// 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 eth
import (
"encoding/json"
"errors"
"fmt"
"math"
"math/big"
"sync"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/consensus"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/eth/downloader"
"github.com/ethereum/go-ethereum/eth/fetcher"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
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 NewTxsEvent.
// The number is referenced from the size of tx pool.
txChanSize = 4096
// minimim number of peers to broadcast new blocks to
minBroadcastPeers = 4
)
var (
syncChallengeTimeout = 15 * time.Second // Time allowance for a node to reply to the sync progress challenge
)
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)
checkpointNumber uint64 // Block number for the sync progress validator to cross reference
checkpointHash common.Hash // Block hash for the sync progress validator to cross reference
txpool txPool
blockchain *core.BlockChain
maxPeers int
downloader *downloader.Downloader
fetcher *fetcher.Fetcher
peers *peerSet
eventMux *event.TypeMux
txsCh chan core.NewTxsEvent
txsSub event.Subscription
minedBlockSub *event.TypeMuxSubscription
whitelist map[uint64]common.Hash
// 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
}
// NewProtocolManager returns a new Ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
// with the Ethereum network.
func NewProtocolManager(config *params.ChainConfig, checkpoint *params.TrustedCheckpoint, mode downloader.SyncMode, networkID uint64, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb ethdb.Database, cacheLimit int, whitelist map[uint64]common.Hash) (*ProtocolManager, error) {
// Create the protocol manager with the base fields
manager := &ProtocolManager{
networkID: networkID,
eventMux: mux,
txpool: txpool,
blockchain: blockchain,
peers: newPeerSet(),
whitelist: whitelist,
newPeerCh: make(chan *peer),
noMorePeers: make(chan struct{}),
txsyncCh: make(chan *txsync),
quitSync: make(chan struct{}),
}
if mode == downloader.FullSync {
// The database seems empty as the current block is the genesis. Yet the fast
// block is ahead, so fast sync was enabled for this node at a certain point.
// The scenarios where this can happen is
// * if the user manually (or via a bad block) rolled back a fast sync node
// below the sync point.
// * the last fast sync is not finished while user specifies a full sync this
// time. But we don't have any recent state for full sync.
// In these cases however it's safe to reenable fast sync.
fullBlock, fastBlock := blockchain.CurrentBlock(), blockchain.CurrentFastBlock()
if fullBlock.NumberU64() == 0 && fastBlock.NumberU64() > 0 {
manager.fastSync = uint32(1)
log.Warn("Switch sync mode from full sync to fast sync")
}
} else {
if blockchain.CurrentBlock().NumberU64() > 0 {
// Print warning log if database is not empty to run fast sync.
log.Warn("Switch sync mode from fast sync to full sync")
} else {
// If fast sync was requested and our database is empty, grant it
manager.fastSync = uint32(1)
}
}
// If we have trusted checkpoints, enforce them on the chain
if checkpoint != nil {
manager.checkpointNumber = (checkpoint.SectionIndex+1)*params.CHTFrequency - 1
manager.checkpointHash = checkpoint.SectionHead
}
// Construct the downloader (long sync) and its backing state bloom if fast
// sync is requested. The downloader is responsible for deallocating the state
// bloom when it's done.
var stateBloom *trie.SyncBloom
if atomic.LoadUint32(&manager.fastSync) == 1 {
stateBloom = trie.NewSyncBloom(uint64(cacheLimit), chaindb)
}
manager.downloader = downloader.New(manager.checkpointNumber, chaindb, stateBloom, manager.eventMux, blockchain, nil, manager.removePeer)
// Construct the fetcher (short sync)
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 sync hasn't reached the checkpoint yet, deny importing weird blocks.
//
// Ideally we would also compare the head block's timestamp and similarly reject
// the propagated block if the head is too old. Unfortunately there is a corner
// case when starting new networks, where the genesis might be ancient (0 unix)
// which would prevent full nodes from accepting it.
if manager.blockchain.CurrentBlock().NumberU64() < manager.checkpointNumber {
log.Warn("Unsynced yet, discarded propagated block", "number", blocks[0].Number(), "hash", blocks[0].Hash())
return 0, nil
}
// If fast sync is running, deny importing weird blocks. This is a problematic
// clause when starting up a new network, because fast-syncing miners might not
// accept each others' blocks until a restart. Unfortunately we haven't figured
// out a way yet where nodes can decide unilaterally whether the network is new
// or not. This should be fixed if we figure out a solution.
if atomic.LoadUint32(&manager.fastSync) == 1 {
log.Warn("Fast syncing, discarded propagated block", "number", blocks[0].Number(), "hash", blocks[0].Hash())
return 0, nil
}
n, err := manager.blockchain.InsertChain(blocks)
if err == nil {
atomic.StoreUint32(&manager.acceptTxs, 1) // Mark initial sync done on any fetcher import
}
return n, err
}
manager.fetcher = fetcher.New(blockchain.GetBlockByHash, validator, manager.BroadcastBlock, heighter, inserter, manager.removePeer)
return manager, nil
}
func (pm *ProtocolManager) makeProtocol(version uint) p2p.Protocol {
length, ok := protocolLengths[version]
if !ok {
panic("makeProtocol for unknown version")
}
return p2p.Protocol{
Name: protocolName,
Version: version,
Length: length,
Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
peer := pm.newPeer(int(version), p, rw)
select {
case pm.newPeerCh <- peer:
pm.wg.Add(1)
defer pm.wg.Done()
return pm.handle(peer)
case <-pm.quitSync:
return p2p.DiscQuitting
}
},
NodeInfo: func() interface{} {
return pm.NodeInfo()
},
PeerInfo: func(id enode.ID) interface{} {
if p := pm.peers.Peer(fmt.Sprintf("%x", id[:8])); p != nil {
return p.Info()
}
return nil
},
}
}
func (pm *ProtocolManager) removePeer(id string) {
// Short circuit if the peer was already removed
peer := pm.peers.Peer(id)
if peer == nil {
return
}
log.Debug("Removing Ethereum peer", "peer", id)
// Unregister the peer from the downloader and Ethereum peer set
pm.downloader.UnregisterPeer(id)
if err := pm.peers.Unregister(id); err != nil {
log.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.txsCh = make(chan core.NewTxsEvent, txChanSize)
pm.txsSub = pm.txpool.SubscribeNewTxsEvent(pm.txsCh)
go pm.txBroadcastLoop()
// 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() {
log.Info("Stopping Ethereum protocol")
pm.txsSub.Unsubscribe() // quits txBroadcastLoop
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()
log.Info("Ethereum 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 eth 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("Ethereum peer connected", "name", p.Name())
// Execute the Ethereum 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("Ethereum 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("Ethereum peer registration failed", "err", err)
return err
}
defer pm.removePeer(p.id)
// 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)
// If we have a trusted CHT, reject all peers below that (avoid fast sync eclipse)
if pm.checkpointHash != (common.Hash{}) {
// Request the peer's checkpoint header for chain height/weight validation
if err := p.RequestHeadersByNumber(pm.checkpointNumber, 1, 0, false); err != nil {
return err
}
// Start a timer to disconnect if the peer doesn't reply in time
p.syncDrop = time.AfterFunc(syncChallengeTimeout, func() {
p.Log().Warn("Checkpoint challenge timed out, dropping", "addr", p.RemoteAddr(), "type", p.Name())
pm.removePeer(p.id)
})
// Make sure it's cleaned up if the peer dies off
defer func() {
if p.syncDrop != nil {
p.syncDrop.Stop()
p.syncDrop = nil
}
}()
}
// If we have any explicit whitelist block hashes, request them
for number := range pm.whitelist {
if err := p.RequestHeadersByNumber(number, 1, 0, false); err != nil {
return err
}
}
// Handle incoming messages until the connection is torn down
for {
if err := pm.handleMsg(p); err != nil {
p.Log().Debug("Ethereum 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 {
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{})
first := true
maxNonCanonical := uint64(100)
// 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 {
if first {
first = false
origin = pm.blockchain.GetHeaderByHash(query.Origin.Hash)
if origin != nil {
query.Origin.Number = origin.Number.Uint64()
}
} else {
origin = pm.blockchain.GetHeader(query.Origin.Hash, query.Origin.Number)
}
} else {
origin = pm.blockchain.GetHeaderByNumber(query.Origin.Number)
}
if origin == nil {
break
}
headers = append(headers, origin)
bytes += estHeaderRlpSize
// Advance to the next header of the query
switch {
case hashMode && query.Reverse:
// Hash based traversal towards the genesis block
ancestor := query.Skip + 1
if ancestor == 0 {
unknown = true
} else {
query.Origin.Hash, query.Origin.Number = pm.blockchain.GetAncestor(query.Origin.Hash, query.Origin.Number, ancestor, &maxNonCanonical)
unknown = (query.Origin.Hash == common.Hash{})
}
case hashMode && !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 {
nextHash := header.Hash()
expOldHash, _ := pm.blockchain.GetAncestor(nextHash, next, query.Skip+1, &maxNonCanonical)
if expOldHash == query.Origin.Hash {
query.Origin.Hash, query.Origin.Number = nextHash, next
} 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)
}
// If no headers were received, but we're expencting a checkpoint header, consider it that
if len(headers) == 0 && p.syncDrop != nil {
// Stop the timer either way, decide later to drop or not
p.syncDrop.Stop()
p.syncDrop = nil
// If we're doing a fast sync, we must enforce the checkpoint block to avoid
// eclipse attacks. Unsynced nodes are welcome to connect after we're done
// joining the network
if atomic.LoadUint32(&pm.fastSync) == 1 {
p.Log().Warn("Dropping unsynced node during fast sync", "addr", p.RemoteAddr(), "type", p.Name())
return errors.New("unsynced node cannot serve fast sync")
}
}
// Filter out any explicitly requested headers, deliver the rest to the downloader
filter := len(headers) == 1
if filter {
// If it's a potential sync progress check, validate the content and advertised chain weight
if p.syncDrop != nil && headers[0].Number.Uint64() == pm.checkpointNumber {
// Disable the sync drop timer
p.syncDrop.Stop()
p.syncDrop = nil
// Validate the header and either drop the peer or continue
if headers[0].Hash() != pm.checkpointHash {
return errors.New("checkpoint hash mismatch")
}
return nil
}
// Otherwise if it's a whitelisted block, validate against the set
if want, ok := pm.whitelist[headers[0].Number.Uint64()]; ok {
if hash := headers[0].Hash(); want != hash {
p.Log().Info("Whitelist mismatch, dropping peer", "number", headers[0].Number.Uint64(), "hash", hash, "want", want)
return errors.New("whitelist block mismatch")
}
p.Log().Debug("Whitelist block verified", "number", headers[0].Number.Uint64(), "hash", want)
}
// 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 {
log.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
transactions := make([][]*types.Transaction, len(request))
uncles := make([][]*types.Header, len(request))
for i, body := range request {
transactions[i] = body.Transactions
uncles[i] = body.Uncles
}
// Filter out any explicitly requested bodies, deliver the rest to the downloader
filter := len(transactions) > 0 || len(uncles) > 0
if filter {
transactions, uncles = pm.fetcher.FilterBodies(p.id, transactions, uncles, time.Now())
}
if len(transactions) > 0 || len(uncles) > 0 || !filter {
err := pm.downloader.DeliverBodies(p.id, transactions, uncles)
if err != nil {
log.Debug("Failed to deliver bodies", "err", err)
}
}
case p.version >= 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 >= 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 {
log.Debug("Failed to deliver node state data", "err", err)
}
case p.version >= 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 {
log.Error("Failed to encode receipt", "err", err)
} else {
receipts = append(receipts, encoded)
bytes += len(encoded)
}
}
return p.SendReceiptsRLP(receipts)
case p.version >= 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 {
log.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)
}
if err := request.sanityCheck(); err != nil {
return 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 peer's 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 single 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)
default:
return errResp(ErrInvalidMsgCode, "%v", msg.Code)
}
return nil
}
// 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 {
log.Error("Propagating dangling block", "number", block.Number(), "hash", hash)
return
}
// Send the block to a subset of our peers
transferLen := int(math.Sqrt(float64(len(peers))))
if transferLen < minBroadcastPeers {
transferLen = minBroadcastPeers
}
if transferLen > len(peers) {
transferLen = len(peers)
}
transfer := peers[:transferLen]
for _, peer := range transfer {
peer.AsyncSendNewBlock(block, td)
}
log.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.AsyncSendNewBlockHash(block)
}
log.Trace("Announced block", "hash", hash, "recipients", len(peers), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
}
}
// BroadcastTxs will propagate a batch of transactions to all peers which are not known to
// already have the given transaction.
func (pm *ProtocolManager) BroadcastTxs(txs types.Transactions) {
var txset = make(map[*peer]types.Transactions)
// Broadcast transactions to a batch of peers not knowing about it
for _, tx := range txs {
peers := pm.peers.PeersWithoutTx(tx.Hash())
for _, peer := range peers {
txset[peer] = append(txset[peer], tx)
}
log.Trace("Broadcast transaction", "hash", tx.Hash(), "recipients", len(peers))
}
// FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
for peer, txs := range txset {
peer.AsyncSendTransactions(txs)
}
}
// Mined broadcast loop
func (pm *ProtocolManager) minedBroadcastLoop() {
// automatically stops if unsubscribe
for obj := range pm.minedBlockSub.Chan() {
if ev, ok := obj.Data.(core.NewMinedBlockEvent); ok {
pm.BroadcastBlock(ev.Block, true) // First propagate block to peers
pm.BroadcastBlock(ev.Block, false) // Only then announce to the rest
}
}
}
func (pm *ProtocolManager) txBroadcastLoop() {
for {
select {
case event := <-pm.txsCh:
pm.BroadcastTxs(event.Txs)
// Err() channel will be closed when unsubscribing.
case <-pm.txsSub.Err():
return
}
}
}
// NodeInfo represents a short summary of the Ethereum sub-protocol metadata
// known about the host peer.
type NodeInfo struct {
Network uint64 `json:"network"` // Ethereum 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 (pm *ProtocolManager) NodeInfo() *NodeInfo {
currentBlock := pm.blockchain.CurrentBlock()
return &NodeInfo{
Network: pm.networkID,
Difficulty: pm.blockchain.GetTd(currentBlock.Hash(), currentBlock.NumberU64()),
Genesis: pm.blockchain.Genesis().Hash(),
Config: pm.blockchain.Config(),
Head: currentBlock.Hash(),
}
}