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, scriptSize *big.Int) *big.Int { totalGas := new(big.Int) totalGas.Add(totalGas, GasCreate) txTotalBytes := new(big.Int).Add(initSize, scriptSize) 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 if ethutil.Config.Debug { ethutil.Config.Log.Debugf("# op\n") } for { // 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) 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(new(big.Int).Mul(mult, GasSStore)) case oBALANCE: useGas(GasBalance) case oCREATE: require(3) args := stack.Get(big.NewInt(3)) initSize := new(big.Int).Add(args[1], args[0]) useGas(CalculateTxGas(initSize, ethutil.Big0)) 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) } // Sub the amount of gas from the remaining closure.Gas.Sub(closure.Gas, gas) switch op { case oLOG: stack.Print() mem.Print() // 0x20 range case oADD: require(2) x, y := stack.Popn() // (x + y) % 2 ** 256 base.Add(x, y) // 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) // 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) // 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.object.Amount) case oORIGIN: stack.Push(ethutil.BigD(vm.vars.Origin)) case oCALLER: stack.Push(ethutil.BigD(closure.Callee().Address())) case oCALLVALUE: stack.Push(vm.vars.Value) case oCALLDATALOAD: require(1) offset := stack.Pop().Int64() val := closure.Args[offset : offset+32] stack.Push(ethutil.BigD(val)) case oCALLDATASIZE: stack.Push(big.NewInt(int64(len(closure.Args)))) case oGASPRICE: stack.Push(closure.Price) // 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 stack.Push(big.NewInt(0)) // 0x50 range case oPUSH1, oPUSH2, oPUSH3, oPUSH4, oPUSH5, oPUSH6, oPUSH7, oPUSH8, oPUSH9, oPUSH10, oPUSH11, oPUSH12, oPUSH13, oPUSH14, oPUSH15, oPUSH16, oPUSH17, oPUSH18, oPUSH19, oPUSH20, oPUSH21, oPUSH22, oPUSH23, oPUSH24, oPUSH25, oPUSH26, oPUSH27, oPUSH28, oPUSH29, oPUSH30, oPUSH31, oPUSH32: a := big.NewInt(int64(op) - int64(oPUSH1) + 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++ 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) //fmt.Println("get", val.BigInt(), "@", loc) stack.Push(val.BigInt()) case oSSTORE: 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 oJUMP: 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 oJUMPI: require(2) cond, pos := stack.Popn() if cond.Cmp(ethutil.BigTrue) == 0 { pc = pos //pc.Sub(pc, ethutil.Big1) continue } case oPC: stack.Push(pc) case oMSIZE: stack.Push(big.NewInt(int64(mem.Len()))) // 0x60 range case oCREATE: 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.Gas.Sub(closure.Gas, gas) // Create the closure closure := NewClosure(closure.callee, closure.Object(), contract.initScript, vm.state, gas, closure.Price) // Call the closure and set the return value as // main script. closure.Script, err = closure.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 oCALL: 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.Gas.Sub(closure.Gas, 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 oRETURN: require(2) size, offset := stack.Popn() ret := mem.Get(offset.Int64(), size.Int64()) return closure.Return(ret), nil case oSUICIDE: require(1) receiver := vm.state.GetAccount(stack.Pop().Bytes()) receiver.AddAmount(closure.object.Amount) vm.state.UpdateStateObject(receiver) closure.object.state.Purge() fallthrough case oSTOP: // 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 { hook(step-1, op, mem, stack) } } }