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"
    "runtime"
    "sync"
    "sync/atomic"

    "github.com/dexon-foundation/dexon/accounts"
    "github.com/dexon-foundation/dexon/common"
    "github.com/dexon-foundation/dexon/common/hexutil"
    "github.com/dexon-foundation/dexon/consensus"
    "github.com/dexon-foundation/dexon/consensus/clique"
    "github.com/dexon-foundation/dexon/consensus/ethash"
    "github.com/dexon-foundation/dexon/core"
    "github.com/dexon-foundation/dexon/core/bloombits"
    "github.com/dexon-foundation/dexon/core/rawdb"
    "github.com/dexon-foundation/dexon/core/types"
    "github.com/dexon-foundation/dexon/core/vm"
    "github.com/dexon-foundation/dexon/eth/downloader"
    "github.com/dexon-foundation/dexon/eth/filters"
    "github.com/dexon-foundation/dexon/eth/gasprice"
    "github.com/dexon-foundation/dexon/ethdb"
    "github.com/dexon-foundation/dexon/event"
    "github.com/dexon-foundation/dexon/internal/ethapi"
    "github.com/dexon-foundation/dexon/log"
    "github.com/dexon-foundation/dexon/miner"
    "github.com/dexon-foundation/dexon/node"
    "github.com/dexon-foundation/dexon/p2p"
    "github.com/dexon-foundation/dexon/params"
    "github.com/dexon-foundation/dexon/rlp"
    "github.com/dexon-foundation/dexon/rpc"
)

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

// Ethereum implements the Ethereum full node service.
type Ethereum struct {
    config      *Config
    chainConfig *params.ChainConfig

    // Channel for shutting down the service
    shutdownChan chan bool // Channel for shutting down the Ethereum

    // Handlers
    txPool          *core.TxPool
    blockchain      *core.BlockChain
    protocolManager *ProtocolManager
    lesServer       LesServer

    // DB interfaces
    chainDb ethdb.Database // Block chain database

    eventMux       *event.TypeMux
    engine         consensus.Engine
    accountManager *accounts.Manager

    bloomRequests chan chan *bloombits.Retrieval // Channel receiving bloom data retrieval requests
    bloomIndexer  *core.ChainIndexer             // Bloom indexer operating during block imports

    APIBackend *EthAPIBackend

    miner     *miner.Miner
    gasPrice  *big.Int
    etherbase common.Address

    networkID     uint64
    netRPCService *ethapi.PublicNetAPI

    lock sync.RWMutex // Protects the variadic fields (e.g. gas price and etherbase)
}

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

// New creates a new Ethereum object (including the
// initialisation of the common Ethereum object)
func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
    // Ensure configuration values are compatible and sane
    if config.SyncMode == downloader.LightSync {
        return nil, errors.New("can't run eth.Ethereum in light sync mode, use les.LightEthereum")
    }
    if !config.SyncMode.IsValid() {
        return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
    }
    if config.MinerGasPrice == nil || config.MinerGasPrice.Cmp(common.Big0) <= 0 {
        log.Warn("Sanitizing invalid miner gas price", "provided", config.MinerGasPrice, "updated", DefaultConfig.MinerGasPrice)
        config.MinerGasPrice = new(big.Int).Set(DefaultConfig.MinerGasPrice)
    }
    // Assemble the Ethereum object
    chainDb, err := CreateDB(ctx, config, "chaindata")
    if err != nil {
        return nil, err
    }
    chainConfig, genesisHash, genesisErr := core.SetupGenesisBlockWithOverride(chainDb, config.Genesis, config.ConstantinopleOverride)
    if _, ok := genesisErr.(*params.ConfigCompatError); genesisErr != nil && !ok {
        return nil, genesisErr
    }
    log.Info("Initialised chain configuration", "config", chainConfig)

    eth := &Ethereum{
        config:         config,
        chainDb:        chainDb,
        chainConfig:    chainConfig,
        eventMux:       ctx.EventMux,
        accountManager: ctx.AccountManager,
        engine:         CreateConsensusEngine(ctx, chainConfig, &config.Ethash, config.MinerNotify, config.MinerNoverify, chainDb),
        shutdownChan:   make(chan bool),
        networkID:      config.NetworkId,
        gasPrice:       config.MinerGasPrice,
        etherbase:      config.Etherbase,
        bloomRequests:  make(chan chan *bloombits.Retrieval),
        bloomIndexer:   NewBloomIndexer(chainDb, params.BloomBitsBlocks, params.BloomConfirms),
    }

    log.Info("Initialising Ethereum protocol", "versions", ProtocolVersions, "network", config.NetworkId)

    if !config.SkipBcVersionCheck {
        bcVersion := rawdb.ReadDatabaseVersion(chainDb)
        if bcVersion != nil && *bcVersion > core.BlockChainVersion {
            return nil, fmt.Errorf("database version is v%d, Geth %s only supports v%d", *bcVersion, params.VersionWithMeta, core.BlockChainVersion)
        } else if bcVersion != nil && *bcVersion < core.BlockChainVersion {
            log.Warn("Upgrade blockchain database version", "from", *bcVersion, "to", core.BlockChainVersion)
        }
        rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
    }
    var (
        vmConfig = vm.Config{
            EnablePreimageRecording: config.EnablePreimageRecording,
            EWASMInterpreter:        config.EWASMInterpreter,
            EVMInterpreter:          config.EVMInterpreter,
        }
        cacheConfig = &core.CacheConfig{Disabled: config.NoPruning, TrieCleanLimit: config.TrieCleanCache, TrieDirtyLimit: config.TrieDirtyCache, TrieTimeLimit: config.TrieTimeout}
    )
    eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, eth.chainConfig, eth.engine, vmConfig, eth.shouldPreserve)
    if err != nil {
        return nil, err
    }
    // Rewind the chain in case of an incompatible config upgrade.
    if compat, ok := genesisErr.(*params.ConfigCompatError); ok {
        log.Warn("Rewinding chain to upgrade configuration", "err", compat)
        eth.blockchain.SetHead(compat.RewindTo)
        rawdb.WriteChainConfig(chainDb, genesisHash, chainConfig)
    }
    eth.bloomIndexer.Start(eth.blockchain)

    if config.TxPool.Journal != "" {
        config.TxPool.Journal = ctx.ResolvePath(config.TxPool.Journal)
    }
    eth.txPool = core.NewTxPool(config.TxPool, eth.chainConfig, eth.blockchain, false)

    if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.SyncMode, config.NetworkId, eth.eventMux, eth.txPool, eth.engine, eth.blockchain, chainDb, config.Whitelist); err != nil {
        return nil, err
    }

    eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine, config.MinerRecommit, config.MinerGasFloor, config.MinerGasCeil, eth.isLocalBlock)
    eth.miner.SetExtra(makeExtraData(config.MinerExtraData))

    eth.APIBackend = &EthAPIBackend{eth, nil}
    gpoParams := config.GPO
    if gpoParams.Default == nil {
        gpoParams.Default = config.MinerGasPrice
    }
    eth.APIBackend.gpo = gasprice.NewOracle(eth.APIBackend, gpoParams)

    return eth, nil
}

func makeExtraData(extra []byte) []byte {
    if len(extra) == 0 {
        // create default extradata
        extra, _ = rlp.EncodeToBytes([]interface{}{
            uint(params.VersionMajor<<16 | params.VersionMinor<<8 | params.VersionPatch),
            "geth",
            runtime.Version(),
            runtime.GOOS,
        })
    }
    if uint64(len(extra)) > params.MaximumExtraDataSize {
        log.Warn("Miner extra data exceed limit", "extra", hexutil.Bytes(extra), "limit", params.MaximumExtraDataSize)
        extra = nil
    }
    return extra
}

// 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 err != nil {
        return nil, err
    }
    if db, ok := db.(*ethdb.LDBDatabase); ok {
        db.Meter("eth/db/chaindata/")
    }
    return db, nil
}

// CreateConsensusEngine creates the required type of consensus engine instance for an Ethereum service
func CreateConsensusEngine(ctx *node.ServiceContext, chainConfig *params.ChainConfig, config *ethash.Config, notify []string, noverify bool, db ethdb.Database) consensus.Engine {
    // If proof-of-authority is requested, set it up
    if chainConfig.Clique != nil {
        return clique.New(chainConfig.Clique, db)
    }
    // Otherwise assume proof-of-work
    switch config.PowMode {
    case ethash.ModeFake:
        log.Warn("Ethash used in fake mode")
        return ethash.NewFaker()
    case ethash.ModeTest:
        log.Warn("Ethash used in test mode")
        return ethash.NewTester(nil, noverify)
    case ethash.ModeShared:
        log.Warn("Ethash used in shared mode")
        return ethash.NewShared()
    default:
        engine := ethash.New(ethash.Config{
            CacheDir:       ctx.ResolvePath(config.CacheDir),
            CachesInMem:    config.CachesInMem,
            CachesOnDisk:   config.CachesOnDisk,
            DatasetDir:     config.DatasetDir,
            DatasetsInMem:  config.DatasetsInMem,
            DatasetsOnDisk: config.DatasetsOnDisk,
        }, notify, noverify)
        engine.SetThreads(-1) // Disable CPU mining
        return engine
    }
}

// APIs return 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 {
    apis := ethapi.GetAPIs(s.APIBackend)

    // Append any APIs exposed explicitly by the consensus engine
    apis = append(apis, s.engine.APIs(s.BlockChain())...)

    // Append all the local APIs and return
    return append(apis, []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) {
    s.lock.RLock()
    etherbase := s.etherbase
    s.lock.RUnlock()

    if etherbase != (common.Address{}) {
        return etherbase, nil
    }
    if wallets := s.AccountManager().Wallets(); len(wallets) > 0 {
        if accounts := wallets[0].Accounts(); len(accounts) > 0 {
            etherbase := accounts[0].Address

            s.lock.Lock()
            s.etherbase = etherbase
            s.lock.Unlock()

            log.Info("Etherbase automatically configured", "address", etherbase)
            return etherbase, nil
        }
    }
    return common.Address{}, fmt.Errorf("etherbase must be explicitly specified")
}

// isLocalBlock checks whether the specified block is mined
// by local miner accounts.
//
// We regard two types of accounts as local miner account: etherbase
// and accounts specified via `txpool.locals` flag.
func (s *Ethereum) isLocalBlock(block *types.Block) bool {
    author, err := s.engine.Author(block.Header())
    if err != nil {
        log.Warn("Failed to retrieve block author", "number", block.NumberU64(), "hash", block.Hash(), "err", err)
        return false
    }
    // Check whether the given address is etherbase.
    s.lock.RLock()
    etherbase := s.etherbase
    s.lock.RUnlock()
    if author == etherbase {
        return true
    }
    // Check whether the given address is specified by `txpool.local`
    // CLI flag.
    for _, account := range s.config.TxPool.Locals {
        if account == author {
            return true
        }
    }
    return false
}

// shouldPreserve checks whether we should preserve the given block
// during the chain reorg depending on whether the author of block
// is a local account.
func (s *Ethereum) shouldPreserve(block *types.Block) bool {
    // The reason we need to disable the self-reorg preserving for clique
    // is it can be probable to introduce a deadlock.
    //
    // e.g. If there are 7 available signers
    //
    // r1   A
    // r2     B
    // r3       C
    // r4         D
    // r5   A      [X] F G
    // r6    [X]
    //
    // In the round5, the inturn signer E is offline, so the worst case
    // is A, F and G sign the block of round5 and reject the block of opponents
    // and in the round6, the last available signer B is offline, the whole
    // network is stuck.
    if _, ok := s.engine.(*clique.Clique); ok {
        return false
    }
    return s.isLocalBlock(block)
}

// SetEtherbase sets the mining reward address.
func (s *Ethereum) SetEtherbase(etherbase common.Address) {
    s.lock.Lock()
    s.etherbase = etherbase
    s.lock.Unlock()

    s.miner.SetEtherbase(etherbase)
}

// StartMining starts the miner with the given number of CPU threads. If mining
// is already running, this method adjust the number of threads allowed to use
// and updates the minimum price required by the transaction pool.
func (s *Ethereum) StartMining(threads int) error {
    // Update the thread count within the consensus engine
    type threaded interface {
        SetThreads(threads int)
    }
    if th, ok := s.engine.(threaded); ok {
        log.Info("Updated mining threads", "threads", threads)
        if threads == 0 {
            threads = -1 // Disable the miner from within
        }
        th.SetThreads(threads)
    }
    // If the miner was not running, initialize it
    if !s.IsMining() {
        // Propagate the initial price point to the transaction pool
        s.lock.RLock()
        price := s.gasPrice
        s.lock.RUnlock()
        s.txPool.SetGasPrice(price)

        // Configure the local mining address
        eb, err := s.Etherbase()
        if err != nil {
            log.Error("Cannot start mining without etherbase", "err", err)
            return fmt.Errorf("etherbase missing: %v", err)
        }
        if clique, ok := s.engine.(*clique.Clique); ok {
            wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
            if wallet == nil || err != nil {
                log.Error("Etherbase account unavailable locally", "err", err)
                return fmt.Errorf("signer missing: %v", err)
            }
            clique.Authorize(eb, wallet.SignHash)
        }
        // If mining is started, we can disable the transaction rejection mechanism
        // introduced to speed sync times.
        atomic.StoreUint32(&s.protocolManager.acceptTxs, 1)

        go s.miner.Start(eb)
    }
    return nil
}

// StopMining terminates the miner, both at the consensus engine level as well as
// at the block creation level.
func (s *Ethereum) StopMining() {
    // Update the thread count within the consensus engine
    type threaded interface {
        SetThreads(threads int)
    }
    if th, ok := s.engine.(threaded); ok {
        th.SetThreads(-1)
    }
    // Stop the block creating itself
    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) Engine() consensus.Engine          { return s.engine }
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() uint64                { return s.networkID }
func (s *Ethereum) Downloader() ethapi.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
    }
    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 {
    // Start the bloom bits servicing goroutines
    s.startBloomHandlers(params.BloomBitsBlocks)

    // Start the RPC service
    s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.NetVersion())

    // Figure out a max peers count based on the server limits
    maxPeers := srvr.MaxPeers
    if s.config.LightServ > 0 {
        if s.config.LightPeers >= srvr.MaxPeers {
            return fmt.Errorf("invalid peer config: light peer count (%d) >= total peer count (%d)", s.config.LightPeers, srvr.MaxPeers)
        }
        maxPeers -= s.config.LightPeers
    }
    // Start the networking layer and the light server if requested
    s.protocolManager.Start(maxPeers)
    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 {
    s.bloomIndexer.Close()
    s.blockchain.Stop()
    s.engine.Close()
    s.protocolManager.Stop()
    if s.lesServer != nil {
        s.lesServer.Stop()
    }
    s.txPool.Stop()
    s.miner.Stop()
    s.eventMux.Stop()

    s.chainDb.Close()
    close(s.shutdownChan)
    return nil
}