plugeth/ethchain/vm.go
obscuren c7d1924c34 sha
2014-06-09 21:35:56 +02:00

558 lines
13 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)
GasTx = big.NewInt(500)
)
func CalculateTxGas(initSize *big.Int) *big.Int {
totalGas := new(big.Int)
txTotalBytes := new(big.Int).Set(initSize)
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
prevStep := 0
if ethutil.Config.Debug {
ethutil.Config.Log.Debugf("# op\n")
}
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())
if ethutil.Config.Debug {
ethutil.Config.Log.Debugf("%-3d %-4s", pc, op.String())
}
gas := new(big.Int)
setStepGasUsage := func(amount *big.Int) {
gas.Add(gas, amount)
}
switch op {
case SHA3:
setStepGasUsage(GasSha)
case SLOAD:
setStepGasUsage(GasSLoad)
case SSTORE:
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
}
setStepGasUsage(new(big.Int).Mul(mult, GasSStore))
case BALANCE:
setStepGasUsage(GasBalance)
case CREATE:
require(3)
args := stack.Get(big.NewInt(3))
initSize := new(big.Int).Add(args[1], args[0])
setStepGasUsage(CalculateTxGas(initSize))
case CALL:
setStepGasUsage(GasCall)
case MLOAD, MSIZE, MSTORE8, MSTORE:
setStepGasUsage(GasMemory)
default:
setStepGasUsage(GasStep)
}
if !closure.UseGas(gas) {
ethutil.Config.Log.Debugln("Insufficient gas", closure.Gas, gas)
return closure.Return(nil), fmt.Errorf("insufficient gas %v %v", closure.Gas, gas)
}
switch op {
case LOG:
stack.Print()
mem.Print()
// 0x20 range
case ADD:
require(2)
x, y := stack.Popn()
// (x + y) % 2 ** 256
base.Add(x, y)
// Pop result back on the stack
stack.Push(base)
case SUB:
require(2)
x, y := stack.Popn()
// (x - y) % 2 ** 256
base.Sub(x, y)
// Pop result back on the stack
stack.Push(base)
case MUL:
require(2)
x, y := stack.Popn()
// (x * y) % 2 ** 256
base.Mul(x, y)
// Pop result back on the stack
stack.Push(base)
case DIV:
require(2)
x, y := stack.Popn()
// floor(x / y)
base.Div(x, y)
// 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()
base.Mod(x, y)
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()
base.Exp(x, y, Pow256)
stack.Push(base)
case NEG:
require(1)
base.Sub(Pow256, stack.Pop())
stack.Push(base)
case LT:
require(2)
x, y := stack.Popn()
// x < y
if x.Cmp(y) < 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case GT:
require(2)
x, y := stack.Popn()
// x > y
if x.Cmp(y) > 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case EQ:
require(2)
x, y := stack.Popn()
// 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.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
// 0x10 range
case AND:
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 OR:
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 XOR:
require(2)
x, y := stack.Popn()
stack.Push(base.Xor(x, y))
case BYTE:
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 SHA3:
require(2)
size, offset := stack.Popn()
data := ethutil.Sha3Bin(mem.Get(offset.Int64(), size.Int64()))
stack.Push(ethutil.BigD(data))
// 0x30 range
case ADDRESS:
stack.Push(ethutil.BigD(closure.Object().Address()))
case BALANCE:
stack.Push(closure.object.Amount)
case ORIGIN:
stack.Push(ethutil.BigD(vm.vars.Origin))
case CALLER:
stack.Push(ethutil.BigD(closure.Callee().Address()))
case CALLVALUE:
stack.Push(vm.vars.Value)
case CALLDATALOAD:
require(1)
offset := stack.Pop().Int64()
var data []byte
if len(closure.Args) >= int(offset+32) {
data = closure.Args[offset : offset+32]
} else {
data = []byte{0}
}
stack.Push(ethutil.BigD(data))
case CALLDATASIZE:
stack.Push(big.NewInt(int64(len(closure.Args))))
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(big.NewInt(int64(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
case POP:
require(1)
stack.Pop()
case DUP:
require(1)
stack.Push(stack.Peek())
case SWAP:
require(2)
x, y := stack.Popn()
stack.Push(y)
stack.Push(x)
case MLOAD:
require(1)
offset := stack.Pop()
stack.Push(ethutil.BigD(mem.Get(offset.Int64(), 32)))
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))
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))
case SLOAD:
require(1)
loc := stack.Pop()
val := closure.GetMem(loc)
//fmt.Println("get", val.BigInt(), "@", loc)
stack.Push(val.BigInt())
case SSTORE:
require(2)
val, loc := stack.Popn()
//fmt.Println("storing", val, "@", loc)
closure.SetStorage(loc, ethutil.NewValue(val))
// Add the change to manifest
vm.state.manifest.AddStorageChange(closure.Object(), loc.Bytes(), 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
//pc.Sub(pc, ethutil.Big1)
continue
case JUMPI:
require(2)
cond, pos := stack.Popn()
if cond.Cmp(ethutil.BigTrue) == 0 {
pc = pos
//pc.Sub(pc, ethutil.Big1)
continue
}
case PC:
stack.Push(pc)
case MSIZE:
stack.Push(big.NewInt(int64(mem.Len())))
// 0x60 range
case CREATE:
require(3)
value := stack.Pop()
size, offset := stack.Popn()
// Snapshot the current stack so we are able to
// revert back to it later.
snapshot := vm.state.Snapshot()
// 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.UseGas(gas)
// Create the closure
c := NewClosure(closure.callee,
closure.Object(),
contract.initScript,
vm.state,
gas,
closure.Price)
// Call the closure and set the return value as
// main script.
c.Script, gas, err = c.Call(vm, nil, hook)
if err != nil {
stack.Push(ethutil.BigFalse)
// Revert the state as it was before.
vm.state.Revert(snapshot)
} else {
stack.Push(ethutil.BigD(addr))
vm.state.UpdateStateObject(contract)
}
case CALL:
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())
snapshot := vm.state.Snapshot()
// Fetch the contract which will serve as the closure body
contract := vm.state.GetStateObject(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.UseGas(gas)
// Add the value to the state object
contract.AddAmount(value)
// Create a new callable closure
closure := NewClosure(closure, 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
vm.state.Revert(snapshot)
} else {
stack.Push(ethutil.BigTrue)
vm.state.UpdateStateObject(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 RETURN:
require(2)
size, offset := stack.Popn()
ret := mem.Get(offset.Int64(), size.Int64())
return closure.Return(ret), nil
case SUICIDE:
require(1)
receiver := vm.state.GetAccount(stack.Pop().Bytes())
receiver.AddAmount(closure.object.Amount)
vm.state.UpdateStateObject(receiver)
closure.object.state.Purge()
fallthrough
case STOP: // 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 {
if !hook(prevStep, op, mem, stack, closure.Object()) {
return nil, nil
}
}
}
}