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[Split fork choice PR] Derisk-ed attestation checks changes (#1154) 

* Derisked attestation pool improvements

* tune down frequent logs

* VoteTracker logging
This commit is contained in:
Mamy Ratsimbazafy 2020-06-10 08:58:12 +02:00 committed by GitHub
parent 4517bf5dd4
commit ce897fe83f
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
14 changed files with 383 additions and 250 deletions
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82
beacon_chain/attestation_aggregation.nim
View File

@ -8,10 +8,10 @@
{.push raises: [Defect].}
import
options,
options, chronicles,
./spec/[beaconstate, datatypes, crypto, digest, helpers, validator,
state_transition_block],
./attestation_pool, ./beacon_node_types
./block_pool, ./attestation_pool, ./beacon_node_types, ./ssz
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/validator.md#aggregation-selection
func is_aggregator(state: BeaconState, slot: Slot, index: CommitteeIndex,
@ -69,3 +69,81 @@ proc aggregate_attestations*(
selection_proof: slot_signature))
none(AggregateAndProof)
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/p2p-interface.md#attestation-subnets
proc isValidAttestation*(
pool: AttestationPool, attestation: Attestation, current_slot: Slot,
topicCommitteeIndex: uint64): bool =
# The attestation's committee index (attestation.data.index) is for the
# correct subnet.
if attestation.data.index != topicCommitteeIndex:
debug "isValidAttestation: attestation's committee index not for the correct subnet",
topicCommitteeIndex = topicCommitteeIndex,
attestation_data_index = attestation.data.index
return false
if not (attestation.data.slot + ATTESTATION_PROPAGATION_SLOT_RANGE >=
current_slot and current_slot >= attestation.data.slot):
debug "isValidAttestation: attestation.data.slot not within ATTESTATION_PROPAGATION_SLOT_RANGE"
return false
# The attestation is unaggregated -- that is, it has exactly one
# participating validator (len([bit for bit in attestation.aggregation_bits
# if bit == 0b1]) == 1).
# TODO a cleverer algorithm, along the lines of countOnes() in nim-stew
# But that belongs in nim-stew, since it'd break abstraction layers, to
# use details of its representation from nim-beacon-chain.
var onesCount = 0
for aggregation_bit in attestation.aggregation_bits:
if not aggregation_bit:
continue
onesCount += 1
if onesCount > 1:
debug "isValidAttestation: attestation has too many aggregation bits",
aggregation_bits = attestation.aggregation_bits
return false
if onesCount != 1:
debug "isValidAttestation: attestation has too few aggregation bits"
return false
# The attestation is the first valid attestation received for the
# participating validator for the slot, attestation.data.slot.
let maybeAttestationsSeen = getAttestationsForSlot(pool, attestation.data.slot)
if maybeAttestationsSeen.isSome:
for attestationEntry in maybeAttestationsSeen.get.attestations:
if attestation.data != attestationEntry.data:
continue
# Attestations might be aggregated eagerly or lazily; allow for both.
for validation in attestationEntry.validations:
if attestation.aggregation_bits.isSubsetOf(validation.aggregation_bits):
debug "isValidAttestation: attestation already exists at slot",
attestation_data_slot = attestation.data.slot,
attestation_aggregation_bits = attestation.aggregation_bits,
attestation_pool_validation = validation.aggregation_bits
return false
# The block being voted for (attestation.data.beacon_block_root) passes
# validation.
# We rely on the block pool to have been validated, so check for the
# existence of the block in the pool.
# TODO: consider a "slush pool" of attestations whose blocks have not yet
# propagated - i.e. imagine that attestations are smaller than blocks and
# therefore propagate faster, thus reordering their arrival in some nodes
if pool.blockPool.get(attestation.data.beacon_block_root).isNone():
debug "isValidAttestation: block doesn't exist in block pool",
attestation_data_beacon_block_root = attestation.data.beacon_block_root
return false
# The signature of attestation is valid.
# TODO need to know above which validator anyway, and this is too general
# as it supports aggregated attestations (which this can't be)
var cache = get_empty_per_epoch_cache()
if not is_valid_indexed_attestation(
pool.blockPool.headState.data.data,
get_indexed_attestation(
pool.blockPool.headState.data.data, attestation, cache), {}):
debug "isValidAttestation: signature verification failed"
return false
true

203
beacon_chain/attestation_pool.nim
View File

@ -11,25 +11,29 @@ import
deques, sequtils, tables, options,
chronicles, stew/[byteutils], json_serialization/std/sets,
./spec/[beaconstate, datatypes, crypto, digest, helpers, validator],
./extras, ./block_pool, ./block_pools/candidate_chains, ./beacon_node_types
./extras, ./block_pool, ./block_pools/candidate_chains, ./beacon_node_types,
./fork_choice/[fork_choice_types, fork_choice]
logScope: topics = "attpool"
func init*(T: type AttestationPool, blockPool: BlockPool): T =
## Initialize an AttestationPool from the blockPool `headState`
## The `finalized_root` works around the finalized_checkpoint of the genesis block
## holding a zero_root.
# TODO blockPool is only used when resolving orphaned attestations - it should
# probably be removed as a dependency of AttestationPool (or some other
# smart refactoring)
T(
slots: initDeque[SlotData](),
mapSlotsToAttestations: initDeque[AttestationsSeen](),
blockPool: blockPool,
unresolved: initTable[Eth2Digest, UnresolvedAttestation](),
latestAttestations: initTable[ValidatorPubKey, BlockRef]()
)
proc combine*(tgt: var Attestation, src: Attestation, flags: UpdateFlags) =
## Combine the signature and participation bitfield, with the assumption that
## the same data is being signed - if the signatures overlap, they are not
## combined.
# TODO: Exported only for testing, all usage are internals
doAssert tgt.data == src.data
@ -44,43 +48,6 @@ proc combine*(tgt: var Attestation, src: Attestation, flags: UpdateFlags) =
else:
trace "Ignoring overlapping attestations"
# TODO remove/merge with p2p-interface validation
proc validate(
state: BeaconState, attestation: Attestation): bool =
# TODO what constitutes a valid attestation when it's about to be added to
# the pool? we're interested in attestations that will become viable
# for inclusion in blocks in the future and on any fork, so we need to
# consider that validations might happen using the state of a different
# fork.
# Some things are always invalid (like out-of-bounds issues etc), but
# others are more subtle - how do we validate the signature for example?
# It might be valid on one fork but not another. One thing that helps
# is that committees are stable per epoch and that it should be OK to
# include an attestation in a block even if the corresponding validator
# was slashed in the same epoch - there's no penalty for doing this and
# the vote counting logic will take care of any ill effects (TODO verify)
let data = attestation.data
# TODO re-enable check
#if not (data.crosslink.shard < SHARD_COUNT):
# notice "Attestation shard too high",
# attestation_shard = data.crosslink.shard
# return
# Without this check, we can't get a slot number for the attestation as
# certain helpers will assert
# TODO this could probably be avoided by being smart about the specific state
# used to validate the attestation: most likely if we pick the state of
# the beacon block being voted for and a slot in the target epoch
# of the attestation, we'll be safe!
# TODO the above state selection logic should probably live here in the
# attestation pool
if not (data.target.epoch == get_previous_epoch(state) or
data.target.epoch == get_current_epoch(state)):
notice "Target epoch not current or previous epoch"
return
true
proc slotIndex(
pool: var AttestationPool, state: BeaconState, attestationSlot: Slot): int =
@ -101,7 +68,7 @@ proc slotIndex(
", attestationSlot: " & $shortLog(attestationSlot) &
", startingSlot: " & $shortLog(pool.startingSlot)
if pool.slots.len == 0:
if pool.mapSlotsToAttestations.len == 0:
# Because the first attestations may arrive in any order, we'll make sure
# to start counting at the last finalized epoch start slot - anything
# earlier than that is thrown out by the above check
@ -111,15 +78,15 @@ proc slotIndex(
pool.startingSlot =
state.finalized_checkpoint.epoch.compute_start_slot_at_epoch()
if pool.startingSlot + pool.slots.len.uint64 <= attestationSlot:
if pool.startingSlot + pool.mapSlotsToAttestations.len.uint64 <= attestationSlot:
trace "Growing attestation pool",
attestationSlot = $shortLog(attestationSlot),
startingSlot = $shortLog(pool.startingSlot),
cat = "caching"
# Make sure there's a pool entry for every slot, even when there's a gap
while pool.startingSlot + pool.slots.len.uint64 <= attestationSlot:
pool.slots.addLast(SlotData())
while pool.startingSlot + pool.mapSlotsToAttestations.len.uint64 <= attestationSlot:
pool.mapSlotsToAttestations.addLast(AttestationsSeen())
if pool.startingSlot <
state.finalized_checkpoint.epoch.compute_start_slot_at_epoch():
@ -133,7 +100,7 @@ proc slotIndex(
# TODO there should be a better way to remove a whole epoch of stuff..
while pool.startingSlot <
state.finalized_checkpoint.epoch.compute_start_slot_at_epoch():
pool.slots.popFirst()
pool.mapSlotsToAttestations.popFirst()
pool.startingSlot += 1
int(attestationSlot - pool.startingSlot)
@ -168,21 +135,36 @@ proc addResolved(pool: var AttestationPool, blck: BlockRef, attestation: Attesta
# reasonable to involve the head being voted for as well as the intended
# slot of the attestation - double-check this with spec
# A basic check is that the attestation is at least as new as the block being
# voted for..
# TODO: How fast is state rewind?
# Can this be a DOS vector.
# TODO: filter valid attestation as much as possible before state rewind
# TODO: the below check does not respect the inclusion delay
# we should use isValidAttestationSlot instead
if blck.slot > attestation.data.slot:
notice "Invalid attestation (too new!)",
attestation = shortLog(attestation),
blockSlot = shortLog(blck.slot)
return
# if not isValidAttestationSlot(attestation.data.slot, blck.slot):
# # Logging in isValidAttestationSlot
# return
# Get a temporary state at the (block, slot) targeted by the attestation
updateStateData(
pool.blockPool, pool.blockPool.tmpState,
BlockSlot(blck: blck, slot: attestation.data.slot))
template state(): BeaconState = pool.blockPool.tmpState.data.data
if not validate(state, attestation):
# Check that the attestation is indeed valid
# TODO: we might want to split checks that depend
# on the state and those that don't to cheaply
# discard invalid attestations before rewinding state.
# TODO: stateCache usage
var stateCache = get_empty_per_epoch_cache()
if not isValidAttestationTargetEpoch(state, attestation):
notice "Invalid attestation",
attestation = shortLog(attestation),
current_epoch = get_current_epoch(state),
@ -195,7 +177,7 @@ proc addResolved(pool: var AttestationPool, blck: BlockRef, attestation: Attesta
let
attestationSlot = attestation.data.slot
idx = pool.slotIndex(state, attestationSlot)
slotData = addr pool.slots[idx]
attestationsSeen = addr pool.mapSlotsToAttestations[idx]
validation = Validation(
aggregation_bits: attestation.aggregation_bits,
aggregate_signature: attestation.signature)
@ -203,7 +185,7 @@ proc addResolved(pool: var AttestationPool, blck: BlockRef, attestation: Attesta
state, attestation.data, validation.aggregation_bits, cache)
var found = false
for a in slotData.attestations.mitems():
for a in attestationsSeen.attestations.mitems():
if a.data == attestation.data:
for v in a.validations:
if validation.aggregation_bits.isSubsetOf(v.aggregation_bits):
@ -251,7 +233,7 @@ proc addResolved(pool: var AttestationPool, blck: BlockRef, attestation: Attesta
break
if not found:
slotData.attestations.add(AttestationEntry(
attestationsSeen.attestations.add(AttestationEntry(
data: attestation.data,
blck: blck,
validations: @[validation]
@ -266,29 +248,33 @@ proc addResolved(pool: var AttestationPool, blck: BlockRef, attestation: Attesta
cat = "filtering"
proc add*(pool: var AttestationPool, attestation: Attestation) =
## Add a verified attestation to the fork choice context
logScope: pcs = "atp_add_attestation"
# Fetch the target block or notify the block pool that it's needed
let blck = pool.blockPool.getOrResolve(attestation.data.beacon_block_root)
# If the block exist, add it to the fork choice context
# Otherwise delay until it resolves
if blck.isNil:
pool.addUnresolved(attestation)
return
pool.addResolved(blck, attestation)
proc getAttestationsForSlot(pool: AttestationPool, newBlockSlot: Slot):
Option[SlotData] =
proc getAttestationsForSlot*(pool: AttestationPool, newBlockSlot: Slot):
Option[AttestationsSeen] =
if newBlockSlot < (GENESIS_SLOT + MIN_ATTESTATION_INCLUSION_DELAY):
debug "Too early for attestations",
newBlockSlot = shortLog(newBlockSlot),
cat = "query"
return none(SlotData)
return none(AttestationsSeen)
if pool.slots.len == 0: # startingSlot not set yet!
if pool.mapSlotsToAttestations.len == 0: # startingSlot not set yet!
info "No attestations found (pool empty)",
newBlockSlot = shortLog(newBlockSlot),
cat = "query"
return none(SlotData)
return none(AttestationsSeen)
let
# TODO in theory we could include attestations from other slots also, but
@ -299,16 +285,16 @@ proc getAttestationsForSlot(pool: AttestationPool, newBlockSlot: Slot):
attestationSlot = newBlockSlot - MIN_ATTESTATION_INCLUSION_DELAY
if attestationSlot < pool.startingSlot or
attestationSlot >= pool.startingSlot + pool.slots.len.uint64:
attestationSlot >= pool.startingSlot + pool.mapSlotsToAttestations.len.uint64:
info "No attestations matching the slot range",
attestationSlot = shortLog(attestationSlot),
startingSlot = shortLog(pool.startingSlot),
endingSlot = shortLog(pool.startingSlot + pool.slots.len.uint64),
endingSlot = shortLog(pool.startingSlot + pool.mapSlotsToAttestations.len.uint64),
cat = "query"
return none(SlotData)
return none(AttestationsSeen)
let slotDequeIdx = int(attestationSlot - pool.startingSlot)
some(pool.slots[slotDequeIdx])
some(pool.mapSlotsToAttestations[slotDequeIdx])
proc getAttestationsForBlock*(pool: AttestationPool,
state: BeaconState): seq[Attestation] =
@ -354,21 +340,17 @@ proc getAttestationsForBlock*(pool: AttestationPool,
signature: a.validations[0].aggregate_signature
)
if not validate(state, attestation):
warn "Attestation no longer validates...",
cat = "query"
continue
# TODO what's going on here is that when producing a block, we need to
# include only such attestations that will not cause block validation
# to fail. How this interacts with voting and the acceptance of
# attestations into the pool in general is an open question that needs
# revisiting - for example, when attestations are added, against which
# state should they be validated, if at all?
# TODO we're checking signatures here every time which is very slow - this
# is needed because validate does nothing for now and we don't want
# TODO we're checking signatures here every time which is very slow and we don't want
# to include a broken attestation
if not check_attestation(state, attestation, {}, cache):
warn "Attestation no longer validates...",
cat = "query"
continue
for v in a.validations[1..^1]:
@ -391,6 +373,8 @@ proc getAttestationsForBlock*(pool: AttestationPool,
return
proc resolve*(pool: var AttestationPool) =
## Check attestations in our unresolved deque
## if they can be integrated to the fork choice
logScope: pcs = "atp_resolve"
var
@ -479,88 +463,3 @@ proc selectHead*(pool: AttestationPool): BlockRef =
lmdGhost(pool, pool.blockPool.justifiedState.data.data, justifiedHead.blck)
newHead
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/p2p-interface.md#attestation-subnets
proc isValidAttestation*(
pool: AttestationPool, attestation: Attestation, current_slot: Slot,
topicCommitteeIndex: uint64, flags: UpdateFlags): bool =
# The attestation's committee index (attestation.data.index) is for the
# correct subnet.
if attestation.data.index != topicCommitteeIndex:
debug "isValidAttestation: attestation's committee index not for the correct subnet",
topicCommitteeIndex = topicCommitteeIndex,
attestation_data_index = attestation.data.index
return false
if not (attestation.data.slot + ATTESTATION_PROPAGATION_SLOT_RANGE >=
current_slot and current_slot >= attestation.data.slot):
debug "isValidAttestation: attestation.data.slot not within ATTESTATION_PROPAGATION_SLOT_RANGE"
return false
# The attestation is unaggregated -- that is, it has exactly one
# participating validator (len([bit for bit in attestation.aggregation_bits
# if bit == 0b1]) == 1).
# TODO a cleverer algorithm, along the lines of countOnes() in nim-stew
# But that belongs in nim-stew, since it'd break abstraction layers, to
# use details of its representation from nim-beacon-chain.
var onesCount = 0
for aggregation_bit in attestation.aggregation_bits:
if not aggregation_bit:
continue
onesCount += 1
if onesCount > 1:
debug "isValidAttestation: attestation has too many aggregation bits",
aggregation_bits = attestation.aggregation_bits
return false
if onesCount != 1:
debug "isValidAttestation: attestation has too few aggregation bits"
return false
# The attestation is the first valid attestation received for the
# participating validator for the slot, attestation.data.slot.
let maybeSlotData = getAttestationsForSlot(pool, attestation.data.slot)
if maybeSlotData.isSome:
for attestationEntry in maybeSlotData.get.attestations:
if attestation.data != attestationEntry.data:
continue
# Attestations might be aggregated eagerly or lazily; allow for both.
for validation in attestationEntry.validations:
if attestation.aggregation_bits.isSubsetOf(validation.aggregation_bits):
debug "isValidAttestation: attestation already exists at slot",
attestation_data_slot = attestation.data.slot,
attestation_aggregation_bits = attestation.aggregation_bits,
attestation_pool_validation = validation.aggregation_bits
return false
# Temporary: on Witti testnet, attestations and blocks routinely come in out
# of order. TODO we need to support this case but to enable participation in
# Witti, before https://github.com/status-im/nim-beacon-chain/issues/1106 is
# fixed, just disable these validations for now.
const kludge = true
if kludge:
return true
# The block being voted for (attestation.data.beacon_block_root) passes
# validation.
# We rely on the block pool to have been validated, so check for the
# existence of the block in the pool.
# TODO: consider a "slush pool" of attestations whose blocks have not yet
# propagated - i.e. imagine that attestations are smaller than blocks and
# therefore propagate faster, thus reordering their arrival in some nodes
if pool.blockPool.get(attestation.data.beacon_block_root).isNone():
debug "isValidAttestation: block doesn't exist in block pool",
attestation_data_beacon_block_root = attestation.data.beacon_block_root
return false
# The signature of attestation is valid.
# TODO need to know above which validator anyway, and this is too general
# as it supports aggregated attestations (which this can't be)
var cache = get_empty_per_epoch_cache()
if not is_valid_indexed_attestation(
pool.blockPool.headState.data.data,
get_indexed_attestation(
pool.blockPool.headState.data.data, attestation, cache), {}):
debug "isValidAttestation: signature verification failed"
return false
true

8
beacon_chain/beacon_node.nim
View File

@ -27,7 +27,7 @@ import
mainchain_monitor, version, ssz/[merkleization],
sync_protocol, request_manager, validator_keygen, interop, statusbar,
sync_manager, state_transition,
validator_duties, validator_api
validator_duties, validator_api, attestation_aggregation
const
genesisFile* = "genesis.ssz"
@ -387,7 +387,7 @@ proc onSlotStart(node: BeaconNode, lastSlot, scheduledSlot: Slot) {.gcsafe, asyn
beacon_head_slot.set slot.int64
# Time passes in here..
head = await node.handleValidatorDuties(head, lastSlot, slot)
asyncCheck node.handleValidatorDuties(lastSlot, slot)
let
nextSlotStart = saturate(node.beaconClock.fromNow(nextSlot))
@ -652,7 +652,7 @@ proc installAttestationHandlers(node: BeaconNode) =
let (afterGenesis, slot) = node.beaconClock.now().toSlot()
if not afterGenesis:
return false
node.attestationPool.isValidAttestation(attestation, slot, ci, {})))
node.attestationPool.isValidAttestation(attestation, slot, ci)))
when ETH2_SPEC == "v0.11.3":
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/p2p-interface.md#interop-3
@ -666,7 +666,7 @@ proc installAttestationHandlers(node: BeaconNode) =
# isValidAttestation checks attestation.data.index == topicCommitteeIndex
# which doesn't make sense here, so rig that check to vacuously pass.
node.attestationPool.isValidAttestation(
attestation, slot, attestation.data.index, {})))
attestation, slot, attestation.data.index)))
waitFor allFutures(attestationSubscriptions)

1
beacon_chain/beacon_node.nim.cfg
View File

@ -5,4 +5,3 @@
-d:"chronicles_sinks=json"
-d:"withoutPrompt"
@end

7
beacon_chain/beacon_node_types.nim
View File

@ -5,7 +5,8 @@ import
stew/endians2,
spec/[datatypes, crypto, digest],
block_pools/block_pools_types,
block_pool # TODO: refactoring compat shim
block_pool, # TODO: refactoring compat shim
fork_choice/fork_choice_types
export block_pools_types
@ -39,7 +40,7 @@ type
## this seq and aggregate only when needed
## TODO there are obvious caching opportunities here..
SlotData* = object
AttestationsSeen* = object
attestations*: seq[AttestationEntry] ## \
## Depending on the world view of the various validators, they may have
## voted on different states - here we collect all the different
@ -59,7 +60,7 @@ type
## contains both votes that have been included in the chain and those that
## have not.
slots*: Deque[SlotData] ## \
mapSlotsToAttestations*: Deque[AttestationsSeen] ## \
## We keep one item per slot such that indexing matches slot number
## together with startingSlot

2
beacon_chain/block_pools/candidate_chains.nim
View File

@ -800,7 +800,7 @@ func latestJustifiedBlock*(dag: CandidateChains): BlockSlot =
## as the latest finalized block
doAssert dag.heads.len > 0,
"We should have at least the genesis block in heaads"
"We should have at least the genesis block in heads"
doAssert (not dag.head.blck.isNil()),
"Genesis block will be head, if nothing else"

8
beacon_chain/block_pools/clearance.nim
View File

@ -114,6 +114,14 @@ proc add*(
## the state parameter may be updated to include the given block, if
## everything checks out
# TODO reevaluate passing the state in like this
# TODO: to facilitate adding the block to the attestation pool
# this should also return justified and finalized epoch corresponding
# to each block.
# This would be easy apart from the "Block already exists"
# early return.
let blck = signedBlock.message
doAssert blockRoot == hash_tree_root(blck)

59
beacon_chain/fork_choice/fork_choice.nim
View File

@ -9,9 +9,9 @@
import
# Standard library
std/tables, std/options, std/typetraits,
std/tables, std/typetraits,
# Status libraries
stew/results,
stew/results, chronicles,
# Internal
../spec/[datatypes, digest],
# Fork choice
@ -43,13 +43,17 @@ func compute_deltas(
# Fork choice routines
# ----------------------------------------------------------------------
logScope:
topics = "fork_choice"
cat = "fork_choice"
# API:
# - The private procs uses the ForkChoiceError error code
# - The public procs use Result
func initForkChoice*(
finalized_block_slot: Slot,
finalized_block_state_root: Eth2Digest,
finalized_block_slot: Slot, # This is unnecessary for fork choice but helps external components
finalized_block_state_root: Eth2Digest, # This is unnecessary for fork choice but helps external components
justified_epoch: Epoch,
finalized_epoch: Epoch,
finalized_root: Eth2Digest
@ -64,7 +68,8 @@ func initForkChoice*(
let err = proto_array.on_block(
finalized_block_slot,
finalized_root,
none(Eth2Digest),
hasParentInForkChoice = false,
default(Eth2Digest),
finalized_block_state_root,
justified_epoch,
finalized_epoch
@ -111,6 +116,31 @@ func process_attestation*(
vote.next_root = block_root
vote.next_epoch = target_epoch
{.noSideEffect.}:
info "Integrating vote in fork choice",
validator_index = $validator_index,
new_vote = shortlog(vote)
else:
{.noSideEffect.}:
if vote.next_epoch != target_epoch or vote.next_root != block_root:
warn "Change of vote ignored for fork choice. Potential for slashing.",
validator_index = $validator_index,
current_vote = shortlog(vote),
ignored_block_root = shortlog(block_root),
ignored_target_epoch = $target_epoch
else:
info "Ignoring double-vote for fork choice",
validator_index = $validator_index,
current_vote = shortlog(vote),
ignored_block_root = shortlog(block_root),
ignored_target_epoch = $target_epoch
func contains*(self: ForkChoice, block_root: Eth2Digest): bool =
## Returns `true` if a block is known to the fork choice
## and `false` otherwise.
##
## In particular, before adding a block, its parent must be known to the fork choice
self.proto_array.indices.contains(block_root)
func process_block*(
self: var ForkChoice,
@ -123,10 +153,18 @@ func process_block*(
): Result[void, string] =
## Add a block to the fork choice context
let err = self.proto_array.on_block(
slot, block_root, some(parent_root), state_root, justified_epoch, finalized_epoch
slot, block_root, hasParentInForkChoice = true, parent_root, state_root, justified_epoch, finalized_epoch
)
if err.kind != fcSuccess:
return err("process_block_error: " & $err)
{.noSideEffect.}:
info "Integrating block in fork choice",
block_root = $shortlog(block_root),
parent_root = $shortlog(parent_root),
justified_epoch = $justified_epoch,
finalized_epoch = $finalized_epoch
return ok()
@ -166,6 +204,13 @@ func find_head*(
if ghost_err.kind != fcSuccess:
return err("find_head failed: " & $ghost_err)
{.noSideEffect.}:
info "Fork choice requested",
justified_epoch = $justified_epoch,
justified_root = shortlog(justified_root),
finalized_epoch = $finalized_epoch,
fork_choice_head = shortlog(new_head)
return ok(new_head)
@ -252,7 +297,7 @@ func compute_deltas(
when isMainModule:
import stew/endians2
func fakeHash*(index: SomeInteger): Eth2Digest =
func fakeHash(index: SomeInteger): Eth2Digest =
## Create fake hashes
## Those are just the value serialized in big-endian
## We add 16x16 to avoid having a zero hash are those are special cased

18
beacon_chain/fork_choice/fork_choice_types.nim
View File

@ -1,4 +1,3 @@
# beacon_chain
# Copyright (c) 2018-2020 Status Research & Development GmbH
# Licensed and distributed under either of
@ -11,6 +10,8 @@
import
# Standard library
std/tables, std/options,
# Status
chronicles,
# Internal
../spec/[datatypes, digest]
@ -44,6 +45,9 @@ type
fcErrInvalidDeltaLen
fcErrRevertedFinalizedEpoch
fcErrInvalidBestNode
# -------------------------
# TODO: Extra error modes beyond Proto/Lighthouse to be reviewed
fcErrUnknownParent
FcUnderflowKind* = enum
## Fork Choice Overflow Kinds
@ -88,6 +92,9 @@ type
head_root*: Eth2Digest
head_justified_epoch*: Epoch
head_finalized_epoch*: Epoch
of fcErrUnknownParent:
child_root*: Eth2Digest
parent_root*: Eth2Digest
ProtoArray* = object
prune_threshold*: int
@ -127,3 +134,12 @@ type
proto_array*: ProtoArray
votes*: seq[VoteTracker]
balances*: seq[Gwei]
func shortlog*(vote: VoteTracker): auto =
(
current_root: vote.current_root,
next_root: vote.next_root,
next_epoch: vote.next_epoch
)
chronicles.formatIt VoteTracker: it.shortLog

34
beacon_chain/fork_choice/proto_array.nim
View File

@ -153,28 +153,38 @@ func on_block*(
self: var ProtoArray,
slot: Slot,
root: Eth2Digest,
parent: Option[Eth2Digest],
hasParentInForkChoice: bool,
parent: Eth2Digest,
state_root: Eth2Digest,
justified_epoch: Epoch,
finalized_epoch: Epoch
): ForkChoiceError =
## Register a block with the fork choice
## A `none` parent is only valid for Genesis
## A block `hasParentInForkChoice` may be false
## on fork choice initialization:
## - either from Genesis
## - or from a finalized state loaded from database
# Note: if parent is an "Option" type, we can run out of stack space.
# If the block is already known, ignore it
if root in self.indices:
return ForkChoiceSuccess
let node_index = self.nodes.len
let parent_index = block:
if parent.isNone:
none(int)
elif parent.unsafeGet() notin self.indices:
# Is this possible?
none(int)
var parent_index: Option[int]
if not hasParentInForkChoice:
# Genesis (but Genesis might not be default(Eth2Digest))
parent_index = none(int)
elif parent notin self.indices:
return ForkChoiceError(
kind: fcErrUnknownParent,
child_root: root,
parent_root: parent
)
else:
some(self.indices.unsafeGet(parent.unsafeGet()))
parent_index = some(self.indices.unsafeGet(parent))
let node_index = self.nodes.len
let node = ProtoNode(
slot: slot,
@ -191,7 +201,7 @@ func on_block*(
self.indices[node.root] = node_index
self.nodes.add node # TODO: if this is costly, we can setLen + construct the node in-place
if parent_index.isSome():
if parent_index.isSome(): # parent_index is always valid except for Genesis
let err = self.maybe_update_best_child_and_descendant(parent_index.unsafeGet(), node_index)
if err.kind != fcSuccess:
return err

100
beacon_chain/spec/beaconstate.nim
View File

@ -473,7 +473,78 @@ func get_indexed_attestation*(state: BeaconState, attestation: Attestation,
signature: attestation.signature
)
# Attestation validation
# ------------------------------------------------------------------------------------------
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.3/specs/phase0/beacon-chain.md#attestations
#
# TODO: Refactor, we need:
# - cheap validations that do not involve the fork state (to avoid unnecessary and costly rewinding which are probably a DOS vector)
# - check that must be done on the targeted state (for example beacon committee consistency)
# - check that requires easily computed data from the targeted sate (slots, epoch, justified checkpoints)
proc isValidAttestationSlot*(attestationSlot, stateSlot: Slot): bool =
## Attestation check that does not depend on the whole block state
## for cheaper prefiltering of attestations that come from the network
## to limit DOS via state rewinding
if not (attestationSlot + MIN_ATTESTATION_INCLUSION_DELAY <= stateSlot):
warn("Attestation too new",
attestation_slot = shortLog(attestationSlot),
state_slot = shortLog(stateSlot))
return false
if not (stateSlot <= attestationSlot + SLOTS_PER_EPOCH):
warn("Attestation too old",
attestation_slot = shortLog(attestationSlot),
state_slot = shortLog(stateSlot))
return false
return true
# TODO remove/merge with p2p-interface validation
proc isValidAttestationTargetEpoch*(
state: BeaconState, attestation: Attestation): bool =
# TODO what constitutes a valid attestation when it's about to be added to
# the pool? we're interested in attestations that will become viable
# for inclusion in blocks in the future and on any fork, so we need to
# consider that validations might happen using the state of a different
# fork.
# Some things are always invalid (like out-of-bounds issues etc), but
# others are more subtle - how do we validate the signature for example?
# It might be valid on one fork but not another. One thing that helps
# is that committees are stable per epoch and that it should be OK to
# include an attestation in a block even if the corresponding validator
# was slashed in the same epoch - there's no penalty for doing this and
# the vote counting logic will take care of any ill effects (TODO verify)
let data = attestation.data
# TODO re-enable check
#if not (data.crosslink.shard < SHARD_COUNT):
# notice "Attestation shard too high",
# attestation_shard = data.crosslink.shard
# return
# Without this check, we can't get a slot number for the attestation as
# certain helpers will assert
# TODO this could probably be avoided by being smart about the specific state
# used to validate the attestation: most likely if we pick the state of
# the beacon block being voted for and a slot in the target epoch
# of the attestation, we'll be safe!
# TODO the above state selection logic should probably live here in the
# attestation pool
if not (data.target.epoch == get_previous_epoch(state) or
data.target.epoch == get_current_epoch(state)):
warn("Target epoch not current or previous epoch")
return
if not (data.target.epoch == compute_epoch_at_slot(data.slot)):
warn("Target epoch inconsistent with epoch of data slot",
target_epoch = data.target.epoch,
data_slot_epoch = compute_epoch_at_slot(data.slot))
return
true
# https://github.com/ethereum/eth2.0-specs/blob/v0.11.2/specs/phase0/beacon-chain.md#attestations
proc check_attestation*(
state: BeaconState, attestation: Attestation, flags: UpdateFlags,
stateCache: var StateCache): bool =
@ -481,6 +552,12 @@ proc check_attestation*(
## at the current slot. When acting as a proposer, the same rules need to
## be followed!
# TODO: When checking attestation from the network, currently rewinding/advancing
# a temporary state is needed.
# If this is too costly we can be DOS-ed.
# We might want to split this into "state-dependent" checks and "state-independent" checks
# The latter one should be made prior to state-rewinding.
let
stateSlot = state.slot
data = attestation.data
@ -494,27 +571,12 @@ proc check_attestation*(
committee_count = get_committee_count_at_slot(state, data.slot))
return
if not (data.target.epoch == get_previous_epoch(state) or
data.target.epoch == get_current_epoch(state)):
warn("Target epoch not current or previous epoch")
if not isValidAttestationTargetEpoch(state, attestation):
# Logging in isValidAttestationTargetEpoch
return
if not (data.target.epoch == compute_epoch_at_slot(data.slot)):
warn("Target epoch inconsistent with epoch of data slot",
target_epoch = data.target.epoch,
data_slot_epoch = compute_epoch_at_slot(data.slot))
return
if not (data.slot + MIN_ATTESTATION_INCLUSION_DELAY <= stateSlot):
warn("Attestation too new",
attestation_slot = shortLog(data.slot),
state_slot = shortLog(stateSlot))
return
if not (stateSlot <= data.slot + SLOTS_PER_EPOCH):
warn("Attestation too old",
attestation_slot = shortLog(data.slot),
state_slot = shortLog(stateSlot))
if not isValidAttestationSlot(data.slot, stateSlot):
# Logging in isValidAttestationSlot
return
let committee = get_beacon_committee(

12
beacon_chain/spec/state_transition_epoch.nim
View File

@ -173,7 +173,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
root: get_block_root(state, previous_epoch))
state.justification_bits.setBit 1
trace "Justified with previous epoch",
info "Justified with previous epoch",
current_epoch = current_epoch,
checkpoint = shortLog(state.current_justified_checkpoint),
cat = "justification"
@ -187,7 +187,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
root: get_block_root(state, current_epoch))
state.justification_bits.setBit 0
trace "Justified with current epoch",
info "Justified with current epoch",
current_epoch = current_epoch,
checkpoint = shortLog(state.current_justified_checkpoint),
cat = "justification"
@ -201,7 +201,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
old_previous_justified_checkpoint.epoch + 3 == current_epoch:
state.finalized_checkpoint = old_previous_justified_checkpoint
trace "Finalized with rule 234",
info "Finalized with rule 234",
current_epoch = current_epoch,
checkpoint = shortLog(state.finalized_checkpoint),
cat = "finalization"
@ -212,7 +212,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
old_previous_justified_checkpoint.epoch + 2 == current_epoch:
state.finalized_checkpoint = old_previous_justified_checkpoint
trace "Finalized with rule 23",
info "Finalized with rule 23",
current_epoch = current_epoch,
checkpoint = shortLog(state.finalized_checkpoint),
cat = "finalization"
@ -223,7 +223,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
old_current_justified_checkpoint.epoch + 2 == current_epoch:
state.finalized_checkpoint = old_current_justified_checkpoint
trace "Finalized with rule 123",
info "Finalized with rule 123",
current_epoch = current_epoch,
checkpoint = shortLog(state.finalized_checkpoint),
cat = "finalization"
@ -234,7 +234,7 @@ proc process_justification_and_finalization*(state: var BeaconState,
old_current_justified_checkpoint.epoch + 1 == current_epoch:
state.finalized_checkpoint = old_current_justified_checkpoint
trace "Finalized with rule 12",
info "Finalized with rule 12",
current_epoch = current_epoch,
checkpoint = shortLog(state.finalized_checkpoint),
cat = "finalization"

10
beacon_chain/validator_duties.nim
View File

@ -398,19 +398,19 @@ proc broadcastAggregatedAttestations(
node.network.broadcast(node.topicAggregateAndProofs, signedAP)
proc handleValidatorDuties*(
node: BeaconNode, head: BlockRef, lastSlot, slot: Slot): Future[BlockRef] {.async.} =
node: BeaconNode, lastSlot, slot: Slot) {.async.} =
## Perform validator duties - create blocks, vote and aggreagte existing votes
var head = node.updateHead()
if node.attachedValidators.count == 0:
# Nothing to do because we have no validator attached
return head
return
if not node.isSynced(head):
notice "Node out of sync, skipping validator duties",
slot, headSlot = head.slot
return head
return
var curSlot = lastSlot + 1
var head = head
# Start by checking if there's work we should have done in the past that we
# can still meaningfully do
@ -493,5 +493,3 @@ proc handleValidatorDuties*(
broadcastAggregatedAttestations(
node, aggregationHead, aggregationSlot, TRAILING_DISTANCE)
return head

89
tests/test_attestation_pool.nim
View File

@ -7,13 +7,17 @@
{.used.}
import
../beacon_chain/spec/datatypes,
../beacon_chain/ssz
import
unittest,
chronicles,
stew/byteutils,
./testutil, ./testblockutil,
../beacon_chain/spec/[datatypes, digest, validator],
../beacon_chain/[beacon_node_types, attestation_pool, block_pool, state_transition, ssz]
../beacon_chain/spec/[digest, validator],
../beacon_chain/[beacon_node_types, attestation_pool, block_pool, state_transition]
suiteReport "Attestation pool processing" & preset():
## For now just test that we can compile and execute block processing with
@ -22,13 +26,15 @@ suiteReport "Attestation pool processing" & preset():
setup:
# Genesis state that results in 3 members per committee
var
blockPool = BlockPool.init(makeTestDB(SLOTS_PER_EPOCH * 3))
pool = AttestationPool.init(blockPool)
state = newClone(loadTailState(blockPool))
blockPool = newClone(BlockPool.init(makeTestDB(SLOTS_PER_EPOCH * 3)))
pool = newClone(AttestationPool.init(blockPool[]))
state = newClone(loadTailState(blockPool[]))
# Slot 0 is a finalized slot - won't be making attestations for it..
check:
process_slots(state.data, state.data.data.slot + 1)
# pool[].add(blockPool[].tail) # Make the tail known to fork choice
timedTest "Can add and retrieve simple attestation" & preset():
var cache = get_empty_per_epoch_cache()
let
@ -38,12 +44,12 @@ suiteReport "Attestation pool processing" & preset():
attestation = makeAttestation(
state.data.data, state.blck.root, beacon_committee[0], cache)
pool.add(attestation)
pool[].add(attestation)
check:
process_slots(state.data, MIN_ATTESTATION_INCLUSION_DELAY.Slot + 1)
let attestations = pool.getAttestationsForBlock(state.data.data)
let attestations = pool[].getAttestationsForBlock(state.data.data)
check:
attestations.len == 1
@ -67,12 +73,12 @@ suiteReport "Attestation pool processing" & preset():
state.data.data, state.blck.root, bc1[0], cache)
# test reverse order
pool.add(attestation1)
pool.add(attestation0)
pool[].add(attestation1)
pool[].add(attestation0)
discard process_slots(state.data, MIN_ATTESTATION_INCLUSION_DELAY.Slot + 1)
let attestations = pool.getAttestationsForBlock(state.data.data)
let attestations = pool[].getAttestationsForBlock(state.data.data)
check:
attestations.len == 1
@ -88,13 +94,13 @@ suiteReport "Attestation pool processing" & preset():
attestation1 = makeAttestation(
state.data.data, state.blck.root, bc0[1], cache)
pool.add(attestation0)
pool.add(attestation1)
pool[].add(attestation0)
pool[].add(attestation1)
check:
process_slots(state.data, MIN_ATTESTATION_INCLUSION_DELAY.Slot + 1)
let attestations = pool.getAttestationsForBlock(state.data.data)
let attestations = pool[].getAttestationsForBlock(state.data.data)
check:
attestations.len == 1
@ -113,13 +119,13 @@ suiteReport "Attestation pool processing" & preset():
attestation0.combine(attestation1, {})
pool.add(attestation0)
pool.add(attestation1)
pool[].add(attestation0)
pool[].add(attestation1)
check:
process_slots(state.data, MIN_ATTESTATION_INCLUSION_DELAY.Slot + 1)
let attestations = pool.getAttestationsForBlock(state.data.data)
let attestations = pool[].getAttestationsForBlock(state.data.data)
check:
attestations.len == 1
@ -137,13 +143,13 @@ suiteReport "Attestation pool processing" & preset():
attestation0.combine(attestation1, {})
pool.add(attestation1)
pool.add(attestation0)
pool[].add(attestation1)
pool[].add(attestation0)
check:
process_slots(state.data, MIN_ATTESTATION_INCLUSION_DELAY.Slot + 1)
let attestations = pool.getAttestationsForBlock(state.data.data)
let attestations = pool[].getAttestationsForBlock(state.data.data)
check:
attestations.len == 1
@ -151,10 +157,12 @@ suiteReport "Attestation pool processing" & preset():
timedTest "Fork choice returns latest block with no attestations":
var cache = get_empty_per_epoch_cache()
let
b1 = addTestBlock(state.data, blockPool.tail.root, cache)
b1 = addTestBlock(state.data, blockPool[].tail.root, cache)
b1Root = hash_tree_root(b1.message)
b1Add = blockPool.add(b1Root, b1)[]
head = pool.selectHead()
b1Add = blockpool[].add(b1Root, b1)[]
# pool[].add(b1Add) - make a block known to the future fork choice
let head = pool[].selectHead()
check:
head == b1Add
@ -162,8 +170,10 @@ suiteReport "Attestation pool processing" & preset():
let
b2 = addTestBlock(state.data, b1Root, cache)
b2Root = hash_tree_root(b2.message)
b2Add = blockPool.add(b2Root, b2)[]
head2 = pool.selectHead()
b2Add = blockpool[].add(b2Root, b2)[]
# pool[].add(b2Add) - make a block known to the future fork choice
let head2 = pool[].selectHead()
check:
head2 == b2Add
@ -171,28 +181,31 @@ suiteReport "Attestation pool processing" & preset():
timedTest "Fork choice returns block with attestation":
var cache = get_empty_per_epoch_cache()
let
b10 = makeTestBlock(state.data, blockPool.tail.root, cache)
b10 = makeTestBlock(state.data, blockPool[].tail.root, cache)
b10Root = hash_tree_root(b10.message)
b10Add = blockPool.add(b10Root, b10)[]
head = pool.selectHead()
b10Add = blockpool[].add(b10Root, b10)[]
# pool[].add(b10Add) - make a block known to the future fork choice
let head = pool[].selectHead()
check:
head == b10Add
let
b11 = makeTestBlock(state.data, blockPool.tail.root, cache,
b11 = makeTestBlock(state.data, blockPool[].tail.root, cache,
graffiti = Eth2Digest(data: [1'u8, 0, 0, 0 ,0 ,0 ,0 ,0 ,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
)
b11Root = hash_tree_root(b11.message)
b11Add = blockPool.add(b11Root, b11)[]
b11Add = blockpool[].add(b11Root, b11)[]
bc1 = get_beacon_committee(
state.data.data, state.data.data.slot, 1.CommitteeIndex, cache)
attestation0 = makeAttestation(state.data.data, b10Root, bc1[0], cache)
pool.add(attestation0)
# pool[].add(b11Add) - make a block known to the future fork choice
pool[].add(attestation0)
let head2 = pool.selectHead()
let head2 = pool[].selectHead()
check:
# Single vote for b10 and no votes for b11
@ -201,18 +214,22 @@ suiteReport "Attestation pool processing" & preset():
let
attestation1 = makeAttestation(state.data.data, b11Root, bc1[1], cache)
attestation2 = makeAttestation(state.data.data, b11Root, bc1[2], cache)
pool.add(attestation1)
pool[].add(attestation1)
let head3 = pool.selectHead()
let head3 = pool[].selectHead()
# Warning - the tiebreak are incorrect and guaranteed consensus fork, it should be bigger
let smaller = if b10Root.data < b11Root.data: b10Add else: b11Add
check:
# Ties broken lexicographically
# Ties broken lexicographically in spec -> ?
# all implementations favor the biggest root
# TODO
# currently using smaller as we have used for over a year
head3 == smaller
pool.add(attestation2)
pool[].add(attestation2)
let head4 = pool.selectHead()
let head4 = pool[].selectHead()
check:
# Two votes for b11