# Nimbus - Common entry point to the EVM from all different callers # # 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. {.push raises: [].} import eth/common/eth_types, stint, options, stew/ptrops, chronos, ".."/[vm_types, vm_state, vm_computation, vm_state_transactions], ".."/[vm_internals, vm_precompiles, vm_gas_costs], ".."/[db/accounts_cache], ../evm/async/operations, ../common/evmforks, ../core/eip4844, ./host_types when defined(evmc_enabled): import ../utils/utils import ./host_services type # Standard call parameters. CallParams* = object vmState*: BaseVMState # Chain, database, state, block, fork. forkOverride*: Option[EVMFork] # Default fork is usually correct. origin*: Option[HostAddress] # Default origin is `sender`. gasPrice*: GasInt # Gas price for this call. gasLimit*: GasInt # Maximum gas available for this call. sender*: HostAddress # Sender account. to*: HostAddress # Recipient (ignored when `isCreate`). isCreate*: bool # True if this is a contract creation. value*: HostValue # Value sent from sender to recipient. input*: seq[byte] # Input data. accessList*: AccessList # EIP-2930 (Berlin) tx access list. versionedHashes*: VersionedHashes # EIP-4844 (Cancun) blob versioned hashes noIntrinsic*: bool # Don't charge intrinsic gas. noAccessList*: bool # Don't initialise EIP-2929 access list. noGasCharge*: bool # Don't charge sender account for gas. noRefund*: bool # Don't apply gas refund/burn rule. sysCall*: bool # System call or ordinary call # Standard call result. (Some fields are beyond what EVMC can return, # and must only be used from tests because they will not always be set). CallResult* = object error*: string # Something if the call failed. gasUsed*: GasInt # Gas used by the call. contractAddress*: EthAddress # Created account (when `isCreate`). output*: seq[byte] # Output data. logEntries*: seq[Log] # Output logs. stack*: Stack # EVM stack on return (for test only). memory*: Memory # EVM memory on return (for test only). func isError*(cr: CallResult): bool = cr.error.len > 0 proc hostToComputationMessage*(msg: EvmcMessage): Message = Message( kind: CallKind(msg.kind.ord), depth: msg.depth, gas: msg.gas, sender: msg.sender.fromEvmc, contractAddress: msg.recipient.fromEvmc, codeAddress: msg.code_address.fromEvmc, value: msg.value.fromEvmc, # When input size is zero, input data pointer may be null. data: if msg.input_size <= 0: @[] else: @(makeOpenArray(msg.input_data, msg.input_size.int)), flags: msg.flags ) func intrinsicGas*(call: CallParams, vmState: BaseVMState): GasInt {.inline.} = # Compute the baseline gas cost for this transaction. This is the amount # of gas needed to send this transaction (but that is not actually used # for computation). let fork = vmState.fork var gas = gasFees[fork][GasTransaction] # EIP-2 (Homestead) extra intrinsic gas for contract creations. if call.isCreate: gas += gasFees[fork][GasTXCreate] if fork >= FkShanghai: gas += (gasFees[fork][GasInitcodeWord] * call.input.len.wordCount) # Input data cost, reduced in EIP-2028 (Istanbul). let gasZero = gasFees[fork][GasTXDataZero] let gasNonZero = gasFees[fork][GasTXDataNonZero] for b in call.input: gas += (if b == 0: gasZero else: gasNonZero) # EIP-2930 (Berlin) intrinsic gas for transaction access list. if fork >= FkBerlin: for account in call.accessList: gas += ACCESS_LIST_ADDRESS_COST gas += account.storageKeys.len * ACCESS_LIST_STORAGE_KEY_COST return gas proc initialAccessListEIP2929(call: CallParams) = # EIP2929 initial access list. let vmState = call.vmState if vmState.fork < FkBerlin: return vmState.mutateStateDB: db.accessList(call.sender) # For contract creations the EVM will add the contract address to the # access list itself, after calculating the new contract address. if not call.isCreate: db.accessList(call.to) # EIP3651 adds coinbase to the list of addresses that should start warm. if vmState.fork >= FkShanghai: db.accessList(vmState.coinbase) # Adds the correct subset of precompiles. for c in activePrecompiles(vmState.fork): db.accessList(c) # EIP2930 optional access list. for account in call.accessList: db.accessList(account.address) for key in account.storageKeys: db.accessList(account.address, UInt256.fromBytesBE(key)) proc setupHost(call: CallParams): TransactionHost = let vmState = call.vmState vmState.setupTxContext( TxContext( origin : call.origin.get(call.sender), gasPrice : call.gasPrice, versionedHashes: call.versionedHashes, blobBaseFee : getBlobGasprice(vmState.blockCtx.excessBlobGas), ), forkOverride = call.forkOverride ) var intrinsicGas: GasInt = 0 if not call.noIntrinsic: intrinsicGas = intrinsicGas(call, vmState) let host = TransactionHost( vmState: vmState, msg: EvmcMessage( kind: if call.isCreate: EVMC_CREATE else: EVMC_CALL, # Default: flags: {}, # Default: depth: 0, gas: call.gasLimit - intrinsicGas, recipient: call.to.toEvmc, code_address: call.to.toEvmc, sender: call.sender.toEvmc, value: call.value.toEvmc, ) # All other defaults in `TransactionHost` are fine. ) # Generate new contract address, prepare code, and update message `recipient` # with the contract address. This differs from the previous Nimbus EVM API. # Guarded under `evmc_enabled` for now so it doesn't break vm2. when defined(evmc_enabled): var code: seq[byte] if call.isCreate: let sender = call.sender let contractAddress = generateAddress(sender, call.vmState.readOnlyStateDB.getNonce(sender)) host.msg.recipient = contractAddress.toEvmc host.msg.input_size = 0 host.msg.input_data = nil code = call.input else: # TODO: Share the underlying data, but only after checking this does not # cause problems with the database. code = host.vmState.readOnlyStateDB.getCode(host.msg.code_address.fromEvmc) if call.input.len > 0: host.msg.input_size = call.input.len.csize_t # Must copy the data so the `host.msg.input_data` pointer # remains valid after the end of `call` lifetime. host.input = call.input host.msg.input_data = host.input[0].addr let cMsg = hostToComputationMessage(host.msg) host.computation = newComputation(vmState, call.sysCall, cMsg, code) host.code = system.move(code) else: if call.input.len > 0: host.msg.input_size = call.input.len.csize_t # Must copy the data so the `host.msg.input_data` pointer # remains valid after the end of `call` lifetime. host.input = call.input host.msg.input_data = host.input[0].addr let cMsg = hostToComputationMessage(host.msg) host.computation = newComputation(vmState, call.sysCall, cMsg) vmState.captureStart(host.computation, call.sender, call.to, call.isCreate, call.input, call.gasLimit, call.value) return host when defined(evmc_enabled): proc doExecEvmc(host: TransactionHost, call: CallParams) {.gcsafe, raises: [CatchableError].} = var callResult = evmcExecComputation(host) let c = host.computation if callResult.status_code == EVMC_SUCCESS: c.error = nil elif callResult.status_code == EVMC_REVERT: c.setError(EVMC_REVERT, false) else: c.setError(callResult.status_code, true) c.gasMeter.gasRemaining = callResult.gas_left c.msg.contractAddress = callResult.create_address.fromEvmc c.output = if callResult.output_size <= 0: @[] else: @(makeOpenArray(callResult.output_data, callResult.output_size.int)) if not callResult.release.isNil: {.gcsafe.}: try: callResult.release(callResult) except Exception as e: {.warning: "Kludge(BareExcept): `evmc_release_fn` in vendor package needs to be updated"} raiseAssert "Ooops evmcExecComputation(): name=" & $e.name & " msg=" & e.msg # FIXME-awkwardFactoring: the factoring out of the pre and # post parts feels awkward to me, but for now I'd really like # not to have too much duplicated code between sync and async. # --Adam proc prepareToRunComputation(host: TransactionHost, call: CallParams) = # Must come after `setupHost` for correct fork. if not call.noAccessList: initialAccessListEIP2929(call) # Charge for gas. if not call.noGasCharge: let vmState = host.vmState fork = vmState.fork vmState.mutateStateDB: db.subBalance(call.sender, call.gasLimit.u256 * call.gasPrice.u256) # EIP-4844 if fork >= FkCancun: let blobFee = calcDataFee(call.versionedHashes.len, vmState.blockCtx.excessBlobGas) db.subBalance(call.sender, blobFee) proc calculateAndPossiblyRefundGas(host: TransactionHost, call: CallParams): GasInt = let c = host.computation # EIP-3529: Reduction in refunds let MaxRefundQuotient = if host.vmState.fork >= FkLondon: 5.GasInt else: 2.GasInt # Calculated gas used, taking into account refund rules. if call.noRefund: result = c.gasMeter.gasRemaining elif not c.shouldBurnGas: let maxRefund = (call.gasLimit - c.gasMeter.gasRemaining) div MaxRefundQuotient let refund = min(c.getGasRefund(), maxRefund) c.gasMeter.returnGas(refund) result = c.gasMeter.gasRemaining # Refund for unused gas. if result > 0 and not call.noGasCharge: host.vmState.mutateStateDB: db.addBalance(call.sender, result.u256 * call.gasPrice.u256) proc finishRunningComputation(host: TransactionHost, call: CallParams): CallResult = let c = host.computation let gasRemaining = calculateAndPossiblyRefundGas(host, call) # evm gas used without intrinsic gas let gasUsed = host.msg.gas - gasRemaining host.vmState.captureEnd(c, c.output, gasUsed, c.errorOpt) if c.isError: result.error = c.error.info result.gasUsed = call.gasLimit - gasRemaining result.output = system.move(c.output) result.contractAddress = if call.isCreate: c.msg.contractAddress else: default(HostAddress) result.logEntries = host.vmState.stateDB.logEntries() result.stack = c.stack result.memory = c.memory proc runComputation*(call: CallParams): CallResult {.gcsafe, raises: [CatchableError].} = let host = setupHost(call) prepareToRunComputation(host, call) when defined(evmc_enabled): doExecEvmc(host, call) else: if host.computation.sysCall: execSysCall(host.computation) else: execComputation(host.computation) finishRunningComputation(host, call) # FIXME-duplicatedForAsync proc asyncRunComputation*(call: CallParams): Future[CallResult] {.async.} = # This has to come before the newComputation call inside setupHost. if not call.isCreate: await ifNecessaryGetCodeForAccounts(call.vmState, @[call.to.toEvmc.fromEvmc]) let host = setupHost(call) prepareToRunComputation(host, call) # FIXME-asyncAndEvmc: I'm not sure what to do with EVMC at the moment. # when defined(evmc_enabled): # doExecEvmc(host, call) # else: await asyncExecComputation(host.computation) return finishRunningComputation(host, call)