go-ethereum/ethchain/vm.go
2014-07-11 16:04:09 +02:00

825 lines
18 KiB
Go

package ethchain
import (
"fmt"
"github.com/ethereum/eth-go/ethcrypto"
"github.com/ethereum/eth-go/ethlog"
"github.com/ethereum/eth-go/ethutil"
"math"
"math/big"
)
var vmlogger = ethlog.NewLogger("VM")
var (
GasStep = big.NewInt(1)
GasSha = big.NewInt(20)
GasSLoad = big.NewInt(20)
GasSStore = big.NewInt(100)
GasBalance = big.NewInt(20)
GasCreate = big.NewInt(100)
GasCall = big.NewInt(20)
GasMemory = big.NewInt(1)
GasData = big.NewInt(5)
GasTx = big.NewInt(500)
LogTyPretty byte = 0x1
LogTyDiff byte = 0x2
)
type Debugger interface {
BreakHook(step int, op OpCode, mem *Memory, stack *Stack, stateObject *StateObject) bool
StepHook(step int, op OpCode, mem *Memory, stack *Stack, stateObject *StateObject) bool
BreakPoints() []int64
SetCode(byteCode []byte)
}
type Vm struct {
// Stack for processing contracts
stack *Stack
// non-persistent key/value memory storage
mem map[string]*big.Int
vars RuntimeVars
state *State
stateManager *StateManager
Verbose bool
logTy byte
logStr string
err error
// Debugging
Dbg Debugger
BreakPoints []int64
Stepping bool
Fn string
}
type RuntimeVars struct {
Origin []byte
Block *Block
BlockNumber *big.Int
PrevHash []byte
Coinbase []byte
Time int64
Diff *big.Int
TxData []string
Value *big.Int
}
func (self *Vm) Printf(format string, v ...interface{}) *Vm {
if self.Verbose && self.logTy == LogTyPretty {
self.logStr += fmt.Sprintf(format, v...)
}
return self
}
func (self *Vm) Endl() *Vm {
if self.Verbose && self.logTy == LogTyPretty {
vmlogger.Debugln(self.logStr)
self.logStr = ""
}
return self
}
func NewVm(state *State, stateManager *StateManager, vars RuntimeVars) *Vm {
lt := LogTyPretty
if ethutil.Config.Diff {
lt = LogTyDiff
}
return &Vm{vars: vars, state: state, stateManager: stateManager, logTy: lt}
}
var Pow256 = ethutil.BigPow(2, 256)
var isRequireError = false
func (vm *Vm) RunClosure(closure *Closure) (ret []byte, err error) {
// Recover from any require exception
defer func() {
if r := recover(); r != nil {
ret = closure.Return(nil)
err = fmt.Errorf("%v", r)
vmlogger.Errorln("vm err", err)
}
}()
// Debug hook
if vm.Dbg != nil {
vm.Dbg.SetCode(closure.Script)
}
// Don't bother with the execution if there's no code.
if len(closure.Script) == 0 {
return closure.Return(nil), nil
}
vmlogger.Debugf("(%s) %x gas: %v (d) %x\n", vm.Fn, closure.Address(), closure.Gas, closure.Args)
var (
op OpCode
mem = &Memory{}
stack = NewStack()
pc = big.NewInt(0)
step = 0
prevStep = 0
require = func(m int) {
if stack.Len() < m {
isRequireError = true
panic(fmt.Sprintf("%04v (%v) stack err size = %d, required = %d", pc, op, stack.Len(), m))
}
}
)
for {
prevStep = step
// The base for all big integer arithmetic
base := new(big.Int)
step++
// Get the memory location of pc
val := closure.Get(pc)
// Get the opcode (it must be an opcode!)
op = OpCode(val.Uint())
// XXX Leave this Println intact. Don't change this to the log system.
// Used for creating diffs between implementations
if vm.logTy == LogTyDiff {
b := pc.Bytes()
if len(b) == 0 {
b = []byte{0}
}
fmt.Printf("%x %x %x %x\n", closure.Address(), b, []byte{byte(op)}, closure.Gas.Bytes())
}
gas := new(big.Int)
addStepGasUsage := func(amount *big.Int) {
if amount.Cmp(ethutil.Big0) >= 0 {
gas.Add(gas, amount)
}
}
addStepGasUsage(GasStep)
var newMemSize uint64 = 0
switch op {
case STOP:
gas.Set(ethutil.Big0)
case SUICIDE:
gas.Set(ethutil.Big0)
case SLOAD:
gas.Set(GasSLoad)
case SSTORE:
var mult *big.Int
y, x := stack.Peekn()
val := closure.GetStorage(x)
if val.IsEmpty() && len(y.Bytes()) > 0 {
mult = ethutil.Big2
} else if !val.IsEmpty() && len(y.Bytes()) == 0 {
mult = ethutil.Big0
} else {
mult = ethutil.Big1
}
gas = new(big.Int).Mul(mult, GasSStore)
case BALANCE:
gas.Set(GasBalance)
case MSTORE:
require(2)
newMemSize = stack.Peek().Uint64() + 32
case MLOAD:
require(1)
newMemSize = stack.Peek().Uint64() + 32
case MSTORE8:
require(2)
newMemSize = stack.Peek().Uint64() + 1
case RETURN:
require(2)
newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-2].Uint64()
case SHA3:
require(2)
gas.Set(GasSha)
newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-2].Uint64()
case CALLDATACOPY:
require(3)
newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-3].Uint64()
case CODECOPY:
require(3)
newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-3].Uint64()
case CALL:
require(7)
gas.Set(GasCall)
addStepGasUsage(stack.data[stack.Len()-1])
x := stack.data[stack.Len()-6].Uint64() + stack.data[stack.Len()-7].Uint64()
y := stack.data[stack.Len()-4].Uint64() + stack.data[stack.Len()-5].Uint64()
newMemSize = uint64(math.Max(float64(x), float64(y)))
case CREATE:
require(3)
gas.Set(GasCreate)
newMemSize = stack.data[stack.Len()-2].Uint64() + stack.data[stack.Len()-3].Uint64()
}
newMemSize = (newMemSize + 31) / 32 * 32
if newMemSize > uint64(mem.Len()) {
m := GasMemory.Uint64() * (newMemSize - uint64(mem.Len())) / 32
addStepGasUsage(big.NewInt(int64(m)))
}
if !closure.UseGas(gas) {
err := fmt.Errorf("Insufficient gas for %v. req %v has %v", op, gas, closure.Gas)
closure.UseGas(closure.Gas)
return closure.Return(nil), err
}
vm.Printf("(pc) %-3d -o- %-14s", pc, op.String())
vm.Printf(" (g) %-3v (%v)", gas, closure.Gas)
mem.Resize(newMemSize)
switch op {
case LOG:
stack.Print()
mem.Print()
// 0x20 range
case ADD:
require(2)
x, y := stack.Popn()
vm.Printf(" %v + %v", y, x)
base.Add(y, x)
vm.Printf(" = %v", base)
// Pop result back on the stack
stack.Push(base)
case SUB:
require(2)
x, y := stack.Popn()
vm.Printf(" %v - %v", y, x)
base.Sub(y, x)
vm.Printf(" = %v", base)
// Pop result back on the stack
stack.Push(base)
case MUL:
require(2)
x, y := stack.Popn()
vm.Printf(" %v * %v", y, x)
base.Mul(y, x)
vm.Printf(" = %v", base)
// Pop result back on the stack
stack.Push(base)
case DIV:
require(2)
x, y := stack.Popn()
vm.Printf(" %v / %v", y, x)
base.Div(y, x)
vm.Printf(" = %v", base)
// Pop result back on the stack
stack.Push(base)
case SDIV:
require(2)
x, y := stack.Popn()
// n > 2**255
if x.Cmp(Pow256) > 0 {
x.Sub(Pow256, x)
}
if y.Cmp(Pow256) > 0 {
y.Sub(Pow256, y)
}
z := new(big.Int)
z.Div(x, y)
if z.Cmp(Pow256) > 0 {
z.Sub(Pow256, z)
}
// Push result on to the stack
stack.Push(z)
case MOD:
require(2)
x, y := stack.Popn()
vm.Printf(" %v %% %v", y, x)
base.Mod(y, x)
vm.Printf(" = %v", base)
stack.Push(base)
case SMOD:
require(2)
x, y := stack.Popn()
// n > 2**255
if x.Cmp(Pow256) > 0 {
x.Sub(Pow256, x)
}
if y.Cmp(Pow256) > 0 {
y.Sub(Pow256, y)
}
z := new(big.Int)
z.Mod(x, y)
if z.Cmp(Pow256) > 0 {
z.Sub(Pow256, z)
}
// Push result on to the stack
stack.Push(z)
case EXP:
require(2)
x, y := stack.Popn()
vm.Printf(" %v ** %v", y, x)
base.Exp(y, x, Pow256)
vm.Printf(" = %v", base)
stack.Push(base)
case NEG:
require(1)
base.Sub(Pow256, stack.Pop())
stack.Push(base)
case LT:
require(2)
x, y := stack.Popn()
vm.Printf(" %v < %v", y, x)
// x < y
if y.Cmp(x) < 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case GT:
require(2)
x, y := stack.Popn()
vm.Printf(" %v > %v", y, x)
// x > y
if y.Cmp(x) > 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case SLT:
require(2)
x, y := stack.Popn()
vm.Printf(" %v < %v", y, x)
// x < y
if y.Cmp(x) < 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case SGT:
require(2)
x, y := stack.Popn()
vm.Printf(" %v > %v", y, x)
// x > y
if y.Cmp(x) > 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case EQ:
require(2)
x, y := stack.Popn()
vm.Printf(" %v == %v", y, x)
// x == y
if x.Cmp(y) == 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case NOT:
require(1)
x := stack.Pop()
if x.Cmp(ethutil.BigFalse) > 0 {
stack.Push(ethutil.BigFalse)
} else {
stack.Push(ethutil.BigTrue)
}
// 0x10 range
case AND:
require(2)
x, y := stack.Popn()
vm.Printf(" %v & %v", y, x)
stack.Push(base.And(y, x))
case OR:
require(2)
x, y := stack.Popn()
vm.Printf(" %v | %v", y, x)
stack.Push(base.Or(y, x))
case XOR:
require(2)
x, y := stack.Popn()
vm.Printf(" %v ^ %v", y, x)
stack.Push(base.Xor(y, x))
case BYTE:
require(2)
val, th := stack.Popn()
if th.Cmp(big.NewInt(32)) < 0 {
byt := big.NewInt(int64(val.Bytes()[th.Int64()]))
stack.Push(byt)
vm.Printf(" => 0x%x", byt.Bytes())
} else {
stack.Push(ethutil.BigFalse)
}
// 0x20 range
case SHA3:
require(2)
size, offset := stack.Popn()
data := ethcrypto.Sha3Bin(mem.Get(offset.Int64(), size.Int64()))
stack.Push(ethutil.BigD(data))
vm.Printf(" => %x", data)
// 0x30 range
case ADDRESS:
stack.Push(ethutil.BigD(closure.Address()))
vm.Printf(" => %x", closure.Address())
case BALANCE:
require(1)
addr := stack.Pop().Bytes()
balance := vm.state.GetBalance(addr)
stack.Push(balance)
vm.Printf(" => %v (%x)", balance, addr)
case ORIGIN:
stack.Push(ethutil.BigD(vm.vars.Origin))
vm.Printf(" => %v", vm.vars.Origin)
case CALLER:
caller := closure.caller.Address()
stack.Push(ethutil.BigD(caller))
vm.Printf(" => %x", caller)
case CALLVALUE:
stack.Push(vm.vars.Value)
vm.Printf(" => %v", vm.vars.Value)
case CALLDATALOAD:
require(1)
offset := stack.Pop().Int64()
data := make([]byte, 32)
if len(closure.Args) >= int(offset) {
l := int64(math.Min(float64(offset+32), float64(len(closure.Args))))
copy(data, closure.Args[offset:l])
}
vm.Printf(" => 0x%x", data)
stack.Push(ethutil.BigD(data))
case CALLDATASIZE:
l := int64(len(closure.Args))
stack.Push(big.NewInt(l))
vm.Printf(" => %d", l)
case CALLDATACOPY:
var (
size = int64(len(closure.Args))
mOff = stack.Pop().Int64()
cOff = stack.Pop().Int64()
l = stack.Pop().Int64()
)
if cOff > size {
cOff = 0
l = 0
} else if cOff+l > size {
l = 0
}
code := closure.Args[cOff : cOff+l]
mem.Set(mOff, l, code)
case CODESIZE:
l := big.NewInt(int64(len(closure.Script)))
stack.Push(l)
vm.Printf(" => %d", l)
case CODECOPY:
var (
size = int64(len(closure.Script))
mOff = stack.Pop().Int64()
cOff = stack.Pop().Int64()
l = stack.Pop().Int64()
)
if cOff > size {
cOff = 0
l = 0
} else if cOff+l > size {
l = 0
}
code := closure.Script[cOff : cOff+l]
mem.Set(mOff, l, code)
case GASPRICE:
stack.Push(closure.Price)
// 0x40 range
case PREVHASH:
stack.Push(ethutil.BigD(vm.vars.PrevHash))
case COINBASE:
stack.Push(ethutil.BigD(vm.vars.Coinbase))
case TIMESTAMP:
stack.Push(big.NewInt(vm.vars.Time))
case NUMBER:
stack.Push(vm.vars.BlockNumber)
case DIFFICULTY:
stack.Push(vm.vars.Diff)
case GASLIMIT:
// TODO
stack.Push(big.NewInt(0))
// 0x50 range
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 := big.NewInt(int64(op) - int64(PUSH1) + 1)
pc.Add(pc, ethutil.Big1)
data := closure.Gets(pc, a)
val := ethutil.BigD(data.Bytes())
// Push value to stack
stack.Push(val)
pc.Add(pc, a.Sub(a, big.NewInt(1)))
step += int(op) - int(PUSH1) + 1
vm.Printf(" => 0x%x", data.Bytes())
case POP:
require(1)
stack.Pop()
case DUP:
require(1)
stack.Push(stack.Peek())
vm.Printf(" => 0x%x", stack.Peek().Bytes())
case SWAP:
require(2)
x, y := stack.Popn()
stack.Push(y)
stack.Push(x)
case MLOAD:
require(1)
offset := stack.Pop()
val := ethutil.BigD(mem.Get(offset.Int64(), 32))
stack.Push(val)
vm.Printf(" => 0x%x", val.Bytes())
case MSTORE: // Store the value at stack top-1 in to memory at location stack top
require(2)
// Pop value of the stack
val, mStart := stack.Popn()
mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(val, 256))
vm.Printf(" => 0x%x", val)
case MSTORE8:
require(2)
val, mStart := stack.Popn()
//base.And(val, new(big.Int).SetInt64(0xff))
//mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(base, 256))
mem.store[mStart.Int64()] = byte(val.Int64() & 0xff)
vm.Printf(" => 0x%x", val)
case SLOAD:
require(1)
loc := stack.Pop()
val := closure.GetStorage(loc)
stack.Push(val.BigInt())
vm.Printf(" {0x%x : 0x%x}", loc.Bytes(), val.Bytes())
case SSTORE:
require(2)
val, loc := stack.Popn()
closure.SetStorage(loc, ethutil.NewValue(val))
// Add the change to manifest
vm.state.manifest.AddStorageChange(closure.Object(), loc.Bytes(), val)
vm.Printf(" {0x%x : 0x%x}", loc, val)
case JUMP:
require(1)
pc = stack.Pop()
// Reduce pc by one because of the increment that's at the end of this for loop
vm.Printf(" ~> %v", pc).Endl()
continue
case JUMPI:
require(2)
cond, pos := stack.Popn()
if cond.Cmp(ethutil.BigTrue) >= 0 {
pc = pos
vm.Printf(" ~> %v (t)", pc).Endl()
continue
} else {
vm.Printf(" (f)")
}
case PC:
stack.Push(pc)
case MSIZE:
stack.Push(big.NewInt(int64(mem.Len())))
case GAS:
stack.Push(closure.Gas)
// 0x60 range
case CREATE:
require(3)
var (
err error
value = stack.Pop()
size, offset = stack.Popn()
// Snapshot the current stack so we are able to
// revert back to it later.
snapshot = vm.state.Copy()
)
// Generate a new address
addr := ethcrypto.CreateAddress(closure.Address(), closure.N().Uint64())
for i := uint64(0); vm.state.GetStateObject(addr) != nil; i++ {
ethcrypto.CreateAddress(closure.Address(), closure.N().Uint64()+i)
}
closure.object.Nonce++
vm.Printf(" (*) %x", addr).Endl()
// Create a new contract
contract := vm.state.NewStateObject(addr)
if contract.Amount.Cmp(value) >= 0 {
closure.object.SubAmount(value)
contract.AddAmount(value)
// Set the init script
contract.initScript = mem.Get(offset.Int64(), size.Int64())
// Transfer all remaining gas to the new
// contract so it may run the init script
gas := new(big.Int).Set(closure.Gas)
closure.UseGas(closure.Gas)
// Create the closure
c := NewClosure(closure, contract, contract.initScript, vm.state, gas, closure.Price)
// Call the closure and set the return value as
// main script.
contract.script, err = Call(vm, c, nil)
} else {
err = fmt.Errorf("Insufficient funds to transfer value. Req %v, has %v", value, closure.object.Amount)
}
if err != nil {
stack.Push(ethutil.BigFalse)
// Revert the state as it was before.
vm.state.Set(snapshot)
vm.Printf("CREATE err %v", err)
} else {
stack.Push(ethutil.BigD(addr))
vm.Printf("CREATE success")
}
vm.Endl()
// Debug hook
if vm.Dbg != nil {
vm.Dbg.SetCode(closure.Script)
}
case CALL:
require(7)
vm.Endl()
gas := stack.Pop()
// Pop gas and value of the stack.
value, addr := stack.Popn()
// Pop input size and offset
inSize, inOffset := stack.Popn()
// Pop return size and offset
retSize, retOffset := stack.Popn()
// Get the arguments from the memory
args := mem.Get(inOffset.Int64(), inSize.Int64())
if closure.object.Amount.Cmp(value) < 0 {
vmlogger.Debugf("Insufficient funds to transfer value. Req %v, has %v", value, closure.object.Amount)
stack.Push(ethutil.BigFalse)
} else {
snapshot := vm.state.Copy()
stateObject := vm.state.GetOrNewStateObject(addr.Bytes())
closure.object.SubAmount(value)
stateObject.AddAmount(value)
// Create a new callable closure
c := NewClosure(closure, stateObject, stateObject.script, vm.state, gas, closure.Price)
// Executer the closure and get the return value (if any)
ret, err := Call(vm, c, args)
if err != nil {
stack.Push(ethutil.BigFalse)
vmlogger.Debugf("Closure execution failed. %v\n", err)
vm.state.Set(snapshot)
} else {
stack.Push(ethutil.BigTrue)
mem.Set(retOffset.Int64(), retSize.Int64(), ret)
}
// Debug hook
if vm.Dbg != nil {
vm.Dbg.SetCode(closure.Script)
}
}
case RETURN:
require(2)
size, offset := stack.Popn()
ret := mem.Get(offset.Int64(), size.Int64())
vm.Printf(" => (%d) 0x%x", len(ret), ret).Endl()
return closure.Return(ret), nil
case SUICIDE:
require(1)
receiver := vm.state.GetOrNewStateObject(stack.Pop().Bytes())
receiver.AddAmount(closure.object.Amount)
closure.object.MarkForDeletion()
fallthrough
case STOP: // Stop the closure
vm.Endl()
return closure.Return(nil), nil
default:
vmlogger.Debugf("(pc) %-3v Invalid opcode %x\n", pc, op)
fmt.Println(Code(closure.Script))
return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op)
}
pc.Add(pc, ethutil.Big1)
vm.Endl()
if vm.Dbg != nil {
for _, instrNo := range vm.Dbg.BreakPoints() {
if pc.Cmp(big.NewInt(instrNo)) == 0 {
vm.Stepping = true
if !vm.Dbg.BreakHook(prevStep, op, mem, stack, closure.Object()) {
return nil, nil
}
} else if vm.Stepping {
if !vm.Dbg.StepHook(prevStep, op, mem, stack, closure.Object()) {
return nil, nil
}
}
}
}
}
}