path: root/eth/backend.go

// Copyright 2014 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 <http://www.gnu.org/licenses/>.

// Package eth implements the Ethereum protocol.
package eth

import (
    "errors"
    "fmt"
    "math/big"
    "os"
    "path/filepath"
    "regexp"
    "strings"
    "sync"
    "time"

    "github.com/ethereum/ethash"
    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/core/vm"
    "github.com/ethereum/go-ethereum/eth/downloader"
    "github.com/ethereum/go-ethereum/eth/filters"
    "github.com/ethereum/go-ethereum/eth/gasprice"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/internal/ethapi"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/miner"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/params"
    "github.com/ethereum/go-ethereum/pow"
    "github.com/ethereum/go-ethereum/rpc"
)

const (
    epochLength    = 30000
    ethashRevision = 23

    autoDAGcheckInterval = 10 * time.Hour
    autoDAGepochHeight   = epochLength / 2
)

var (
    datadirInUseErrnos = map[uint]bool{11: true, 32: true, 35: true}
    portInUseErrRE     = regexp.MustCompile("address already in use")
)

type Config struct {
    ChainConfig *params.ChainConfig // chain configuration

    NetworkId  int    // Network ID to use for selecting peers to connect to
    Genesis    string // Genesis JSON to seed the chain database with
    FastSync   bool   // Enables the state download based fast synchronisation algorithm
    LightMode  bool   // Running in light client mode
    LightServ  int    // Maximum percentage of time allowed for serving LES requests
    LightPeers int    // Maximum number of LES client peers
    MaxPeers   int    // Maximum number of global peers

    SkipBcVersionCheck bool // e.g. blockchain export
    DatabaseCache      int
    DatabaseHandles    int

    DocRoot   string
    AutoDAG   bool
    PowFake   bool
    PowTest   bool
    PowShared bool
    ExtraData []byte

    Etherbase    common.Address
    GasPrice     *big.Int
    MinerThreads int
    SolcPath     string

    GpoMinGasPrice          *big.Int
    GpoMaxGasPrice          *big.Int
    GpoFullBlockRatio       int
    GpobaseStepDown         int
    GpobaseStepUp           int
    GpobaseCorrectionFactor int

    EnablePreimageRecording bool

    TestGenesisBlock *types.Block   // Genesis block to seed the chain database with (testing only!)
    TestGenesisState ethdb.Database // Genesis state to seed the database with (testing only!)
}

type LesServer interface {
    Start(srvr *p2p.Server)
    Stop()
    Protocols() []p2p.Protocol
}

// Ethereum implements the Ethereum full node service.
type Ethereum struct {
    chainConfig *params.ChainConfig
    // Channel for shutting down the service
    shutdownChan  chan bool // Channel for shutting down the ethereum
    stopDbUpgrade func()    // stop chain db sequential key upgrade
    // Handlers
    txPool          *core.TxPool
    txMu            sync.Mutex
    blockchain      *core.BlockChain
    protocolManager *ProtocolManager
    lesServer       LesServer
    // DB interfaces
    chainDb ethdb.Database // Block chain database

    eventMux       *event.TypeMux
    pow            pow.PoW
    accountManager *accounts.Manager

    ApiBackend *EthApiBackend

    miner        *miner.Miner
    Mining       bool
    MinerThreads int
    AutoDAG      bool
    autodagquit  chan bool
    etherbase    common.Address
    solcPath     string

    netVersionId  int
    netRPCService *ethapi.PublicNetAPI
}

func (s *Ethereum) AddLesServer(ls LesServer) {
    s.lesServer = ls
    s.protocolManager.lesServer = ls
}

// New creates a new Ethereum object (including the
// initialisation of the common Ethereum object)
func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
    chainDb, err := CreateDB(ctx, config, "chaindata")
    if err != nil {
        return nil, err
    }
    stopDbUpgrade := upgradeSequentialKeys(chainDb)
    if err := SetupGenesisBlock(&chainDb, config); err != nil {
        return nil, err
    }
    pow, err := CreatePoW(config)
    if err != nil {
        return nil, err
    }

    eth := &Ethereum{
        chainDb:        chainDb,
        eventMux:       ctx.EventMux,
        accountManager: ctx.AccountManager,
        pow:            pow,
        shutdownChan:   make(chan bool),
        stopDbUpgrade:  stopDbUpgrade,
        netVersionId:   config.NetworkId,
        etherbase:      config.Etherbase,
        MinerThreads:   config.MinerThreads,
        AutoDAG:        config.AutoDAG,
        solcPath:       config.SolcPath,
    }

    if err := addMipmapBloomBins(chainDb); err != nil {
        return nil, err
    }

    log.Info(fmt.Sprintf("Protocol Versions: %v, Network Id: %v", ProtocolVersions, config.NetworkId))

    if !config.SkipBcVersionCheck {
        bcVersion := core.GetBlockChainVersion(chainDb)
        if bcVersion != core.BlockChainVersion && bcVersion != 0 {
            return nil, fmt.Errorf("Blockchain DB version mismatch (%d / %d). Run geth upgradedb.\n", bcVersion, core.BlockChainVersion)
        }
        core.WriteBlockChainVersion(chainDb, core.BlockChainVersion)
    }

    // load the genesis block or write a new one if no genesis
    // block is prenent in the database.
    genesis := core.GetBlock(chainDb, core.GetCanonicalHash(chainDb, 0), 0)
    if genesis == nil {
        genesis, err = core.WriteDefaultGenesisBlock(chainDb)
        if err != nil {
            return nil, err
        }
        log.Info(fmt.Sprint("WARNING: Wrote default ethereum genesis block"))
    }

    if config.ChainConfig == nil {
        return nil, errors.New("missing chain config")
    }
    core.WriteChainConfig(chainDb, genesis.Hash(), config.ChainConfig)

    eth.chainConfig = config.ChainConfig

    log.Info(fmt.Sprint("Chain config:", eth.chainConfig))

    eth.blockchain, err = core.NewBlockChain(chainDb, eth.chainConfig, eth.pow, eth.EventMux(), vm.Config{EnablePreimageRecording: config.EnablePreimageRecording})
    if err != nil {
        if err == core.ErrNoGenesis {
            return nil, fmt.Errorf(`No chain found. Please initialise a new chain using the "init" subcommand.`)
        }
        return nil, err
    }
    newPool := core.NewTxPool(eth.chainConfig, eth.EventMux(), eth.blockchain.State, eth.blockchain.GasLimit)
    eth.txPool = newPool

    maxPeers := config.MaxPeers
    if config.LightServ > 0 {
        // if we are running a light server, limit the number of ETH peers so that we reserve some space for incoming LES connections
        // temporary solution until the new peer connectivity API is finished
        halfPeers := maxPeers / 2
        maxPeers -= config.LightPeers
        if maxPeers < halfPeers {
            maxPeers = halfPeers
        }
    }

    if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.FastSync, config.NetworkId, maxPeers, eth.eventMux, eth.txPool, eth.pow, eth.blockchain, chainDb); err != nil {
        return nil, err
    }
    eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.pow)
    eth.miner.SetGasPrice(config.GasPrice)
    eth.miner.SetExtra(config.ExtraData)

    gpoParams := &gasprice.GpoParams{
        GpoMinGasPrice:          config.GpoMinGasPrice,
        GpoMaxGasPrice:          config.GpoMaxGasPrice,
        GpoFullBlockRatio:       config.GpoFullBlockRatio,
        GpobaseStepDown:         config.GpobaseStepDown,
        GpobaseStepUp:           config.GpobaseStepUp,
        GpobaseCorrectionFactor: config.GpobaseCorrectionFactor,
    }
    gpo := gasprice.NewGasPriceOracle(eth.blockchain, chainDb, eth.eventMux, gpoParams)
    eth.ApiBackend = &EthApiBackend{eth, gpo}

    return eth, nil
}

// CreateDB creates the chain database.
func CreateDB(ctx *node.ServiceContext, config *Config, name string) (ethdb.Database, error) {
    db, err := ctx.OpenDatabase(name, config.DatabaseCache, config.DatabaseHandles)
    if db, ok := db.(*ethdb.LDBDatabase); ok {
        db.Meter("eth/db/chaindata/")
    }
    return db, err
}

// SetupGenesisBlock initializes the genesis block for an Ethereum service
func SetupGenesisBlock(chainDb *ethdb.Database, config *Config) error {
    // Load up any custom genesis block if requested
    if len(config.Genesis) > 0 {
        block, err := core.WriteGenesisBlock(*chainDb, strings.NewReader(config.Genesis))
        if err != nil {
            return err
        }
        log.Info(fmt.Sprintf("Successfully wrote custom genesis block: %x", block.Hash()))
    }
    // Load up a test setup if directly injected
    if config.TestGenesisState != nil {
        *chainDb = config.TestGenesisState
    }
    if config.TestGenesisBlock != nil {
        core.WriteTd(*chainDb, config.TestGenesisBlock.Hash(), config.TestGenesisBlock.NumberU64(), config.TestGenesisBlock.Difficulty())
        core.WriteBlock(*chainDb, config.TestGenesisBlock)
        core.WriteCanonicalHash(*chainDb, config.TestGenesisBlock.Hash(), config.TestGenesisBlock.NumberU64())
        core.WriteHeadBlockHash(*chainDb, config.TestGenesisBlock.Hash())
    }
    return nil
}

// CreatePoW creates the required type of PoW instance for an Ethereum service
func CreatePoW(config *Config) (pow.PoW, error) {
    switch {
    case config.PowFake:
        log.Info(fmt.Sprintf("ethash used in fake mode"))
        return pow.PoW(core.FakePow{}), nil
    case config.PowTest:
        log.Info(fmt.Sprintf("ethash used in test mode"))
        return ethash.NewForTesting()
    case config.PowShared:
        log.Info(fmt.Sprintf("ethash used in shared mode"))
        return ethash.NewShared(), nil
    default:
        return ethash.New(), nil
    }
}

// APIs returns the collection of RPC services the ethereum package offers.
// NOTE, some of these services probably need to be moved to somewhere else.
func (s *Ethereum) APIs() []rpc.API {
    return append(ethapi.GetAPIs(s.ApiBackend, s.solcPath), []rpc.API{
        {
            Namespace: "eth",
            Version:   "1.0",
            Service:   NewPublicEthereumAPI(s),
            Public:    true,
        }, {
            Namespace: "eth",
            Version:   "1.0",
            Service:   NewPublicMinerAPI(s),
            Public:    true,
        }, {
            Namespace: "eth",
            Version:   "1.0",
            Service:   downloader.NewPublicDownloaderAPI(s.protocolManager.downloader, s.eventMux),
            Public:    true,
        }, {
            Namespace: "miner",
            Version:   "1.0",
            Service:   NewPrivateMinerAPI(s),
            Public:    false,
        }, {
            Namespace: "eth",
            Version:   "1.0",
            Service:   filters.NewPublicFilterAPI(s.ApiBackend, false),
            Public:    true,
        }, {
            Namespace: "admin",
            Version:   "1.0",
            Service:   NewPrivateAdminAPI(s),
        }, {
            Namespace: "debug",
            Version:   "1.0",
            Service:   NewPublicDebugAPI(s),
            Public:    true,
        }, {
            Namespace: "debug",
            Version:   "1.0",
            Service:   NewPrivateDebugAPI(s.chainConfig, s),
        }, {
            Namespace: "net",
            Version:   "1.0",
            Service:   s.netRPCService,
            Public:    true,
        },
    }...)
}

func (s *Ethereum) ResetWithGenesisBlock(gb *types.Block) {
    s.blockchain.ResetWithGenesisBlock(gb)
}

func (s *Ethereum) Etherbase() (eb common.Address, err error) {
    if s.etherbase != (common.Address{}) {
        return s.etherbase, nil
    }
    if wallets := s.AccountManager().Wallets(); len(wallets) > 0 {
        if accounts := wallets[0].Accounts(); len(accounts) > 0 {
            return accounts[0].Address, nil
        }
    }
    return common.Address{}, fmt.Errorf("etherbase address must be explicitly specified")
}

// set in js console via admin interface or wrapper from cli flags
func (self *Ethereum) SetEtherbase(etherbase common.Address) {
    self.etherbase = etherbase
    self.miner.SetEtherbase(etherbase)
}

func (s *Ethereum) StartMining(threads int) error {
    eb, err := s.Etherbase()
    if err != nil {
        err = fmt.Errorf("Cannot start mining without etherbase address: %v", err)
        log.Error(fmt.Sprint(err))
        return err
    }
    go s.miner.Start(eb, threads)
    return nil
}

func (s *Ethereum) StopMining()         { s.miner.Stop() }
func (s *Ethereum) IsMining() bool      { return s.miner.Mining() }
func (s *Ethereum) Miner() *miner.Miner { return s.miner }

func (s *Ethereum) AccountManager() *accounts.Manager  { return s.accountManager }
func (s *Ethereum) BlockChain() *core.BlockChain       { return s.blockchain }
func (s *Ethereum) TxPool() *core.TxPool               { return s.txPool }
func (s *Ethereum) EventMux() *event.TypeMux           { return s.eventMux }
func (s *Ethereum) Pow() pow.PoW                       { return s.pow }
func (s *Ethereum) ChainDb() ethdb.Database            { return s.chainDb }
func (s *Ethereum) IsListening() bool                  { return true } // Always listening
func (s *Ethereum) EthVersion() int                    { return int(s.protocolManager.SubProtocols[0].Version) }
func (s *Ethereum) NetVersion() int                    { return s.netVersionId }
func (s *Ethereum) Downloader() *downloader.Downloader { return s.protocolManager.downloader }

// Protocols implements node.Service, returning all the currently configured
// network protocols to start.
func (s *Ethereum) Protocols() []p2p.Protocol {
    if s.lesServer == nil {
        return s.protocolManager.SubProtocols
    } else {
        return append(s.protocolManager.SubProtocols, s.lesServer.Protocols()...)
    }
}

// Start implements node.Service, starting all internal goroutines needed by the
// Ethereum protocol implementation.
func (s *Ethereum) Start(srvr *p2p.Server) error {
    s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.NetVersion())
    if s.AutoDAG {
        s.StartAutoDAG()
    }
    s.protocolManager.Start()
    if s.lesServer != nil {
        s.lesServer.Start(srvr)
    }
    return nil
}

// Stop implements node.Service, terminating all internal goroutines used by the
// Ethereum protocol.
func (s *Ethereum) Stop() error {
    if s.stopDbUpgrade != nil {
        s.stopDbUpgrade()
    }
    s.blockchain.Stop()
    s.protocolManager.Stop()
    if s.lesServer != nil {
        s.lesServer.Stop()
    }
    s.txPool.Stop()
    s.miner.Stop()
    s.eventMux.Stop()

    s.StopAutoDAG()

    s.chainDb.Close()
    close(s.shutdownChan)

    return nil
}

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

// StartAutoDAG() spawns a go routine that checks the DAG every autoDAGcheckInterval
// by default that is 10 times per epoch
// in epoch n, if we past autoDAGepochHeight within-epoch blocks,
// it calls ethash.MakeDAG  to pregenerate the DAG for the next epoch n+1
// if it does not exist yet as well as remove the DAG for epoch n-1
// the loop quits if autodagquit channel is closed, it can safely restart and
// stop any number of times.
// For any more sophisticated pattern of DAG generation, use CLI subcommand
// makedag
func (self *Ethereum) StartAutoDAG() {
    if self.autodagquit != nil {
        return // already started
    }
    go func() {
        log.Info(fmt.Sprintf("Automatic pregeneration of ethash DAG ON (ethash dir: %s)", ethash.DefaultDir))
        var nextEpoch uint64
        timer := time.After(0)
        self.autodagquit = make(chan bool)
        for {
            select {
            case <-timer:
                log.Info(fmt.Sprintf("checking DAG (ethash dir: %s)", ethash.DefaultDir))
                currentBlock := self.BlockChain().CurrentBlock().NumberU64()
                thisEpoch := currentBlock / epochLength
                if nextEpoch <= thisEpoch {
                    if currentBlock%epochLength > autoDAGepochHeight {
                        if thisEpoch > 0 {
                            previousDag, previousDagFull := dagFiles(thisEpoch - 1)
                            os.Remove(filepath.Join(ethash.DefaultDir, previousDag))
                            os.Remove(filepath.Join(ethash.DefaultDir, previousDagFull))
                            log.Info(fmt.Sprintf("removed DAG for epoch %d (%s)", thisEpoch-1, previousDag))
                        }
                        nextEpoch = thisEpoch + 1
                        dag, _ := dagFiles(nextEpoch)
                        if _, err := os.Stat(dag); os.IsNotExist(err) {
                            log.Info(fmt.Sprintf("Pregenerating DAG for epoch %d (%s)", nextEpoch, dag))
                            err := ethash.MakeDAG(nextEpoch*epochLength, "") // "" -> ethash.DefaultDir
                            if err != nil {
                                log.Error(fmt.Sprintf("Error generating DAG for epoch %d (%s)", nextEpoch, dag))
                                return
                            }
                        } else {
                            log.Error(fmt.Sprintf("DAG for epoch %d (%s)", nextEpoch, dag))
                        }
                    }
                }
                timer = time.After(autoDAGcheckInterval)
            case <-self.autodagquit:
                return
            }
        }
    }()
}

// stopAutoDAG stops automatic DAG pregeneration by quitting the loop
func (self *Ethereum) StopAutoDAG() {
    if self.autodagquit != nil {
        close(self.autodagquit)
        self.autodagquit = nil
    }
    log.Info(fmt.Sprintf("Automatic pregeneration of ethash DAG OFF (ethash dir: %s)", ethash.DefaultDir))
}

// dagFiles(epoch) returns the two alternative DAG filenames (not a path)
// 1) <revision>-<hex(seedhash[8])> 2) full-R<revision>-<hex(seedhash[8])>
func dagFiles(epoch uint64) (string, string) {
    seedHash, _ := ethash.GetSeedHash(epoch * epochLength)
    dag := fmt.Sprintf("full-R%d-%x", ethashRevision, seedHash[:8])
    return dag, "full-R" + dag
}