# beacon_chain # Copyright (c) 2018-2020 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. import # Standard library os, tables, random, strutils, times, # Nimble packages stew/[objects, bitseqs, byteutils], stew/shims/macros, chronos, chronicles, confutils, metrics, json_rpc/[rpcserver, jsonmarshal], json_serialization/std/[options, sets, net], serialization/errors, eth/db/kvstore, eth/db/kvstore_sqlite3, eth/p2p/enode, eth/[keys, async_utils], eth/p2p/discoveryv5/[protocol, enr], # Local modules spec/[datatypes, digest, crypto, beaconstate, helpers, validator, network, state_transition_block], spec/presets/custom, conf, time, beacon_chain_db, validator_pool, extras, attestation_pool, block_pool, eth2_network, eth2_discovery, beacon_node_types, mainchain_monitor, version, ssz, ssz/dynamic_navigator, sync_protocol, request_manager, validator_keygen, interop, statusbar, attestation_aggregation, sync_manager const genesisFile = "genesis.ssz" hasPrompt = not defined(withoutPrompt) maxEmptySlotCount = uint64(10*60) div SECONDS_PER_SLOT type KeyPair = eth2_network.KeyPair RpcServer = RpcHttpServer template init(T: type RpcHttpServer, ip: IpAddress, port: Port): T = newRpcHttpServer([initTAddress(ip, port)]) # https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics declareGauge beacon_slot, "Latest slot of the beacon chain state" declareGauge beacon_head_slot, "Slot of the head block of the beacon chain" declareGauge beacon_head_root, "Root of the head block of the beacon chain" # Metrics for tracking attestation and beacon block loss declareCounter beacon_attestations_sent, "Number of beacon chain attestations sent by this peer" declareCounter beacon_attestations_received, "Number of beacon chain attestations received by this peer" declareCounter beacon_blocks_proposed, "Number of beacon chain blocks sent by this peer" declareCounter beacon_blocks_received, "Number of beacon chain blocks received by this peer" logScope: topics = "beacnde" type BeaconNode = ref object nickname: string network: Eth2Node netKeys: KeyPair requestManager: RequestManager db: BeaconChainDB config: BeaconNodeConf attachedValidators: ValidatorPool blockPool: BlockPool attestationPool: AttestationPool mainchainMonitor: MainchainMonitor beaconClock: BeaconClock rpcServer: RpcServer forkDigest: ForkDigest topicBeaconBlocks: string topicAggregateAndProofs: string syncLoop: Future[void] proc onBeaconBlock*(node: BeaconNode, signedBlock: SignedBeaconBlock) {.gcsafe.} proc updateHead(node: BeaconNode): BlockRef proc saveValidatorKey(keyName, key: string, conf: BeaconNodeConf) = let validatorsDir = conf.localValidatorsDir let outputFile = validatorsDir / keyName createDir validatorsDir writeFile(outputFile, key) info "Imported validator key", file = outputFile proc getStateFromSnapshot(conf: BeaconNodeConf): NilableBeaconStateRef = var genesisPath = conf.dataDir/genesisFile snapshotContents: TaintedString writeGenesisFile = false if conf.stateSnapshot.isSome: let snapshotPath = conf.stateSnapshot.get.string snapshotExt = splitFile(snapshotPath).ext if cmpIgnoreCase(snapshotExt, ".ssz") != 0: error "The supplied state snapshot must be a SSZ file", suppliedPath = snapshotPath quit 1 snapshotContents = readFile(snapshotPath) if fileExists(genesisPath): let genesisContents = readFile(genesisPath) if snapshotContents != genesisContents: error "Data directory not empty. Existing genesis state differs from supplied snapshot", dataDir = conf.dataDir.string, snapshot = snapshotPath quit 1 else: debug "No previous genesis state. Importing snapshot", genesisPath, dataDir = conf.dataDir.string writeGenesisFile = true genesisPath = snapshotPath else: try: snapshotContents = readFile(genesisPath) except CatchableError as err: error "Failed to read genesis file", err = err.msg quit 1 try: result = SSZ.decode(snapshotContents, BeaconStateRef) except SerializationError: error "Failed to import genesis file", path = genesisPath quit 1 info "Loaded genesis state", path = genesisPath if writeGenesisFile: try: notice "Writing genesis to data directory", path = conf.dataDir/genesisFile writeFile(conf.dataDir/genesisFile, snapshotContents.string) except CatchableError as err: error "Failed to persist genesis file to data dir", err = err.msg, genesisFile = conf.dataDir/genesisFile quit 1 proc enrForkIdFromState(state: BeaconState): ENRForkID = let forkVer = state.fork.current_version forkDigest = compute_fork_digest(forkVer, state.genesis_validators_root) ENRForkID( fork_digest: forkDigest, next_fork_version: forkVer, next_fork_epoch: FAR_FUTURE_EPOCH) proc init*(T: type BeaconNode, conf: BeaconNodeConf): Future[BeaconNode] {.async.} = let netKeys = getPersistentNetKeys(conf) nickname = if conf.nodeName == "auto": shortForm(netKeys) else: conf.nodeName db = BeaconChainDB.init(kvStore SqStoreRef.init(conf.databaseDir, "nbc").tryGet()) var mainchainMonitor: MainchainMonitor if not BlockPool.isInitialized(db): # Fresh start - need to load a genesis state from somewhere var genesisState = conf.getStateFromSnapshot() # Try file from command line first if genesisState.isNil: # Didn't work, try creating a genesis state using main chain monitor # TODO Could move this to a separate "GenesisMonitor" process or task # that would do only this - see if conf.web3Url.len > 0 and conf.depositContractAddress.len > 0: mainchainMonitor = MainchainMonitor.init( web3Provider(conf.web3Url), conf.depositContractAddress, Eth2Digest()) mainchainMonitor.start() else: error "No initial state, need genesis state or deposit contract address" quit 1 genesisState = await mainchainMonitor.getGenesis() # This is needed to prove the not nil property from here on if genesisState == nil: doAssert false else: if genesisState.slot != GENESIS_SLOT: # TODO how to get a block from a non-genesis state? error "Starting from non-genesis state not supported", stateSlot = genesisState.slot, stateRoot = hash_tree_root(genesisState) quit 1 let tailBlock = get_initial_beacon_block(genesisState[]) try: BlockPool.preInit(db, genesisState, tailBlock) doAssert BlockPool.isInitialized(db), "preInit should have initialized db" except CatchableError as e: error "Failed to initialize database", err = e.msg quit 1 # TODO check that genesis given on command line (if any) matches database let blockPool = BlockPool.init(db) if mainchainMonitor.isNil and conf.web3Url.len > 0 and conf.depositContractAddress.len > 0: mainchainMonitor = MainchainMonitor.init( web3Provider(conf.web3Url), conf.depositContractAddress, blockPool.headState.data.data.eth1_data.block_hash) # TODO if we don't have any validators attached, we don't need a mainchain # monitor mainchainMonitor.start() let rpcServer = if conf.rpcEnabled: RpcServer.init(conf.rpcAddress, conf.rpcPort) else: nil let enrForkId = enrForkIdFromState(blockPool.headState.data.data[]) topicBeaconBlocks = getBeaconBlocksTopic(enrForkId.forkDigest) topicAggregateAndProofs = getAggregateAndProofsTopic(enrForkId.forkDigest) network = await createEth2Node(conf, enrForkId) var res = BeaconNode( nickname: nickname, network: network, netKeys: netKeys, requestManager: RequestManager.init(network), db: db, config: conf, attachedValidators: ValidatorPool.init(), blockPool: blockPool, attestationPool: AttestationPool.init(blockPool), mainchainMonitor: mainchainMonitor, beaconClock: BeaconClock.init(blockPool.headState.data.data[]), rpcServer: rpcServer, forkDigest: enrForkId.forkDigest, topicBeaconBlocks: topicBeaconBlocks, topicAggregateAndProofs: topicAggregateAndProofs, ) # TODO sync is called when a remote peer is connected - is that the right # time to do so? network.initBeaconSync(blockPool, enrForkId.forkDigest, proc(signedBlock: SignedBeaconBlock) = if signedBlock.message.slot mod SLOTS_PER_EPOCH == 0: # TODO this is a hack to make sure that lmd ghost is run regularly # while syncing blocks - it's poor form to keep it here though - # the logic should be moved elsewhere # TODO why only when syncing? well, because the way the code is written # we require a connection to a boot node to start, and that boot # node will start syncing as part of connection setup - it looks # like it needs to finish syncing before the slot timer starts # ticking which is a problem: all the synced blocks will be added # to the block pool without any periodic head updates while this # process is ongoing (during a blank start for example), which # leads to an unhealthy buildup of blocks in the non-finalized part # of the block pool # TODO is it a problem that someone sending us a block can force # a potentially expensive head resolution? discard res.updateHead() onBeaconBlock(res, signedBlock)) return res proc connectToNetwork(node: BeaconNode) {.async.} = await node.network.connectToNetwork() let addressFile = node.config.dataDir / "beacon_node.address" writeFile(addressFile, node.network.announcedENR.toURI) template findIt(s: openarray, predicate: untyped): int = var res = -1 for i, it {.inject.} in s: if predicate: res = i break res proc addLocalValidator(node: BeaconNode, state: BeaconState, privKey: ValidatorPrivKey) = let pubKey = privKey.toPubKey() let idx = state.validators.findIt(it.pubKey == pubKey) if idx == -1: # We allow adding a validator even if its key is not in the state registry: # it might be that the deposit for this validator has not yet been processed warn "Validator not in registry (yet?)", pubKey node.attachedValidators.addLocalValidator(pubKey, privKey) proc addLocalValidators(node: BeaconNode, state: BeaconState) = for validatorKey in node.config.validatorKeys: node.addLocalValidator state, validatorKey info "Local validators attached ", count = node.attachedValidators.count func getAttachedValidator(node: BeaconNode, state: BeaconState, idx: ValidatorIndex): AttachedValidator = let validatorKey = state.validators[idx].pubkey node.attachedValidators.getValidator(validatorKey) proc isSynced(node: BeaconNode, head: BlockRef): bool = ## TODO This function is here as a placeholder for some better heurestics to ## determine if we're in sync and should be producing blocks and ## attestations. Generally, the problem is that slot time keeps advancing ## even when there are no blocks being produced, so there's no way to ## distinguish validators geniunely going missing from the node not being ## well connected (during a network split or an internet outage for ## example). It would generally be correct to simply keep running as if ## we were the only legit node left alive, but then we run into issues: ## with enough many empty slots, the validator pool is emptied leading ## to empty committees and lots of empty slot processing that will be ## thrown away as soon as we're synced again. let # The slot we should be at, according to the clock beaconTime = node.beaconClock.now() wallSlot = beaconTime.toSlot() # TODO if everyone follows this logic, the network will not recover from a # halt: nobody will be producing blocks because everone expects someone # else to do it if wallSlot.afterGenesis and head.slot + maxEmptySlotCount < wallSlot.slot: false else: true proc updateHead(node: BeaconNode): BlockRef = # Check pending attestations - maybe we found some blocks for them node.attestationPool.resolve() # Grab the new head according to our latest attestation data let newHead = node.attestationPool.selectHead() # Store the new head in the block pool - this may cause epochs to be # justified and finalized node.blockPool.updateHead(newHead) beacon_head_root.set newHead.root.toGaugeValue newHead proc sendAttestation(node: BeaconNode, fork: Fork, genesis_validators_root: Eth2Digest, validator: AttachedValidator, attestationData: AttestationData, committeeLen: int, indexInCommittee: int) {.async.} = logScope: pcs = "send_attestation" let validatorSignature = await validator.signAttestation(attestationData, fork, genesis_validators_root) var aggregationBits = CommitteeValidatorsBits.init(committeeLen) aggregationBits.setBit indexInCommittee var attestation = Attestation( data: attestationData, signature: validatorSignature, aggregation_bits: aggregationBits ) # https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/validator.md#broadcast-attestation node.network.broadcast( getAttestationTopic(node.forkDigest, attestationData.index), attestation) if node.config.dumpEnabled: SSZ.saveFile( node.config.dumpDir / "att-" & $attestationData.slot & "-" & $attestationData.index & "-" & validator.pubKey.shortLog & ".ssz", attestation) info "Attestation sent", attestation = shortLog(attestation), validator = shortLog(validator), indexInCommittee = indexInCommittee, cat = "consensus" beacon_attestations_sent.inc() proc proposeBlock(node: BeaconNode, validator: AttachedValidator, head: BlockRef, slot: Slot): Future[BlockRef] {.async.} = logScope: pcs = "block_proposal" if head.slot >= slot: # We should normally not have a head newer than the slot we're proposing for # but this can happen if block proposal is delayed warn "Skipping proposal, have newer head already", headSlot = shortLog(head.slot), headBlockRoot = shortLog(head.root), slot = shortLog(slot), cat = "fastforward" return head # Advance state to the slot that we're proposing for - this is the equivalent # of running `process_slots` up to the slot of the new block. let (nroot, nblck) = node.blockPool.withState( node.blockPool.tmpState, head.atSlot(slot)): let (eth1data, deposits) = if node.mainchainMonitor.isNil: (get_eth1data_stub(state.eth1_deposit_index, slot.compute_epoch_at_slot()), newSeq[Deposit]()) else: node.mainchainMonitor.getBlockProposalData(state[]) let message = makeBeaconBlock( state[], head.root, validator.genRandaoReveal(state.fork, state.genesis_validators_root, slot), eth1data, Eth2Digest(), node.attestationPool.getAttestationsForBlock(state[]), deposits) if not message.isSome(): return head # already logged elsewhere! var newBlock = SignedBeaconBlock( message: message.get() ) let blockRoot = hash_tree_root(newBlock.message) # Careful, state no longer valid after here because of the await.. newBlock.signature = await validator.signBlockProposal( state.fork, state.genesis_validators_root, slot, blockRoot) (blockRoot, newBlock) let newBlockRef = node.blockPool.add(nroot, nblck) if newBlockRef == nil: warn "Unable to add proposed block to block pool", newBlock = shortLog(newBlock.message), blockRoot = shortLog(blockRoot), cat = "bug" return head info "Block proposed", blck = shortLog(newBlock.message), blockRoot = shortLog(newBlockRef.root), validator = shortLog(validator), cat = "consensus" if node.config.dumpEnabled: SSZ.saveFile( node.config.dumpDir / "block-" & $newBlock.message.slot & "-" & shortLog(newBlockRef.root) & ".ssz", newBlock) node.blockPool.withState( node.blockPool.tmpState, newBlockRef.atSlot(newBlockRef.slot)): SSZ.saveFile( node.config.dumpDir / "state-" & $state.slot & "-" & shortLog(newBlockRef.root) & "-" & shortLog(root()) & ".ssz", state) node.network.broadcast(node.topicBeaconBlocks, newBlock) beacon_blocks_proposed.inc() return newBlockRef proc onAttestation(node: BeaconNode, attestation: Attestation) = # We received an attestation from the network but don't know much about it # yet - in particular, we haven't verified that it belongs to particular chain # we're on, or that it follows the rules of the protocol logScope: pcs = "on_attestation" let wallSlot = node.beaconClock.now().toSlot() head = node.blockPool.head debug "Attestation received", attestation = shortLog(attestation), headRoot = shortLog(head.blck.root), headSlot = shortLog(head.blck.slot), wallSlot = shortLog(wallSlot.slot), cat = "consensus" # Tag "consensus|attestation"? if not wallSlot.afterGenesis or wallSlot.slot < head.blck.slot: warn "Received attestation before genesis or head - clock is wrong?", afterGenesis = wallSlot.afterGenesis, wallSlot = shortLog(wallSlot.slot), headSlot = shortLog(head.blck.slot), cat = "clock_drift" # Tag "attestation|clock_drift"? return if attestation.data.slot > head.blck.slot and (attestation.data.slot - head.blck.slot) > maxEmptySlotCount: warn "Ignoring attestation, head block too old (out of sync?)", attestationSlot = attestation.data.slot, headSlot = head.blck.slot return node.attestationPool.add(attestation) proc storeBlock(node: BeaconNode, signedBlock: SignedBeaconBlock): bool = let blockRoot = hash_tree_root(signedBlock.message) debug "Block received", signedBlock = shortLog(signedBlock.message), blockRoot = shortLog(blockRoot), cat = "block_listener", pcs = "receive_block" beacon_blocks_received.inc() if node.blockPool.add(blockRoot, signedBlock).isNil: return false # The block we received contains attestations, and we might not yet know about # all of them. Let's add them to the attestation pool - in case they block # is not yet resolved, neither will the attestations be! # But please note that we only care about recent attestations. # TODO shouldn't add attestations if the block turns out to be invalid.. let currentSlot = node.beaconClock.now.toSlot if currentSlot.afterGenesis and signedBlock.message.slot.epoch + 1 >= currentSlot.slot.epoch: for attestation in signedBlock.message.body.attestations: node.onAttestation(attestation) return true proc onBeaconBlock(node: BeaconNode, signedBlock: SignedBeaconBlock) = # We received a block but don't know much about it yet - in particular, we # don't know if it's part of the chain we're currently building. discard node.storeBlock(signedBlock) proc handleAttestations(node: BeaconNode, head: BlockRef, slot: Slot) = ## Perform all attestations that the validators attached to this node should ## perform during the given slot logScope: pcs = "on_attestation" if slot + SLOTS_PER_EPOCH < head.slot: # The latest block we know about is a lot newer than the slot we're being # asked to attest to - this makes it unlikely that it will be included # at all. # TODO the oldest attestations allowed are those that are older than the # finalized epoch.. also, it seems that posting very old attestations # is risky from a slashing perspective. More work is needed here. notice "Skipping attestation, head is too recent", headSlot = shortLog(head.slot), slot = shortLog(slot) return let attestationHead = head.findAncestorBySlot(slot) if head != attestationHead.blck: # In rare cases, such as when we're busy syncing or just slow, we'll be # attesting to a past state - we must then recreate the world as it looked # like back then notice "Attesting to a state in the past, falling behind?", headSlot = shortLog(head.slot), attestationHeadSlot = shortLog(attestationHead.slot), attestationSlot = shortLog(slot) trace "Checking attestations", attestationHeadRoot = shortLog(attestationHead.blck.root), attestationSlot = shortLog(slot), cat = "attestation" # Collect data to send before node.stateCache grows stale var attestations: seq[tuple[ data: AttestationData, committeeLen, indexInCommittee: int, validator: AttachedValidator]] # We need to run attestations exactly for the slot that we're attesting to. # In case blocks went missing, this means advancing past the latest block # using empty slots as fillers. # https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/validator/0_beacon-chain-validator.md#validator-assignments # TODO we could cache the validator assignment since it's valid for the entire # epoch since it doesn't change, but that has to be weighed against # the complexity of handling forks correctly - instead, we use an adapted # version here that calculates the committee for a single slot only node.blockPool.withState(node.blockPool.tmpState, attestationHead): var cache = get_empty_per_epoch_cache() let committees_per_slot = get_committee_count_at_slot(state[], slot) for committee_index in 0'u64..= 4 to check finalization const SETTLING_TIME_OFFSET = 1'u64 let epoch = slot.compute_epoch_at_slot() # Don't static-assert this -- if this isn't called, don't require it doAssert SLOTS_PER_EPOCH > SETTLING_TIME_OFFSET # Intentionally, loudly assert. Point is to fail visibly and unignorably # during testing. if epoch >= 4 and slot mod SLOTS_PER_EPOCH > SETTLING_TIME_OFFSET: let finalizedEpoch = node.blockPool.finalizedHead.blck.slot.compute_epoch_at_slot() doAssert finalizedEpoch + 2 == epoch proc broadcastAggregatedAttestations( node: BeaconNode, aggregationHead: BlockRef, aggregationSlot: Slot, trailing_distance: uint64) = # The index is via a # locally attested validator. Unlike in handleAttestations(...) there's a # single one at most per slot (because that's how aggregation attestation # works), so the machinery that has to handle looping across, basically a # set of locally attached validators is in principle not necessary, but a # way to organize this. Then the private key for that validator should be # the corresponding one -- whatver they are, they match. let bs = BlockSlot(blck: aggregationHead, slot: aggregationSlot) node.blockPool.withState(node.blockPool.tmpState, bs): let committees_per_slot = get_committee_count_at_slot(state[], aggregationSlot) var cache = get_empty_per_epoch_cache() for committee_index in 0'u64.. 2: sleepToSlotOffset( seconds(int64(SECONDS_PER_SLOT * 2) div 3), "Waiting to aggregate attestations") const TRAILING_DISTANCE = 1 let aggregationSlot = slot - TRAILING_DISTANCE aggregationHead = getAncestorAt(head, aggregationSlot) broadcastAggregatedAttestations( node, aggregationHead, aggregationSlot, TRAILING_DISTANCE) return head proc onSlotStart(node: BeaconNode, lastSlot, scheduledSlot: Slot) {.gcsafe, async.} = ## Called at the beginning of a slot - usually every slot, but sometimes might ## skip a few in case we're running late. ## lastSlot: the last slot that we sucessfully processed, so we know where to ## start work from ## scheduledSlot: the slot that we were aiming for, in terms of timing logScope: pcs = "slot_start" let # The slot we should be at, according to the clock beaconTime = node.beaconClock.now() wallSlot = beaconTime.toSlot() info "Slot start", lastSlot = shortLog(lastSlot), scheduledSlot = shortLog(scheduledSlot), beaconTime = shortLog(beaconTime), peers = node.network.peersCount, headSlot = shortLog(node.blockPool.head.blck.slot), headEpoch = shortLog(node.blockPool.head.blck.slot.compute_epoch_at_slot()), headRoot = shortLog(node.blockPool.head.blck.root), finalizedSlot = shortLog(node.blockPool.finalizedHead.blck.slot), finalizedRoot = shortLog(node.blockPool.finalizedHead.blck.root), finalizedEpoch = shortLog(node.blockPool.finalizedHead.blck.slot.compute_epoch_at_slot()), cat = "scheduling" # Check before any re-scheduling of onSlotStart() if node.config.stopAtEpoch > 0'u64 and scheduledSlot.compute_epoch_at_slot() >= node.config.stopAtEpoch: info "Stopping at pre-chosen epoch", chosenEpoch = node.config.stopAtEpoch, epoch = scheduledSlot.compute_epoch_at_slot(), slot = scheduledSlot # Brute-force, but ensure it's reliably enough to run in CI. quit(0) if not wallSlot.afterGenesis or (wallSlot.slot < lastSlot): let slot = if wallSlot.afterGenesis: wallSlot.slot else: GENESIS_SLOT nextSlot = slot + 1 # At least GENESIS_SLOT + 1! # This can happen if the system clock changes time for example, and it's # pretty bad # TODO shut down? time either was or is bad, and PoS relies on accuracy.. warn "Beacon clock time moved back, rescheduling slot actions", beaconTime = shortLog(beaconTime), lastSlot = shortLog(lastSlot), scheduledSlot = shortLog(scheduledSlot), nextSlot = shortLog(nextSlot), cat = "clock_drift" # tag "scheduling|clock_drift"? addTimer(saturate(node.beaconClock.fromNow(nextSlot))) do (p: pointer): asyncCheck node.onSlotStart(slot, nextSlot) return let slot = wallSlot.slot # afterGenesis == true! nextSlot = slot + 1 beacon_slot.set slot.int64 if node.config.verifyFinalization: verifyFinalization(node, scheduledSlot) if slot > lastSlot + SLOTS_PER_EPOCH: # We've fallen behind more than an epoch - there's nothing clever we can # do here really, except skip all the work and try again later. # TODO how long should the period be? Using an epoch because that's roughly # how long attestations remain interesting # TODO should we shut down instead? clearly we're unable to keep up warn "Unable to keep up, skipping ahead", lastSlot = shortLog(lastSlot), slot = shortLog(slot), nextSlot = shortLog(nextSlot), scheduledSlot = shortLog(scheduledSlot), cat = "overload" addTimer(saturate(node.beaconClock.fromNow(nextSlot))) do (p: pointer): # We pass the current slot here to indicate that work should be skipped! asyncCheck node.onSlotStart(slot, nextSlot) return # Whatever we do during the slot, we need to know the head, because this will # give us a state to work with and thus a shuffling. # TODO typically, what consitutes correct actions stays constant between slot # updates and is stable across some epoch transitions as well - see how # we can avoid recalculating everything here # TODO if the head is very old, that is indicative of something being very # wrong - us being out of sync or disconnected from the network - need # to consider what to do in that case: # * nothing - the other parts of the application will reconnect and # start listening to broadcasts, learn a new head etc.. # risky, because the network might stall if everyone does # this, because no blocks will be produced # * shut down - this allows the user to notice and take action, but is # kind of harsh # * keep going - we create blocks and attestations as usual and send them # out - if network conditions improve, fork choice should # eventually select the correct head and the rest will # disappear naturally - risky because user is not aware, # and might lose stake on canonical chain but "just works" # when reconnected.. var head = node.updateHead() # TODO is the slot of the clock or the head block more interesting? provide # rationale in comment beacon_head_slot.set slot.int64 # Time passes in here.. head = await node.handleValidatorDuties(head, lastSlot, slot) let nextSlotStart = saturate(node.beaconClock.fromNow(nextSlot)) info "Slot end", slot = shortLog(slot), nextSlot = shortLog(nextSlot), headSlot = shortLog(node.blockPool.head.blck.slot), headEpoch = shortLog(node.blockPool.head.blck.slot.compute_epoch_at_slot()), headRoot = shortLog(node.blockPool.head.blck.root), finalizedSlot = shortLog(node.blockPool.finalizedHead.blck.slot), finalizedEpoch = shortLog(node.blockPool.finalizedHead.blck.slot.compute_epoch_at_slot()), finalizedRoot = shortLog(node.blockPool.finalizedHead.blck.root), cat = "scheduling" addTimer(nextSlotStart) do (p: pointer): asyncCheck node.onSlotStart(slot, nextSlot) proc handleMissingBlocks(node: BeaconNode) = let missingBlocks = node.blockPool.checkMissing() if missingBlocks.len > 0: var left = missingBlocks.len info "Requesting detected missing blocks", missingBlocks node.requestManager.fetchAncestorBlocks(missingBlocks) do (b: SignedBeaconBlock): onBeaconBlock(node, b) # TODO instead of waiting for a full second to try the next missing block # fetching, we'll do it here again in case we get all blocks we asked # for (there might be new parents to fetch). of course, this is not # good because the onSecond fetching also kicks in regardless but # whatever - this is just a quick fix for making the testnet easier # work with while the sync problem is dealt with more systematically # dec left # if left == 0: # discard setTimer(Moment.now()) do (p: pointer): # handleMissingBlocks(node) proc onSecond(node: BeaconNode, moment: Moment) {.async.} = node.handleMissingBlocks() let nextSecond = max(Moment.now(), moment + chronos.seconds(1)) discard setTimer(nextSecond) do (p: pointer): asyncCheck node.onSecond(nextSecond) proc getHeadSlot*(peer: Peer): Slot {.inline.} = ## Returns head slot for specific peer ``peer``. result = peer.state(BeaconSync).statusMsg.headSlot proc updateStatus*(peer: Peer): Future[bool] {.async.} = ## Request `status` of remote peer ``peer``. let nstate = peer.networkState(BeaconSync) finalizedHead = nstate.blockPool.finalizedHead headBlock = nstate.blockPool.head.blck ourStatus = StatusMsg( forkDigest: nstate.forkDigest, finalizedRoot: finalizedHead.blck.root, finalizedEpoch: finalizedHead.slot.compute_epoch_at_slot(), headRoot: headBlock.root, headSlot: headBlock.slot ) let theirStatus = await peer.status(ourStatus, timeout = chronos.seconds(60)) if theirStatus.isSome(): peer.state(BeaconSync).statusMsg = theirStatus.get() result = true proc runSyncLoop(node: BeaconNode) {.async.} = proc getLocalHeadSlot(): Slot = result = node.blockPool.head.blck.slot proc getLocalWallSlot(): Slot {.gcsafe.} = let epoch = node.beaconClock.now().toSlot().slot.compute_epoch_at_slot() + 1'u64 result = epoch.compute_start_slot_at_epoch() proc updateLocalBlocks(list: openarray[SignedBeaconBlock]): bool = debug "Forward sync imported blocks", count = len(list), local_head_slot = getLocalHeadSlot() for blk in list: if not(node.storeBlock(blk)): return false discard node.updateHead() info "Forward sync blocks got imported sucessfully", count = len(list), local_head_slot = getLocalHeadSlot() result = true proc scoreCheck(peer: Peer): bool = if peer.score < PeerScoreLimit: try: debug "Peer score is too low, removing it from PeerPool", peer = peer, peer_score = peer.score, score_limit = PeerScoreLimit except: discard result = false else: result = true node.network.peerPool.setScoreCheck(scoreCheck) var syncman = newSyncManager[Peer, PeerID]( node.network.peerPool, getLocalHeadSlot, getLocalWallSlot, updateLocalBlocks ) await syncman.sync() # TODO: Should we move these to other modules? # This would require moving around other type definitions proc installValidatorApiHandlers(rpcServer: RpcServer, node: BeaconNode) = discard func slotOrZero(time: BeaconTime): Slot = let exSlot = time.toSlot if exSlot.afterGenesis: exSlot.slot else: Slot(0) proc currentSlot(node: BeaconNode): Slot = node.beaconClock.now.slotOrZero proc connectedPeersCount(node: BeaconNode): int = libp2p_peers.value.int proc fromJson(n: JsonNode; argName: string; result: var Slot) = var i: int fromJson(n, argName, i) result = Slot(i) proc installBeaconApiHandlers(rpcServer: RpcServer, node: BeaconNode) = rpcServer.rpc("getBeaconHead") do () -> Slot: return node.currentSlot template requireOneOf(x, y: distinct Option) = if x.isNone xor y.isNone: raise newException(CatchableError, "Please specify one of " & astToStr(x) & " or " & astToStr(y)) template jsonResult(x: auto): auto = StringOfJson(Json.encode(x)) rpcServer.rpc("getBeaconBlock") do (slot: Option[Slot], root: Option[Eth2Digest]) -> StringOfJson: requireOneOf(slot, root) var blockHash: Eth2Digest if root.isSome: blockHash = root.get else: let foundRef = node.blockPool.getBlockByPreciseSlot(slot.get) if foundRef != nil: blockHash = foundRef.root else: return StringOfJson("null") let dbBlock = node.db.getBlock(blockHash) if dbBlock.isSome: return jsonResult(dbBlock.get) else: return StringOfJson("null") rpcServer.rpc("getBeaconState") do (slot: Option[Slot], root: Option[Eth2Digest]) -> StringOfJson: requireOneOf(slot, root) if slot.isSome: let blk = node.blockPool.head.blck.atSlot(slot.get) var tmpState = emptyStateData() node.blockPool.withState(tmpState, blk): return jsonResult(state) else: let state = node.db.getState(root.get) if state.isSome: return jsonResult(state.get) else: return StringOfJson("null") rpcServer.rpc("getNetworkPeerId") do () -> string: return $publicKey(node.network) rpcServer.rpc("getNetworkPeers") do () -> seq[string]: for peerId, peer in node.network.peerPool: result.add $peerId rpcServer.rpc("getNetworkEnr") do () -> string: return $node.network.discovery.localNode.record proc installDebugApiHandlers(rpcServer: RpcServer, node: BeaconNode) = rpcServer.rpc("getSpecPreset") do () -> JsonNode: var res = newJObject() genCode: for setting in BeaconChainConstants: let settingSym = ident($setting) settingKey = newLit(toLowerAscii($setting)) yield quote do: res[`settingKey`] = %`settingSym` return res proc installRpcHandlers(rpcServer: RpcServer, node: BeaconNode) = rpcServer.installValidatorApiHandlers(node) rpcServer.installBeaconApiHandlers(node) rpcServer.installDebugApiHandlers(node) proc run*(node: BeaconNode) = if node.rpcServer != nil: node.rpcServer.installRpcHandlers(node) node.rpcServer.start() waitFor node.network.subscribe(node.topicBeaconBlocks) do (signedBlock: SignedBeaconBlock): onBeaconBlock(node, signedBlock) do (signedBlock: SignedBeaconBlock) -> bool: let (afterGenesis, slot) = node.beaconClock.now.toSlot() if not afterGenesis: return false node.blockPool.isValidBeaconBlock(signedBlock, slot, {}) proc attestationHandler(attestation: Attestation) = # Avoid double-counting attestation-topic attestations on shared codepath # when they're reflected through beacon blocks beacon_attestations_received.inc() node.onAttestation(attestation) var attestationSubscriptions: seq[Future[void]] = @[] for it in 0'u64 ..< ATTESTATION_SUBNET_COUNT.uint64: closureScope: let ci = it attestationSubscriptions.add(node.network.subscribe( getAttestationTopic(node.forkDigest, ci), attestationHandler, proc(attestation: Attestation): bool = # https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/p2p-interface.md#attestation-subnets let (afterGenesis, slot) = node.beaconClock.now().toSlot() if not afterGenesis: return false node.attestationPool.isValidAttestation(attestation, slot, ci, {}))) waitFor allFutures(attestationSubscriptions) let t = node.beaconClock.now().toSlot() curSlot = if t.afterGenesis: t.slot else: GENESIS_SLOT nextSlot = curSlot + 1 # No earlier than GENESIS_SLOT + 1 fromNow = saturate(node.beaconClock.fromNow(nextSlot)) info "Scheduling first slot action", beaconTime = shortLog(node.beaconClock.now()), nextSlot = shortLog(nextSlot), fromNow = shortLog(fromNow), cat = "scheduling" addTimer(fromNow) do (p: pointer): asyncCheck node.onSlotStart(curSlot, nextSlot) let second = Moment.now() + chronos.seconds(1) discard setTimer(second) do (p: pointer): asyncCheck node.onSecond(second) node.syncLoop = runSyncLoop(node) runForever() var gPidFile: string proc createPidFile(filename: string) = createDir splitFile(filename).dir writeFile filename, $os.getCurrentProcessId() gPidFile = filename addQuitProc proc {.noconv.} = removeFile gPidFile proc start(node: BeaconNode) = # TODO: while it's nice to cheat by waiting for connections here, we # actually need to make this part of normal application flow - # losing all connections might happen at any time and we should be # prepared to handle it. waitFor node.connectToNetwork() let head = node.blockPool.head finalizedHead = node.blockPool.finalizedHead info "Starting beacon node", version = fullVersionStr, timeSinceFinalization = int64(finalizedHead.slot.toBeaconTime()) - int64(node.beaconClock.now()), headSlot = shortLog(head.blck.slot), headRoot = shortLog(head.blck.root), finalizedSlot = shortLog(finalizedHead.blck.slot), finalizedRoot = shortLog(finalizedHead.blck.root), SLOTS_PER_EPOCH, SECONDS_PER_SLOT, SPEC_VERSION, dataDir = node.config.dataDir.string, cat = "init", pcs = "start_beacon_node" let bs = BlockSlot(blck: head.blck, slot: head.blck.slot) node.blockPool.withState(node.blockPool.tmpState, bs): node.addLocalValidators(state[]) node.run() func formatGwei(amount: uint64): string = # TODO This is implemented in a quite a silly way. # Better routines for formatting decimal numbers # should exists somewhere else. let eth = amount div 1000000000 remainder = amount mod 1000000000 result = $eth if remainder != 0: result.add '.' result.add $remainder while result[^1] == '0': result.setLen(result.len - 1) when hasPrompt: from unicode import Rune import terminal, prompt proc providePromptCompletions*(line: seq[Rune], cursorPos: int): seq[string] = # TODO # The completions should be generated with the general-purpose command-line # parsing API of Confutils result = @[] proc processPromptCommands(p: ptr Prompt) {.thread.} = while true: var cmd = p[].readLine() case cmd of "quit": quit 0 else: p[].writeLine("Unknown command: " & cmd) proc initPrompt(node: BeaconNode) = if isatty(stdout) and node.config.statusBarEnabled: enableTrueColors() # TODO: nim-prompt seems to have threading issues at the moment # which result in sporadic crashes. We should introduce a # lock that guards the access to the internal prompt line # variable. # # var p = Prompt.init("nimbus > ", providePromptCompletions) # p.useHistoryFile() proc dataResolver(expr: string): string = # TODO: # We should introduce a general API for resolving dot expressions # such as `db.latest_block.slot` or `metrics.connected_peers`. # Such an API can be shared between the RPC back-end, CLI tools # such as ncli, a potential GraphQL back-end and so on. # The status bar feature would allow the user to specify an # arbitrary expression that is resolvable through this API. case expr.toLowerAscii of "connected_peers": $(node.connectedPeersCount) of "last_finalized_epoch": var head = node.blockPool.finalizedHead # TODO: Should we display a state root instead? $(head.slot.epoch) & " (" & shortLog(head.blck.root) & ")" of "epoch": $node.beaconClock.now.slotOrZero.epoch of "epoch_slot": $(node.beaconClock.now.slotOrZero mod SLOTS_PER_EPOCH) of "slots_per_epoch": $SLOTS_PER_EPOCH of "slot": $node.currentSlot of "slot_trailing_digits": var slotStr = $node.beaconClock.now.slotOrZero if slotStr.len > 3: slotStr = slotStr[^3..^1] slotStr of "attached_validators_balance": var balance = uint64(0) # TODO slow linear scan! for idx, b in node.blockPool.headState.data.data.balances: if node.getAttachedValidator( node.blockPool.headState.data.data[], ValidatorIndex(idx)) != nil: balance += b formatGwei(balance) else: # We ignore typos for now and just render the expression # as it was written. TODO: come up with a good way to show # an error message to the user. "$" & expr var statusBar = StatusBarView.init( node.config.statusBarContents, dataResolver) when compiles(defaultChroniclesStream.output.writer): defaultChroniclesStream.output.writer = proc (logLevel: LogLevel, msg: LogOutputStr) {.gcsafe, raises: [Defect].} = try: # p.hidePrompt erase statusBar # p.writeLine msg stdout.write msg render statusBar # p.showPrompt except Exception as e: # render raises Exception logLoggingFailure(cstring(msg), e) proc statusBarUpdatesPollingLoop() {.async.} = while true: update statusBar await sleepAsync(chronos.seconds(1)) traceAsyncErrors statusBarUpdatesPollingLoop() # var t: Thread[ptr Prompt] # createThread(t, processPromptCommands, addr p) programMain: let banner = clientId & "\p" & copyrights & "\p\p" & nimBanner config = BeaconNodeConf.load(version = banner, copyrightBanner = banner) when compiles(defaultChroniclesStream.output.writer): defaultChroniclesStream.output.writer = proc (logLevel: LogLevel, msg: LogOutputStr) {.gcsafe, raises: [Defect].} = try: stdout.write(msg) except IOError as err: logLoggingFailure(cstring(msg), err) randomize() if config.logLevel != LogLevel.NONE: setLogLevel(config.logLevel) ## Ctrl+C handling proc controlCHandler() {.noconv.} = when defined(windows): # workaround for https://github.com/nim-lang/Nim/issues/4057 setupForeignThreadGc() debug "Shutting down after having received SIGINT" quit(QuitFailure) setControlCHook(controlCHandler) case config.cmd of createTestnet: var deposits: seq[Deposit] for i in config.firstValidator.int ..< config.totalValidators.int: let depositFile = config.validatorsDir / validatorFileBaseName(i) & ".deposit.json" try: deposits.add Json.loadFile(depositFile, Deposit) except SerializationError as err: stderr.write "Error while loading a deposit file:\n" stderr.write err.formatMsg(depositFile), "\n" stderr.write "Please regenerate the deposit files by running makeDeposits again\n" quit 1 let startTime = uint64(times.toUnix(times.getTime()) + config.genesisOffset) outGenesis = config.outputGenesis.string eth1Hash = if config.web3Url.len == 0: eth1BlockHash else: waitFor getLatestEth1BlockHash(config.web3Url) var initialState = initialize_beacon_state_from_eth1( eth1Hash, startTime, deposits, {skipBlsValidation, skipMerkleValidation}) # https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#create-genesis-state initialState.genesis_time = startTime doAssert initialState.validators.len > 0 let outGenesisExt = splitFile(outGenesis).ext if cmpIgnoreCase(outGenesisExt, ".json") == 0: Json.saveFile(outGenesis, initialState, pretty = true) echo "Wrote ", outGenesis let outSszGenesis = outGenesis.changeFileExt "ssz" SSZ.saveFile(outSszGenesis, initialState) echo "Wrote ", outSszGenesis let bootstrapFile = config.outputBootstrapFile.string if bootstrapFile.len > 0: let networkKeys = getPersistentNetKeys(config) metadata = getPersistentNetMetadata(config) bootstrapEnr = enr.Record.init( 1, # sequence number networkKeys.seckey.asEthKey, some(config.bootstrapAddress), config.bootstrapPort, config.bootstrapPort, [toFieldPair("eth2", SSZ.encode(enrForkIdFromState initialState[])), toFieldPair("attnets", SSZ.encode(metadata.attnets))]) writeFile(bootstrapFile, bootstrapEnr.toURI) echo "Wrote ", bootstrapFile of importValidator: template reportFailureFor(keyExpr) = error "Failed to import validator key", key = keyExpr programResult = 1 if config.keyFiles.len == 0: stderr.write "Please specify at least one keyfile to import." quit 1 for keyFile in config.keyFiles: try: saveValidatorKey(keyFile.string.extractFilename, readFile(keyFile.string), config) except: reportFailureFor keyFile.string of noCommand: debug "Launching beacon node", version = fullVersionStr, cmdParams = commandLineParams(), config createPidFile(config.dataDir.string / "beacon_node.pid") var node = waitFor BeaconNode.init(config) when hasPrompt: initPrompt(node) when useInsecureFeatures: if config.metricsEnabled: let metricsAddress = config.metricsAddress info "Starting metrics HTTP server", address = metricsAddress, port = config.metricsPort metrics.startHttpServer($metricsAddress, config.metricsPort) if node.nickname != "": dynamicLogScope(node = node.nickname): node.start() else: node.start() of makeDeposits: createDir(config.depositsDir) let quickstartDeposits = generateDeposits( config.totalQuickstartDeposits, config.depositsDir, false) randomDeposits = generateDeposits( config.totalRandomDeposits, config.depositsDir, true, firstIdx = config.totalQuickstartDeposits) if config.web3Url.len > 0 and config.depositContractAddress.len > 0: if config.minDelay > config.maxDelay: echo "The minimum delay should not be larger than the maximum delay" quit 1 var delayGenerator: DelayGenerator if config.maxDelay > 0.0: delayGenerator = proc (): chronos.Duration {.gcsafe.} = chronos.milliseconds (rand(config.minDelay..config.maxDelay)*1000).int info "Sending deposits", web3 = config.web3Url, depositContract = config.depositContractAddress waitFor sendDeposits( quickstartDeposits & randomDeposits, config.web3Url, config.depositContractAddress, config.depositPrivateKey, delayGenerator) of query: case config.queryCmd of QueryCmd.nimQuery: # TODO: This will handle a simple subset of Nim using # dot syntax and `[]` indexing. echo "nim query: ", config.nimQueryExpression of QueryCmd.get: let pathFragments = config.getQueryPath.split('/', maxsplit = 1) let bytes = case pathFragments[0] of "genesis_state": readFile(config.dataDir/genesisFile).string.toBytes() else: stderr.write config.getQueryPath & " is not a valid path" quit 1 let navigator = DynamicSszNavigator.init(bytes, BeaconState) echo navigator.navigatePath(pathFragments[1 .. ^1]).toJson