package ethchain import ( "fmt" "github.com/ethereum/eth-go/ethutil" "github.com/ethereum/eth-go/ethlog" "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 } 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, hook DebugHook) (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.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 } 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 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 := 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: 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.GetMem(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 := ethutil.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, hook) 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 := closure.Call(vm, args, hook) 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) 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("Invalid opcode %x\n", op) return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op) } pc.Add(pc, ethutil.Big1) vm.Endl() if hook != nil { if !hook(prevStep, op, mem, stack, closure.Object()) { return nil, nil } } } }