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" ) const ( forceSyncCycle = 10 * time.Second // Time interval to force syncs, even if few peers are available blockProcCycle = 500 * time.Millisecond // Time interval to check for new blocks to process notifyCheckCycle = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested minDesiredPeerCount = 5 // Amount of peers desired to start syncing blockProcAmount = 256 ) 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 newPeerCh chan *peer newHashCh chan []*blockAnnounce 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), 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() go pm.syncer() go pm.fetcher() } 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 the sync handler // 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, short circuit if fails if err := p.handleStatus(); err != nil { return err } // Register the peer locally and in the downloader too 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) if err := pm.downloader.RegisterPeer(p.id, p.recentHash, p.requestHashes, p.requestBlocks); err != nil { return err } // propagate existing transactions. new transactions appearing // after this will be sent via broadcasts. if err := p.sendTransactions(pm.txpool.GetTransactions()); err != nil { return err } // 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 > downloader.MaxHashFetch { request.Amount = 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 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) } if i == downloader.MaxBlockFetch { break } } return p.sendBlocks(blocks) case BlocksMsg: var blocks []*types.Block msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size)) if err := msgStream.Decode(&blocks); err != nil { glog.V(logger.Detail).Infoln("Decode error", err) blocks = nil } // Either deliver to the downloader or the importer if self.downloader.Synchronising() { self.downloader.DeliverBlocks(p.id, blocks) } else { for _, block := range blocks { if err := self.importBlock(p, block, nil); err != nil { return err } } } 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.recentHash = 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 { self.newHashCh <- announces } 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.recentHash = hash if td != nil { p.td = td } // Log the block's arrival _, chainHead, _ := pm.chainman.Status() jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{ BlockHash: hash.Hex(), BlockNumber: block.Number(), // this surely must be zero 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.td = 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) } }