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 := 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() val := closure.Args[offset : offset+32] stack.Push(ethutil.BigD(val)) 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, _, 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.Object(), 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 } } } }