nimbus-eth2/beacon_chain/rpc/rpc_utils.nim
Jacek Sieka 0a4728a241
Handle access to historical data for which there is no state (#3217)
With checkpoint sync in particular, and state pruning in the future,
loading states or state-dependent data may fail. This PR adjusts the
code to allow this to be handled gracefully.

In particular, the new availability assumption is that states are always
available for the finalized checkpoint and newer, but may fail for
anything older.

The `tail` remains the point where state loading de-facto fails, meaning
that between the tail and the finalized checkpoint, we can still get
historical data (but code should be prepared to handle this as an
error).

However, to harden the code against long replays, several operations
which are assumed to work only with non-final data (such as gossip
verification and validator duties) now limit their search horizon to
post-finalized data.

* harden several state-dependent operations by logging an error instead
of introducing a panic when state loading fails
* `withState` -> `withUpdatedState` to differentiate from the other
`withState`
* `updateStateData` can now fail if no state is found in database - it
is also hardened against excessively long replays
* `getEpochRef` can now fail when replay fails
* reject blocks with invalid target root - they would be ignored
previously
* fix recursion bug in `isProposed`
2022-01-05 19:38:04 +01:00

95 lines
3.8 KiB
Nim

# beacon_chain
# Copyright (c) 2018-2021 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].}
import
std/[strutils, parseutils],
stew/byteutils,
../beacon_node, ../validators/validator_duties,
../consensus_object_pools/[block_pools_types, blockchain_dag],
../spec/datatypes/base,
../spec/[forks, helpers],
../spec/eth2_apis/[rpc_types, eth2_json_rpc_serialization]
export forks, rpc_types, eth2_json_rpc_serialization, blockchain_dag
template raiseNoAltairSupport*() =
raise (ref ValueError)(msg:
"The JSON-RPC interface does not support certain Altair operations due to changes in block structure - see https://nimbus.guide/rest-api.html for full altair support")
template withStateForStateId*(stateId: string, body: untyped): untyped =
let
bs = node.stateIdToBlockSlot(stateId)
template isState(state: StateData): bool =
state.blck.atSlot(getStateField(state.data, slot)) == bs
if isState(node.dag.headState):
withStateVars(node.dag.headState):
var cache {.inject, used.}: StateCache
body
else:
let rpcState = assignClone(node.dag.headState)
node.dag.withUpdatedState(rpcState[], bs) do:
body
do:
raise (ref CatchableError)(msg: "Trying to access pruned state")
proc parseRoot*(str: string): Eth2Digest {.raises: [Defect, ValueError].} =
Eth2Digest(data: hexToByteArray[32](str))
func checkEpochToSlotOverflow*(epoch: Epoch) {.raises: [Defect, ValueError].} =
const maxEpoch = compute_epoch_at_slot(not 0'u64)
if epoch >= maxEpoch:
raise newException(
ValueError, "Requesting epoch for which slot would overflow")
proc doChecksAndGetCurrentHead*(node: BeaconNode, slot: Slot): BlockRef {.raises: [Defect, CatchableError].} =
result = node.dag.head
if not node.isSynced(result):
raise newException(CatchableError, "Cannot fulfill request until node is synced")
# TODO for now we limit the requests arbitrarily by up to 2 epochs into the future
if result.slot + uint64(2 * SLOTS_PER_EPOCH) < slot:
raise newException(CatchableError, "Requesting way ahead of the current head")
proc doChecksAndGetCurrentHead*(node: BeaconNode, epoch: Epoch): BlockRef {.raises: [Defect, CatchableError].} =
checkEpochToSlotOverflow(epoch)
node.doChecksAndGetCurrentHead(epoch.compute_start_slot_at_epoch)
proc getBlockSlotFromString*(node: BeaconNode, slot: string): BlockSlot {.raises: [Defect, CatchableError].} =
if slot.len == 0:
raise newException(ValueError, "Empty slot number not allowed")
var parsed: BiggestUInt
if parseBiggestUInt(slot, parsed) != slot.len:
raise newException(ValueError, "Not a valid slot number")
let head = node.doChecksAndGetCurrentHead(parsed.Slot)
head.atSlot(parsed.Slot)
proc stateIdToBlockSlot*(node: BeaconNode, stateId: string): BlockSlot {.raises: [Defect, CatchableError].} =
case stateId:
of "head":
node.dag.head.atSlot()
of "genesis":
node.dag.genesis.atSlot()
of "finalized":
node.dag.finalizedHead
of "justified":
node.dag.head.atEpochStart(
getStateField(node.dag.headState.data, current_justified_checkpoint).epoch)
else:
if stateId.startsWith("0x"):
let stateRoot = parseRoot(stateId)
if stateRoot == getStateRoot(node.dag.headState.data):
node.dag.headState.blck.atSlot()
else:
# We don't have a state root -> BlockSlot mapping
raise (ref ValueError)(msg: "State not found")
else: # Parse as slot number
node.getBlockSlotFromString(stateId)