Official Go implementation of the Ethereum protocol
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go-ethereum/ethchain/vm.go

399 lines
9.1 KiB

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)
func (vm *Vm) RunClosure(closure *Closure) []byte {
// 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()
// 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.GetMem(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 {
return closure.Return(nil)
}
switch op {
case oLOG:
stack.Print()
mem.Print()
case oSTOP: // Stop the closure
return closure.Return(nil)
// 0x20 range
case oADD:
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:
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:
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:
x, y := stack.Popn()
// floor(x / y)
base.Div(x, y)
// Pop result back on the stack
stack.Push(base)
case oSDIV:
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:
x, y := stack.Popn()
base.Mod(x, y)
stack.Push(base)
case oSMOD:
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:
x, y := stack.Popn()
base.Exp(x, y, Pow256)
stack.Push(base)
case oNEG:
base.Sub(Pow256, stack.Pop())
stack.Push(base)
case oLT:
x, y := stack.Popn()
// x < y
if x.Cmp(y) < 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oGT:
x, y := stack.Popn()
// x > y
if x.Cmp(y) > 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
case oNOT:
x, y := stack.Popn()
// x != y
if x.Cmp(y) != 0 {
stack.Push(ethutil.BigTrue)
} else {
stack.Push(ethutil.BigFalse)
}
// 0x10 range
case oAND:
case oOR:
case oXOR:
case oBYTE:
// 0x20 range
case oSHA3:
// 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:
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)
val := closure.GetMem(pc).BigInt()
stack.Push(val)
case oPOP:
stack.Pop()
case oDUP:
stack.Push(stack.Peek())
case oSWAP:
x, y := stack.Popn()
stack.Push(y)
stack.Push(x)
case oMLOAD:
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
// Pop value of the stack
val, mStart := stack.Popn()
mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(val, 256))
case oMSTORE8:
val, mStart := stack.Popn()
base.And(val, new(big.Int).SetInt64(0xff))
mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(base, 256))
case oSLOAD:
loc := stack.Pop()
val := closure.GetMem(loc)
stack.Push(val.BigInt())
case oSSTORE:
val, loc := stack.Popn()
closure.SetMem(loc, ethutil.NewValue(val))
case oJUMP:
pc = stack.Pop()
case oJUMPI:
pos, cond := stack.Popn()
if cond.Cmp(big.NewInt(0)) > 0 {
pc = pos
}
case oPC:
stack.Push(pc)
case oMSIZE:
stack.Push(big.NewInt(int64(mem.Len())))
// 0x60 range
case oCALL:
// Pop return size and offset
retSize, retOffset := stack.Popn()
// Pop input size and offset
inSize, inOffset := stack.Popn()
// Get the arguments from the memory
args := mem.Get(inOffset.Int64(), inSize.Int64())
// Pop gas and value of the stack.
gas, value := stack.Popn()
// Closure addr
addr := stack.Pop()
// 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, vm.state, gas, value)
// Executer the closure and get the return value (if any)
ret := closure.Call(vm, args)
mem.Set(retOffset.Int64(), retSize.Int64(), ret)
case oRETURN:
size, offset := stack.Popn()
ret := mem.Get(offset.Int64(), size.Int64())
return closure.Return(ret)
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.Debugln("Invalid opcode", op)
}
pc.Add(pc, ethutil.Big1)
}
}
/*
func makeInlineTx(addr []byte, value, from, length *big.Int, contract *Contract, state *State) {
ethutil.Config.Log.Debugf(" => creating inline tx %x %v %v %v", addr, value, from, length)
j := int64(0)
dataItems := make([]string, int(length.Uint64()))
for i := from.Int64(); i < length.Int64(); i++ {
dataItems[j] = contract.GetMem(big.NewInt(j)).Str()
j++
}
tx := NewTransaction(addr, value, dataItems)
if tx.IsContract() {
contract := MakeContract(tx, state)
state.UpdateContract(contract)
} else {
account := state.GetAccount(tx.Recipient)
account.Amount.Add(account.Amount, tx.Value)
state.UpdateAccount(tx.Recipient, account)
}
}
// Returns an address from the specified contract's address
func contractMemory(state *State, contractAddr []byte, memAddr *big.Int) *big.Int {
contract := state.GetContract(contractAddr)
if contract == nil {
log.Panicf("invalid contract addr %x", contractAddr)
}
val := state.trie.Get(memAddr.String())
// decode the object as a big integer
decoder := ethutil.NewValueFromBytes([]byte(val))
if decoder.IsNil() {
return ethutil.BigFalse
}
return decoder.BigInt()
}
*/