path: root/eth/backend.go

package eth

import (
    "crypto/ecdsa"
    "fmt"
    "io/ioutil"
    "path"
    "strings"

    "github.com/ethereum/ethash"
    "github.com/ethereum/go-ethereum/blockpool"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/miner"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/discover"
    "github.com/ethereum/go-ethereum/p2p/nat"
    "github.com/ethereum/go-ethereum/pow/ezp"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/whisper"
)

var (
    ethlogger  = logger.NewLogger("SERV")
    jsonlogger = logger.NewJsonLogger()

    defaultBootNodes = []*discover.Node{
        // ETH/DEV cmd/bootnode
        discover.MustParseNode("enode://6cdd090303f394a1cac34ecc9f7cda18127eafa2a3a06de39f6d920b0e583e062a7362097c7c65ee490a758b442acd5c80c6fce4b148c6a391e946b45131365b@54.169.166.226:30303"),
        // ETH/DEV cpp-ethereum (poc-8.ethdev.com)
        discover.MustParseNode("enode://4a44599974518ea5b0f14c31c4463692ac0329cb84851f3435e6d1b18ee4eae4aa495f846a0fa1219bd58035671881d44423876e57db2abd57254d0197da0ebe@5.1.83.226:30303"),
    }
)

type Config struct {
    Name      string
    KeyStore  string
    DataDir   string
    LogFile   string
    LogLevel  int
    KeyRing   string
    LogFormat string

    MaxPeers int
    Port     string

    // This should be a space-separated list of
    // discovery node URLs.
    BootNodes string

    // This key is used to identify the node on the network.
    // If nil, an ephemeral key is used.
    NodeKey *ecdsa.PrivateKey

    NAT  nat.Interface
    Shh  bool
    Dial bool

    MinerThreads int

    KeyManager *crypto.KeyManager
}

func (cfg *Config) parseBootNodes() []*discover.Node {
    if cfg.BootNodes == "" {
        return defaultBootNodes
    }
    var ns []*discover.Node
    for _, url := range strings.Split(cfg.BootNodes, " ") {
        if url == "" {
            continue
        }
        n, err := discover.ParseNode(url)
        if err != nil {
            ethlogger.Errorf("Bootstrap URL %s: %v\n", url, err)
            continue
        }
        ns = append(ns, n)
    }
    return ns
}

func (cfg *Config) nodeKey() (*ecdsa.PrivateKey, error) {
    // use explicit key from command line args if set
    if cfg.NodeKey != nil {
        return cfg.NodeKey, nil
    }
    // use persistent key if present
    keyfile := path.Join(cfg.DataDir, "nodekey")
    key, err := crypto.LoadECDSA(keyfile)
    if err == nil {
        return key, nil
    }
    // no persistent key, generate and store a new one
    if key, err = crypto.GenerateKey(); err != nil {
        return nil, fmt.Errorf("could not generate server key: %v", err)
    }
    if err := ioutil.WriteFile(keyfile, crypto.FromECDSA(key), 0600); err != nil {
        ethlogger.Errorln("could not persist nodekey: ", err)
    }
    return key, nil
}

type Ethereum struct {
    // Channel for shutting down the ethereum
    shutdownChan chan bool
    quit         chan bool

    // DB interface
    db        ethutil.Database
    blacklist p2p.Blacklist

    //*** SERVICES ***
    // State manager for processing new blocks and managing the over all states
    blockProcessor *core.BlockProcessor
    txPool         *core.TxPool
    chainManager   *core.ChainManager
    blockPool      *blockpool.BlockPool
    whisper        *whisper.Whisper

    net      *p2p.Server
    eventMux *event.TypeMux
    txSub    event.Subscription
    blockSub event.Subscription
    miner    *miner.Miner

    RpcServer  rpc.RpcServer
    keyManager *crypto.KeyManager

    logger logger.LogSystem

    Mining bool
}

func New(config *Config) (*Ethereum, error) {
    // Boostrap database
    ethlogger := logger.New(config.DataDir, config.LogFile, config.LogLevel, config.LogFormat)
    db, err := ethdb.NewLDBDatabase("blockchain")
    if err != nil {
        return nil, err
    }

    // Perform database sanity checks
    d, _ := db.Get([]byte("ProtocolVersion"))
    protov := ethutil.NewValue(d).Uint()
    if protov != ProtocolVersion && protov != 0 {
        path := path.Join(config.DataDir, "blockchain")
        return nil, fmt.Errorf("Database version mismatch. Protocol(%d / %d). `rm -rf %s`", protov, ProtocolVersion, path)
    }

    // Create new keymanager
    var keyManager *crypto.KeyManager
    switch config.KeyStore {
    case "db":
        keyManager = crypto.NewDBKeyManager(db)
    case "file":
        keyManager = crypto.NewFileKeyManager(config.DataDir)
    default:
        return nil, fmt.Errorf("unknown keystore type: %s", config.KeyStore)
    }
    // Initialise the keyring
    keyManager.Init(config.KeyRing, 0, false)

    saveProtocolVersion(db)
    //ethutil.Config.Db = db

    eth := &Ethereum{
        shutdownChan: make(chan bool),
        quit:         make(chan bool),
        db:           db,
        keyManager:   keyManager,
        blacklist:    p2p.NewBlacklist(),
        eventMux:     &event.TypeMux{},
        logger:       ethlogger,
    }

    eth.chainManager = core.NewChainManager(db, eth.EventMux())
    pow := ethash.New(eth.chainManager)

    eth.txPool = core.NewTxPool(eth.EventMux())
    eth.blockProcessor = core.NewBlockProcessor(db, pow, eth.txPool, eth.chainManager, eth.EventMux())
    eth.chainManager.SetProcessor(eth.blockProcessor)
    eth.whisper = whisper.New()
    eth.miner = miner.New(keyManager.Address(), eth, pow, config.MinerThreads)

    hasBlock := eth.chainManager.HasBlock
    insertChain := eth.chainManager.InsertChain
    eth.blockPool = blockpool.New(hasBlock, insertChain, ezp.Verify)

    netprv, err := config.nodeKey()
    if err != nil {
        return nil, err
    }
    ethProto := EthProtocol(eth.txPool, eth.chainManager, eth.blockPool)
    protocols := []p2p.Protocol{ethProto}
    if config.Shh {
        protocols = append(protocols, eth.whisper.Protocol())
    }

    eth.net = &p2p.Server{
        PrivateKey:     netprv,
        Name:           config.Name,
        MaxPeers:       config.MaxPeers,
        Protocols:      protocols,
        Blacklist:      eth.blacklist,
        NAT:            config.NAT,
        NoDial:         !config.Dial,
        BootstrapNodes: config.parseBootNodes(),
    }
    if len(config.Port) > 0 {
        eth.net.ListenAddr = ":" + config.Port
    }

    return eth, nil
}

func (s *Ethereum) KeyManager() *crypto.KeyManager       { return s.keyManager }
func (s *Ethereum) Logger() logger.LogSystem             { return s.logger }
func (s *Ethereum) Name() string                         { return s.net.Name }
func (s *Ethereum) ChainManager() *core.ChainManager     { return s.chainManager }
func (s *Ethereum) BlockProcessor() *core.BlockProcessor { return s.blockProcessor }
func (s *Ethereum) TxPool() *core.TxPool                 { return s.txPool }
func (s *Ethereum) BlockPool() *blockpool.BlockPool      { return s.blockPool }
func (s *Ethereum) Whisper() *whisper.Whisper            { return s.whisper }
func (s *Ethereum) EventMux() *event.TypeMux             { return s.eventMux }
func (s *Ethereum) Db() ethutil.Database                 { return s.db }
func (s *Ethereum) Miner() *miner.Miner                  { return s.miner }
func (s *Ethereum) IsListening() bool                    { return true } // Always listening
func (s *Ethereum) PeerCount() int                       { return s.net.PeerCount() }
func (s *Ethereum) Peers() []*p2p.Peer                   { return s.net.Peers() }
func (s *Ethereum) MaxPeers() int                        { return s.net.MaxPeers }
func (s *Ethereum) Coinbase() []byte                     { return nil } // TODO

// Start the ethereum
func (s *Ethereum) Start() error {
    jsonlogger.LogJson(&logger.LogStarting{
        ClientString:    s.net.Name,
        ProtocolVersion: ProtocolVersion,
    })

    err := s.net.Start()
    if err != nil {
        return err
    }

    // Start services
    s.txPool.Start()
    s.blockPool.Start()

    if s.whisper != nil {
        s.whisper.Start()
    }

    // broadcast transactions
    s.txSub = s.eventMux.Subscribe(core.TxPreEvent{})
    go s.txBroadcastLoop()

    // broadcast mined blocks
    s.blockSub = s.eventMux.Subscribe(core.NewMinedBlockEvent{})
    go s.blockBroadcastLoop()

    ethlogger.Infoln("Server started")
    return nil
}

func (self *Ethereum) SuggestPeer(nodeURL string) error {
    n, err := discover.ParseNode(nodeURL)
    if err != nil {
        return fmt.Errorf("invalid node URL: %v", err)
    }
    self.net.SuggestPeer(n)
    return nil
}

func (s *Ethereum) Stop() {
    // Close the database
    defer s.db.Close()

    close(s.quit)

    s.txSub.Unsubscribe()    // quits txBroadcastLoop
    s.blockSub.Unsubscribe() // quits blockBroadcastLoop

    if s.RpcServer != nil {
        s.RpcServer.Stop()
    }

    s.txPool.Stop()
    s.eventMux.Stop()
    s.blockPool.Stop()
    if s.whisper != nil {
        s.whisper.Stop()
    }

    ethlogger.Infoln("Server stopped")
    close(s.shutdownChan)
}

// This function will wait for a shutdown and resumes main thread execution
func (s *Ethereum) WaitForShutdown() {
    <-s.shutdownChan
}

// now tx broadcasting is taken out of txPool
// handled here via subscription, efficiency?
func (self *Ethereum) txBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.txSub.Chan() {
        event := obj.(core.TxPreEvent)
        self.net.Broadcast("eth", TxMsg, event.Tx.RlpData())
    }
}

func (self *Ethereum) blockBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.blockSub.Chan() {
        switch ev := obj.(type) {
        case core.NewMinedBlockEvent:
            self.net.Broadcast("eth", NewBlockMsg, ev.Block.RlpData(), ev.Block.Td)
        }
    }
}

func saveProtocolVersion(db ethutil.Database) {
    d, _ := db.Get([]byte("ProtocolVersion"))
    protocolVersion := ethutil.NewValue(d).Uint()

    if protocolVersion == 0 {
        db.Put([]byte("ProtocolVersion"), ethutil.NewValue(ProtocolVersion).Bytes())
    }
}