nimbus-eth1/nimbus/evm/computation.nim

379 lines
12 KiB
Nim

# Nimbus
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.
import
".."/[db/accounts_cache, constants],
"."/[code_stream, memory, message, stack, state],
"."/[transaction_tracer, types],
./interpreter/[gas_meter, gas_costs, op_codes],
../common/[common, evmforks],
../utils/utils,
chronicles, chronos,
eth/[keys],
sets
export
common
{.push raises: [].}
logScope:
topics = "vm computation"
when defined(chronicles_log_level):
import stew/byteutils
when defined(evmc_enabled):
import
evmc/evmc,
evmc_helpers,
evmc_api,
stew/ranges/ptr_arith
export
evmc,
evmc_helpers,
evmc_api,
ptr_arith
const
evmc_enabled* = defined(evmc_enabled)
# ------------------------------------------------------------------------------
# Helpers
# ------------------------------------------------------------------------------
proc generateContractAddress(c: Computation, salt: ContractSalt): EthAddress =
if c.msg.kind == evmcCreate:
let creationNonce = c.vmState.readOnlyStateDB().getNonce(c.msg.sender)
result = generateAddress(c.msg.sender, creationNonce)
else:
result = generateSafeAddress(c.msg.sender, salt, c.msg.data)
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
template getCoinbase*(c: Computation): EthAddress =
when evmc_enabled:
c.host.getTxContext().block_coinbase
else:
c.vmState.coinbase
template getTimestamp*(c: Computation): int64 =
when evmc_enabled:
c.host.getTxContext().block_timestamp
else:
c.vmState.timestamp.toUnix
template getBlockNumber*(c: Computation): UInt256 =
when evmc_enabled:
c.host.getTxContext().block_number.u256
else:
c.vmState.blockNumber.blockNumberToVmWord
template getDifficulty*(c: Computation): DifficultyInt =
when evmc_enabled:
UInt256.fromEvmc c.host.getTxContext().block_prev_randao
else:
c.vmState.difficulty
template getGasLimit*(c: Computation): GasInt =
when evmc_enabled:
c.host.getTxContext().block_gas_limit.GasInt
else:
c.vmState.gasLimit
template getBaseFee*(c: Computation): UInt256 =
when evmc_enabled:
UInt256.fromEvmc c.host.getTxContext().block_base_fee
else:
c.vmState.baseFee
template getChainId*(c: Computation): uint =
when evmc_enabled:
UInt256.fromEvmc(c.host.getTxContext().chain_id).truncate(uint)
else:
c.vmState.com.chainId.uint
template getOrigin*(c: Computation): EthAddress =
when evmc_enabled:
c.host.getTxContext().tx_origin
else:
c.vmState.txOrigin
template getGasPrice*(c: Computation): GasInt =
when evmc_enabled:
UInt256.fromEvmc(c.host.getTxContext().tx_gas_price).truncate(GasInt)
else:
c.vmState.txGasPrice
proc getBlockHash*(c: Computation, number: UInt256): Hash256
{.gcsafe, raises: [CatchableError].} =
when evmc_enabled:
let
blockNumber = c.host.getTxContext().block_number.u256
ancestorDepth = blockNumber - number - 1
if ancestorDepth >= constants.MAX_PREV_HEADER_DEPTH:
return
if number >= blockNumber:
return
c.host.getBlockHash(number)
else:
let
blockNumber = c.vmState.blockNumber
ancestorDepth = blockNumber - number - 1
if ancestorDepth >= constants.MAX_PREV_HEADER_DEPTH:
return
if number >= blockNumber:
return
c.vmState.getAncestorHash(number.vmWordToBlockNumber)
template accountExists*(c: Computation, address: EthAddress): bool =
when evmc_enabled:
c.host.accountExists(address)
else:
if c.fork >= FkSpurious:
not c.vmState.readOnlyStateDB.isDeadAccount(address)
else:
c.vmState.readOnlyStateDB.accountExists(address)
template getStorage*(c: Computation, slot: UInt256): UInt256 =
when evmc_enabled:
c.host.getStorage(c.msg.contractAddress, slot)
else:
c.vmState.readOnlyStateDB.getStorage(c.msg.contractAddress, slot)
template getBalance*(c: Computation, address: EthAddress): UInt256 =
when evmc_enabled:
c.host.getBalance(address)
else:
c.vmState.readOnlyStateDB.getBalance(address)
template getCodeSize*(c: Computation, address: EthAddress): uint =
when evmc_enabled:
c.host.getCodeSize(address)
else:
uint(c.vmState.readOnlyStateDB.getCodeSize(address))
template getCodeHash*(c: Computation, address: EthAddress): Hash256 =
when evmc_enabled:
c.host.getCodeHash(address)
else:
let
db = c.vmState.readOnlyStateDB
if not db.accountExists(address) or db.isEmptyAccount(address):
default(Hash256)
else:
db.getCodeHash(address)
template selfDestruct*(c: Computation, address: EthAddress) =
when evmc_enabled:
c.host.selfDestruct(c.msg.contractAddress, address)
else:
c.execSelfDestruct(address)
template getCode*(c: Computation, address: EthAddress): seq[byte] =
when evmc_enabled:
c.host.copyCode(address)
else:
c.vmState.readOnlyStateDB.getCode(address)
proc newComputation*(vmState: BaseVMState, message: Message,
salt: ContractSalt = ZERO_CONTRACTSALT): Computation =
new result
result.vmState = vmState
result.msg = message
result.memory = Memory()
result.stack = newStack()
result.returnStack = @[]
result.gasMeter.init(message.gas)
if result.msg.isCreate():
result.msg.contractAddress = result.generateContractAddress(salt)
result.code = newCodeStream(message.data)
message.data = @[]
else:
result.code = newCodeStream(
vmState.readOnlyStateDB.getCode(message.codeAddress))
proc newComputation*(vmState: BaseVMState, message: Message, code: seq[byte]): Computation =
new result
result.vmState = vmState
result.msg = message
result.memory = Memory()
result.stack = newStack()
result.returnStack = @[]
result.gasMeter.init(message.gas)
result.code = newCodeStream(code)
template gasCosts*(c: Computation): untyped =
c.vmState.gasCosts
template fork*(c: Computation): untyped =
c.vmState.fork
proc isOriginComputation*(c: Computation): bool =
# Is this computation the computation initiated by a transaction
c.msg.sender == c.vmState.txOrigin
template isSuccess*(c: Computation): bool =
c.error.isNil
template isError*(c: Computation): bool =
not c.isSuccess
func shouldBurnGas*(c: Computation): bool =
c.isError and c.error.burnsGas
proc snapshot*(c: Computation) =
c.savePoint = c.vmState.stateDB.beginSavepoint()
proc commit*(c: Computation) =
c.vmState.stateDB.commit(c.savePoint)
proc dispose*(c: Computation) =
c.vmState.stateDB.safeDispose(c.savePoint)
c.savePoint = nil
proc rollback*(c: Computation) =
c.vmState.stateDB.rollback(c.savePoint)
proc setError*(c: Computation, msg: string, burnsGas = false) =
c.error = Error(info: msg, burnsGas: burnsGas)
proc writeContract*(c: Computation)
{.gcsafe, raises: [CatchableError].} =
template withExtra(tracer: untyped, args: varargs[untyped]) =
tracer args, newContract=($c.msg.contractAddress),
blockNumber=c.vmState.blockNumber,
parentHash=($c.vmState.parent.blockHash)
# In each check below, they are guarded by `len > 0`. This includes writing
# out the code, because the account already has zero-length code to handle
# nested calls (this is specified). May as well simplify other branches.
let (len, fork) = (c.output.len, c.fork)
if len == 0:
return
# EIP-3541 constraint (https://eips.ethereum.org/EIPS/eip-3541).
if fork >= FkLondon and c.output[0] == 0xEF.byte:
withExtra trace, "New contract code starts with 0xEF byte, not allowed by EIP-3541"
# TODO: Return `EVMC_CONTRACT_VALIDATION_FAILURE` (like Silkworm).
c.setError("EVMC_CONTRACT_VALIDATION_FAILURE", true)
return
# EIP-170 constraint (https://eips.ethereum.org/EIPS/eip-3541).
if fork >= FkSpurious and len > EIP170_MAX_CODE_SIZE:
withExtra trace, "New contract code exceeds EIP-170 limit",
codeSize=len, maxSize=EIP170_MAX_CODE_SIZE
# TODO: Return `EVMC_OUT_OF_GAS` (like Silkworm).
c.setError("EVMC_OUT_OF_GAS", true)
return
# Charge gas and write the code even if the code address is self-destructed.
# Non-empty code in a newly created, self-destructed account is possible if
# the init code calls `DELEGATECALL` or `CALLCODE` to other code which uses
# `SELFDESTRUCT`. This shows on Mainnet blocks 6001128..6001204, where the
# gas difference matters. The new code can be called later in the
# transaction too, before self-destruction wipes the account at the end.
let gasParams = GasParams(kind: Create, cr_memLength: len)
let codeCost = c.gasCosts[Create].c_handler(0.u256, gasParams).gasCost
if codeCost <= c.gasMeter.gasRemaining:
c.gasMeter.consumeGas(codeCost, reason = "Write new contract code")
c.vmState.mutateStateDB:
db.setCode(c.msg.contractAddress, c.output)
withExtra trace, "Writing new contract code"
return
if fork >= FkHomestead:
# EIP-2 (https://eips.ethereum.org/EIPS/eip-2).
# TODO: Return `EVMC_OUT_OF_GAS` (like Silkworm).
c.setError("EVMC_OUT_OF_GAS", true)
else:
# Before EIP-2, when out of gas for code storage, the account ends up with
# zero-length code and no error. No gas is charged. Code cited in EIP-2:
# https://github.com/ethereum/pyethereum/blob/d117c8f3fd93/ethereum/processblock.py#L304
# https://github.com/ethereum/go-ethereum/blob/401354976bb4/core/vm/instructions.go#L586
# The account already has zero-length code to handle nested calls.
withExtra trace, "New contract given empty code by pre-Homestead rules"
template chainTo*(c: Computation, toChild: typeof(c.child), after: untyped) =
c.child = toChild
c.continuation = proc() =
c.continuation = nil
after
# Register an async operation to be performed before the continuation is called.
template asyncChainTo*(c: Computation, asyncOperation: Future[void], after: untyped) =
c.pendingAsyncOperation = asyncOperation
c.continuation = proc() =
c.continuation = nil
after
proc merge*(c, child: Computation) =
c.gasMeter.refundGas(child.gasMeter.gasRefunded)
proc execSelfDestruct*(c: Computation, beneficiary: EthAddress)
{.gcsafe, raises: [CatchableError].} =
c.vmState.mutateStateDB:
let localBalance = c.getBalance(c.msg.contractAddress)
# Transfer to beneficiary
db.addBalance(beneficiary, localBalance)
# Zero the balance of the address being deleted.
# This must come after sending to beneficiary in case the
# contract named itself as the beneficiary.
db.setBalance(c.msg.contractAddress, 0.u256)
# Register the account to be deleted
db.selfDestruct(c.msg.contractAddress)
trace "SELFDESTRUCT",
contractAddress = c.msg.contractAddress.toHex,
localBalance = localBalance.toString,
beneficiary = beneficiary.toHex
proc addLogEntry*(c: Computation, log: Log) =
c.vmState.stateDB.addLogEntry(log)
proc getGasRefund*(c: Computation): GasInt =
if c.isSuccess:
result = c.gasMeter.gasRefunded
proc refundSelfDestruct*(c: Computation) =
let cost = gasFees[c.fork][RefundSelfDestruct]
let num = c.vmState.stateDB.selfDestructLen
c.gasMeter.refundGas(cost * num)
proc tracingEnabled*(c: Computation): bool =
TracerFlags.EnableTracing in c.vmState.tracer.flags
proc traceOpCodeStarted*(c: Computation, op: Op): int
{.gcsafe, raises: [CatchableError].} =
c.vmState.tracer.traceOpCodeStarted(c, op)
proc traceOpCodeEnded*(c: Computation, op: Op, lastIndex: int)
{.gcsafe, raises: [CatchableError].} =
c.vmState.tracer.traceOpCodeEnded(c, op, lastIndex)
proc traceError*(c: Computation)
{.gcsafe, raises: [CatchableError].} =
c.vmState.tracer.traceError(c)
proc prepareTracer*(c: Computation) =
c.vmState.tracer.prepare(c.msg.depth)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------