bsc/ethchain/vm.go
2014-07-02 11:30:14 +02:00

751 lines
16 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)
)
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
Verbose bool
logStr string
err error
Hook DebugHook
}
type DebugHook func(step int, op OpCode, mem *Memory, stack *Stack, stateObject *StateObject) bool
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.logStr += fmt.Sprintf(format, v...)
}
return self
}
func (self *Vm) Endl() *Vm {
if self.Verbose {
vmlogger.Infoln(self.logStr)
self.logStr = ""
}
return self
}
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) (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)
}
}()
vmlogger.Debugf("(~) %x gas: %v (d) %x\n", closure.object.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())
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:
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 {
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 := ethcrypto.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:
caller := closure.caller.Address()
stack.Push(ethutil.BigD(caller))
vm.Printf(" => %x", caller)
case CALLVALUE:
stack.Push(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))
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)
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.caller.Address(), closure.caller.N())
vm.Printf(" (*) %x", addr).Endl()
// Create a new contract
contract := vm.state.NewStateObject(addr)
contract.Amount = value
// Set the init script
contract.initScript = ethutil.BigD(mem.Get(offset.Int64(), size.Int64())).Bytes()
// Transfer all remaining gas to the new
// contract so it may run the init script
gas := new(big.Int).Set(closure.Gas)
// Create the closure
c := NewClosure(closure.caller,
closure.Object(),
contract.initScript,
vm.state,
gas,
closure.Price)
// Call the closure and set the return value as
// main script.
var err error
c.Script, gas, err = c.Call(vm, nil)
if err != nil {
stack.Push(ethutil.BigFalse)
// Revert the state as it was before.
vm.state.Set(snapshot)
} else {
stack.Push(ethutil.BigD(addr))
}
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)
// Add the value to the state object
stateObject.AddAmount(value)
// Create a new callable closure
closure := NewClosure(closure, stateObject, stateObject.script, vm.state, gas, closure.Price)
// Executer the closure and get the return value (if any)
ret, err, _ := Call(vm, closure, args)
if err != nil {
stack.Push(ethutil.BigFalse)
vmlogger.Debugf("Closure execution failed. %v\n", err)
vm.err = err
vm.state.Set(snapshot)
} else {
stack.Push(ethutil.BigTrue)
mem.Set(retOffset.Int64(), retSize.Int64(), ret)
}
}
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.GetAccount(stack.Pop().Bytes())
receiver.AddAmount(closure.object.Amount)
closure.object.MarkForDeletion()
/*
trie := closure.object.state.trie
trie.NewIterator().Each(func(key string, v *ethutil.Value) {
trie.Delete(key)
})
*/
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.Hook != nil {
if !vm.Hook(prevStep, op, mem, stack, closure.Object()) {
return nil, nil
}
}
}
}