nimbus-eth1/nimbus/transaction/call_evm.nim

228 lines
8.3 KiB
Nim

# Nimbus - Various ways of calling the EVM
#
# Copyright (c) 2018-2021 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
std/[options, times],
chronicles,
chronos,
eth/[common/eth_types_rlp, trie/db],
stint,
".."/[vm_types, vm_state, vm_gas_costs, forks, constants],
".."/[db/db_chain, db/accounts_cache, chain_config],
./call_common
type
RpcCallData* = object
source* : Option[EthAddress]
to* : Option[EthAddress]
gasLimit* : Option[GasInt]
gasPrice* : Option[GasInt]
maxFee* : Option[GasInt]
maxPriorityFee*: Option[GasInt]
value* : Option[UInt256]
data* : seq[byte]
accessList* : AccessList
proc toCallParams(vmState: BaseVMState, cd: RpcCallData,
globalGasCap: GasInt, baseFee: Option[UInt256],
forkOverride = none(Fork)): CallParams =
# Reject invalid combinations of pre- and post-1559 fee styles
if cd.gasPrice.isSome and (cd.maxFee.isSome or cd.maxPriorityFee.isSome):
raise newException(ValueError, "both gasPrice and (maxFeePerGas or maxPriorityFeePerGas) specified")
# Set default gas & gas price if none were set
var gasLimit = globalGasCap
if gasLimit == 0:
gasLimit = GasInt(high(uint64) div 2)
if cd.gasLimit.isSome:
gasLimit = cd.gasLimit.get()
if globalGasCap != 0 and globalGasCap < gasLimit:
warn "Caller gas above allowance, capping", requested = gasLimit, cap = globalGasCap
gasLimit = globalGasCap
var gasPrice = cd.gasPrice.get(0.GasInt)
if baseFee.isSome:
# A basefee is provided, necessitating EIP-1559-type execution
let maxPriorityFee = cd.maxPriorityFee.get(0.GasInt)
let maxFee = cd.maxFee.get(0.GasInt)
# Backfill the legacy gasPrice for EVM execution, unless we're all zeroes
if maxPriorityFee > 0 or maxFee > 0:
let baseFee = baseFee.get().truncate(GasInt)
let priorityFee = min(maxPriorityFee, maxFee - baseFee)
gasPrice = priorityFee + baseFee
CallParams(
vmState: vmState,
forkOverride: forkOverride,
sender: cd.source.get(ZERO_ADDRESS),
to: cd.to.get(ZERO_ADDRESS),
isCreate: cd.to.isNone,
gasLimit: gasLimit,
gasPrice: gasPrice,
value: cd.value.get(0.u256),
input: cd.data,
accessList: cd.accessList
)
proc rpcCallEvm*(call: RpcCallData, header: BlockHeader, chainDB: BaseChainDB): CallResult =
const globalGasCap = 0 # TODO: globalGasCap should configurable by user
let topHeader = BlockHeader(
parentHash: header.blockHash,
timestamp: getTime().utc.toTime,
gasLimit: 0.GasInt, ## ???
fee: UInt256.none()) ## ???
let vmState = BaseVMState.new(topHeader, chainDB)
let params = toCallParams(vmState, call, globalGasCap, header.fee)
var dbTx = chainDB.db.beginTransaction()
defer: dbTx.dispose() # always dispose state changes
runComputation(params)
proc rpcEstimateGas*(cd: RpcCallData, header: BlockHeader, chainDB: BaseChainDB, gasCap: GasInt): GasInt =
# Binary search the gas requirement, as it may be higher than the amount used
let topHeader = BlockHeader(
parentHash: header.blockHash,
timestamp: getTime().utc.toTime,
gasLimit: 0.GasInt, ## ???
fee: UInt256.none()) ## ???
let vmState = BaseVMState.new(topHeader, chainDB)
let fork = chainDB.config.toFork(header.blockNumber)
let txGas = gasFees[fork][GasTransaction] # txGas always 21000, use constants?
var params = toCallParams(vmState, cd, gasCap, header.fee)
var
lo : GasInt = txGas - 1
hi : GasInt = cd.gasLimit.get(0.GasInt)
cap: GasInt
var dbTx = chainDB.db.beginTransaction()
defer: dbTx.dispose() # always dispose state changes
# Determine the highest gas limit can be used during the estimation.
if hi < txGas:
# block's gasLimit act as the gas ceiling
hi = header.gasLimit
# Normalize the max fee per gas the call is willing to spend.
var feeCap = cd.gasPrice.get(0.GasInt)
if cd.gasPrice.isSome and (cd.maxFee.isSome or cd.maxPriorityFee.isSome):
raise newException(ValueError, "both gasPrice and (maxFeePerGas or maxPriorityFeePerGas) specified")
elif cd.maxFee.isSome:
feeCap = cd.maxFee.get
# Recap the highest gas limit with account's available balance.
if feeCap > 0:
if cd.source.isNone:
raise newException(ValueError, "`from` can't be null")
let balance = vmState.readOnlyStateDB.getBalance(cd.source.get)
var available = balance
if cd.value.isSome:
let value = cd.value.get
if value > available:
raise newException(ValueError, "insufficient funds for transfer")
available -= value
let allowance = available div feeCap.u256
# If the allowance is larger than maximum GasInt, skip checking
if allowance < high(GasInt).u256 and hi > allowance.truncate(GasInt):
let transfer = cd.value.get(0.u256)
warn "Gas estimation capped by limited funds", original=hi, balance,
sent=transfer, maxFeePerGas=feeCap, fundable=allowance
hi = allowance.truncate(GasInt)
# Recap the highest gas allowance with specified gasCap.
if gasCap != 0 and hi > gasCap:
warn "Caller gas above allowance, capping", requested=hi, cap=gasCap
hi = gasCap
cap = hi
let intrinsicGas = intrinsicGas(params, fork)
# Create a helper to check if a gas allowance results in an executable transaction
proc executable(gasLimit: GasInt): bool =
if intrinsicGas > gasLimit:
# Special case, raise gas limit
return true
params.gasLimit = gasLimit
# TODO: bail out on consensus error similar to validateTransaction
runComputation(params).isError
# Execute the binary search and hone in on an executable gas limit
while lo+1 < hi:
let mid = (hi + lo) div 2
let failed = executable(mid)
if failed:
lo = mid
else:
hi = mid
# Reject the transaction as invalid if it still fails at the highest allowance
if hi == cap:
let failed = executable(hi)
if failed:
# TODO: provide more descriptive EVM error beside out of gas
# e.g. revert and other EVM errors
raise newException(ValueError, "gas required exceeds allowance " & $cap)
hi
proc callParamsForTx(tx: Transaction, sender: EthAddress, vmState: BaseVMState, fork: Fork): CallParams =
# Is there a nice idiom for this kind of thing? Should I
# just be writing this as a bunch of assignment statements?
result = CallParams(
vmState: vmState,
forkOverride: some(fork),
gasPrice: tx.gasPrice,
gasLimit: tx.gasLimit,
sender: sender,
to: tx.destination,
isCreate: tx.contractCreation,
value: tx.value,
input: tx.payload
)
if tx.txType > TxLegacy:
shallowCopy(result.accessList, tx.accessList)
proc callParamsForTest(tx: Transaction, sender: EthAddress, vmState: BaseVMState, fork: Fork): CallParams =
result = CallParams(
vmState: vmState,
forkOverride: some(fork),
gasPrice: tx.gasPrice,
gasLimit: tx.gasLimit,
sender: sender,
to: tx.destination,
isCreate: tx.contractCreation,
value: tx.value,
input: tx.payload,
noIntrinsic: true, # Don't charge intrinsic gas.
noRefund: true, # Don't apply gas refund/burn rule.
)
if tx.txType > TxLegacy:
shallowCopy(result.accessList, tx.accessList)
proc txCallEvm*(tx: Transaction, sender: EthAddress, vmState: BaseVMState, fork: Fork): GasInt =
let call = callParamsForTx(tx, sender, vmState, fork)
return runComputation(call).gasUsed
proc testCallEvm*(tx: Transaction, sender: EthAddress, vmState: BaseVMState, fork: Fork): CallResult =
let call = callParamsForTest(tx, sender, vmState, fork)
runComputation(call)
# FIXME-duplicatedForAsync
proc asyncTestCallEvm*(tx: Transaction, sender: EthAddress, vmState: BaseVMState, fork: Fork): Future[CallResult] {.async.} =
let call = callParamsForTest(tx, sender, vmState, fork)
return await asyncRunComputation(call)