package eth
import (
"fmt"
"math"
"math/big"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"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/event"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rlp"
)
// This is the target maximum size of returned blocks for the
// getBlocks message. The reply message may exceed it
// if a single block is larger than the limit.
const maxBlockRespSize = 2 * 1024 * 1024
func errResp(code errCode, format string, v ...interface{}) error {
return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}
type hashFetcherFn func(common.Hash) error
type blockFetcherFn func([]common.Hash) error
// extProt is an interface which is passed around so we can expose GetHashes and GetBlock without exposing it to the rest of the protocol
// extProt is passed around to peers which require to GetHashes and GetBlocks
type extProt struct {
getHashes hashFetcherFn
getBlocks blockFetcherFn
}
func (ep extProt) GetHashes(hash common.Hash) error { return ep.getHashes(hash) }
func (ep extProt) GetBlock(hashes []common.Hash) error { return ep.getBlocks(hashes) }
type ProtocolManager struct {
protVer, netId int
txpool txPool
chainman *core.ChainManager
downloader *downloader.Downloader
peers *peerSet
SubProtocol p2p.Protocol
eventMux *event.TypeMux
txSub event.Subscription
minedBlockSub event.Subscription
// channels for fetcher, syncer, txsyncLoop
newPeerCh chan *peer
newHashCh chan []*blockAnnounce
newBlockCh chan chan []*types.Block
txsyncCh chan *txsync
quitSync chan struct{}
// wait group is used for graceful shutdowns during downloading
// and processing
wg sync.WaitGroup
quit bool
}
// NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
// with the ethereum network.
func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpool txPool, chainman *core.ChainManager, downloader *downloader.Downloader) *ProtocolManager {
manager := &ProtocolManager{
eventMux: mux,
txpool: txpool,
chainman: chainman,
downloader: downloader,
peers: newPeerSet(),
newPeerCh: make(chan *peer, 1),
newHashCh: make(chan []*blockAnnounce, 1),
newBlockCh: make(chan chan []*types.Block),
txsyncCh: make(chan *txsync),
quitSync: make(chan struct{}),
}
manager.SubProtocol = p2p.Protocol{
Name: "eth",
Version: uint(protocolVersion),
Length: ProtocolLength,
Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
peer := manager.newPeer(protocolVersion, networkId, p, rw)
manager.newPeerCh <- peer
return manager.handle(peer)
},
}
return manager
}
func (pm *ProtocolManager) removePeer(id string) {
// Short circuit if the peer was already removed
peer := pm.peers.Peer(id)
if peer == nil {
return
}
glog.V(logger.Debug).Infoln("Removing peer", id)
// Unregister the peer from the downloader and Ethereum peer set
pm.downloader.UnregisterPeer(id)
if err := pm.peers.Unregister(id); err != nil {
glog.V(logger.Error).Infoln("Removal failed:", err)
}
// Hard disconnect at the networking layer
if peer != nil {
peer.Peer.Disconnect(p2p.DiscUselessPeer)
}
}
func (pm *ProtocolManager) Start() {
// broadcast transactions
pm.txSub = pm.eventMux.Subscribe(core.TxPreEvent{})
go pm.txBroadcastLoop()
// broadcast mined blocks
pm.minedBlockSub = pm.eventMux.Subscribe(core.NewMinedBlockEvent{})
go pm.minedBroadcastLoop()
// start sync handlers
go pm.syncer()
go pm.fetcher()
go pm.txsyncLoop()
}
func (pm *ProtocolManager) Stop() {
// Showing a log message. During download / process this could actually
// take between 5 to 10 seconds and therefor feedback is required.
glog.V(logger.Info).Infoln("Stopping ethereum protocol handler...")
pm.quit = true
pm.txSub.Unsubscribe() // quits txBroadcastLoop
pm.minedBlockSub.Unsubscribe() // quits blockBroadcastLoop
close(pm.quitSync) // quits syncer, fetcher, txsyncLoop
// Wait for any process action
pm.wg.Wait()
glog.V(logger.Info).Infoln("Ethereum protocol handler stopped")
}
func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
td, current, genesis := pm.chainman.Status()
return newPeer(pv, nv, genesis, current, td, p, rw)
}
func (pm *ProtocolManager) handle(p *peer) error {
// Execute the Ethereum handshake.
if err := p.handleStatus(); err != nil {
return err
}
// Register the peer locally.
glog.V(logger.Detail).Infoln("Adding peer", p.id)
if err := pm.peers.Register(p); err != nil {
glog.V(logger.Error).Infoln("Addition failed:", 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.Head(), p.requestHashes, p.requestBlocks); err != nil {
return err
}
// Propagate existing transactions. new transactions appearing
// after this will be sent via broadcasts.
pm.syncTransactions(p)
// main loop. handle incoming messages.
for {
if err := pm.handleMsg(p); err != nil {
return err
}
}
return nil
}
func (self *ProtocolManager) handleMsg(p *peer) error {
msg, err := p.rw.ReadMsg()
if err != nil {
return err
}
if msg.Size > ProtocolMaxMsgSize {
return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
}
// make sure that the payload has been fully consumed
defer msg.Discard()
switch msg.Code {
case StatusMsg:
return errResp(ErrExtraStatusMsg, "uncontrolled status message")
case TxMsg:
// TODO: rework using lazy RLP stream
var txs []*types.Transaction
if err := msg.Decode(&txs); err != nil {
return errResp(ErrDecode, "msg %v: %v", msg, err)
}
for i, tx := range txs {
if tx == nil {
return errResp(ErrDecode, "transaction %d is nil", i)
}
jsonlogger.LogJson(&logger.EthTxReceived{
TxHash: tx.Hash().Hex(),
RemoteId: p.ID().String(),
})
}
self.txpool.AddTransactions(txs)
case GetBlockHashesMsg:
var request getBlockHashesMsgData
if err := msg.Decode(&request); err != nil {
return errResp(ErrDecode, "->msg %v: %v", msg, err)
}
if request.Amount > uint64(downloader.MaxHashFetch) {
request.Amount = uint64(downloader.MaxHashFetch)
}
hashes := self.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)
if glog.V(logger.Debug) {
if len(hashes) == 0 {
glog.Infof("invalid block hash %x", request.Hash.Bytes()[:4])
}
}
// returns either requested hashes or nothing (i.e. not found)
return p.sendBlockHashes(hashes)
case BlockHashesMsg:
msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
var hashes []common.Hash
if err := msgStream.Decode(&hashes); err != nil {
break
}
err := self.downloader.DeliverHashes(p.id, hashes)
if err != nil {
glog.V(logger.Debug).Infoln(err)
}
case GetBlocksMsg:
var blocks []*types.Block
msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
if _, err := msgStream.List(); err != nil {
return err
}
var (
i int
totalsize common.StorageSize
)
for {
i++
var hash common.Hash
err := msgStream.Decode(&hash)
if err == rlp.EOL {
break
} else if err != nil {
return errResp(ErrDecode, "msg %v: %v", msg, err)
}
block := self.chainman.GetBlock(hash)
if block != nil {
blocks = append(blocks, block)
totalsize += block.Size()
}
if i == downloader.MaxBlockFetch || totalsize > maxBlockRespSize {
break
}
}
return p.sendBlocks(blocks)
case BlocksMsg:
// Decode the arrived block message
msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
var blocks []*types.Block
if err := msgStream.Decode(&blocks); err != nil {
glog.V(logger.Detail).Infoln("Decode error", err)
blocks = nil
}
// Filter out any explicitly requested blocks (cascading select to get blocking back to peer)
filter := make(chan []*types.Block)
select {
case <-self.quitSync:
case self.newBlockCh <- filter:
select {
case <-self.quitSync:
case filter <- blocks:
select {
case <-self.quitSync:
case blocks := <-filter:
self.downloader.DeliverBlocks(p.id, blocks)
}
}
}
case NewBlockHashesMsg:
// Retrieve and deseralize the remote new block hashes notification
msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
var hashes []common.Hash
if err := msgStream.Decode(&hashes); err != nil {
break
}
// Mark the hashes as present at the remote node
for _, hash := range hashes {
p.blockHashes.Add(hash)
p.SetHead(hash)
}
// Schedule all the unknown hashes for retrieval
unknown := make([]common.Hash, 0, len(hashes))
for _, hash := range hashes {
if !self.chainman.HasBlock(hash) {
unknown = append(unknown, hash)
}
}
announces := make([]*blockAnnounce, len(unknown))
for i, hash := range unknown {
announces[i] = &blockAnnounce{
hash: hash,
peer: p,
time: time.Now(),
}
}
if len(announces) > 0 {
select {
case self.newHashCh <- announces:
case <-self.quitSync:
}
}
case NewBlockMsg:
var request newBlockMsgData
if err := msg.Decode(&request); err != nil {
return errResp(ErrDecode, "%v: %v", msg, err)
}
if err := request.Block.ValidateFields(); err != nil {
return errResp(ErrDecode, "block validation %v: %v", msg, err)
}
request.Block.ReceivedAt = msg.ReceivedAt
if err := self.importBlock(p, request.Block, request.TD); err != nil {
return err
}
default:
return errResp(ErrInvalidMsgCode, "%v", msg.Code)
}
return nil
}
// importBlocks injects a new block retrieved from the given peer into the chain
// manager.
func (pm *ProtocolManager) importBlock(p *peer, block *types.Block, td *big.Int) error {
hash := block.Hash()
// Mark the block as present at the remote node (don't duplicate already held data)
p.blockHashes.Add(hash)
p.SetHead(hash)
if td != nil {
p.SetTd(td)
}
// Log the block's arrival
_, chainHead, _ := pm.chainman.Status()
jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{
BlockHash: hash.Hex(),
BlockNumber: block.Number(),
ChainHeadHash: chainHead.Hex(),
BlockPrevHash: block.ParentHash().Hex(),
RemoteId: p.ID().String(),
})
// If the block's already known or its difficulty is lower than ours, drop
if pm.chainman.HasBlock(hash) {
p.SetTd(pm.chainman.GetBlock(hash).Td) // update the peer's TD to the real value
return nil
}
if td != nil && pm.chainman.Td().Cmp(td) > 0 && new(big.Int).Add(block.Number(), big.NewInt(7)).Cmp(pm.chainman.CurrentBlock().Number()) < 0 {
glog.V(logger.Debug).Infof("[%s] dropped block %v due to low TD %v\n", p.id, block.Number(), td)
return nil
}
// Attempt to insert the newly received block and propagate to our peers
if pm.chainman.HasBlock(block.ParentHash()) {
if _, err := pm.chainman.InsertChain(types.Blocks{block}); err != nil {
glog.V(logger.Error).Infoln("removed peer (", p.id, ") due to block error", err)
return err
}
if td != nil && block.Td.Cmp(td) != 0 {
err := fmt.Errorf("invalid TD on block(%v) from peer(%s): block.td=%v, request.td=%v", block.Number(), p.id, block.Td, td)
glog.V(logger.Error).Infoln(err)
return err
}
pm.BroadcastBlock(hash, block)
return nil
}
// Parent of the block is unknown, try to sync with this peer if it seems to be good
if td != nil {
go pm.synchronise(p)
}
return nil
}
// BroadcastBlock will propagate the block to a subset of its connected peers,
// only notifying the rest of the block's appearance.
func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block) {
// Retrieve all the target peers and split between full broadcast or only notification
peers := pm.peers.PeersWithoutBlock(hash)
split := int(math.Sqrt(float64(len(peers))))
transfer := peers[:split]
notify := peers[split:]
// Send out the data transfers and the notifications
for _, peer := range notify {
peer.sendNewBlockHashes([]common.Hash{hash})
}
glog.V(logger.Detail).Infoln("broadcast hash to", len(notify), "peers.")
for _, peer := range transfer {
peer.sendNewBlock(block)
}
glog.V(logger.Detail).Infoln("broadcast block to", len(transfer), "peers. Total processing time:", time.Since(block.ReceivedAt))
}
// BroadcastTx will propagate the block to its connected peers. It will sort
// out which peers do not contain the block in their block set and will do a
// sqrt(peers) to determine the amount of peers we broadcast to.
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.sendTransaction(tx)
}
glog.V(logger.Detail).Infoln("broadcast tx to", len(peers), "peers")
}
// Mined broadcast loop
func (self *ProtocolManager) minedBroadcastLoop() {
// automatically stops if unsubscribe
for obj := range self.minedBlockSub.Chan() {
switch ev := obj.(type) {
case core.NewMinedBlockEvent:
self.BroadcastBlock(ev.Block.Hash(), ev.Block)
}
}
}
func (self *ProtocolManager) txBroadcastLoop() {
// automatically stops if unsubscribe
for obj := range self.txSub.Chan() {
event := obj.(core.TxPreEvent)
self.BroadcastTx(event.Tx.Hash(), event.Tx)
}
}
