nimbus-eth2/beacon_chain/light_client.nim

371 lines
13 KiB
Nim

# beacon_chain
# Copyright (c) 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.
{.push raises: [Defect].}
# This implements the pre-release proposal of the libp2p based light client sync
# protocol. See https://github.com/ethereum/consensus-specs/pull/2802
import
chronicles,
eth/keys,
./gossip_processing/light_client_processor,
./networking/eth2_network,
./spec/datatypes/altair,
./spec/helpers,
./sync/light_client_manager,
"."/[beacon_clock, conf_light_client]
export LightClientFinalizationMode, eth2_network, conf_light_client
logScope: topics = "lightcl"
type
LightClientCallback* =
proc(lightClient: LightClient) {.gcsafe, raises: [Defect].}
LightClient* = ref object
network: Eth2Node
cfg: RuntimeConfig
forkDigests: ref ForkDigests
getBeaconTime: GetBeaconTimeFn
store: ref Option[LightClientStore]
processor: ref LightClientProcessor
manager: LightClientManager
gossipState: GossipState
onFinalizedHeader*, onOptimisticHeader*: LightClientCallback
trustedBlockRoot*: Option[Eth2Digest]
func finalizedHeader*(lightClient: LightClient): Opt[BeaconBlockHeader] =
if lightClient.store[].isSome:
ok lightClient.store[].get.finalized_header
else:
err()
func optimisticHeader*(lightClient: LightClient): Opt[BeaconBlockHeader] =
if lightClient.store[].isSome:
ok lightClient.store[].get.optimistic_header
else:
err()
proc createLightClient(
network: Eth2Node,
rng: ref HmacDrbgContext,
dumpEnabled: bool,
dumpDirInvalid, dumpDirIncoming: string,
cfg: RuntimeConfig,
forkDigests: ref ForkDigests,
getBeaconTime: GetBeaconTimeFn,
genesis_validators_root: Eth2Digest,
finalizationMode: LightClientFinalizationMode
): LightClient =
let lightClient = LightClient(
network: network,
cfg: cfg,
forkDigests: forkDigests,
getBeaconTime: getBeaconTime,
store: (ref Option[LightClientStore])())
func getTrustedBlockRoot(): Option[Eth2Digest] =
lightClient.trustedBlockRoot
proc onStoreInitialized() =
discard
proc onFinalizedHeader() =
if lightClient.onFinalizedHeader != nil:
lightClient.onFinalizedHeader(lightClient)
proc onOptimisticHeader() =
if lightClient.onOptimisticHeader != nil:
lightClient.onOptimisticHeader(lightClient)
lightClient.processor = LightClientProcessor.new(
dumpEnabled, dumpDirInvalid, dumpDirIncoming,
cfg, genesis_validators_root, finalizationMode,
lightClient.store, getBeaconTime, getTrustedBlockRoot,
onStoreInitialized, onFinalizedHeader, onOptimisticHeader)
proc lightClientVerifier(obj: SomeLightClientObject):
Future[Result[void, BlockError]] =
let resfut = newFuture[Result[void, BlockError]]("lightClientVerifier")
lightClient.processor[].addObject(MsgSource.gossip, obj, resfut)
resfut
proc bootstrapVerifier(obj: altair.LightClientBootstrap): auto =
lightClientVerifier(obj)
proc updateVerifier(obj: altair.LightClientUpdate): auto =
lightClientVerifier(obj)
proc finalityVerifier(obj: altair.LightClientFinalityUpdate): auto =
lightClientVerifier(obj)
proc optimisticVerifier(obj: altair.LightClientOptimisticUpdate): auto =
lightClientVerifier(obj)
func isLightClientStoreInitialized(): bool =
lightClient.store[].isSome
func isNextSyncCommitteeKnown(): bool =
if lightClient.store[].isSome:
lightClient.store[].get.is_next_sync_committee_known
else:
false
func getFinalizedPeriod(): SyncCommitteePeriod =
if lightClient.store[].isSome:
lightClient.store[].get.finalized_header.slot.sync_committee_period
else:
GENESIS_SLOT.sync_committee_period
func getOptimisticPeriod(): SyncCommitteePeriod =
if lightClient.store[].isSome:
lightClient.store[].get.optimistic_header.slot.sync_committee_period
else:
GENESIS_SLOT.sync_committee_period
lightClient.manager = LightClientManager.init(
lightClient.network, rng, getTrustedBlockRoot,
bootstrapVerifier, updateVerifier, finalityVerifier, optimisticVerifier,
isLightClientStoreInitialized, isNextSyncCommitteeKnown,
getFinalizedPeriod, getOptimisticPeriod, getBeaconTime)
lightClient.gossipState = {}
lightClient
proc createLightClient*(
network: Eth2Node,
rng: ref HmacDrbgContext,
config: BeaconNodeConf,
cfg: RuntimeConfig,
forkDigests: ref ForkDigests,
getBeaconTime: GetBeaconTimeFn,
genesis_validators_root: Eth2Digest,
finalizationMode: LightClientFinalizationMode
): LightClient =
createLightClient(
network, rng,
config.dumpEnabled, config.dumpDirInvalid, config.dumpDirIncoming,
cfg, forkDigests, getBeaconTime, genesis_validators_root, finalizationMode)
proc createLightClient*(
network: Eth2Node,
rng: ref HmacDrbgContext,
config: LightClientConf,
cfg: RuntimeConfig,
forkDigests: ref ForkDigests,
getBeaconTime: GetBeaconTimeFn,
genesis_validators_root: Eth2Digest,
finalizationMode: LightClientFinalizationMode
): LightClient =
createLightClient(
network, rng,
dumpEnabled = false, dumpDirInvalid = ".", dumpDirIncoming = ".",
cfg, forkDigests, getBeaconTime, genesis_validators_root, finalizationMode)
proc start*(lightClient: LightClient) =
notice "Starting light client",
trusted_block_root = lightClient.trustedBlockRoot
lightClient.manager.start()
proc resetToFinalizedHeader*(
lightClient: LightClient,
header: BeaconBlockHeader,
current_sync_committee: SyncCommittee) =
lightClient.processor[].resetToFinalizedHeader(header, current_sync_committee)
import metrics
from
libp2p/protocols/pubsub/gossipsub
import
TopicParams, validateParameters, init
from
./gossip_processing/eth2_processor
import
processLightClientFinalityUpdate, processLightClientOptimisticUpdate
declareCounter beacon_light_client_finality_updates_received,
"Number of valid LC finality updates processed by this node"
declareCounter beacon_light_client_finality_updates_dropped,
"Number of invalid LC finality updates dropped by this node", labels = ["reason"]
declareCounter beacon_light_client_optimistic_updates_received,
"Number of valid LC optimistic updates processed by this node"
declareCounter beacon_light_client_optimistic_updates_dropped,
"Number of invalid LC optimistic updates dropped by this node", labels = ["reason"]
template logReceived(
msg: altair.LightClientFinalityUpdate) =
debug "LC finality update received", finality_update = msg
template logValidated(
msg: altair.LightClientFinalityUpdate) =
trace "LC finality update validated", finality_update = msg
beacon_light_client_finality_updates_received.inc()
proc logDropped(
msg: altair.LightClientFinalityUpdate, es: varargs[ValidationError]) =
for e in es:
debug "Dropping LC finality update", finality_update = msg, error = e
beacon_light_client_finality_updates_dropped.inc(1, [$es[0][0]])
template logReceived(
msg: altair.LightClientOptimisticUpdate) =
debug "LC optimistic update received", optimistic_update = msg
template logValidated(
msg: altair.LightClientOptimisticUpdate) =
trace "LC optimistic update validated", optimistic_update = msg
beacon_light_client_optimistic_updates_received.inc()
proc logDropped(
msg: altair.LightClientOptimisticUpdate, es: varargs[ValidationError]) =
for e in es:
debug "Dropping LC optimistic update", optimistic_update = msg, error = e
beacon_light_client_optimistic_updates_dropped.inc(1, [$es[0][0]])
proc installMessageValidators*(
lightClient: LightClient, eth2Processor: ref Eth2Processor = nil) =
# When registering multiple message validators, IGNORE results take precedence
# over ACCEPT results. However, because the opposite behaviour is needed here,
# we handle both full node and light client validation in this module
template getLocalWallPeriod(): auto =
lightClient.getBeaconTime().slotOrZero().sync_committee_period
template validate[T: SomeLightClientObject](
msg: T, validatorProcName: untyped): ValidationResult =
msg.logReceived()
var
ignoreErrors {.noinit.}: array[2, ValidationError]
numIgnoreErrors = 0
let res1 =
if eth2Processor != nil:
let
v = eth2Processor[].`validatorProcName`(MsgSource.gossip, msg)
res = v.toValidationResult()
if res == ValidationResult.Reject:
msg.logDropped(v.error)
return res
if res == ValidationResult.Ignore:
ignoreErrors[numIgnoreErrors] = v.error
inc numIgnoreErrors
res
else:
ValidationResult.Ignore
let res2 =
if lightClient.manager.isGossipSupported(getLocalWallPeriod()):
let
v = lightClient.processor[].`validatorProcName`(MsgSource.gossip, msg)
res = v.toValidationResult()
if res == ValidationResult.Reject:
msg.logDropped(v.error)
return res
if res == ValidationResult.Ignore:
ignoreErrors[numIgnoreErrors] = v.error
inc numIgnoreErrors
res
else:
ValidationResult.Ignore
if res1 == ValidationResult.Accept or res2 == ValidationResult.Accept:
msg.logValidated()
return ValidationResult.Accept
doAssert res1 == ValidationResult.Ignore and res2 == ValidationResult.Ignore
if numIgnoreErrors == 0:
ignoreErrors[numIgnoreErrors] = static:
(ValidationResult.Ignore, cstring T.name & ": irrelevant")
inc numIgnoreErrors
msg.logDropped(ignoreErrors.toOpenArray(0, numIgnoreErrors - 1))
ValidationResult.Ignore
let forkDigests = lightClient.forkDigests
for digest in [forkDigests.altair, forkDigests.bellatrix]:
lightClient.network.addValidator(
getLightClientFinalityUpdateTopic(digest),
proc(msg: altair.LightClientFinalityUpdate): ValidationResult =
validate(msg, processLightClientFinalityUpdate))
lightClient.network.addValidator(
getLightClientOptimisticUpdateTopic(digest),
proc(msg: altair.LightClientOptimisticUpdate): ValidationResult =
validate(msg, processLightClientOptimisticUpdate))
const lightClientTopicParams = TopicParams.init()
static: lightClientTopicParams.validateParameters().tryGet()
proc updateGossipStatus*(
lightClient: LightClient, slot: Slot, dagIsBehind = default(Option[bool])) =
template cfg(): auto = lightClient.cfg
let
epoch = slot.epoch
lcBehind =
not lightClient.manager.isGossipSupported(slot.sync_committee_period)
dagBehind =
# While separate message validators can be installed for both
# full node and light client (both are called unless one rejects msg),
# only a single subscription is supported per topic.
# The full node subscription is also handled in this module, even though
# it does not directly relate to the client side of the LC sync protocol
dagIsBehind.get(true)
isBehind = lcBehind and dagBehind
currentEpochTargetGossipState = getTargetGossipState(
epoch, cfg.ALTAIR_FORK_EPOCH, cfg.BELLATRIX_FORK_EPOCH, isBehind)
targetGossipState =
if lcBehind or epoch < 1:
currentEpochTargetGossipState
else:
# The fork digest for light client topics depends on the attested slot,
# which is in the past relative to the signature slot (current slot).
# Therefore, LC topic subscriptions are kept for 1 extra epoch.
let previousEpochTargetGossipState = getTargetGossipState(
epoch - 1, cfg.ALTAIR_FORK_EPOCH, cfg.BELLATRIX_FORK_EPOCH, isBehind)
currentEpochTargetGossipState + previousEpochTargetGossipState
template currentGossipState(): auto = lightClient.gossipState
if currentGossipState == targetGossipState:
return
if currentGossipState.card == 0 and targetGossipState.card > 0:
debug "Enabling LC topic subscriptions",
wallSlot = slot, targetGossipState
elif currentGossipState.card > 0 and targetGossipState.card == 0:
debug "Disabling LC topic subscriptions",
wallSlot = slot
else:
# Individual forks added / removed
discard
let
newGossipForks = targetGossipState - currentGossipState
oldGossipForks = currentGossipState - targetGossipState
for gossipFork in oldGossipForks:
if gossipFork >= BeaconStateFork.Altair:
let forkDigest = lightClient.forkDigests[].atStateFork(gossipFork)
lightClient.network.unsubscribe(
getLightClientFinalityUpdateTopic(forkDigest))
lightClient.network.unsubscribe(
getLightClientOptimisticUpdateTopic(forkDigest))
for gossipFork in newGossipForks:
if gossipFork >= BeaconStateFork.Altair:
let forkDigest = lightClient.forkDigests[].atStateFork(gossipFork)
lightClient.network.subscribe(
getLightClientFinalityUpdateTopic(forkDigest),
lightClientTopicParams)
lightClient.network.subscribe(
getLightClientOptimisticUpdateTopic(forkDigest),
lightClientTopicParams)
lightClient.gossipState = targetGossipState