
if parent.slot >= blck.slot:
# A block whose parent is newer than the block itself is clearly invalid -
# discard it immediately
debug "Block older than parent",
parent = shortLog(parent)
return err(BlockError.Invalid)
# The block is resolved, now it's time to validate it to ensure that the
# blocks we add to the database are clean for the given state
let startTick = Moment.now()
# The clearance state works as the canonical
# "let's make things permanent" point and saves things to the database -
# storing things is slow, so we don't want to do so before there's a
# reasonable chance that the information will become more permanently useful -
# by the time a new block reaches this point, the parent block will already
# have "established" itself in the network to some degree at least.
var cache = StateCache()
# We've verified that the slot of the new block is newer than that of the
# parent, so we should now be able to create an approriate clearance state
# onto which we can apply the new block
let clearanceBlock = BlockSlotId.init(parent.bid, signedBlock.message.slot)
if not updateState(
dag, dag.clearanceState, clearanceBlock, true, cache):
# We should never end up here - the parent must be a block no older than and
# rooted in the finalized checkpoint, hence we should always be able to
# load its corresponding state
error "Unable to load clearance state for parent block, database corrupt?",
clearanceBlock = shortLog(clearanceBlock)
return err(BlockError.MissingParent)
let stateDataTick = Moment.now()
# First, batch-verify all signatures in block
if skipBlsValidation notin dag.updateFlags:
# TODO: remove skipBlsValidation
var sigs: seq[SignatureSet]
if (let e = sigs.collectSignatureSets(
signedBlock, dag.db.immutableValidators,
dag.clearanceState, cache); e.isErr()):
# A PublicKey or Signature isn't on the BLS12-381 curve
info "Unable to load signature sets",
err = e.error()
return err(BlockError.Invalid)
if not verifier.batchVerify(sigs):
info "Block signature verification failed",
signature = shortLog(signedBlock.signature)
return err(BlockError.Invalid)
let sigVerifyTick = Moment.now()
? checkStateTransition(dag, signedBlock.asSigVerified(), cache)
let stateVerifyTick = Moment.now()
# Careful, clearanceState.data has been updated but not blck - we need to
# create the BlockRef first!
ok addResolvedHeadBlock(
dag, dag.clearanceState,
signedBlock.asTrusted(),
blockVerified = blockVerified,
parent, cache,
onBlockAdded,
stateDataDur = stateDataTick - startTick,
sigVerifyDur = sigVerifyTick - stateDataTick,
stateVerifyDur = stateVerifyTick - sigVerifyTick)
proc addHeadBlock*(
dag: ChainDAGRef, verifier: var BatchVerifier,
signedBlock: ForkySignedBeaconBlock,
onBlockAdded: OnPhase0BlockAdded | OnAltairBlockAdded |
OnBellatrixBlockAdded
): Result[BlockRef, BlockError] =
addHeadBlock(
dag, verifier, signedBlock, blockVerified = true, onBlockAdded)
proc addBackfillBlock*(
dag: ChainDAGRef,
signedBlock: ForkySignedBeaconBlock): Result[void, BlockError] =
## When performing checkpoint sync, we need to backfill historical blocks
## in order to respond to GetBlocksByRange requests. Backfill blocks are
## added in backwards order, one by one, based on the `parent_root` of the
## earliest block we know about.
##
## Because only one history is relevant when backfilling, one doesn't have to
## consider forks or other finalization-related issues - a block is either
## valid and finalized, or not.
logScope:
blockRoot = shortLog(signedBlock.root)
blck = shortLog(signedBlock.message)
signature = shortLog(signedBlock.signature)
backfill = (dag.backfill.slot, shortLog(dag.backfill.parent_root))
template blck(): untyped = signedBlock.message # shortcuts without copy
template blockRoot(): untyped = signedBlock.root
let startTick = Moment.now()
if blck.slot >= dag.backfill.slot:
let existing = dag.getBlockIdAtSlot(blck.slot)
if existing.isSome:
if existing.get().bid.slot == blck.slot and
existing.get().bid.root == blockRoot:
# We should not call the block added callback for blocks that already
# existed in the pool, as that may confuse consumers such as the fork
# choice.
debug "Duplicate block"
return err(BlockError.Duplicate)
# Block is older than finalized, but different from the block in our
# canonical history: it must be from an unviable branch
debug "Block from unviable fork",
existing = shortLog(existing.get()),
finalizedHead = shortLog(dag.finalizedHead)
return err(BlockError.UnviableFork)
if blck.slot == dag.frontfill.slot and
dag.backfill.parent_root == dag.frontfill.root:
if blockRoot != dag.frontfill.root:
# We've matched the backfill blocks all the way back to frontfill via the
# `parent_root` chain and ended up at a different block - one way this
# can happen is when an invalid `--network` parameter is given during
# startup (though in theory, we check that - maybe the database was
# swapped or something?).
fatal "Checkpoint given during initial startup inconsistent with genesis block - wrong network used when starting the node?",
genesis = shortLog(dag.genesis), tail = shortLog(dag.tail),
head = shortLog(dag.head)
quit 1
# Signal that we're done by resetting backfill
reset(dag.backfill)
dag.db.finalizedBlocks.insert(blck.slot, blockRoot)
dag.updateFrontfillBlocks()
notice "Received final block during backfill, backfill complete"
# Backfill done - dag.backfill.slot now points to genesis block just like
# it would if we loaded a fully synced database - returning duplicate
# here is appropriate, though one could also call it ... ok?
return err(BlockError.Duplicate)
if dag.backfill.parent_root != blockRoot:
debug "Block does not match expected backfill root"
return err(BlockError.MissingParent) # MissingChild really, but ..
# If the hash is correct, the block itself must be correct, but the root does
# not cover the signature, which we check next
let proposerKey = dag.validatorKey(blck.proposer_index)
if proposerKey.isNone():
# We've verified that the block root matches our expectations by following
# the chain of parents all the way from checkpoint. If all those blocks
# were valid, the proposer_index in this block must also be valid, and we
# should have a key for it but we don't: this is either a bug on our from
# which we cannot recover, or an invalid checkpoint state was given in which
# case we're in trouble.
fatal "Invalid proposer in backfill block - checkpoint state corrupt?",
head = shortLog(dag.head), tail = shortLog(dag.tail),
genesis = shortLog(dag.genesis)
quit 1
if not verify_block_signature(
dag.forkAtEpoch(blck.slot.epoch),
getStateField(dag.headState, genesis_validators_root),
blck.slot,
signedBlock.root,
proposerKey.get(),
signedBlock.signature):
info "Block signature verification failed"
return err(BlockError.Invalid)
let sigVerifyTick = Moment.now
dag.putBlock(signedBlock.asTrusted())
dag.db.finalizedBlocks.insert(blck.slot, blockRoot)
dag.backfill = blck.toBeaconBlockSummary()
let putBlockTick = Moment.now
debug "Block backfilled",
sigVerifyDur = sigVerifyTick - startTick,
putBlockDur = putBlockTick - sigVerifyTick
ok()