plugeth/ethchain/vm.go

474 lines
10 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)
)
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
}
type RuntimeVars struct {
Origin []byte
BlockNumber uint64
PrevHash []byte
Coinbase []byte
Time int64
Diff *big.Int
TxData []string
}
func NewVm(state *State, vars RuntimeVars) *Vm {
return &Vm{vars: vars, state: state}
}
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 {
fmt.Println(r)
ret = closure.Return(nil)
err = fmt.Errorf("%v", r)
}
}()
// If the amount of gas supplied is less equal to 0
if closure.Gas.Cmp(big.NewInt(0)) <= 0 {
// TODO Do something
}
// Memory for the current closure
mem := &Memory{}
// New stack (should this be shared?)
stack := NewStack()
require := func(m int) {
if stack.Len()-1 > m {
isRequireError = true
panic(fmt.Sprintf("stack = %d, req = %d", stack.Len(), m))
}
}
// Instruction pointer
pc := big.NewInt(0)
// Current step count
step := 0
// The base for all big integer arithmetic
base := new(big.Int)
/*
if ethutil.Config.Debug {
ethutil.Config.Log.Debugf("# op\n")
}
*/
for {
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())
}
*/
// TODO Get each instruction cost properly
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(base.Mul(mult, GasSStore))
case oBALANCE:
useGas(GasBalance)
case oCREATE:
useGas(GasCreate)
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)
}
switch op {
case oLOG:
stack.Print()
mem.Print()
case oSTOP: // Stop the closure
return closure.Return(nil), nil
// 0x20 range
case oADD:
require(2)
x, y := stack.Popn()
// (x + y) % 2 ** 256
base.Add(x, y)
base.Mod(base, Pow256)
// 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)
base.Mod(base, Pow256)
// 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)
base.Mod(base, Pow256)
// 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.Value)
case oORIGIN:
stack.Push(ethutil.BigD(vm.vars.Origin))
case oCALLER:
stack.Push(ethutil.BigD(closure.Callee().Address()))
case oCALLVALUE:
// FIXME: Original value of the call, not the current value
stack.Push(closure.Value)
case oCALLDATA:
require(1)
offset := stack.Pop()
mem.Set(offset.Int64(), int64(len(closure.Args)), closure.Args)
case oCALLDATASIZE:
stack.Push(big.NewInt(int64(len(closure.Args))))
case oGASPRICE:
// TODO
// 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
// 0x50 range
case oPUSH: // Push PC+1 on to the stack
pc.Add(pc, ethutil.Big1)
data := closure.Gets(pc, big.NewInt(32))
val := ethutil.BigD(data.Bytes())
// Push value to stack
stack.Push(val)
pc.Add(pc, big.NewInt(31))
step++
case oPUSH20:
pc.Add(pc, ethutil.Big1)
data := closure.Gets(pc, big.NewInt(20))
val := ethutil.BigD(data.Bytes())
// Push value to stack
stack.Push(val)
pc.Add(pc, big.NewInt(19))
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.SetMem(loc, ethutil.NewValue(val))
case oJUMP:
require(1)
pc = stack.Pop()
case oJUMPI:
require(2)
cond, pos := stack.Popn()
if cond.Cmp(ethutil.BigTrue) == 0 {
pc = pos
}
case oPC:
stack.Push(pc)
case oMSIZE:
stack.Push(big.NewInt(int64(mem.Len())))
// 0x60 range
case oCREATE:
case oCALL:
require(8)
// 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()
// 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())
// Create a new callable closure
closure := NewClosure(closure, contract, contract.script, vm.state, gas, value)
// Executer the closure and get the return value (if any)
ret, err := closure.Call(vm, args, hook)
if err != nil {
stack.Push(ethutil.BigFalse)
} else {
stack.Push(ethutil.BigTrue)
}
mem.Set(retOffset.Int64(), retSize.Int64(), ret)
case oRETURN:
require(2)
size, offset := stack.Popn()
ret := mem.Get(offset.Int64(), size.Int64())
return closure.Return(ret), nil
case oSUICIDE:
/*
recAddr := stack.Pop().Bytes()
// Purge all memory
deletedMemory := contract.state.Purge()
// Add refunds to the pop'ed address
refund := new(big.Int).Mul(StoreFee, big.NewInt(int64(deletedMemory)))
account := state.GetAccount(recAddr)
account.Amount.Add(account.Amount, refund)
// Update the refunding address
state.UpdateAccount(recAddr, account)
// Delete the contract
state.trie.Update(string(addr), "")
ethutil.Config.Log.Debugf("(%d) => %x\n", deletedMemory, recAddr)
break out
*/
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)
}
}
}