path: root/cmd/geth/js.go

// Copyright 2015 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package main

import (
    "fmt"
    "math/big"
    "os"
    "os/signal"
    "path/filepath"
    "regexp"
    "sort"
    "strings"

    "github.com/codegangsta/cli"
    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/cmd/utils"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/registrar"
    "github.com/ethereum/go-ethereum/eth"
    re "github.com/ethereum/go-ethereum/jsre"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/peterh/liner"
    "github.com/robertkrimen/otto"
)

var (
    passwordRegexp = regexp.MustCompile("personal.[nu]")
    leadingSpace   = regexp.MustCompile("^ ")
    onlyws         = regexp.MustCompile("^\\s*$")
    exit           = regexp.MustCompile("^\\s*exit\\s*;*\\s*$")
)

type jsre struct {
    re         *re.JSRE
    stack      *node.Node
    wait       chan *big.Int
    ps1        string
    atexit     func()
    corsDomain string
    client     rpc.Client
}

func makeCompleter(re *jsre) liner.WordCompleter {
    return func(line string, pos int) (head string, completions []string, tail string) {
        if len(line) == 0 || pos == 0 {
            return "", nil, ""
        }
        // chuck data to relevant part for autocompletion, e.g. in case of nested lines eth.getBalance(eth.coinb<tab><tab>
        i := 0
        for i = pos - 1; i > 0; i-- {
            if line[i] == '.' || (line[i] >= 'a' && line[i] <= 'z') || (line[i] >= 'A' && line[i] <= 'Z') {
                continue
            }
            if i >= 3 && line[i] == '3' && line[i-3] == 'w' && line[i-2] == 'e' && line[i-1] == 'b' {
                continue
            }
            i += 1
            break
        }
        return line[:i], re.re.CompleteKeywords(line[i:pos]), line[pos:]
    }
}

func newLightweightJSRE(docRoot string, client rpc.Client, datadir string, interactive bool) *jsre {
    js := &jsre{ps1: "> "}
    js.wait = make(chan *big.Int)
    js.client = client
    js.re = re.New(docRoot)
    if err := js.apiBindings(); err != nil {
        utils.Fatalf("Unable to initialize console - %v", err)
    }
    js.setupInput(datadir)
    return js
}

func newJSRE(stack *node.Node, docRoot, corsDomain string, client rpc.Client, interactive bool) *jsre {
    js := &jsre{stack: stack, ps1: "> "}
    // set default cors domain used by startRpc from CLI flag
    js.corsDomain = corsDomain
    js.wait = make(chan *big.Int)
    js.client = client
    js.re = re.New(docRoot)
    if err := js.apiBindings(); err != nil {
        utils.Fatalf("Unable to connect - %v", err)
    }
    js.setupInput(stack.DataDir())
    return js
}

func (self *jsre) setupInput(datadir string) {
    self.withHistory(datadir, func(hist *os.File) { utils.Stdin.ReadHistory(hist) })
    utils.Stdin.SetCtrlCAborts(true)
    utils.Stdin.SetWordCompleter(makeCompleter(self))
    utils.Stdin.SetTabCompletionStyle(liner.TabPrints)
    self.atexit = func() {
        self.withHistory(datadir, func(hist *os.File) {
            hist.Truncate(0)
            utils.Stdin.WriteHistory(hist)
        })
        utils.Stdin.Close()
        close(self.wait)
    }
}

func (self *jsre) batch(statement string) {
    err := self.re.EvalAndPrettyPrint(statement)

    if err != nil {
        fmt.Printf("error: %v", err)
    }

    if self.atexit != nil {
        self.atexit()
    }

    self.re.Stop(false)
}

// show summary of current geth instance
func (self *jsre) welcome() {
    self.re.Run(`
    (function () {
      console.log('instance: ' + web3.version.node);
      console.log("coinbase: " + eth.coinbase);
      var ts = 1000 * eth.getBlock(eth.blockNumber).timestamp;
      console.log("at block: " + eth.blockNumber + " (" + new Date(ts) + ")");
      console.log(' datadir: ' + admin.datadir);
    })();
  `)
    if modules, err := self.supportedApis(); err == nil {
        loadedModules := make([]string, 0)
        for api, version := range modules {
            loadedModules = append(loadedModules, fmt.Sprintf("%s:%s", api, version))
        }
        sort.Strings(loadedModules)
    }
}

func (self *jsre) supportedApis() (map[string]string, error) {
    return self.client.SupportedModules()
}

func (js *jsre) apiBindings() error {
    apis, err := js.supportedApis()
    if err != nil {
        return err
    }

    apiNames := make([]string, 0, len(apis))
    for a, _ := range apis {
        apiNames = append(apiNames, a)
    }

    jeth := utils.NewJeth(js.re, js.client)
    js.re.Set("jeth", struct{}{})
    t, _ := js.re.Get("jeth")
    jethObj := t.Object()

    jethObj.Set("send", jeth.Send)
    jethObj.Set("sendAsync", jeth.Send)

    err = js.re.Compile("bignumber.js", re.BigNumber_JS)
    if err != nil {
        utils.Fatalf("Error loading bignumber.js: %v", err)
    }

    err = js.re.Compile("web3.js", re.Web3_JS)
    if err != nil {
        utils.Fatalf("Error loading web3.js: %v", err)
    }

    _, err = js.re.Run("var Web3 = require('web3');")
    if err != nil {
        utils.Fatalf("Error requiring web3: %v", err)
    }

    _, err = js.re.Run("var web3 = new Web3(jeth);")
    if err != nil {
        utils.Fatalf("Error setting web3 provider: %v", err)
    }

    // load only supported API's in javascript runtime
    shortcuts := "var eth = web3.eth; var personal = web3.personal; "
    for _, apiName := range apiNames {
        if apiName == "web3" || apiName == "rpc" {
            continue // manually mapped or ignore
        }

        if jsFile, ok := rpc.WEB3Extensions[apiName]; ok {
            if err = js.re.Compile(fmt.Sprintf("%s.js", apiName), jsFile); err == nil {
                shortcuts += fmt.Sprintf("var %s = web3.%s; ", apiName, apiName)
            } else {
                utils.Fatalf("Error loading %s.js: %v", apiName, err)
            }
        }
    }

    _, err = js.re.Run(shortcuts)
    if err != nil {
        utils.Fatalf("Error setting namespaces: %v", err)
    }

    js.re.Run(`var GlobalRegistrar = eth.contract(` + registrar.GlobalRegistrarAbi + `);   registrar = GlobalRegistrar.at("` + registrar.GlobalRegistrarAddr + `");`)

    // overrule some of the methods that require password as input and ask for it interactively
    p, err := js.re.Get("personal")
    if err != nil {
        fmt.Println("Unable to overrule sensitive methods in personal module")
        return nil
    }

    // Override the unlockAccount and newAccount methods on the personal object since these require user interaction.
    // Assign the jeth.unlockAccount and jeth.newAccount in the jsre the original web3 callbacks. These will be called
    // by the jeth.* methods after they got the password from the user and send the original web3 request to the backend.
    if persObj := p.Object(); persObj != nil { // make sure the personal api is enabled over the interface
        js.re.Run(`jeth.unlockAccount = personal.unlockAccount;`)
        persObj.Set("unlockAccount", jeth.UnlockAccount)
        js.re.Run(`jeth.newAccount = personal.newAccount;`)
        persObj.Set("newAccount", jeth.NewAccount)
    }

    // The admin.sleep and admin.sleepBlocks are offered by the console and not by the RPC layer.
    // Bind these if the admin module is available.
    if a, err := js.re.Get("admin"); err == nil {
        if adminObj := a.Object(); adminObj != nil {
            adminObj.Set("sleepBlocks", jeth.SleepBlocks)
            adminObj.Set("sleep", jeth.Sleep)
        }
    }

    return nil
}

func (self *jsre) AskPassword() (string, bool) {
    pass, err := utils.Stdin.PasswordPrompt("Passphrase: ")
    if err != nil {
        return "", false
    }
    return pass, true
}

func (self *jsre) ConfirmTransaction(tx string) bool {
    // Retrieve the Ethereum instance from the node
    var ethereum *eth.Ethereum
    if err := self.stack.Service(&ethereum); err != nil {
        return false
    }
    // If natspec is enabled, ask for permission
    if ethereum.NatSpec && false /* disabled for now */ {
        //      notice := natspec.GetNotice(self.xeth, tx, ethereum.HTTPClient())
        //      fmt.Println(notice)
        //      answer, _ := self.Prompt("Confirm Transaction [y/n]")
        //      return strings.HasPrefix(strings.Trim(answer, " "), "y")
    }
    return true
}

func (self *jsre) UnlockAccount(addr []byte) bool {
    fmt.Printf("Please unlock account %x.\n", addr)
    pass, err := utils.Stdin.PasswordPrompt("Passphrase: ")
    if err != nil {
        return false
    }
    // TODO: allow retry
    var ethereum *eth.Ethereum
    if err := self.stack.Service(&ethereum); err != nil {
        return false
    }
    a := accounts.Account{Address: common.BytesToAddress(addr)}
    if err := ethereum.AccountManager().Unlock(a, pass); err != nil {
        return false
    } else {
        fmt.Println("Account is now unlocked for this session.")
        return true
    }
}

// preloadJSFiles loads JS files that the user has specified with ctx.PreLoadJSFlag into
// the JSRE. If not all files could be loaded it will return an error describing the error.
func (self *jsre) preloadJSFiles(ctx *cli.Context) error {
    if ctx.GlobalString(utils.PreLoadJSFlag.Name) != "" {
        assetPath := ctx.GlobalString(utils.JSpathFlag.Name)
        jsFiles := strings.Split(ctx.GlobalString(utils.PreLoadJSFlag.Name), ",")
        for _, file := range jsFiles {
            filename := common.AbsolutePath(assetPath, strings.TrimSpace(file))
            if err := self.re.Exec(filename); err != nil {
                return fmt.Errorf("%s: %v", file, err)
            }
        }
    }
    return nil
}

// exec executes the JS file with the given filename and stops the JSRE
func (self *jsre) exec(filename string) error {
    if err := self.re.Exec(filename); err != nil {
        self.re.Stop(false)
        return fmt.Errorf("Javascript Error: %v", err)
    }
    self.re.Stop(true)
    return nil
}

func (self *jsre) interactive() {
    // Read input lines.
    prompt := make(chan string)
    inputln := make(chan string)
    go func() {
        defer close(inputln)
        for {
            line, err := utils.Stdin.Prompt(<-prompt)
            if err != nil {
                if err == liner.ErrPromptAborted { // ctrl-C
                    self.resetPrompt()
                    inputln <- ""
                    continue
                }
                return
            }
            inputln <- line
        }
    }()
    // Wait for Ctrl-C, too.
    sig := make(chan os.Signal, 1)
    signal.Notify(sig, os.Interrupt)

    defer func() {
        if self.atexit != nil {
            self.atexit()
        }
        self.re.Stop(false)
    }()
    for {
        prompt <- self.ps1
        select {
        case <-sig:
            fmt.Println("caught interrupt, exiting")
            return
        case input, ok := <-inputln:
            if !ok || indentCount <= 0 && exit.MatchString(input) {
                return
            }
            if onlyws.MatchString(input) {
                continue
            }
            str += input + "\n"
            self.setIndent()
            if indentCount <= 0 {
                if mustLogInHistory(str) {
                    utils.Stdin.AppendHistory(str[:len(str)-1])
                }
                self.parseInput(str)
                str = ""
            }
        }
    }
}

func mustLogInHistory(input string) bool {
    return len(input) == 0 ||
        passwordRegexp.MatchString(input) ||
        !leadingSpace.MatchString(input)
}

func (self *jsre) withHistory(datadir string, op func(*os.File)) {
    hist, err := os.OpenFile(filepath.Join(datadir, "history"), os.O_RDWR|os.O_CREATE, os.ModePerm)
    if err != nil {
        fmt.Printf("unable to open history file: %v\n", err)
        return
    }
    op(hist)
    hist.Close()
}

func (self *jsre) parseInput(code string) {
    defer func() {
        if r := recover(); r != nil {
            fmt.Println("[native] error", r)
        }
    }()
    if err := self.re.EvalAndPrettyPrint(code); err != nil {
        if ottoErr, ok := err.(*otto.Error); ok {
            fmt.Println(ottoErr.String())
        } else {
            fmt.Println(err)
        }
        return
    }
}

var indentCount = 0
var str = ""

func (self *jsre) resetPrompt() {
    indentCount = 0
    str = ""
    self.ps1 = "> "
}

func (self *jsre) setIndent() {
    open := strings.Count(str, "{")
    open += strings.Count(str, "(")
    closed := strings.Count(str, "}")
    closed += strings.Count(str, ")")
    indentCount = open - closed
    if indentCount <= 0 {
        self.ps1 = "> "
    } else {
        self.ps1 = strings.Join(make([]string, indentCount*2), "..")
        self.ps1 += " "
    }
}