github.com/intfoundation/intchain@v0.0.0-20220727031208-4316ad31ca73/intprotocol/handler.go

// Copyright 2015 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 intprotocol

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/intfoundation/intchain/core/rawdb"
	"math"
	"math/big"
	"sync"
	"sync/atomic"
	"time"

	"github.com/intfoundation/intchain/common"
	"github.com/intfoundation/intchain/consensus"
	"github.com/intfoundation/intchain/core"
	"github.com/intfoundation/intchain/core/types"
	"github.com/intfoundation/intchain/crypto"
	"github.com/intfoundation/intchain/event"
	"github.com/intfoundation/intchain/intdb"
	"github.com/intfoundation/intchain/intprotocol/downloader"
	"github.com/intfoundation/intchain/intprotocol/fetcher"
	"github.com/intfoundation/intchain/log"
	"github.com/intfoundation/intchain/p2p"
	"github.com/intfoundation/intchain/p2p/discover"
	"github.com/intfoundation/intchain/params"
	"github.com/intfoundation/intchain/rlp"
)

const (
	softResponseLimit = 2 * 1024 * 1024 // Target maximum size of returned blocks, headers or node data.
	estHeaderRlpSize  = 500             // Approximate size of an RLP encoded block header

	// txChanSize is the size of channel listening to TxPreEvent.
	// The number is referenced from the size of tx pool.
	txChanSize = 4096

	// tx3PrfDtChainSize is the size of channel listening to Tx3PrfDataEvent.
	// The number is referenced from the size of tx pool.
	tx3PrfDtChainSize = 4096
)

var (
	daoChallengeTimeout = 15 * time.Second // Time allowance for a node to reply to the DAO handshake challenge
)

// errIncompatibleConfig is returned if the requested protocols and configs are
// not compatible (low protocol version restrictions and high requirements).
var errIncompatibleConfig = errors.New("incompatible configuration")

func errResp(code errCode, format string, v ...interface{}) error {
	return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}

type ProtocolManager struct {
	networkId uint64

	fastSync  uint32 // Flag whether fast sync is enabled (gets disabled if we already have blocks)
	acceptTxs uint32 // Flag whether we're considered synchronised (enables transaction processing)

	txpool      txPool
	blockchain  *core.BlockChain
	chainconfig *params.ChainConfig
	maxPeers    int

	downloader *downloader.Downloader
	fetcher    *fetcher.Fetcher
	peers      *peerSet

	SubProtocols []p2p.Protocol

	eventMux *event.TypeMux
	txCh     chan core.TxPreEvent
	txSub    event.Subscription

	tx3PrfDtCh    chan core.Tx3ProofDataEvent
	tx3PrfDtFeed  event.Feed
	tx3PrfDtScope event.SubscriptionScope
	tx3PrfDtSub   event.Subscription

	minedBlockSub *event.TypeMuxSubscription

	// channels for fetcher, syncer, txsyncLoop
	newPeerCh   chan *peer
	txsyncCh    chan *txsync
	quitSync    chan struct{}
	noMorePeers chan struct{}

	// wait group is used for graceful shutdowns during downloading
	// and processing
	wg sync.WaitGroup

	engine consensus.Engine

	cch core.CrossChainHelper

	logger         log.Logger
	preimageLogger log.Logger
}

// NewProtocolManager returns a new INT Chain sub protocol manager. The INT Chain sub protocol manages peers capable
// with the INT Chain network.
func NewProtocolManager(config *params.ChainConfig, mode downloader.SyncMode, networkId uint64, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb intdb.Database, cch core.CrossChainHelper) (*ProtocolManager, error) {
	// Create the protocol manager with the base fields
	manager := &ProtocolManager{
		networkId:      networkId,
		eventMux:       mux,
		txpool:         txpool,
		blockchain:     blockchain,
		chainconfig:    config,
		peers:          newPeerSet(),
		newPeerCh:      make(chan *peer),
		noMorePeers:    make(chan struct{}),
		txsyncCh:       make(chan *txsync),
		quitSync:       make(chan struct{}),
		engine:         engine,
		cch:            cch,
		logger:         config.ChainLogger,
		preimageLogger: config.ChainLogger.New("module", "preimages"),
	}

	if handler, ok := manager.engine.(consensus.Handler); ok {
		handler.SetBroadcaster(manager)
	}

	// Figure out whether to allow fast sync or not
	if mode == downloader.FastSync && blockchain.CurrentBlock().NumberU64() > 0 {
		manager.logger.Warn("Blockchain not empty, fast sync disabled")
		mode = downloader.FullSync
	}
	if mode == downloader.FastSync {
		manager.fastSync = uint32(1)
	}
	protocol := engine.Protocol()
	// Initiate a sub-protocol for every implemented version we can handle
	manager.SubProtocols = make([]p2p.Protocol, 0, len(protocol.Versions))
	for i, version := range protocol.Versions {
		// Skip protocol version if incompatible with the mode of operation
		if mode == downloader.FastSync && version < consensus.Eth63 {
			continue
		}
		// Compatible; initialise the sub-protocol
		version := version // Closure for the run
		manager.SubProtocols = append(manager.SubProtocols, p2p.Protocol{
			Name:    protocol.Name,
			Version: version,
			Length:  protocol.Lengths[i],
			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
				peer := manager.newPeer(int(version), p, rw)
				select {
				case manager.newPeerCh <- peer:
					manager.wg.Add(1)
					defer manager.wg.Done()
					return manager.handle(peer)
				case <-manager.quitSync:
					return p2p.DiscQuitting
				}
			},
			NodeInfo: func() interface{} {
				return manager.NodeInfo()
			},
			PeerInfo: func(id discover.NodeID) interface{} {
				if p := manager.peers.Peer(fmt.Sprintf("%x", id[:8])); p != nil {
					return p.Info()
				}
				return nil
			},
		})
	}
	if len(manager.SubProtocols) == 0 {
		return nil, errIncompatibleConfig
	}
	// Construct the different synchronisation mechanisms
	manager.downloader = downloader.New(mode, chaindb, manager.eventMux, blockchain, nil, manager.removePeer, manager.logger)

	validator := func(header *types.Header) error {
		return engine.VerifyHeader(blockchain, header, true)
	}
	heighter := func() uint64 {
		return blockchain.CurrentBlock().NumberU64()
	}
	inserter := func(blocks types.Blocks) (int, error) {
		// If fast sync is running, deny importing weird blocks
		if atomic.LoadUint32(&manager.fastSync) == 1 {
			manager.logger.Warn("Discarded bad propagated block", "number", blocks[0].Number(), "hash", blocks[0].Hash())
			return 0, nil
		}
		atomic.StoreUint32(&manager.acceptTxs, 1) // Mark initial sync done on any fetcher import
		return manager.blockchain.InsertChain(blocks)
	}
	manager.fetcher = fetcher.New(blockchain.GetBlockByHash, validator, manager.BroadcastBlock, heighter, inserter, manager.removePeer)

	return manager, nil
}

func (pm *ProtocolManager) removePeer(id string) {
	// Short circuit if the peer was already removed
	peer := pm.peers.Peer(id)
	if peer == nil {
		return
	}
	pm.logger.Debug("Removing INT Chain peer", "peer", id)

	// Unregister the peer from the downloader and INT Chain peer set
	pm.downloader.UnregisterPeer(id)
	if err := pm.peers.Unregister(id); err != nil {
		pm.logger.Error("Peer removal failed", "peer", id, "err", err)
	}
	// Hard disconnect at the networking layer
	if peer != nil {
		peer.Peer.Disconnect(p2p.DiscUselessPeer)
	}
}

func (pm *ProtocolManager) Start(maxPeers int) {
	pm.maxPeers = maxPeers

	// broadcast transactions
	pm.txCh = make(chan core.TxPreEvent, txChanSize)
	pm.txSub = pm.txpool.SubscribeTxPreEvent(pm.txCh)
	go pm.txBroadcastLoop()

	pm.tx3PrfDtCh = make(chan core.Tx3ProofDataEvent, tx3PrfDtChainSize)
	pm.tx3PrfDtSub = pm.tx3PrfDtScope.Track(pm.tx3PrfDtFeed.Subscribe(pm.tx3PrfDtCh))
	go pm.tx3PrfDtBroadcastLoop()

	// broadcast mined blocks
	pm.minedBlockSub = pm.eventMux.Subscribe(core.NewMinedBlockEvent{})
	go pm.minedBroadcastLoop()

	// start sync handlers
	go pm.syncer()
	go pm.txsyncLoop()
}

func (pm *ProtocolManager) Stop() {
	pm.logger.Info("Stopping INT Chain protocol")

	pm.txSub.Unsubscribe()         // quits txBroadcastLoop
	pm.tx3PrfDtSub.Unsubscribe()   // quits tx3PrfDtBroadcastLoop
	pm.minedBlockSub.Unsubscribe() // quits blockBroadcastLoop

	// Quit the sync loop.
	// After this send has completed, no new peers will be accepted.
	pm.noMorePeers <- struct{}{}

	// Quit fetcher, txsyncLoop.
	close(pm.quitSync)

	// Disconnect existing sessions.
	// This also closes the gate for any new registrations on the peer set.
	// sessions which are already established but not added to pm.peers yet
	// will exit when they try to register.
	pm.peers.Close()

	// Wait for all peer handler goroutines and the loops to come down.
	pm.wg.Wait()

	pm.logger.Info("INT Chain protocol stopped")
}

func (pm *ProtocolManager) newPeer(pv int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
	return newPeer(pv, p, newMeteredMsgWriter(rw))
}

// handle is the callback invoked to manage the life cycle of an intprotocol peer. When
// this function terminates, the peer is disconnected.
func (pm *ProtocolManager) handle(p *peer) error {
	// Ignore maxPeers if this is a trusted peer
	if pm.peers.Len() >= pm.maxPeers && !p.Peer.Info().Network.Trusted {
		return p2p.DiscTooManyPeers
	}
	p.Log().Debug("INT Chain peer connected", "name", p.Name())

	// Execute the INT Chain handshake
	var (
		genesis = pm.blockchain.Genesis()
		head    = pm.blockchain.CurrentHeader()
		hash    = head.Hash()
		number  = head.Number.Uint64()
		td      = pm.blockchain.GetTd(hash, number)
	)
	if err := p.Handshake(pm.networkId, td, hash, genesis.Hash()); err != nil {
		p.Log().Debug("INT Chain handshake failed", "err", err)
		return err
	}
	if rw, ok := p.rw.(*meteredMsgReadWriter); ok {
		rw.Init(p.version)
	}
	// Register the peer locally
	if err := pm.peers.Register(p); err != nil {
		p.Log().Error("INT Chain peer registration failed", "err", err)
		return err
	}

	defer func() {
		pm.removePeer(p.id)
		if handler, ok := pm.engine.(consensus.Handler); ok {
			handler.RemovePeer(p)
		}
	}()

	// Register the peer in the downloader. If the downloader considers it banned, we disconnect
	if err := pm.downloader.RegisterPeer(p.id, p.version, p); err != nil {
		return err
	}
	// Propagate existing transactions. new transactions appearing
	// after this will be sent via broadcasts.
	pm.syncTransactions(p)

	// Add Peer to Consensus Engine
	if handler, ok := pm.engine.(consensus.Handler); ok {
		handler.AddPeer(p)
	} else {
		p.Log().Info("AddPeer not executed")
	}

	// main loop. handle incoming messages.
	for {
		if err := pm.handleMsg(p); err != nil {
			p.Log().Debug("INT Chain message handling failed", "err", err)
			return err
		}
	}
}

// handleMsg is invoked whenever an inbound message is received from a remote
// peer. The remote connection is torn down upon returning any error.
func (pm *ProtocolManager) handleMsg(p *peer) error {
	// Read the next message from the remote peer, and ensure it's fully consumed
	msg, err := p.rw.ReadMsg()
	if err != nil {
		return err
	}
	if msg.Size > ProtocolMaxMsgSize {
		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
	}
	defer msg.Discard()

	// Handle the message depending on its contents
	switch {
	// IntChain Consensus Message
	case msg.Code >= 0x20 && msg.Code <= 0x23:
		if handler, ok := pm.engine.(consensus.Handler); ok {
			var msgBytes []byte
			if err := msg.Decode(&msgBytes); err != nil {
				return errResp(ErrDecode, "msg %v: %v", msg, err)
			}
			handler.HandleMsg(msg.Code, p, msgBytes)
		}
	case msg.Code == StatusMsg:
		// Status messages should never arrive after the handshake
		return errResp(ErrExtraStatusMsg, "uncontrolled status message")

	// Block header query, collect the requested headers and reply
	case msg.Code == GetBlockHeadersMsg:
		// Decode the complex header query
		var query getBlockHeadersData
		if err := msg.Decode(&query); err != nil {
			return errResp(ErrDecode, "%v: %v", msg, err)
		}
		hashMode := query.Origin.Hash != (common.Hash{})

		// Gather headers until the fetch or network limits is reached
		var (
			bytes   common.StorageSize
			headers []*types.Header
			unknown bool
		)
		for !unknown && len(headers) < int(query.Amount) && bytes < softResponseLimit && len(headers) < downloader.MaxHeaderFetch {
			// Retrieve the next header satisfying the query
			var origin *types.Header
			if hashMode {
				origin = pm.blockchain.GetHeaderByHash(query.Origin.Hash)
			} else {
				origin = pm.blockchain.GetHeaderByNumber(query.Origin.Number)
			}
			if origin == nil {
				break
			}
			number := origin.Number.Uint64()
			headers = append(headers, origin)
			bytes += estHeaderRlpSize

			// Advance to the next header of the query
			switch {
			case query.Origin.Hash != (common.Hash{}) && query.Reverse:
				// Hash based traversal towards the genesis block
				for i := 0; i < int(query.Skip)+1; i++ {
					if header := pm.blockchain.GetHeader(query.Origin.Hash, number); header != nil {
						query.Origin.Hash = header.ParentHash
						number--
					} else {
						unknown = true
						break
					}
				}
			case query.Origin.Hash != (common.Hash{}) && !query.Reverse:
				// Hash based traversal towards the leaf block
				var (
					current = origin.Number.Uint64()
					next    = current + query.Skip + 1
				)
				if next <= current {
					infos, _ := json.MarshalIndent(p.Peer.Info(), "", "  ")
					p.Log().Warn("GetBlockHeaders skip overflow attack", "current", current, "skip", query.Skip, "next", next, "attacker", infos)
					unknown = true
				} else {
					if header := pm.blockchain.GetHeaderByNumber(next); header != nil {
						if pm.blockchain.GetBlockHashesFromHash(header.Hash(), query.Skip+1)[query.Skip] == query.Origin.Hash {
							query.Origin.Hash = header.Hash()
						} else {
							unknown = true
						}
					} else {
						unknown = true
					}
				}
			case query.Reverse:
				// Number based traversal towards the genesis block
				if query.Origin.Number >= query.Skip+1 {
					query.Origin.Number -= query.Skip + 1
				} else {
					unknown = true
				}

			case !query.Reverse:
				// Number based traversal towards the leaf block
				query.Origin.Number += query.Skip + 1
			}
		}
		return p.SendBlockHeaders(headers)

	case msg.Code == BlockHeadersMsg:
		// A batch of headers arrived to one of our previous requests
		var headers []*types.Header
		if err := msg.Decode(&headers); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}

		// Filter out any explicitly requested headers, deliver the rest to the downloader
		filter := len(headers) == 1
		if filter {
			// Irrelevant of the fork checks, send the header to the fetcher just in case
			headers = pm.fetcher.FilterHeaders(p.id, headers, time.Now())
		}
		if len(headers) > 0 || !filter {
			err := pm.downloader.DeliverHeaders(p.id, headers)
			if err != nil {
				pm.logger.Debug("Failed to deliver headers", "err", err)
			}
		}

	case msg.Code == GetBlockBodiesMsg:
		// Decode the retrieval message
		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
		if _, err := msgStream.List(); err != nil {
			return err
		}
		// Gather blocks until the fetch or network limits is reached
		var (
			hash   common.Hash
			bytes  int
			bodies []rlp.RawValue
		)
		for bytes < softResponseLimit && len(bodies) < downloader.MaxBlockFetch {
			// Retrieve the hash of the next block
			if err := msgStream.Decode(&hash); err == rlp.EOL {
				break
			} else if err != nil {
				return errResp(ErrDecode, "msg %v: %v", msg, err)
			}
			// Retrieve the requested block body, stopping if enough was found
			if data := pm.blockchain.GetBodyRLP(hash); len(data) != 0 {
				bodies = append(bodies, data)
				bytes += len(data)
			}
		}
		return p.SendBlockBodiesRLP(bodies)

	case msg.Code == BlockBodiesMsg:
		// A batch of block bodies arrived to one of our previous requests
		var request blockBodiesData
		if err := msg.Decode(&request); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		// Deliver them all to the downloader for queuing
		trasactions := make([][]*types.Transaction, len(request))
		uncles := make([][]*types.Header, len(request))

		for i, body := range request {
			trasactions[i] = body.Transactions
			uncles[i] = body.Uncles
		}
		// Filter out any explicitly requested bodies, deliver the rest to the downloader
		filter := len(trasactions) > 0 || len(uncles) > 0
		if filter {
			trasactions, uncles = pm.fetcher.FilterBodies(p.id, trasactions, uncles, time.Now())
		}
		if len(trasactions) > 0 || len(uncles) > 0 || !filter {
			err := pm.downloader.DeliverBodies(p.id, trasactions, uncles)
			if err != nil {
				pm.logger.Debug("Failed to deliver bodies", "err", err)
			}
		}

	case p.version >= consensus.Eth63 && msg.Code == GetNodeDataMsg:
		// Decode the retrieval message
		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
		if _, err := msgStream.List(); err != nil {
			return err
		}
		// Gather state data until the fetch or network limits is reached
		var (
			hash  common.Hash
			bytes int
			data  [][]byte
		)
		for bytes < softResponseLimit && len(data) < downloader.MaxStateFetch {
			// Retrieve the hash of the next state entry
			if err := msgStream.Decode(&hash); err == rlp.EOL {
				break
			} else if err != nil {
				return errResp(ErrDecode, "msg %v: %v", msg, err)
			}
			// Retrieve the requested state entry, stopping if enough was found
			if entry, err := pm.blockchain.TrieNode(hash); err == nil {
				data = append(data, entry)
				bytes += len(entry)
			}
		}
		return p.SendNodeData(data)

	case p.version >= consensus.Eth63 && msg.Code == NodeDataMsg:
		// A batch of node state data arrived to one of our previous requests
		var data [][]byte
		if err := msg.Decode(&data); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		// Deliver all to the downloader
		if err := pm.downloader.DeliverNodeData(p.id, data); err != nil {
			pm.logger.Debug("Failed to deliver node state data", "err", err)
		}

	case p.version >= consensus.Eth63 && msg.Code == GetReceiptsMsg:
		// Decode the retrieval message
		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
		if _, err := msgStream.List(); err != nil {
			return err
		}
		// Gather state data until the fetch or network limits is reached
		var (
			hash     common.Hash
			bytes    int
			receipts []rlp.RawValue
		)
		for bytes < softResponseLimit && len(receipts) < downloader.MaxReceiptFetch {
			// Retrieve the hash of the next block
			if err := msgStream.Decode(&hash); err == rlp.EOL {
				break
			} else if err != nil {
				return errResp(ErrDecode, "msg %v: %v", msg, err)
			}
			// Retrieve the requested block's receipts, skipping if unknown to us
			results := pm.blockchain.GetReceiptsByHash(hash)
			if results == nil {
				if header := pm.blockchain.GetHeaderByHash(hash); header == nil || header.ReceiptHash != types.EmptyRootHash {
					continue
				}
			}
			// If known, encode and queue for response packet
			if encoded, err := rlp.EncodeToBytes(results); err != nil {
				pm.logger.Error("Failed to encode receipt", "err", err)
			} else {
				receipts = append(receipts, encoded)
				bytes += len(encoded)
			}
		}
		return p.SendReceiptsRLP(receipts)

	case p.version >= consensus.Eth63 && msg.Code == ReceiptsMsg:
		// A batch of receipts arrived to one of our previous requests
		var receipts [][]*types.Receipt
		if err := msg.Decode(&receipts); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		// Deliver all to the downloader
		if err := pm.downloader.DeliverReceipts(p.id, receipts); err != nil {
			pm.logger.Debug("Failed to deliver receipts", "err", err)
		}

	case msg.Code == NewBlockHashesMsg:
		var announces newBlockHashesData
		if err := msg.Decode(&announces); err != nil {
			return errResp(ErrDecode, "%v: %v", msg, err)
		}
		// Mark the hashes as present at the remote node
		for _, block := range announces {
			p.MarkBlock(block.Hash)
		}
		// Schedule all the unknown hashes for retrieval
		unknown := make(newBlockHashesData, 0, len(announces))
		for _, block := range announces {
			if !pm.blockchain.HasBlock(block.Hash, block.Number) {
				unknown = append(unknown, block)
			}
		}
		for _, block := range unknown {
			pm.fetcher.Notify(p.id, block.Hash, block.Number, time.Now(), p.RequestOneHeader, p.RequestBodies)
		}

	case msg.Code == NewBlockMsg:
		// Retrieve and decode the propagated block
		var request newBlockData
		if err := msg.Decode(&request); err != nil {
			return errResp(ErrDecode, "%v: %v", msg, err)
		}
		request.Block.ReceivedAt = msg.ReceivedAt
		request.Block.ReceivedFrom = p

		// Mark the peer as owning the block and schedule it for import
		p.MarkBlock(request.Block.Hash())
		pm.fetcher.Enqueue(p.id, request.Block)

		// Assuming the block is importable by the peer, but possibly not yet done so,
		// calculate the head hash and TD that the peer truly must have.
		var (
			trueHead = request.Block.ParentHash()
			trueTD   = new(big.Int).Sub(request.TD, request.Block.Difficulty())
		)
		// Update the peers total difficulty if better than the previous
		if _, td := p.Head(); trueTD.Cmp(td) > 0 {
			p.SetHead(trueHead, trueTD)

			// Schedule a sync if above ours. Note, this will not fire a sync for a gap of
			// a singe block (as the true TD is below the propagated block), however this
			// scenario should easily be covered by the fetcher.
			currentBlock := pm.blockchain.CurrentBlock()
			if trueTD.Cmp(pm.blockchain.GetTd(currentBlock.Hash(), currentBlock.NumberU64())) > 0 {
				go pm.synchronise(p)
			}
		}

	case msg.Code == TxMsg:
		// Transactions arrived, make sure we have a valid and fresh chain to handle them
		if atomic.LoadUint32(&pm.acceptTxs) == 0 {
			break
		}
		// Transactions can be processed, parse all of them and deliver to the pool
		var txs []*types.Transaction
		if err := msg.Decode(&txs); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		for i, tx := range txs {
			// Validate and mark the remote transaction
			if tx == nil {
				return errResp(ErrDecode, "transaction %d is nil", i)
			}
			p.MarkTransaction(tx.Hash())
		}
		pm.txpool.AddRemotes(txs)

	case msg.Code == TX3ProofDataMsg:
		pm.logger.Debug("TX3ProofDataMsg received")
		var proofDatas []*types.TX3ProofData
		if err := msg.Decode(&proofDatas); err != nil {
			pm.logger.Error("TX3ProofDataMsg decode error", "msg", msg, "error", err)
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		for _, proofData := range proofDatas {
			// Validate and mark the remote TX3ProofData
			if err := pm.cch.ValidateTX3ProofData(proofData); err != nil {
				pm.logger.Error("TX3ProofDataMsg validate error", "msg", msg, "error", err)
				return errResp(ErrTX3ValidateFail, "msg %v: %v", msg, err)
			}
			p.MarkTX3ProofData(proofData.Header.Hash())
			// Write the remote TX3ProofData
			if err := pm.cch.WriteTX3ProofData(proofData); err != nil {
				pm.logger.Error("TX3ProofDataMsg write error", "msg", msg, "error", err)
			}

			go pm.tx3PrfDtFeed.Send(core.Tx3ProofDataEvent{proofData})
		}

	case msg.Code == GetPreImagesMsg:
		pm.preimageLogger.Debug("GetPreImagesMsg received")
		// Decode the retrieval message
		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
		if _, err := msgStream.List(); err != nil {
			return err
		}
		// Gather state data until the fetch or network limits is reached
		var (
			hash      common.Hash
			bytes     int
			preimages [][]byte
		)

		for bytes < softResponseLimit && len(preimages) < downloader.MaxReceiptFetch {
			// Retrieve the hash of the next block
			if err := msgStream.Decode(&hash); err == rlp.EOL {
				break
			} else if err != nil {

				return errResp(ErrDecode, "msg %v: %v", msg, err)
			}
			// Retrieve the requested block's receipts, skipping if unknown to us
			preimage := rawdb.ReadPreimage(pm.blockchain.StateCache().TrieDB().DiskDB(), hash)
			// Double check the local preimage
			if hash != crypto.Keccak256Hash(preimage) {
				pm.preimageLogger.Errorf("Failed to pass the preimage double check. Request hash %x, Local Preimage %x", hash, preimage)
				continue
			}

			preimages = append(preimages, preimage)
			bytes += len(preimage)
		}
		return p.SendPreimagesRLP(preimages)

	case msg.Code == PreImagesMsg:
		pm.preimageLogger.Debug("PreImagesMsg received")
		var preimages [][]byte
		if err := msg.Decode(&preimages); err != nil {
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}

		preimagesMap := make(map[common.Hash][]byte)
		for _, preimage := range preimages {
			pm.preimageLogger.Debugf("PreImagesMsg received: %x", preimage)
			preimagesMap[crypto.Keccak256Hash(preimage)] = common.CopyBytes(preimage)
		}
		if len(preimagesMap) > 0 {
			db, _ := pm.blockchain.StateCache().TrieDB().DiskDB().(intdb.Database)
			rawdb.WritePreimages(db, preimagesMap)
			pm.preimageLogger.Info("PreImages wrote into database")
		}
	case msg.Code == TrieNodeDataMsg:
		pm.logger.Debug("TrieNodeDataMsg received")
		var trienodes [][]byte
		if err := msg.Decode(&trienodes); err != nil {
			pm.logger.Warnf("Unable decode TrieNodeData %v", err)
			return errResp(ErrDecode, "msg %v: %v", msg, err)
		}
		pm.logger.Debugf("%d TrieNodeData received", len(trienodes))

		db, _ := pm.blockchain.StateCache().TrieDB().DiskDB().(intdb.Database)
		for _, tnode := range trienodes {
			thash := crypto.Keccak256Hash(tnode)
			if has, herr := db.Has(thash.Bytes()); !has && herr == nil {
				puterr := db.Put(thash.Bytes(), tnode)
				if puterr == nil {
					pm.logger.Debugf("Insert TrieNodeData %x", thash)
				}
			} else if has {
				pm.logger.Debugf("TrieNodeData %x already existed", thash)
			}
		}
	default:
		return errResp(ErrInvalidMsgCode, "%v", msg.Code)
	}
	return nil
}

func (pm *ProtocolManager) Enqueue(id string, block *types.Block) {
	pm.fetcher.Enqueue(id, block)
}

// BroadcastBlock will either propagate a block to a subset of it's peers, or
// will only announce it's availability (depending what's requested).
func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
	hash := block.Hash()
	peers := pm.peers.PeersWithoutBlock(hash)

	// If propagation is requested, send to a subset of the peer
	if propagate {
		// Calculate the TD of the block (it's not imported yet, so block.Td is not valid)
		var td *big.Int
		if parent := pm.blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1); parent != nil {
			td = new(big.Int).Add(block.Difficulty(), pm.blockchain.GetTd(block.ParentHash(), block.NumberU64()-1))
		} else {
			pm.logger.Error("Propagating dangling block", "number", block.Number(), "hash", hash)
			return
		}
		// Send the block to a subset of our peers
		transfer := peers[:int(math.Sqrt(float64(len(peers))))]
		for _, peer := range transfer {
			peer.SendNewBlock(block, td)
		}
		pm.logger.Trace("Propagated block", "hash", hash, "recipients", len(transfer), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
		return
	}
	// Otherwise if the block is indeed in out own chain, announce it
	if pm.blockchain.HasBlock(hash, block.NumberU64()) {
		for _, peer := range peers {
			peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
		}
		pm.logger.Trace("Announced block", "hash", hash, "recipients", len(peers), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
	}
}

// BroadcastTx will propagate a transaction to all peers which are not known to
// already have the given transaction.
func (pm *ProtocolManager) BroadcastTx(hash common.Hash, tx *types.Transaction) {
	// Broadcast transaction to a batch of peers not knowing about it
	peers := pm.peers.PeersWithoutTx(hash)
	//FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
	for _, peer := range peers {
		peer.SendTransactions(types.Transactions{tx})
	}
	pm.logger.Trace("Broadcast transaction", "hash", hash, "recipients", len(peers))
}

// BroadcastTX3ProofData will propagate a TX3ProofData to all peers which are not known to
// already have the given TX3ProofData.
func (pm *ProtocolManager) BroadcastTX3ProofData(hash common.Hash, proofData *types.TX3ProofData) {
	// Broadcast TX3ProofData to a batch of peers not knowing about it
	peers := pm.peers.PeersWithoutTX3ProofData(hash)
	for _, peer := range peers {
		peer.SendTX3ProofData([]*types.TX3ProofData{proofData})
	}
	pm.logger.Trace("Broadcast TX3ProofData", "hash", hash, "recipients", len(peers))
}

func (pm *ProtocolManager) BroadcastMessage(msgcode uint64, data interface{}) {
	recipients := 0
	for _, peer := range pm.peers.Peers() {
		peer.Send(msgcode, data)
		recipients++
	}
	pm.logger.Trace("Broadcast p2p message", "code", msgcode, "recipients", recipients, "msg", data)
}

func (pm *ProtocolManager) TryFixBadPreimages() {
	// Record all preimages (Testing)
	images := make(map[common.Hash][]byte)

	var hashes []common.Hash

	// Iterate the entire sha3 preimages for checking
	db, _ := pm.blockchain.StateCache().TrieDB().DiskDB().(intdb.Database)
	it := db.NewIteratorWithPrefix([]byte("secure-key-"))
	for it.Next() {
		keyHash := common.BytesToHash(it.Key())
		valueHash := crypto.Keccak256Hash(it.Value())
		if keyHash != valueHash {
			// If value's hash doesn't match the key hash, add to list and send to other peer for correct
			hashes = append(hashes, keyHash)
		}
		// Add to all preimages (Testing)
		images[keyHash] = common.CopyBytes(it.Value())
	}
	it.Release()

	if len(hashes) > 0 {
		pm.preimageLogger.Critf("Found %d Bad Preimage(s)", len(hashes))
		pm.preimageLogger.Critf("Bad Preimages: %x", hashes)

		// Print all preimages (Testing)
		//pm.preimageLogger.Crit("All Preimage(s)")
		//var list []common.Hash
		//for k := range images {
		//	list = append(list, k)
		//}
		//sort.Slice(list, func(i, j int) bool {
		//	return bytes.Compare(list[i][:], list[j][:]) == 1
		//})
		//for _, k := range list {
		//	pm.preimageLogger.Crit(k.Hex(), common.Bytes2Hex(images[k]))
		//}

		//panic("Stop the system when found bad preimages, for testing purpose")

		pm.peers.BestPeer().RequestPreimages(hashes)
	}

}

// Mined broadcast loop
func (self *ProtocolManager) minedBroadcastLoop() {
	// automatically stops if unsubscribe
	for obj := range self.minedBlockSub.Chan() {
		switch ev := obj.Data.(type) {
		case core.NewMinedBlockEvent:
			self.BroadcastBlock(ev.Block, true)  // First propagate block to peers
			self.BroadcastBlock(ev.Block, false) // Only then announce to the rest
		}
	}
}

func (self *ProtocolManager) txBroadcastLoop() {
	for {
		select {
		case event := <-self.txCh:
			self.BroadcastTx(event.Tx.Hash(), event.Tx)

		// Err() channel will be closed when unsubscribing.
		case <-self.txSub.Err():
			return
		}
	}
}

func (self *ProtocolManager) tx3PrfDtBroadcastLoop() {
	for {
		select {
		case event := <-self.tx3PrfDtCh:
			self.BroadcastTX3ProofData(event.Tx3PrfDt.Header.Hash(), event.Tx3PrfDt)

		// Err() channel will be closed when unsubscribing.
		case <-self.tx3PrfDtSub.Err():
			return
		}
	}
}

// NodeInfo represents a short summary of the INT Chain sub-protocol metadata
// known about the host peer.
type NodeInfo struct {
	Network    uint64              `json:"network"`    // INT Chain network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
	Difficulty *big.Int            `json:"difficulty"` // Total difficulty of the host's blockchain
	Genesis    common.Hash         `json:"genesis"`    // SHA3 hash of the host's genesis block
	Config     *params.ChainConfig `json:"config"`     // Chain configuration for the fork rules
	Head       common.Hash         `json:"head"`       // SHA3 hash of the host's best owned block
}

// NodeInfo retrieves some protocol metadata about the running host node.
func (self *ProtocolManager) NodeInfo() *NodeInfo {
	currentBlock := self.blockchain.CurrentBlock()
	return &NodeInfo{
		Network:    self.networkId,
		Difficulty: self.blockchain.GetTd(currentBlock.Hash(), currentBlock.NumberU64()),
		Genesis:    self.blockchain.Genesis().Hash(),
		Config:     self.blockchain.Config(),
		Head:       currentBlock.Hash(),
	}
}

func (self *ProtocolManager) FindPeers(targets map[common.Address]bool) map[common.Address]consensus.Peer {
	m := make(map[common.Address]consensus.Peer)
	for _, p := range self.peers.Peers() {
		pubKey, err := p.ID().Pubkey()
		if err != nil {
			continue
		}
		addr := crypto.PubkeyToAddress(*pubKey)
		if targets[addr] {
			m[addr] = p
		}
	}
	return m
}