github.com/carter-ya/go-ethereum@v0.0.0-20230628080049-d2309be3983b/eth/backend.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Package eth implements the Ethereum protocol.
    18  package eth
    19  
    20  import (
    21  	"errors"
    22  	"fmt"
    23  	"math/big"
    24  	"runtime"
    25  	"sync"
    26  	"sync/atomic"
    27  
    28  	"github.com/ethereum/go-ethereum/accounts"
    29  	"github.com/ethereum/go-ethereum/common"
    30  	"github.com/ethereum/go-ethereum/common/hexutil"
    31  	"github.com/ethereum/go-ethereum/consensus"
    32  	"github.com/ethereum/go-ethereum/consensus/beacon"
    33  	"github.com/ethereum/go-ethereum/consensus/clique"
    34  	"github.com/ethereum/go-ethereum/core"
    35  	"github.com/ethereum/go-ethereum/core/bloombits"
    36  	"github.com/ethereum/go-ethereum/core/rawdb"
    37  	"github.com/ethereum/go-ethereum/core/state/pruner"
    38  	"github.com/ethereum/go-ethereum/core/types"
    39  	"github.com/ethereum/go-ethereum/core/vm"
    40  	"github.com/ethereum/go-ethereum/eth/downloader"
    41  	"github.com/ethereum/go-ethereum/eth/ethconfig"
    42  	"github.com/ethereum/go-ethereum/eth/gasprice"
    43  	"github.com/ethereum/go-ethereum/eth/protocols/eth"
    44  	"github.com/ethereum/go-ethereum/eth/protocols/snap"
    45  	"github.com/ethereum/go-ethereum/ethdb"
    46  	"github.com/ethereum/go-ethereum/event"
    47  	"github.com/ethereum/go-ethereum/internal/ethapi"
    48  	"github.com/ethereum/go-ethereum/internal/shutdowncheck"
    49  	"github.com/ethereum/go-ethereum/log"
    50  	"github.com/ethereum/go-ethereum/miner"
    51  	"github.com/ethereum/go-ethereum/node"
    52  	"github.com/ethereum/go-ethereum/p2p"
    53  	"github.com/ethereum/go-ethereum/p2p/dnsdisc"
    54  	"github.com/ethereum/go-ethereum/p2p/enode"
    55  	"github.com/ethereum/go-ethereum/params"
    56  	"github.com/ethereum/go-ethereum/rlp"
    57  	"github.com/ethereum/go-ethereum/rpc"
    58  )
    59  
    60  // Config contains the configuration options of the ETH protocol.
    61  // Deprecated: use ethconfig.Config instead.
    62  type Config = ethconfig.Config
    63  
    64  // Ethereum implements the Ethereum full node service.
    65  type Ethereum struct {
    66  	config *ethconfig.Config
    67  
    68  	// Handlers
    69  	txPool             *core.TxPool
    70  	blockchain         *core.BlockChain
    71  	handler            *handler
    72  	ethDialCandidates  enode.Iterator
    73  	snapDialCandidates enode.Iterator
    74  	merger             *consensus.Merger
    75  
    76  	// DB interfaces
    77  	chainDb ethdb.Database // Block chain database
    78  
    79  	eventMux       *event.TypeMux
    80  	engine         consensus.Engine
    81  	accountManager *accounts.Manager
    82  
    83  	bloomRequests     chan chan *bloombits.Retrieval // Channel receiving bloom data retrieval requests
    84  	bloomIndexer      *core.ChainIndexer             // Bloom indexer operating during block imports
    85  	closeBloomHandler chan struct{}
    86  
    87  	APIBackend *EthAPIBackend
    88  
    89  	miner     *miner.Miner
    90  	gasPrice  *big.Int
    91  	etherbase common.Address
    92  
    93  	networkID     uint64
    94  	netRPCService *ethapi.NetAPI
    95  
    96  	p2pServer *p2p.Server
    97  
    98  	lock sync.RWMutex // Protects the variadic fields (e.g. gas price and etherbase)
    99  
   100  	shutdownTracker *shutdowncheck.ShutdownTracker // Tracks if and when the node has shutdown ungracefully
   101  }
   102  
   103  // New creates a new Ethereum object (including the
   104  // initialisation of the common Ethereum object)
   105  func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
   106  	// Ensure configuration values are compatible and sane
   107  	if config.SyncMode == downloader.LightSync {
   108  		return nil, errors.New("can't run eth.Ethereum in light sync mode, use les.LightEthereum")
   109  	}
   110  	if !config.SyncMode.IsValid() {
   111  		return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
   112  	}
   113  	if config.Miner.GasPrice == nil || config.Miner.GasPrice.Cmp(common.Big0) <= 0 {
   114  		log.Warn("Sanitizing invalid miner gas price", "provided", config.Miner.GasPrice, "updated", ethconfig.Defaults.Miner.GasPrice)
   115  		config.Miner.GasPrice = new(big.Int).Set(ethconfig.Defaults.Miner.GasPrice)
   116  	}
   117  	if config.NoPruning && config.TrieDirtyCache > 0 {
   118  		if config.SnapshotCache > 0 {
   119  			config.TrieCleanCache += config.TrieDirtyCache * 3 / 5
   120  			config.SnapshotCache += config.TrieDirtyCache * 2 / 5
   121  		} else {
   122  			config.TrieCleanCache += config.TrieDirtyCache
   123  		}
   124  		config.TrieDirtyCache = 0
   125  	}
   126  	log.Info("Allocated trie memory caches", "clean", common.StorageSize(config.TrieCleanCache)*1024*1024, "dirty", common.StorageSize(config.TrieDirtyCache)*1024*1024)
   127  
   128  	// Assemble the Ethereum object
   129  	chainDb, err := stack.OpenDatabaseWithFreezer("chaindata", config.DatabaseCache, config.DatabaseHandles, config.DatabaseFreezer, "eth/db/chaindata/", false)
   130  	if err != nil {
   131  		return nil, err
   132  	}
   133  	if err := pruner.RecoverPruning(stack.ResolvePath(""), chainDb, stack.ResolvePath(config.TrieCleanCacheJournal)); err != nil {
   134  		log.Error("Failed to recover state", "error", err)
   135  	}
   136  	// Transfer mining-related config to the ethash config.
   137  	ethashConfig := config.Ethash
   138  	ethashConfig.NotifyFull = config.Miner.NotifyFull
   139  	cliqueConfig, err := core.LoadCliqueConfig(chainDb, config.Genesis)
   140  	if err != nil {
   141  		return nil, err
   142  	}
   143  	engine := ethconfig.CreateConsensusEngine(stack, &ethashConfig, cliqueConfig, config.Miner.Notify, config.Miner.Noverify, chainDb)
   144  
   145  	eth := &Ethereum{
   146  		config:            config,
   147  		merger:            consensus.NewMerger(chainDb),
   148  		chainDb:           chainDb,
   149  		eventMux:          stack.EventMux(),
   150  		accountManager:    stack.AccountManager(),
   151  		engine:            engine,
   152  		closeBloomHandler: make(chan struct{}),
   153  		networkID:         config.NetworkId,
   154  		gasPrice:          config.Miner.GasPrice,
   155  		etherbase:         config.Miner.Etherbase,
   156  		bloomRequests:     make(chan chan *bloombits.Retrieval),
   157  		bloomIndexer:      core.NewBloomIndexer(chainDb, params.BloomBitsBlocks, params.BloomConfirms),
   158  		p2pServer:         stack.Server(),
   159  		shutdownTracker:   shutdowncheck.NewShutdownTracker(chainDb),
   160  	}
   161  
   162  	bcVersion := rawdb.ReadDatabaseVersion(chainDb)
   163  	var dbVer = "<nil>"
   164  	if bcVersion != nil {
   165  		dbVer = fmt.Sprintf("%d", *bcVersion)
   166  	}
   167  	log.Info("Initialising Ethereum protocol", "network", config.NetworkId, "dbversion", dbVer)
   168  
   169  	if !config.SkipBcVersionCheck {
   170  		if bcVersion != nil && *bcVersion > core.BlockChainVersion {
   171  			return nil, fmt.Errorf("database version is v%d, Geth %s only supports v%d", *bcVersion, params.VersionWithMeta, core.BlockChainVersion)
   172  		} else if bcVersion == nil || *bcVersion < core.BlockChainVersion {
   173  			if bcVersion != nil { // only print warning on upgrade, not on init
   174  				log.Warn("Upgrade blockchain database version", "from", dbVer, "to", core.BlockChainVersion)
   175  			}
   176  			rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
   177  		}
   178  	}
   179  	var (
   180  		vmConfig = vm.Config{
   181  			EnablePreimageRecording: config.EnablePreimageRecording,
   182  		}
   183  		cacheConfig = &core.CacheConfig{
   184  			TrieCleanLimit:      config.TrieCleanCache,
   185  			TrieCleanJournal:    stack.ResolvePath(config.TrieCleanCacheJournal),
   186  			TrieCleanRejournal:  config.TrieCleanCacheRejournal,
   187  			TrieCleanNoPrefetch: config.NoPrefetch,
   188  			TrieDirtyLimit:      config.TrieDirtyCache,
   189  			TrieDirtyDisabled:   config.NoPruning,
   190  			TrieTimeLimit:       config.TrieTimeout,
   191  			SnapshotLimit:       config.SnapshotCache,
   192  			Preimages:           config.Preimages,
   193  		}
   194  	)
   195  	// Override the chain config with provided settings.
   196  	var overrides core.ChainOverrides
   197  	if config.OverrideTerminalTotalDifficulty != nil {
   198  		overrides.OverrideTerminalTotalDifficulty = config.OverrideTerminalTotalDifficulty
   199  	}
   200  	if config.OverrideTerminalTotalDifficultyPassed != nil {
   201  		overrides.OverrideTerminalTotalDifficultyPassed = config.OverrideTerminalTotalDifficultyPassed
   202  	}
   203  	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, config.Genesis, &overrides, eth.engine, vmConfig, eth.shouldPreserve, &config.TxLookupLimit)
   204  	if err != nil {
   205  		return nil, err
   206  	}
   207  	eth.bloomIndexer.Start(eth.blockchain)
   208  
   209  	if config.TxPool.Journal != "" {
   210  		config.TxPool.Journal = stack.ResolvePath(config.TxPool.Journal)
   211  	}
   212  	eth.txPool = core.NewTxPool(config.TxPool, eth.blockchain.Config(), eth.blockchain)
   213  
   214  	// Permit the downloader to use the trie cache allowance during fast sync
   215  	cacheLimit := cacheConfig.TrieCleanLimit + cacheConfig.TrieDirtyLimit + cacheConfig.SnapshotLimit
   216  	checkpoint := config.Checkpoint
   217  	if checkpoint == nil {
   218  		checkpoint = params.TrustedCheckpoints[eth.blockchain.Genesis().Hash()]
   219  	}
   220  	if eth.handler, err = newHandler(&handlerConfig{
   221  		Database:       chainDb,
   222  		Chain:          eth.blockchain,
   223  		TxPool:         eth.txPool,
   224  		Merger:         eth.merger,
   225  		Network:        config.NetworkId,
   226  		Sync:           config.SyncMode,
   227  		BloomCache:     uint64(cacheLimit),
   228  		EventMux:       eth.eventMux,
   229  		Checkpoint:     checkpoint,
   230  		RequiredBlocks: config.RequiredBlocks,
   231  	}); err != nil {
   232  		return nil, err
   233  	}
   234  
   235  	eth.miner = miner.New(eth, &config.Miner, eth.blockchain.Config(), eth.EventMux(), eth.engine, eth.isLocalBlock)
   236  	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))
   237  
   238  	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, eth, nil}
   239  	if eth.APIBackend.allowUnprotectedTxs {
   240  		log.Info("Unprotected transactions allowed")
   241  	}
   242  	gpoParams := config.GPO
   243  	if gpoParams.Default == nil {
   244  		gpoParams.Default = config.Miner.GasPrice
   245  	}
   246  	eth.APIBackend.gpo = gasprice.NewOracle(eth.APIBackend, gpoParams)
   247  
   248  	// Setup DNS discovery iterators.
   249  	dnsclient := dnsdisc.NewClient(dnsdisc.Config{})
   250  	eth.ethDialCandidates, err = dnsclient.NewIterator(eth.config.EthDiscoveryURLs...)
   251  	if err != nil {
   252  		return nil, err
   253  	}
   254  	eth.snapDialCandidates, err = dnsclient.NewIterator(eth.config.SnapDiscoveryURLs...)
   255  	if err != nil {
   256  		return nil, err
   257  	}
   258  
   259  	// Start the RPC service
   260  	eth.netRPCService = ethapi.NewNetAPI(eth.p2pServer, config.NetworkId)
   261  
   262  	// Register the backend on the node
   263  	stack.RegisterAPIs(eth.APIs())
   264  	stack.RegisterProtocols(eth.Protocols())
   265  	stack.RegisterLifecycle(eth)
   266  
   267  	// Successful startup; push a marker and check previous unclean shutdowns.
   268  	eth.shutdownTracker.MarkStartup()
   269  
   270  	return eth, nil
   271  }
   272  
   273  func makeExtraData(extra []byte) []byte {
   274  	if len(extra) == 0 {
   275  		// create default extradata
   276  		extra, _ = rlp.EncodeToBytes([]interface{}{
   277  			uint(params.VersionMajor<<16 | params.VersionMinor<<8 | params.VersionPatch),
   278  			"geth",
   279  			runtime.Version(),
   280  			runtime.GOOS,
   281  		})
   282  	}
   283  	if uint64(len(extra)) > params.MaximumExtraDataSize {
   284  		log.Warn("Miner extra data exceed limit", "extra", hexutil.Bytes(extra), "limit", params.MaximumExtraDataSize)
   285  		extra = nil
   286  	}
   287  	return extra
   288  }
   289  
   290  // APIs return the collection of RPC services the ethereum package offers.
   291  // NOTE, some of these services probably need to be moved to somewhere else.
   292  func (s *Ethereum) APIs() []rpc.API {
   293  	apis := ethapi.GetAPIs(s.APIBackend)
   294  
   295  	// Append any APIs exposed explicitly by the consensus engine
   296  	apis = append(apis, s.engine.APIs(s.BlockChain())...)
   297  
   298  	// Append all the local APIs and return
   299  	return append(apis, []rpc.API{
   300  		{
   301  			Namespace: "eth",
   302  			Service:   NewEthereumAPI(s),
   303  		}, {
   304  			Namespace: "miner",
   305  			Service:   NewMinerAPI(s),
   306  		}, {
   307  			Namespace: "eth",
   308  			Service:   downloader.NewDownloaderAPI(s.handler.downloader, s.eventMux),
   309  		}, {
   310  			Namespace: "admin",
   311  			Service:   NewAdminAPI(s),
   312  		}, {
   313  			Namespace: "debug",
   314  			Service:   NewDebugAPI(s),
   315  		}, {
   316  			Namespace: "net",
   317  			Service:   s.netRPCService,
   318  		},
   319  	}...)
   320  }
   321  
   322  func (s *Ethereum) ResetWithGenesisBlock(gb *types.Block) {
   323  	s.blockchain.ResetWithGenesisBlock(gb)
   324  }
   325  
   326  func (s *Ethereum) Etherbase() (eb common.Address, err error) {
   327  	s.lock.RLock()
   328  	etherbase := s.etherbase
   329  	s.lock.RUnlock()
   330  
   331  	if etherbase != (common.Address{}) {
   332  		return etherbase, nil
   333  	}
   334  	if wallets := s.AccountManager().Wallets(); len(wallets) > 0 {
   335  		if accounts := wallets[0].Accounts(); len(accounts) > 0 {
   336  			etherbase := accounts[0].Address
   337  
   338  			s.lock.Lock()
   339  			s.etherbase = etherbase
   340  			s.lock.Unlock()
   341  
   342  			log.Info("Etherbase automatically configured", "address", etherbase)
   343  			return etherbase, nil
   344  		}
   345  	}
   346  	return common.Address{}, fmt.Errorf("etherbase must be explicitly specified")
   347  }
   348  
   349  // isLocalBlock checks whether the specified block is mined
   350  // by local miner accounts.
   351  //
   352  // We regard two types of accounts as local miner account: etherbase
   353  // and accounts specified via `txpool.locals` flag.
   354  func (s *Ethereum) isLocalBlock(header *types.Header) bool {
   355  	author, err := s.engine.Author(header)
   356  	if err != nil {
   357  		log.Warn("Failed to retrieve block author", "number", header.Number.Uint64(), "hash", header.Hash(), "err", err)
   358  		return false
   359  	}
   360  	// Check whether the given address is etherbase.
   361  	s.lock.RLock()
   362  	etherbase := s.etherbase
   363  	s.lock.RUnlock()
   364  	if author == etherbase {
   365  		return true
   366  	}
   367  	// Check whether the given address is specified by `txpool.local`
   368  	// CLI flag.
   369  	for _, account := range s.config.TxPool.Locals {
   370  		if account == author {
   371  			return true
   372  		}
   373  	}
   374  	return false
   375  }
   376  
   377  // shouldPreserve checks whether we should preserve the given block
   378  // during the chain reorg depending on whether the author of block
   379  // is a local account.
   380  func (s *Ethereum) shouldPreserve(header *types.Header) bool {
   381  	// The reason we need to disable the self-reorg preserving for clique
   382  	// is it can be probable to introduce a deadlock.
   383  	//
   384  	// e.g. If there are 7 available signers
   385  	//
   386  	// r1   A
   387  	// r2     B
   388  	// r3       C
   389  	// r4         D
   390  	// r5   A      [X] F G
   391  	// r6    [X]
   392  	//
   393  	// In the round5, the inturn signer E is offline, so the worst case
   394  	// is A, F and G sign the block of round5 and reject the block of opponents
   395  	// and in the round6, the last available signer B is offline, the whole
   396  	// network is stuck.
   397  	if _, ok := s.engine.(*clique.Clique); ok {
   398  		return false
   399  	}
   400  	return s.isLocalBlock(header)
   401  }
   402  
   403  // SetEtherbase sets the mining reward address.
   404  func (s *Ethereum) SetEtherbase(etherbase common.Address) {
   405  	s.lock.Lock()
   406  	s.etherbase = etherbase
   407  	s.lock.Unlock()
   408  
   409  	s.miner.SetEtherbase(etherbase)
   410  }
   411  
   412  // StartMining starts the miner with the given number of CPU threads. If mining
   413  // is already running, this method adjust the number of threads allowed to use
   414  // and updates the minimum price required by the transaction pool.
   415  func (s *Ethereum) StartMining(threads int) error {
   416  	// Update the thread count within the consensus engine
   417  	type threaded interface {
   418  		SetThreads(threads int)
   419  	}
   420  	if th, ok := s.engine.(threaded); ok {
   421  		log.Info("Updated mining threads", "threads", threads)
   422  		if threads == 0 {
   423  			threads = -1 // Disable the miner from within
   424  		}
   425  		th.SetThreads(threads)
   426  	}
   427  	// If the miner was not running, initialize it
   428  	if !s.IsMining() {
   429  		// Propagate the initial price point to the transaction pool
   430  		s.lock.RLock()
   431  		price := s.gasPrice
   432  		s.lock.RUnlock()
   433  		s.txPool.SetGasPrice(price)
   434  
   435  		// Configure the local mining address
   436  		eb, err := s.Etherbase()
   437  		if err != nil {
   438  			log.Error("Cannot start mining without etherbase", "err", err)
   439  			return fmt.Errorf("etherbase missing: %v", err)
   440  		}
   441  		var cli *clique.Clique
   442  		if c, ok := s.engine.(*clique.Clique); ok {
   443  			cli = c
   444  		} else if cl, ok := s.engine.(*beacon.Beacon); ok {
   445  			if c, ok := cl.InnerEngine().(*clique.Clique); ok {
   446  				cli = c
   447  			}
   448  		}
   449  		if cli != nil {
   450  			wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
   451  			if wallet == nil || err != nil {
   452  				log.Error("Etherbase account unavailable locally", "err", err)
   453  				return fmt.Errorf("signer missing: %v", err)
   454  			}
   455  			cli.Authorize(eb, wallet.SignData)
   456  		}
   457  		// If mining is started, we can disable the transaction rejection mechanism
   458  		// introduced to speed sync times.
   459  		atomic.StoreUint32(&s.handler.acceptTxs, 1)
   460  
   461  		go s.miner.Start(eb)
   462  	}
   463  	return nil
   464  }
   465  
   466  // StopMining terminates the miner, both at the consensus engine level as well as
   467  // at the block creation level.
   468  func (s *Ethereum) StopMining() {
   469  	// Update the thread count within the consensus engine
   470  	type threaded interface {
   471  		SetThreads(threads int)
   472  	}
   473  	if th, ok := s.engine.(threaded); ok {
   474  		th.SetThreads(-1)
   475  	}
   476  	// Stop the block creating itself
   477  	s.miner.Stop()
   478  }
   479  
   480  func (s *Ethereum) IsMining() bool      { return s.miner.Mining() }
   481  func (s *Ethereum) Miner() *miner.Miner { return s.miner }
   482  
   483  func (s *Ethereum) AccountManager() *accounts.Manager  { return s.accountManager }
   484  func (s *Ethereum) BlockChain() *core.BlockChain       { return s.blockchain }
   485  func (s *Ethereum) TxPool() *core.TxPool               { return s.txPool }
   486  func (s *Ethereum) EventMux() *event.TypeMux           { return s.eventMux }
   487  func (s *Ethereum) Engine() consensus.Engine           { return s.engine }
   488  func (s *Ethereum) ChainDb() ethdb.Database            { return s.chainDb }
   489  func (s *Ethereum) IsListening() bool                  { return true } // Always listening
   490  func (s *Ethereum) Downloader() *downloader.Downloader { return s.handler.downloader }
   491  func (s *Ethereum) Synced() bool                       { return atomic.LoadUint32(&s.handler.acceptTxs) == 1 }
   492  func (s *Ethereum) SetSynced()                         { atomic.StoreUint32(&s.handler.acceptTxs, 1) }
   493  func (s *Ethereum) ArchiveMode() bool                  { return s.config.NoPruning }
   494  func (s *Ethereum) BloomIndexer() *core.ChainIndexer   { return s.bloomIndexer }
   495  func (s *Ethereum) Merger() *consensus.Merger          { return s.merger }
   496  func (s *Ethereum) SyncMode() downloader.SyncMode {
   497  	mode, _ := s.handler.chainSync.modeAndLocalHead()
   498  	return mode
   499  }
   500  
   501  // Protocols returns all the currently configured
   502  // network protocols to start.
   503  func (s *Ethereum) Protocols() []p2p.Protocol {
   504  	protos := eth.MakeProtocols((*ethHandler)(s.handler), s.networkID, s.ethDialCandidates)
   505  	if s.config.SnapshotCache > 0 {
   506  		protos = append(protos, snap.MakeProtocols((*snapHandler)(s.handler), s.snapDialCandidates)...)
   507  	}
   508  	return protos
   509  }
   510  
   511  // Start implements node.Lifecycle, starting all internal goroutines needed by the
   512  // Ethereum protocol implementation.
   513  func (s *Ethereum) Start() error {
   514  	eth.StartENRUpdater(s.blockchain, s.p2pServer.LocalNode())
   515  
   516  	// Start the bloom bits servicing goroutines
   517  	s.startBloomHandlers(params.BloomBitsBlocks)
   518  
   519  	// Regularly update shutdown marker
   520  	s.shutdownTracker.Start()
   521  
   522  	// Figure out a max peers count based on the server limits
   523  	maxPeers := s.p2pServer.MaxPeers
   524  	if s.config.LightServ > 0 {
   525  		if s.config.LightPeers >= s.p2pServer.MaxPeers {
   526  			return fmt.Errorf("invalid peer config: light peer count (%d) >= total peer count (%d)", s.config.LightPeers, s.p2pServer.MaxPeers)
   527  		}
   528  		maxPeers -= s.config.LightPeers
   529  	}
   530  	// Start the networking layer and the light server if requested
   531  	s.handler.Start(maxPeers)
   532  	return nil
   533  }
   534  
   535  // Stop implements node.Lifecycle, terminating all internal goroutines used by the
   536  // Ethereum protocol.
   537  func (s *Ethereum) Stop() error {
   538  	// Stop all the peer-related stuff first.
   539  	s.ethDialCandidates.Close()
   540  	s.snapDialCandidates.Close()
   541  	s.handler.Stop()
   542  
   543  	// Then stop everything else.
   544  	s.bloomIndexer.Close()
   545  	close(s.closeBloomHandler)
   546  	s.txPool.Stop()
   547  	s.miner.Close()
   548  	s.blockchain.Stop()
   549  	s.engine.Close()
   550  
   551  	// Clean shutdown marker as the last thing before closing db
   552  	s.shutdownTracker.Stop()
   553  
   554  	s.chainDb.Close()
   555  	s.eventMux.Stop()
   556  
   557  	return nil
   558  }