From 2f9972090165f25f953f986014d78b172e334497 Mon Sep 17 00:00:00 2001 From: Nick Johnson Date: Mon, 22 Aug 2016 15:03:30 +0100 Subject: core/vm, eth: Add support for javascript trace functions --- internal/ethapi/tracer.go | 300 +++++++++++++++++++++++++++++++++++++++++ internal/ethapi/tracer_test.go | 186 +++++++++++++++++++++++++ internal/web3ext/web3ext.go | 3 +- 3 files changed, 488 insertions(+), 1 deletion(-) create mode 100644 internal/ethapi/tracer.go create mode 100644 internal/ethapi/tracer_test.go (limited to 'internal') diff --git a/internal/ethapi/tracer.go b/internal/ethapi/tracer.go new file mode 100644 index 000000000..27af1166b --- /dev/null +++ b/internal/ethapi/tracer.go @@ -0,0 +1,300 @@ +// Copyright 2016 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package ethapi + +import ( + "errors" + "fmt" + "math/big" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/core/vm" + "github.com/robertkrimen/otto" +) + +// fakeBig is used to provide an interface to Javascript for 'big.NewInt' +type fakeBig struct{} + +// NewInt creates a new big.Int with the specified int64 value. +func (fb *fakeBig) NewInt(x int64) *big.Int { + return big.NewInt(x) +} + +// OpCodeWrapper provides a JavaScript-friendly wrapper around OpCode, to convince Otto to treat it +// as an object, instead of a number. +type opCodeWrapper struct { + op vm.OpCode +} + +// toNumber returns the ID of this opcode as an integer +func (ocw *opCodeWrapper) toNumber() int { + return int(ocw.op) +} + +// toString returns the string representation of the opcode +func (ocw *opCodeWrapper) toString() string { + return ocw.op.String() +} + +// isPush returns true if the op is a Push +func (ocw *opCodeWrapper) isPush() bool { + return ocw.op.IsPush() +} + +// toValue returns an otto.Value for the opCodeWrapper +func (ocw *opCodeWrapper) toValue(vm *otto.Otto) otto.Value { + value, _ := vm.ToValue(ocw) + obj := value.Object() + obj.Set("toNumber", ocw.toNumber) + obj.Set("toString", ocw.toString) + obj.Set("isPush", ocw.isPush) + return value +} + +// memoryWrapper provides a JS wrapper around vm.Memory +type memoryWrapper struct { + memory *vm.Memory +} + +// slice returns the requested range of memory as a byte slice +func (mw *memoryWrapper) slice(begin, end int64) []byte { + return mw.memory.Get(begin, end-begin) +} + +// getUint returns the 32 bytes at the specified address interpreted +// as an unsigned integer +func (mw *memoryWrapper) getUint(addr int64) *big.Int { + ret := big.NewInt(0) + ret.SetBytes(mw.memory.GetPtr(addr, 32)) + return ret +} + +// toValue returns an otto.Value for the memoryWrapper +func (mw *memoryWrapper) toValue(vm *otto.Otto) otto.Value { + value, _ := vm.ToValue(mw) + obj := value.Object() + obj.Set("slice", mw.slice) + obj.Set("getUint", mw.getUint) + return value +} + +// stackWrapper provides a JS wrapper around vm.Stack +type stackWrapper struct { + stack *vm.Stack +} + +// peek returns the nth-from-the-top element of the stack. +func (sw *stackWrapper) peek(idx int) *big.Int { + return sw.stack.Data()[len(sw.stack.Data())-idx-1] +} + +// length returns the length of the stack +func (sw *stackWrapper) length() int { + return len(sw.stack.Data()) +} + +// toValue returns an otto.Value for the stackWrapper +func (sw *stackWrapper) toValue(vm *otto.Otto) otto.Value { + value, _ := vm.ToValue(sw) + obj := value.Object() + obj.Set("peek", sw.peek) + obj.Set("length", sw.length) + return value +} + +// dbWrapper provides a JS wrapper around vm.Database +type dbWrapper struct { + db vm.Database +} + +// getBalance retrieves an account's balance +func (dw *dbWrapper) getBalance(addr common.Address) *big.Int { + return dw.db.GetBalance(addr) +} + +// getNonce retrieves an account's nonce +func (dw *dbWrapper) getNonce(addr common.Address) uint64 { + return dw.db.GetNonce(addr) +} + +// getCode retrieves an account's code +func (dw *dbWrapper) getCode(addr common.Address) []byte { + return dw.db.GetCode(addr) +} + +// getState retrieves an account's state data for the given hash +func (dw *dbWrapper) getState(addr common.Address, hash common.Hash) common.Hash { + return dw.db.GetState(addr, hash) +} + +// exists returns true iff the account exists +func (dw *dbWrapper) exists(addr common.Address) bool { + return dw.db.Exist(addr) +} + +// toValue returns an otto.Value for the dbWrapper +func (dw *dbWrapper) toValue(vm *otto.Otto) otto.Value { + value, _ := vm.ToValue(dw) + obj := value.Object() + obj.Set("getBalance", dw.getBalance) + obj.Set("getNonce", dw.getNonce) + obj.Set("getCode", dw.getCode) + obj.Set("getState", dw.getState) + obj.Set("exists", dw.exists) + return value +} + +// JavascriptTracer provides an implementation of Tracer that evaluates a +// Javascript function for each VM execution step. +type JavascriptTracer struct { + vm *otto.Otto // Javascript VM instance + traceobj *otto.Object // User-supplied object to call + log map[string]interface{} // (Reusable) map for the `log` arg to `step` + logvalue otto.Value // JS view of `log` + opcode *opCodeWrapper // Wrapper around the opcode + opcodevalue otto.Value // JS view of 'opcode' + memory *memoryWrapper // Wrapper around the VM memory + memvalue otto.Value // JS view of `memory` + stack *stackWrapper // Wrapper around the VM stack + stackvalue otto.Value // JS view of `stack` + db *dbWrapper // Wrapper around the VM environment + dbvalue otto.Value // JS view of `db` + err error // Error, if one has occurred +} + +// NewJavascriptTracer instantiates a new JavascriptTracer instance. +// code specifies a Javascript snippet, which must evaluate to an expression +// returning an object with 'step' and 'result' functions. +func NewJavascriptTracer(code string) (*JavascriptTracer, error) { + vm := otto.New() + vm.Interrupt = make(chan func(), 1) + + // Set up builtins for this environment + vm.Set("big", &fakeBig{}) + + jstracer, err := vm.Object("(" + code + ")") + if err != nil { + return nil, err + } + + // Check the required functions exist + step, err := jstracer.Get("step") + if err != nil { + return nil, err + } + if !step.IsFunction() { + return nil, fmt.Errorf("Trace object must expose a function step()") + } + + result, err := jstracer.Get("result") + if err != nil { + return nil, err + } + if !result.IsFunction() { + return nil, fmt.Errorf("Trace object must expose a function result()") + } + + // Create the persistent log object + log := make(map[string]interface{}) + logvalue, _ := vm.ToValue(log) + + // Create persistent wrappers for memory and stack + opcode := &opCodeWrapper{} + mem := &memoryWrapper{} + stack := &stackWrapper{} + db := &dbWrapper{} + + return &JavascriptTracer{ + vm: vm, + traceobj: jstracer, + log: log, + logvalue: logvalue, + opcode: opcode, + opcodevalue: opcode.toValue(vm), + memory: mem, + memvalue: mem.toValue(vm), + stack: stack, + stackvalue: stack.toValue(vm), + db: db, + dbvalue: db.toValue(vm), + err: nil, + }, nil +} + +// Stop terminates execution of any JavaScript +func (jst *JavascriptTracer) Stop(err error) { + jst.vm.Interrupt <- func() { + panic(err) + } +} + +// callSafely executes a method on a JS object, catching any panics and +// returning them as error objects. +func (jst *JavascriptTracer) callSafely(method string, argumentList ...interface{}) (ret interface{}, err error) { + defer func() { + if caught := recover(); caught != nil { + switch caught := caught.(type) { + case error: + err = caught + case string: + err = errors.New(caught) + case fmt.Stringer: + err = errors.New(caught.String()) + default: + panic(caught) + } + } + }() + + value, err := jst.traceobj.Call(method, argumentList...) + ret, _ = value.Export() + return ret, err +} + +// CaptureState implements the Tracer interface to trace a single step of VM execution +func (jst *JavascriptTracer) CaptureState(env vm.Environment, pc uint64, op vm.OpCode, gas, cost *big.Int, memory *vm.Memory, stack *vm.Stack, contract *vm.Contract, depth int, err error) { + if jst.err == nil { + jst.opcode.op = op + jst.memory.memory = memory + jst.stack.stack = stack + jst.db.db = env.Db() + + jst.log["pc"] = pc + jst.log["op"] = jst.opcodevalue + jst.log["gas"] = gas.Int64() + jst.log["gasPrice"] = cost.Int64() + jst.log["memory"] = jst.memvalue + jst.log["stack"] = jst.stackvalue + jst.log["depth"] = depth + jst.log["account"] = contract.Address() + jst.log["err"] = err + + _, err := jst.callSafely("step", jst.logvalue, jst.dbvalue) + if err != nil { + jst.err = err + } + } +} + +// GetResult calls the Javascript 'result' function and returns its value, or any accumulated error +func (jst *JavascriptTracer) GetResult() (result interface{}, err error) { + if jst.err != nil { + return nil, jst.err + } + + return jst.callSafely("result") +} diff --git a/internal/ethapi/tracer_test.go b/internal/ethapi/tracer_test.go new file mode 100644 index 000000000..2f1dfa0be --- /dev/null +++ b/internal/ethapi/tracer_test.go @@ -0,0 +1,186 @@ +// Copyright 2016 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package ethapi + +import ( + "errors" + "math/big" + "testing" + "time" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/core/vm" + "github.com/ethereum/go-ethereum/crypto" +) + +type ruleSet struct{} + +func (self *ruleSet) IsHomestead(*big.Int) bool { return true } + +type Env struct { + gasLimit *big.Int + depth int + evm *vm.EVM +} + +func NewEnv(config *vm.Config) *Env { + env := &Env{gasLimit: big.NewInt(10000), depth: 0} + env.evm = vm.New(env, *config) + return env +} + +func (self *Env) RuleSet() vm.RuleSet { return &ruleSet{} } +func (self *Env) Vm() vm.Vm { return self.evm } +func (self *Env) Origin() common.Address { return common.Address{} } +func (self *Env) BlockNumber() *big.Int { return big.NewInt(0) } + +//func (self *Env) PrevHash() []byte { return self.parent } +func (self *Env) Coinbase() common.Address { return common.Address{} } +func (self *Env) MakeSnapshot() vm.Database { return nil } +func (self *Env) SetSnapshot(vm.Database) {} +func (self *Env) Time() *big.Int { return big.NewInt(time.Now().Unix()) } +func (self *Env) Difficulty() *big.Int { return big.NewInt(0) } +func (self *Env) Db() vm.Database { return nil } +func (self *Env) GasLimit() *big.Int { return self.gasLimit } +func (self *Env) VmType() vm.Type { return vm.StdVmTy } +func (self *Env) GetHash(n uint64) common.Hash { + return common.BytesToHash(crypto.Keccak256([]byte(big.NewInt(int64(n)).String()))) +} +func (self *Env) AddLog(log *vm.Log) { +} +func (self *Env) Depth() int { return self.depth } +func (self *Env) SetDepth(i int) { self.depth = i } +func (self *Env) CanTransfer(from common.Address, balance *big.Int) bool { + return true +} +func (self *Env) Transfer(from, to vm.Account, amount *big.Int) {} +func (self *Env) Call(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) { + return nil, nil +} +func (self *Env) CallCode(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) { + return nil, nil +} +func (self *Env) Create(caller vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) { + return nil, common.Address{}, nil +} +func (self *Env) DelegateCall(me vm.ContractRef, addr common.Address, data []byte, gas, price *big.Int) ([]byte, error) { + return nil, nil +} + +type account struct{} + +func (account) SubBalance(amount *big.Int) {} +func (account) AddBalance(amount *big.Int) {} +func (account) SetAddress(common.Address) {} +func (account) Value() *big.Int { return nil } +func (account) SetBalance(*big.Int) {} +func (account) SetNonce(uint64) {} +func (account) Balance() *big.Int { return nil } +func (account) Address() common.Address { return common.Address{} } +func (account) ReturnGas(*big.Int, *big.Int) {} +func (account) SetCode([]byte) {} +func (account) ForEachStorage(cb func(key, value common.Hash) bool) {} + +func runTrace(tracer *JavascriptTracer) (interface{}, error) { + env := NewEnv(&vm.Config{Debug: true, Tracer: tracer}) + + contract := vm.NewContract(account{}, account{}, big.NewInt(0), env.GasLimit(), big.NewInt(1)) + contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x1, 0x0} + + _, err := env.Vm().Run(contract, []byte{}) + if err != nil { + return nil, err + } + + return tracer.GetResult() +} + +func TestTracing(t *testing.T) { + tracer, err := NewJavascriptTracer("{count: 0, step: function() { this.count += 1; }, result: function() { return this.count; }}") + if err != nil { + t.Fatal(err) + } + + ret, err := runTrace(tracer) + if err != nil { + t.Fatal(err) + } + + value, ok := ret.(float64) + if !ok { + t.Errorf("Expected return value to be float64, was %T", ret) + } + if value != 3 { + t.Errorf("Expected return value to be 3, got %v", value) + } +} + +func TestStack(t *testing.T) { + tracer, err := NewJavascriptTracer("{depths: [], step: function(log) { this.depths.push(log.stack.length()); }, result: function() { return this.depths; }}") + if err != nil { + t.Fatal(err) + } + + ret, err := runTrace(tracer) + if err != nil { + t.Fatal(err) + } + + value, ok := ret.([]int) + if !ok { + t.Errorf("Expected return value to be []int, was %T", ret) + } + if len(value) != 3 || value[0] != 0 || value[1] != 1 || value[2] != 2 { + t.Errorf("Expected return value to be [0 1 2], got %v", value) + } +} + +func TestHalt(t *testing.T) { + timeout := errors.New("stahp") + tracer, err := NewJavascriptTracer("{step: function() { while(1); }, result: function() { return null; }}") + if err != nil { + t.Fatal(err) + } + + go func() { + time.Sleep(1 * time.Second) + tracer.Stop(timeout) + }() + + if _, err = runTrace(tracer); err != timeout { + t.Errorf("Expected timeout error, got %v", err) + } +} + +func TestHaltBetweenSteps(t *testing.T) { + tracer, err := NewJavascriptTracer("{step: function() {}, result: function() { return null; }}") + if err != nil { + t.Fatal(err) + } + + env := NewEnv(&vm.Config{Debug: true, Tracer: tracer}) + contract := vm.NewContract(&account{}, &account{}, big.NewInt(0), big.NewInt(0), big.NewInt(0)) + + tracer.CaptureState(env, 0, 0, big.NewInt(0), big.NewInt(0), nil, nil, contract, 0, nil) + timeout := errors.New("stahp") + tracer.Stop(timeout) + tracer.CaptureState(env, 0, 0, big.NewInt(0), big.NewInt(0), nil, nil, contract, 0, nil) + + if _, err := tracer.GetResult(); err != timeout { + t.Errorf("Expected timeout error, got %v", err) + } +} diff --git a/internal/web3ext/web3ext.go b/internal/web3ext/web3ext.go index e76e15177..748b37c84 100644 --- a/internal/web3ext/web3ext.go +++ b/internal/web3ext/web3ext.go @@ -284,7 +284,8 @@ web3._extend({ new web3._extend.Method({ name: 'traceTransaction', call: 'debug_traceTransaction', - params: 1 + params: 2, + inputFormatter: [null, null] }) ], properties: [] -- cgit v1.2.3