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/
vm.go
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/
vm.go
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// Copyright 2017 Monax Industries Limited
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package evm
import (
"bytes"
"encoding/binary"
"fmt"
"io/ioutil"
"math/big"
"strings"
"github.com/hyperledger/burrow/execution/evm/abi"
"github.com/hyperledger/burrow/acm"
"github.com/hyperledger/burrow/acm/acmstate"
. "github.com/hyperledger/burrow/binary"
"github.com/hyperledger/burrow/crypto"
"github.com/hyperledger/burrow/crypto/sha3"
"github.com/hyperledger/burrow/execution/errors"
. "github.com/hyperledger/burrow/execution/evm/asm"
"github.com/hyperledger/burrow/execution/exec"
"github.com/hyperledger/burrow/logging"
"github.com/hyperledger/burrow/permission"
"github.com/hyperledger/burrow/txs"
)
const (
DataStackInitialCapacity = 1024
MaximumAllowedBlockLookBack = 256
uint64Length = 8
)
type Params struct {
BlockHeight uint64
BlockTime int64
GasLimit uint64
CallStackMaxDepth uint64
DataStackInitialCapacity uint64
DataStackMaxDepth uint64
}
type VM struct {
memoryProvider func(errors.Sink) Memory
params Params
origin crypto.Address
nonce []byte
stackDepth uint64
logger *logging.Logger
debugOpcodes bool
dumpTokens bool
sequence uint64
}
// Create a new EVM instance. Nonce is required to be globally unique (nearly almost surely) to avoid duplicate
// addresses for EVM created accounts. In Burrow we use TxHash for this but a random nonce or sequence number could be
// used.
func NewVM(params Params, origin crypto.Address, nonce []byte, logger *logging.Logger, options ...func(*VM)) *VM {
vm := &VM{
memoryProvider: DefaultDynamicMemoryProvider,
params: params,
origin: origin,
stackDepth: 0,
nonce: nonce,
logger: logger.WithScope("NewVM"),
}
for _, option := range options {
option(vm)
}
return vm
}
func (vm *VM) Debugf(format string, a ...interface{}) {
// Uncomment for quick and dirty debug
//fmt.Printf(format, a...)
if vm.debugOpcodes {
vm.logger.TraceMsg(fmt.Sprintf(format, a...), "tag", "DebugOpcodes")
}
}
// CONTRACT: it is the duty of the contract writer to call known permissions
// we do not convey if a permission is not set
// (unlike in state/execution, where we guarantee HasPermission is called
// on known permissions and panics else)
// If the perm is not defined in the acc nor set by default in GlobalPermissions,
// this function returns false.
func HasPermission(st Interface, address crypto.Address, perm permission.PermFlag) bool {
globalPerms := st.GetPermissions(acm.GlobalPermissionsAddress)
accPerms := st.GetPermissions(address)
perms := accPerms.Base.Compose(globalPerms.Base)
value, err := perms.Get(perm)
if err != nil {
return false
}
return value
}
func EnsurePermission(st Interface, address crypto.Address, perm permission.PermFlag) {
if !HasPermission(st, address, perm) {
st.PushError(errors.PermissionDenied{
Address: address,
Perm: perm,
})
}
}
func (vm *VM) fireCallEvent(eventSink EventSink, callType exec.CallType, errProvider errors.Provider, output *[]byte,
callerAddress, calleeAddress crypto.Address, input []byte, value uint64, gas *uint64, errSink errors.Sink) {
// fire the post call event (including exception if applicable)
eventErr := eventSink.Call(&exec.CallEvent{
CallType: callType,
CallData: &exec.CallData{
Caller: callerAddress,
Callee: calleeAddress,
Data: input,
Value: value,
Gas: *gas,
},
Origin: vm.origin,
StackDepth: vm.stackDepth,
Return: *output,
}, errors.AsException(errProvider.Error()))
errSink.PushError(eventErr)
}
// Initiate an EVM call against the provided state pushing events to eventSink. code should contain the EVM bytecode,
// input the CallData (readable by CALLDATALOAD), value the amount of native token to transfer with the call
// an quantity metering the number of computational steps available to the execution according to the gas schedule.
func (vm *VM) Call(callState Interface, eventSink EventSink, caller, callee crypto.Address, code,
input []byte, value uint64, gas *uint64) (output []byte, err errors.CodedError) {
// Always return output - we may have a reverted exception for which the return is meaningful
output, err = vm.call(callState, eventSink, caller, callee, code, input, value, gas, exec.CallTypeCall)
if err == nil {
err = callState.Error()
}
return
}
func (vm *VM) call(callState Interface, eventSink EventSink, caller, callee crypto.Address, code,
input []byte, value uint64, gas *uint64, callType exec.CallType) (output []byte, err errors.CodedError) {
// fire the post call event (including exception if applicable) and make sure we return the accumulated call error
defer func() {
vm.fireCallEvent(eventSink, callType, callState, &output, caller, callee, input, value, gas, callState)
err = callState.Error()
}()
callState.PushError(transfer(callState, caller, callee, value))
callState.PushError(vm.ensureStackDepth())
// Early exit
if callState.Error() != nil {
return
}
if len(code) > 0 {
vm.stackDepth += 1
output = vm.execute(callState, eventSink, caller, callee, code, input, value, gas)
vm.stackDepth -= 1
if err != nil {
callState.PushError(err)
callState.PushError(transfer(callState, callee, caller, value))
}
}
return
}
// DelegateCall is executed by the DELEGATECALL opcode, introduced as off Ethereum Homestead.
// The intent of delegate call is to run the code of the callee in the storage context of the caller;
// while preserving the original caller to the previous callee.
// Different to the normal CALL or CALLCODE, the value does not need to be transferred to the callee.
func (vm *VM) delegateCall(callState Interface, eventSink EventSink, caller, callee crypto.Address,
code, input []byte, value uint64, gas *uint64,
callType exec.CallType) (output []byte, err errors.CodedError) {
// fire the post call event (including exception if applicable) and make sure we return the accumulated call error
defer func() {
vm.fireCallEvent(eventSink, callType, callState, &output, caller, callee, input, value, gas, callState)
err = callState.Error()
}()
// DelegateCall does not transfer the value to the callee.
callState.PushError(vm.ensureStackDepth())
// Early exit
if callState.Error() != nil {
return
}
if len(code) > 0 {
vm.stackDepth += 1
output = vm.execute(callState, eventSink, caller, callee, code, input, value, gas)
vm.stackDepth -= 1
}
return
}
// Try to deduct gasToUse from gasLeft. If ok return false, otherwise
// set err and return true.
func useGasNegative(gasLeft *uint64, gasToUse uint64, err errors.Sink) {
if *gasLeft >= gasToUse {
*gasLeft -= gasToUse
} else {
err.PushError(errors.ErrorCodeInsufficientGas)
}
}
// Executes the EVM code passed in the appropriate context
func (vm *VM) execute(callState Interface, eventSink EventSink, caller, callee crypto.Address,
code, input []byte, value uint64, gas *uint64) (returnData []byte) {
vm.Debugf("(%d) (%s) %s (code=%d) gas: %v (d) %X\n", vm.stackDepth, caller, callee, len(code), *gas, input)
logger := vm.logger.With("evm_nonce", vm.nonce)
if vm.dumpTokens {
dumpTokens(vm.nonce, caller, callee, code)
}
// Program counter - the index into code that tracks current instruction
pc := int64(0)
// Provide stack and memory storage - passing in the callState as an error provider
stack := NewStack(vm.params.DataStackInitialCapacity, vm.params.DataStackMaxDepth, gas, callState)
memory := vm.memoryProvider(callState)
for {
// Check for any error accrued to state
if callState.Error() != nil {
return
}
var op = codeGetOp(code, pc)
vm.Debugf("(pc) %-3d (op) %-14s (st) %-4d (gas) %d", pc, op.String(), stack.Len(), *gas)
// Use BaseOp gas.
useGasNegative(gas, GasBaseOp, callState)
switch op {
case ADD: // 0x01
x, y := stack.PopBigInt(), stack.PopBigInt()
sum := new(big.Int).Add(x, y)
res := stack.PushBigInt(sum)
vm.Debugf(" %v + %v = %v (%X)\n", x, y, sum, res)
case MUL: // 0x02
x, y := stack.PopBigInt(), stack.PopBigInt()
prod := new(big.Int).Mul(x, y)
res := stack.PushBigInt(prod)
vm.Debugf(" %v * %v = %v (%X)\n", x, y, prod, res)
case SUB: // 0x03
x, y := stack.PopBigInt(), stack.PopBigInt()
diff := new(big.Int).Sub(x, y)
res := stack.PushBigInt(diff)
vm.Debugf(" %v - %v = %v (%X)\n", x, y, diff, res)
case DIV: // 0x04
x, y := stack.PopBigInt(), stack.PopBigInt()
if y.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %x / %x = %v\n", x, y, 0)
} else {
div := new(big.Int).Div(x, y)
res := stack.PushBigInt(div)
vm.Debugf(" %v / %v = %v (%X)\n", x, y, div, res)
}
case SDIV: // 0x05
x, y := stack.PopBigIntSigned(), stack.PopBigIntSigned()
if y.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %x / %x = %v\n", x, y, 0)
} else {
div := new(big.Int).Div(x, y)
res := stack.PushBigInt(div)
vm.Debugf(" %v / %v = %v (%X)\n", x, y, div, res)
}
case MOD: // 0x06
x, y := stack.PopBigInt(), stack.PopBigInt()
if y.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %v %% %v = %v\n", x, y, 0)
} else {
mod := new(big.Int).Mod(x, y)
res := stack.PushBigInt(mod)
vm.Debugf(" %v %% %v = %v (%X)\n", x, y, mod, res)
}
case SMOD: // 0x07
x, y := stack.PopBigIntSigned(), stack.PopBigIntSigned()
if y.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %v %% %v = %v\n", x, y, 0)
} else {
mod := new(big.Int).Mod(x, y)
res := stack.PushBigInt(mod)
vm.Debugf(" %v %% %v = %v (%X)\n", x, y, mod, res)
}
case ADDMOD: // 0x08
x, y, z := stack.PopBigInt(), stack.PopBigInt(), stack.PopBigInt()
if z.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %v %% %v = %v\n", x, y, 0)
} else {
add := new(big.Int).Add(x, y)
mod := add.Mod(add, z)
res := stack.PushBigInt(mod)
vm.Debugf(" %v + %v %% %v = %v (%X)\n", x, y, z, mod, res)
}
case MULMOD: // 0x09
x, y, z := stack.PopBigInt(), stack.PopBigInt(), stack.PopBigInt()
if z.Sign() == 0 {
stack.Push(Zero256)
vm.Debugf(" %v %% %v = %v\n", x, y, 0)
} else {
mul := new(big.Int).Mul(x, y)
mod := mul.Mod(mul, z)
res := stack.PushBigInt(mod)
vm.Debugf(" %v * %v %% %v = %v (%X)\n", x, y, z, mod, res)
}
case EXP: // 0x0A
x, y := stack.PopBigInt(), stack.PopBigInt()
pow := new(big.Int).Exp(x, y, nil)
res := stack.PushBigInt(pow)
vm.Debugf(" %v ** %v = %v (%X)\n", x, y, pow, res)
case SIGNEXTEND: // 0x0B
back := stack.PopU64()
if back < Word256Length-1 {
stack.PushBigInt(SignExtend(back, stack.PopBigInt()))
}
case LT: // 0x10
x, y := stack.PopBigInt(), stack.PopBigInt()
if x.Cmp(y) < 0 {
stack.Push(One256)
vm.Debugf(" %v < %v = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %v < %v = %v\n", x, y, 0)
}
case GT: // 0x11
x, y := stack.PopBigInt(), stack.PopBigInt()
if x.Cmp(y) > 0 {
stack.Push(One256)
vm.Debugf(" %v > %v = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %v > %v = %v\n", x, y, 0)
}
case SLT: // 0x12
x, y := stack.PopBigIntSigned(), stack.PopBigIntSigned()
if x.Cmp(y) < 0 {
stack.Push(One256)
vm.Debugf(" %v < %v = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %v < %v = %v\n", x, y, 0)
}
case SGT: // 0x13
x, y := stack.PopBigIntSigned(), stack.PopBigIntSigned()
if x.Cmp(y) > 0 {
stack.Push(One256)
vm.Debugf(" %v > %v = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %v > %v = %v\n", x, y, 0)
}
case EQ: // 0x14
x, y := stack.Pop(), stack.Pop()
if bytes.Equal(x[:], y[:]) {
stack.Push(One256)
vm.Debugf(" %X == %X = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %X == %X = %v\n", x, y, 0)
}
case ISZERO: // 0x15
x := stack.Pop()
if x.IsZero() {
stack.Push(One256)
vm.Debugf(" %X == 0 = %v\n", x, 1)
} else {
stack.Push(Zero256)
vm.Debugf(" %X == 0 = %v\n", x, 0)
}
case AND: // 0x16
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] & y[i]
}
stack.Push(z)
vm.Debugf(" %X & %X = %X\n", x, y, z)
case OR: // 0x17
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] | y[i]
}
stack.Push(z)
vm.Debugf(" %X | %X = %X\n", x, y, z)
case XOR: // 0x18
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] ^ y[i]
}
stack.Push(z)
vm.Debugf(" %X ^ %X = %X\n", x, y, z)
case NOT: // 0x19
x := stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = ^x[i]
}
stack.Push(z)
vm.Debugf(" !%X = %X\n", x, z)
case BYTE: // 0x1A
idx := stack.Pop64()
val := stack.Pop()
res := byte(0)
if idx < 32 {
res = val[idx]
}
stack.Push64(int64(res))
vm.Debugf(" => 0x%X\n", res)
case SHL: //0x1B
shift, x := stack.PopBigInt(), stack.PopBigInt()
if shift.Cmp(Big256) >= 0 {
reset := big.NewInt(0)
stack.PushBigInt(reset)
vm.Debugf(" %v << %v = %v\n", x, shift, reset)
} else {
shiftedValue := x.Lsh(x, uint(shift.Uint64()))
stack.PushBigInt(shiftedValue)
vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
}
case SHR: //0x1C
shift, x := stack.PopBigInt(), stack.PopBigInt()
if shift.Cmp(Big256) >= 0 {
reset := big.NewInt(0)
stack.PushBigInt(reset)
vm.Debugf(" %v << %v = %v\n", x, shift, reset)
} else {
shiftedValue := x.Rsh(x, uint(shift.Uint64()))
stack.PushBigInt(shiftedValue)
vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
}
case SAR: //0x1D
shift, x := stack.PopBigInt(), stack.PopBigIntSigned()
if shift.Cmp(Big256) >= 0 {
reset := big.NewInt(0)
if x.Sign() < 0 {
reset.SetInt64(-1)
}
stack.PushBigInt(reset)
vm.Debugf(" %v << %v = %v\n", x, shift, reset)
} else {
shiftedValue := x.Rsh(x, uint(shift.Uint64()))
stack.PushBigInt(shiftedValue)
vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
}
case SHA3: // 0x20
useGasNegative(gas, GasSha3, callState)
offset, size := stack.PopBigInt(), stack.PopBigInt()
data := memory.Read(offset, size)
data = sha3.Sha3(data)
stack.PushBytes(data)
vm.Debugf(" => (%v) %X\n", size, data)
case ADDRESS: // 0x30
stack.Push(callee.Word256())
vm.Debugf(" => %X\n", callee)
case BALANCE: // 0x31
address := stack.PopAddress()
useGasNegative(gas, GasGetAccount, callState)
balance := callState.GetBalance(address)
stack.PushU64(balance)
vm.Debugf(" => %v (%X)\n", balance, address)
case ORIGIN: // 0x32
stack.Push(vm.origin.Word256())
vm.Debugf(" => %X\n", vm.origin)
case CALLER: // 0x33
stack.Push(caller.Word256())
vm.Debugf(" => %X\n", caller)
case CALLVALUE: // 0x34
stack.PushU64(value)
vm.Debugf(" => %v\n", value)
case CALLDATALOAD: // 0x35
offset := stack.Pop64()
data := subslice(input, offset, 32, callState)
res := LeftPadWord256(data)
stack.Push(res)
vm.Debugf(" => 0x%X\n", res)
case CALLDATASIZE: // 0x36
stack.Push64(int64(len(input)))
vm.Debugf(" => %d\n", len(input))
case CALLDATACOPY: // 0x37
memOff := stack.PopBigInt()
inputOff := stack.Pop64()
length := stack.Pop64()
data := subslice(input, inputOff, length, callState)
memory.Write(memOff, data)
vm.Debugf(" => [%v, %v, %v] %X\n", memOff, inputOff, length, data)
case CODESIZE: // 0x38
l := int64(len(code))
stack.Push64(l)
vm.Debugf(" => %d\n", l)
case CODECOPY: // 0x39
memOff := stack.PopBigInt()
codeOff := stack.Pop64()
length := stack.Pop64()
data := subslice(code, codeOff, length, callState)
memory.Write(memOff, data)
vm.Debugf(" => [%v, %v, %v] %X\n", memOff, codeOff, length, data)
case GASPRICE_DEPRECATED: // 0x3A
stack.Push(Zero256)
vm.Debugf(" => %X (GASPRICE IS DEPRECATED)\n", Zero256)
case EXTCODESIZE: // 0x3B
address := stack.PopAddress()
useGasNegative(gas, GasGetAccount, callState)
if callState.Exists(address) {
code := callState.GetEVMCode(address)
l := int64(len(code))
stack.Push64(l)
vm.Debugf(" => %d\n", l)
} else {
if _, ok := registeredNativeContracts[address]; !ok {
callState.PushError(errors.ErrorCodeUnknownAddress)
continue
}
vm.Debugf(" => returning code size of 1 to indicated existence of native contract at %X\n", address)
stack.Push(One256)
}
case EXTCODECOPY: // 0x3C
address := stack.PopAddress()
useGasNegative(gas, GasGetAccount, callState)
if !callState.Exists(address) {
if _, ok := registeredNativeContracts[address]; ok {
vm.Debugf(" => attempted to copy native contract at %v but this is not supported\n", address)
callState.PushError(errors.ErrorCodeNativeContractCodeCopy)
}
callState.PushError(errors.ErrorCodeUnknownAddress)
continue
}
code := callState.GetEVMCode(address)
memOff := stack.PopBigInt()
codeOff := stack.Pop64()
length := stack.Pop64()
data := subslice(code, codeOff, length, callState)
memory.Write(memOff, data)
vm.Debugf(" => [%v, %v, %v] %X\n", memOff, codeOff, length, data)
case RETURNDATASIZE: // 0x3D
stack.Push64(int64(len(returnData)))
vm.Debugf(" => %d\n", len(returnData))
case RETURNDATACOPY: // 0x3E
memOff, outputOff, length := stack.PopBigInt(), stack.PopBigInt(), stack.PopBigInt()
end := new(big.Int).Add(outputOff, length)
if end.BitLen() > 64 || uint64(len(returnData)) < end.Uint64() {
callState.PushError(errors.ErrorCodeReturnDataOutOfBounds)
continue
}
memory.Write(memOff, returnData)
vm.Debugf(" => [%v, %v, %v] %X\n", memOff, outputOff, length, returnData)
case EXTCODEHASH: // 0x3F
address := stack.PopAddress()
if !callState.Exists(address) {
// In case the account does not exist 0 is pushed to the stack.
stack.PushU64(0)
} else {
// keccak256 hash of a contract's code
var extcodehash Word256
codehash := callState.GetCodeHash(address)
if codehash != nil {
copy(extcodehash[:], codehash)
} else {
hash := sha3.NewKeccak256()
copy(extcodehash[:], hash.Sum(nil))
}
stack.Push(extcodehash)
}
case BLOCKHASH: // 0x40
blockNumber := stack.PopU64()
if blockNumber >= vm.params.BlockHeight {
vm.Debugf(" => attempted to get block hash of a non-existent block: %v", blockNumber)
callState.PushError(errors.ErrorCodeInvalidBlockNumber)
} else if vm.params.BlockHeight-blockNumber > MaximumAllowedBlockLookBack {
vm.Debugf(" => attempted to get block hash of a block %d outside of the allowed range "+
"(must be within %d blocks)", blockNumber, MaximumAllowedBlockLookBack)
callState.PushError(errors.ErrorCodeBlockNumberOutOfRange)
} else {
blockHash, err := callState.GetBlockHash(blockNumber)
if err != nil {
vm.Debugf(" => error attempted to get block hash: %v, %v", blockNumber, err)
callState.PushError(errors.ErrorCodeInvalidBlockNumber)
} else {
stack.Push(blockHash)
vm.Debugf(" => 0x%X\n", blockHash)
}
}
case COINBASE: // 0x41
stack.Push(Zero256)
vm.Debugf(" => 0x%X (NOT SUPPORTED)\n", stack.Peek().Bytes())
case TIMESTAMP: // 0x42
time := vm.params.BlockTime
stack.Push64(int64(time))
vm.Debugf(" => 0x%X\n", time)
case BLOCKHEIGHT: // 0x43
number := vm.params.BlockHeight
stack.PushU64(number)
vm.Debugf(" => 0x%X\n", number)
case GASLIMIT: // 0x45
stack.PushU64(vm.params.GasLimit)
vm.Debugf(" => %v\n", vm.params.GasLimit)
case POP: // 0x50
popped := stack.Pop()
vm.Debugf(" => 0x%X\n", popped)
case MLOAD: // 0x51
offset := stack.PopBigInt()
data := memory.Read(offset, BigWord256Length)
stack.Push(LeftPadWord256(data))
vm.Debugf(" => 0x%X @ 0x%X\n", data, offset)
case MSTORE: // 0x52
offset, data := stack.PopBigInt(), stack.Pop()
memory.Write(offset, data.Bytes())
vm.Debugf(" => 0x%X @ 0x%X\n", data, offset)
case MSTORE8: // 0x53
offset := stack.PopBigInt()
val64 := stack.Pop64()
val := byte(val64 & 0xFF)
memory.Write(offset, []byte{val})
vm.Debugf(" => [%v] 0x%X\n", offset, val)
case SLOAD: // 0x54
loc := stack.Pop()
data := LeftPadWord256(callState.GetStorage(callee, loc))
stack.Push(data)
vm.Debugf("%s {0x%X = 0x%X}\n", callee, loc, data)
case SSTORE: // 0x55
loc, data := stack.Pop(), stack.Pop()
useGasNegative(gas, GasStorageUpdate, callState)
callState.SetStorage(callee, loc, data.Bytes())
vm.Debugf("%s {0x%X := 0x%X}\n", callee, loc, data)
case JUMP: // 0x56
to := stack.Pop64()
vm.jump(code, to, &pc, callState)
continue
case JUMPI: // 0x57
pos := stack.Pop64()
cond := stack.Pop()
if !cond.IsZero() {
vm.jump(code, pos, &pc, callState)
continue
}
vm.Debugf(" ~> false\n")
case PC: // 0x58
stack.Push64(pc)
case MSIZE: // 0x59
// Note: Solidity will write to this offset expecting to find guaranteed
// free memory to be allocated for it if a subsequent MSTORE is made to
// this offset.
capacity := memory.Capacity()
stack.PushBigInt(capacity)
vm.Debugf(" => 0x%X\n", capacity)
case GAS: // 0x5A
stack.PushU64(*gas)
vm.Debugf(" => %X\n", *gas)
case JUMPDEST: // 0x5B
vm.Debugf("\n")
// Do nothing
case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
a := int64(op - PUSH1 + 1)
codeSegment := subslice(code, pc+1, a, callState)
res := LeftPadWord256(codeSegment)
stack.Push(res)
pc += a
vm.Debugf(" => 0x%X\n", res)
case DUP1, DUP2, DUP3, DUP4, DUP5, DUP6, DUP7, DUP8, DUP9, DUP10, DUP11, DUP12, DUP13, DUP14, DUP15, DUP16:
n := int(op - DUP1 + 1)
stack.Dup(n)
vm.Debugf(" => [%d] 0x%X\n", n, stack.Peek().Bytes())
case SWAP1, SWAP2, SWAP3, SWAP4, SWAP5, SWAP6, SWAP7, SWAP8, SWAP9, SWAP10, SWAP11, SWAP12, SWAP13, SWAP14, SWAP15, SWAP16:
n := int(op - SWAP1 + 2)
stack.Swap(n)
vm.Debugf(" => [%d] %X\n", n, stack.Peek())
case LOG0, LOG1, LOG2, LOG3, LOG4:
n := int(op - LOG0)
topics := make([]Word256, n)
offset, size := stack.PopBigInt(), stack.PopBigInt()
for i := 0; i < n; i++ {
topics[i] = stack.Pop()
}
data := memory.Read(offset, size)
callState.PushError(eventSink.Log(&exec.LogEvent{
Address: callee,
Topics: topics,
Data: data,
}))
vm.Debugf(" => T:%X D:%X\n", topics, data)
case CREATE, CREATE2: // 0xF0, 0xFB
returnData = nil
contractValue := stack.PopU64()
offset, size := stack.PopBigInt(), stack.PopBigInt()
input := memory.Read(offset, size)
// TODO charge for gas to create account _ the code length * GasCreateByte
useGasNegative(gas, GasCreateAccount, callState)
var newAccount crypto.Address
if op == CREATE {
vm.sequence++
nonce := make([]byte, txs.HashLength+uint64Length)
copy(nonce, vm.nonce)
binary.BigEndian.PutUint64(nonce[txs.HashLength:], vm.sequence)
newAccount = crypto.NewContractAddress(callee, nonce)
} else if op == CREATE2 {
salt := stack.Pop()
newAccount = crypto.NewContractAddress2(callee, salt, callState.GetEVMCode(callee))
}
// Check the CreateContract permission for this account
EnsurePermission(callState, callee, permission.CreateContract)
if callState.Error() != nil {
continue
}
// Establish a frame in which the putative account exists
childCallState := callState.NewCache()
create(childCallState, newAccount)
// Run the input to get the contract code.
// NOTE: no need to copy 'input' as per Call contract.
ret, callErr := vm.Call(childCallState, eventSink, callee, newAccount, input, input, contractValue, gas)
if callErr != nil {
stack.Push(Zero256)
// Note we both set the return buffer and return the result normally
returnData = ret
} else {
// Update the account with its initialised contract code
forebear := callState.GetForebear(callee)
childCallState.InitChildCode(newAccount, forebear, ret)
callState.PushError(childCallState.Sync())
stack.PushAddress(newAccount)
}
case CALL, CALLCODE, DELEGATECALL, STATICCALL: // 0xF1, 0xF2, 0xF4, 0xFA
returnData = nil
EnsurePermission(callState, callee, permission.Call)
if callState.Error() != nil {
continue
}
gasLimit := stack.PopU64()
address := stack.PopAddress()
// NOTE: for DELEGATECALL value is preserved from the original
// caller, as such it is not stored on stack as an argument
// for DELEGATECALL and should not be popped. Instead previous
// caller value is used. for CALL and CALLCODE value is stored
// on stack and needs to be overwritten from the given value.
if op != DELEGATECALL && op != STATICCALL {
value = stack.PopU64()
}
// inputs
inOffset, inSize := stack.PopBigInt(), stack.PopBigInt()
// outputs
retOffset := stack.PopBigInt()
retSize := stack.Pop64()
vm.Debugf(" => %v\n", address)
// Get the arguments from the memory
args := memory.Read(inOffset, inSize)
// Ensure that gasLimit is reasonable
if *gas < gasLimit {
// EIP150 - the 63/64 rule - rather than errors.CodedError we pass this specified fraction of the total available gas
gasLimit = *gas - *gas/64
}
// NOTE: we will return any used gas later.
*gas -= gasLimit
// Begin execution
var callErr errors.CodedError
// Establish a stack frame and perform the call
var childCallState Interface
if IsRegisteredNativeContract(address) {
// Native contract
childCallState = callState.NewCache()
returnData, callErr = ExecuteNativeContract(address, childCallState, callee, args, &gasLimit, logger)
childCallState.PushError(callErr)
// for now we fire the Call event. maybe later we'll fire more particulars
// NOTE: these fire call go_events and not particular go_events for eg name reg or permissions
vm.fireCallEvent(eventSink, exec.CallTypeSNative, childCallState, &returnData, callee, address, args, value,
&gasLimit, childCallState)
} else {
// EVM contract
useGasNegative(gas, GasGetAccount, callState)
// since CALL is used also for sending funds,
// acc may not exist yet. This is an errors.CodedError for
// CALLCODE, but not for CALL, though I don't think
// ethereum actually cares
if !callState.Exists(address) {
if op != CALL {
callState.PushError(errors.ErrorCodeUnknownAddress)
continue
}
// We're sending funds to a new account so we must create it first
createAccount(callState, callee, address)
if callState.Error() != nil {
continue
}
}
switch op {
case CALL:
childCallState = callState.NewCache()
returnData, callErr = vm.call(childCallState, eventSink, callee, address, callState.GetEVMCode(address),
args, value, &gasLimit, exec.CallTypeCall)
case CALLCODE:
childCallState = callState.NewCache()
returnData, callErr = vm.call(childCallState, eventSink, callee, callee, callState.GetEVMCode(address),
args, value, &gasLimit, exec.CallTypeCode)
case DELEGATECALL:
childCallState = callState.NewCache()
returnData, callErr = vm.delegateCall(childCallState, eventSink, caller, callee,
callState.GetEVMCode(address), args, value, &gasLimit, exec.CallTypeDelegate)
case STATICCALL:
childCallState = callState.NewCache(acmstate.ReadOnly)
returnData, callErr = vm.delegateCall(childCallState, NewLogFreeEventSink(eventSink),
callee, address, callState.GetEVMCode(address), args, value, &gasLimit, exec.CallTypeStatic)
default:
panic(fmt.Errorf("switch statement should be exhaustive so this should not have been reached"))
}
}
if callErr == nil {
// Sync error is a hard stop
callState.PushError(childCallState.Sync())
}
// Push result
if callErr != nil {
vm.Debugf("error from nested sub-call (depth: %v): %s\n", vm.stackDepth, callErr.Error())
// So we can return nested errors.CodedError if the top level return is an errors.CodedError
stack.Push(Zero256)
if callErr.ErrorCode() == errors.ErrorCodeExecutionReverted {
memory.Write(retOffset, RightPadBytes(returnData, int(retSize)))
}
} else {
stack.Push(One256)
// Should probably only be necessary when there is no return value and
// returnData is empty, but since EVM expects retSize to be respected this will
// defensively pad or truncate the portion of returnData to be returned.
memory.Write(retOffset, RightPadBytes(returnData, int(retSize)))
}
// Handle remaining gas.
*gas += gasLimit
vm.Debugf("resume %s (%v)\n", callee, gas)
case RETURN: // 0xF3
offset, size := stack.PopBigInt(), stack.PopBigInt()
output := memory.Read(offset, size)
vm.Debugf(" => [%v, %v] (%d) 0x%X\n", offset, size, len(output), output)
return output
case REVERT: // 0xFD
offset, size := stack.PopBigInt(), stack.PopBigInt()
output := memory.Read(offset, size)
vm.Debugf(" => [%v, %v] (%d) 0x%X\n", offset, size, len(output), output)
callState.PushError(newRevertException(output))
return output
case INVALID: // 0xFE
callState.PushError(errors.ErrorCodeExecutionAborted)
return nil
case SELFDESTRUCT: // 0xFF
receiver := stack.PopAddress()
useGasNegative(gas, GasGetAccount, callState)
if !callState.Exists(receiver) {
// If receiver address doesn't exist, try to create it
useGasNegative(gas, GasCreateAccount, callState)
createAccount(callState, callee, receiver)
if callState.Error() != nil {
continue
}
}
balance := callState.GetBalance(callee)
callState.AddToBalance(receiver, balance)
callState.RemoveAccount(callee)
vm.Debugf(" => (%X) %v\n", receiver[:4], balance)
return nil
case STOP: // 0x00
return nil
default:
vm.Debugf("(pc) %-3v Unknown opcode %v\n", pc, op)
callState.PushError(errors.Errorf("unknown opcode %v", op))
return nil
}
pc++
}
return
}
func createAccount(st Interface, creator, address crypto.Address) {
EnsurePermission(st, creator, permission.CreateAccount)
create(st, address)
}
func create(st Interface, address crypto.Address) {
if IsRegisteredNativeContract(address) {
st.PushError(errors.ErrorCodef(errors.ErrorCodeReservedAddress,
"cannot create account at %v because that address is reserved for a native contract", address))
}
st.CreateAccount(address)