package eth import ( "fmt" "math" "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/eth/fetcher" "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/pow" "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 fetcher *fetcher.Fetcher peers *peerSet SubProtocol p2p.Protocol eventMux *event.TypeMux txSub event.Subscription minedBlockSub event.Subscription // channels for fetcher, syncer, txsyncLoop newPeerCh chan *peer 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, pow pow.PoW, chainman *core.ChainManager) *ProtocolManager { // Create the protocol manager and initialize peer handlers manager := &ProtocolManager{ eventMux: mux, txpool: txpool, chainman: chainman, peers: newPeerSet(), newPeerCh: make(chan *peer, 1), 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) }, } // Construct the different synchronisation mechanisms manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.chainman.InsertChain, manager.removePeer) validator := func(block *types.Block, parent *types.Block) error { return core.ValidateHeader(pow, block.Header(), parent, true) } heighter := func() uint64 { return manager.chainman.CurrentBlock().NumberU64() } manager.fetcher = fetcher.New(manager.chainman.GetBlock, validator, manager.BroadcastBlock, heighter, manager.chainman.InsertChain, manager.removePeer) 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.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 (pm *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(), }) } pm.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 := pm.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 := pm.downloader.DeliverHashes(p.id, hashes) if err != nil { glog.V(logger.Debug).Infoln(err) } case GetBlocksMsg: // 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 common.StorageSize hashes []common.Hash blocks []*types.Block ) for { err := msgStream.Decode(&hash) if err == rlp.EOL { break } else if err != nil { return errResp(ErrDecode, "msg %v: %v", msg, err) } hashes = append(hashes, hash) // Retrieve the requested block, stopping if enough was found if block := pm.chainman.GetBlock(hash); block != nil { blocks = append(blocks, block) bytes += block.Size() if len(blocks) >= downloader.MaxBlockFetch || bytes > maxBlockRespSize { break } } } if glog.V(logger.Detail) && len(blocks) == 0 && len(hashes) > 0 { list := "[" for _, hash := range hashes { list += fmt.Sprintf("%x, ", hash[:4]) } list = list[:len(list)-2] + "]" glog.Infof("Peer %s: no blocks found for requested hashes %s", p.id, list) } 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 } // Update the receive timestamp of each block for i := 0; i < len(blocks); i++ { blocks[i].ReceivedAt = msg.ReceivedAt } // Filter out any explicitly requested blocks, deliver the rest to the downloader if blocks := pm.fetcher.Filter(blocks); len(blocks) > 0 { pm.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 !pm.chainman.HasBlock(hash) { unknown = append(unknown, hash) } } for _, hash := range unknown { pm.fetcher.Notify(p.id, hash, time.Now(), p.requestBlocks) } case NewBlockMsg: // Retrieve and decode the propagated block 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 // Mark the block's arrival for whatever reason _, chainHead, _ := pm.chainman.Status() jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{ BlockHash: request.Block.Hash().Hex(), BlockNumber: request.Block.Number(), ChainHeadHash: chainHead.Hex(), BlockPrevHash: request.Block.ParentHash().Hex(), RemoteId: p.ID().String(), }) // Mark the peer as owning the block and schedule it for import p.blockHashes.Add(request.Block.Hash()) p.SetHead(request.Block.Hash()) pm.fetcher.Enqueue(p.id, request.Block) // TODO: Schedule a sync to cover potential gaps (this needs proto update) p.SetTd(request.TD) go pm.synchronise(p) 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 { transfer := peers[:int(math.Sqrt(float64(len(peers))))] for _, peer := range transfer { peer.sendNewBlock(block) } glog.V(logger.Detail).Infof("propagated block %x to %d peers in %v", hash[:4], len(transfer), time.Since(block.ReceivedAt)) } // Otherwise if the block is indeed in out own chain, announce it if pm.chainman.HasBlock(hash) { for _, peer := range peers { peer.sendNewBlockHashes([]common.Hash{hash}) } glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), 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, true) // First propagate block to peers self.BroadcastBlock(ev.Block, false) // Only then announce to the rest } } } 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) } }