plugeth/ethchain/vm.go
2014-05-08 19:09:36 +02:00

539 lines
12 KiB
Go

package ethchain
import (
_ "bytes"
"fmt"
"github.com/ethereum/eth-go/ethutil"
_ "github.com/obscuren/secp256k1-go"
_ "math"
"math/big"
)
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)
)
func CalculateTxGas(initSize, scriptSize *big.Int) *big.Int {
totalGas := new(big.Int)
totalGas.Add(totalGas, GasCreate)
txTotalBytes := new(big.Int).Add(initSize, scriptSize)
txTotalBytes.Div(txTotalBytes, ethutil.Big32)
totalGas.Add(totalGas, new(big.Int).Mul(txTotalBytes, GasSStore))
return totalGas
}
type Vm struct {
txPool *TxPool
// Stack for processing contracts
stack *Stack
// non-persistent key/value memory storage
mem map[string]*big.Int
vars RuntimeVars
state *State
stateManager *StateManager
}
type RuntimeVars struct {
Origin []byte
BlockNumber uint64
PrevHash []byte
Coinbase []byte
Time int64
Diff *big.Int
TxData []string
Value *big.Int
}
func NewVm(state *State, stateManager *StateManager, vars RuntimeVars) *Vm {
return &Vm{vars: vars, state: state, stateManager: stateManager}
}
var Pow256 = ethutil.BigPow(2, 256)
var isRequireError = false
func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err error) {
// Recover from any require exception
defer func() {
if r := recover(); r != nil /*&& isRequireError*/ {
ret = closure.Return(nil)
err = fmt.Errorf("%v", r)
fmt.Println("vm err", err)
}
}()
ethutil.Config.Log.Debugf("[VM] Running closure %x\n", closure.object.Address())
// Memory for the current closure
mem := &Memory{}
// New stack (should this be shared?)
stack := NewStack()
require := func(m int) {
if stack.Len() < m {
isRequireError = true
panic(fmt.Sprintf("stack = %d, req = %d", stack.Len(), m))
}
}
// Instruction pointer
pc := big.NewInt(0)
// Current step count
step := 0
if ethutil.Config.Debug {
ethutil.Config.Log.Debugf("# op\n")
}
fmt.Println(closure.Script)
for {
// 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())
if ethutil.Config.Debug {
ethutil.Config.Log.Debugf("%-3d %-4s", pc, op.String())
}
gas := new(big.Int)
useGas := func(amount *big.Int) {
gas.Add(gas, amount)
}
switch op {
case oSHA3:
useGas(GasSha)
case oSLOAD:
useGas(GasSLoad)
case oSSTORE:
var mult *big.Int
y, x := stack.Peekn()
val := closure.GetMem(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
}
useGas(new(big.Int).Mul(mult, GasSStore))
case oBALANCE:
useGas(GasBalance)
case oCREATE:
require(3)
args := stack.Get(big.NewInt(3))
initSize := new(big.Int).Add(args[1], args[0])
useGas(CalculateTxGas(initSize, ethutil.Big0))
case oCALL:
useGas(GasCall)
case oMLOAD, oMSIZE, oMSTORE8, oMSTORE:
useGas(GasMemory)
default:
useGas(GasStep)
}
if closure.Gas.Cmp(gas) < 0 {
ethutil.Config.Log.Debugln("Insufficient gas", closure.Gas, gas)
return closure.Return(nil), fmt.Errorf("insufficient gas %v %v", closure.Gas, gas)
}
// Sub the amount of gas from the remaining
closure.Gas.Sub(closure.Gas, gas)
switch op {
case oLOG:
stack.Print()
mem.Print()
// 0x20 range
case oADD:
require(2)
x, y := stack.Popn()
// (x + y) % 2 ** 256
base.Add(x, y)
// Pop result back on the stack
stack.Push(base)
case oSUB:
require(2)
x, y := stack.Popn()
// (x - y) % 2 ** 256
base.Sub(x, y)
// Pop result back on the stack
stack.Push(base)
case oMUL:
require(2)
x, y := stack.Popn()
// (x * y) % 2 ** 256
base.Mul(x, y)
// Pop result back on the stack
stack.Push(base)
case oDIV:
require(2)
x, y := stack.Popn()
// floor(x / y)
base.Div(x, y)
// Pop result back on the stack
stack.Push(base)
case oSDIV:
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 oMOD:
require(2)
x, y := stack.Popn()
base.Mod(x, y)
stack.Push(base)
case oSMOD:
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 oEXP:
require(2)
x, y := stack.Popn()
base.Exp(x, y, Pow256)
stack.Push(base)
case oNEG:
require(1)
base.Sub(Pow256, stack.Pop())
stack.Push(base)
case oLT:
require(2)
x, y := stack.Popn()
// x < y
if x.Cmp(y) < 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oGT:
require(2)
x, y := stack.Popn()
// x > y
if x.Cmp(y) > 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oEQ:
require(2)
x, y := stack.Popn()
// x == y
if x.Cmp(y) == 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oNOT:
require(1)
x := stack.Pop()
if x.Cmp(ethutil.BigFalse) == 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
// 0x10 range
case oAND:
require(2)
x, y := stack.Popn()
if (x.Cmp(ethutil.BigTrue) >= 0) && (y.Cmp(ethutil.BigTrue) >= 0) {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oOR:
require(2)
x, y := stack.Popn()
if (x.Cmp(ethutil.BigInt0) >= 0) || (y.Cmp(ethutil.BigInt0) >= 0) {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oXOR:
require(2)
x, y := stack.Popn()
stack.Push(base.Xor(x, y))
case oBYTE:
require(2)
val, th := stack.Popn()
if th.Cmp(big.NewInt(32)) < 0 {
stack.Push(big.NewInt(int64(len(val.Bytes())-1) - th.Int64()))
} else {
stack.Push(ethutil.BigFalse)
}
// 0x20 range
case oSHA3:
require(2)
size, offset := stack.Popn()
data := mem.Get(offset.Int64(), size.Int64())
stack.Push(ethutil.BigD(data))
// 0x30 range
case oADDRESS:
stack.Push(ethutil.BigD(closure.Object().Address()))
case oBALANCE:
stack.Push(closure.object.Amount)
case oORIGIN:
stack.Push(ethutil.BigD(vm.vars.Origin))
case oCALLER:
stack.Push(ethutil.BigD(closure.Callee().Address()))
case oCALLVALUE:
stack.Push(vm.vars.Value)
case oCALLDATALOAD:
require(1)
offset := stack.Pop().Int64()
val := closure.Args[offset : offset+32]
stack.Push(ethutil.BigD(val))
case oCALLDATASIZE:
stack.Push(big.NewInt(int64(len(closure.Args))))
case oGASPRICE:
stack.Push(closure.Price)
// 0x40 range
case oPREVHASH:
stack.Push(ethutil.BigD(vm.vars.PrevHash))
case oCOINBASE:
stack.Push(ethutil.BigD(vm.vars.Coinbase))
case oTIMESTAMP:
stack.Push(big.NewInt(vm.vars.Time))
case oNUMBER:
stack.Push(big.NewInt(int64(vm.vars.BlockNumber)))
case oDIFFICULTY:
stack.Push(vm.vars.Diff)
case oGASLIMIT:
// TODO
stack.Push(big.NewInt(0))
// 0x50 range
case oPUSH1, oPUSH2, oPUSH3, oPUSH4, oPUSH5, oPUSH6, oPUSH7, oPUSH8, oPUSH9, oPUSH10, oPUSH11, oPUSH12, oPUSH13, oPUSH14, oPUSH15, oPUSH16, oPUSH17, oPUSH18, oPUSH19, oPUSH20, oPUSH21, oPUSH22, oPUSH23, oPUSH24, oPUSH25, oPUSH26, oPUSH27, oPUSH28, oPUSH29, oPUSH30, oPUSH31, oPUSH32:
a := big.NewInt(int64(op) - int64(oPUSH1) + 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++
case oPOP:
require(1)
stack.Pop()
case oDUP:
require(1)
stack.Push(stack.Peek())
case oSWAP:
require(2)
x, y := stack.Popn()
stack.Push(y)
stack.Push(x)
case oMLOAD:
require(1)
offset := stack.Pop()
stack.Push(ethutil.BigD(mem.Get(offset.Int64(), 32)))
case oMSTORE: // 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))
case oMSTORE8:
require(2)
val, mStart := stack.Popn()
base.And(val, new(big.Int).SetInt64(0xff))
mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(base, 256))
case oSLOAD:
require(1)
loc := stack.Pop()
val := closure.GetMem(loc)
stack.Push(val.BigInt())
case oSSTORE:
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)
case oJUMP:
require(1)
pc = stack.Pop()
// Reduce pc by one because of the increment that's at the end of this for loop
//pc.Sub(pc, ethutil.Big1)
continue
case oJUMPI:
require(2)
cond, pos := stack.Popn()
if cond.Cmp(ethutil.BigTrue) == 0 {
pc = pos
//pc.Sub(pc, ethutil.Big1)
continue
}
case oPC:
stack.Push(pc)
case oMSIZE:
stack.Push(big.NewInt(int64(mem.Len())))
// 0x60 range
case oCREATE:
require(3)
value := stack.Pop()
size, offset := stack.Popn()
// Generate a new address
addr := ethutil.CreateAddress(closure.callee.Address(), closure.callee.N())
// Create a new contract
contract := NewContract(addr, value, []byte(""))
// 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.Gas.Sub(closure.Gas, gas)
// Create the closure
closure := NewClosure(closure.callee,
closure.Object(),
contract.initScript,
vm.state,
gas,
closure.Price)
// Call the closure and set the return value as
// main script.
closure.Script, err = closure.Call(vm, nil, hook)
if err != nil {
stack.Push(ethutil.BigFalse)
} else {
stack.Push(ethutil.BigD(addr))
vm.state.SetStateObject(contract)
}
case oCALL:
require(7)
// Closure addr
addr := stack.Pop()
// Pop gas and value of the stack.
gas, value := stack.Popn()
// Pop input size and offset
inSize, inOffset := stack.Popn()
// Pop return size and offset
retSize, retOffset := stack.Popn()
// Make sure there's enough gas
if closure.Gas.Cmp(gas) < 0 {
stack.Push(ethutil.BigFalse)
break
}
// Get the arguments from the memory
args := mem.Get(inOffset.Int64(), inSize.Int64())
// Fetch the contract which will serve as the closure body
contract := vm.state.GetContract(addr.Bytes())
if contract != nil {
// Prepay for the gas
// If gas is set to 0 use all remaining gas for the next call
if gas.Cmp(big.NewInt(0)) == 0 {
// Copy
gas = new(big.Int).Set(closure.Gas)
}
closure.Gas.Sub(closure.Gas, gas)
// Add the value to the state object
contract.AddAmount(value)
// Create a new callable closure
closure := NewClosure(closure.Object(), contract, contract.script, vm.state, gas, closure.Price)
// Executer the closure and get the return value (if any)
ret, err := closure.Call(vm, args, hook)
if err != nil {
stack.Push(ethutil.BigFalse)
// Reset the changes applied this object
//contract.State().Reset()
} else {
stack.Push(ethutil.BigTrue)
}
vm.state.SetStateObject(contract)
mem.Set(retOffset.Int64(), retSize.Int64(), ret)
} else {
ethutil.Config.Log.Debugf("Contract %x not found\n", addr.Bytes())
stack.Push(ethutil.BigFalse)
}
case oRETURN:
require(2)
size, offset := stack.Popn()
ret := mem.Get(offset.Int64(), size.Int64())
return closure.Return(ret), nil
case oSUICIDE:
require(1)
receiver := vm.state.GetAccount(stack.Pop().Bytes())
receiver.AddAmount(closure.object.Amount)
vm.state.SetStateObject(receiver)
closure.object.state.Purge()
fallthrough
case oSTOP: // Stop the closure
return closure.Return(nil), nil
default:
ethutil.Config.Log.Debugf("Invalid opcode %x\n", op)
return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op)
}
pc.Add(pc, ethutil.Big1)
if hook != nil {
hook(step-1, op, mem, stack)
}
}
}