package eth import ( "bytes" "container/list" "fmt" "math" "math/big" "net" "strconv" "strings" "sync/atomic" "time" "github.com/ethereum/eth-go/ethchain" "github.com/ethereum/eth-go/ethlog" "github.com/ethereum/eth-go/ethutil" "github.com/ethereum/eth-go/ethwire" ) var peerlogger = ethlog.NewLogger("PEER") const ( // The size of the output buffer for writing messages outputBufferSize = 50 // Current protocol version ProtocolVersion = 32 // Current P2P version P2PVersion = 0 // Interval for ping/pong message pingPongTimer = 2 * time.Second ) type DiscReason byte const ( // Values are given explicitly instead of by iota because these values are // defined by the wire protocol spec; it is easier for humans to ensure // correctness when values are explicit. DiscReRequested = 0x00 DiscReTcpSysErr = 0x01 DiscBadProto = 0x02 DiscBadPeer = 0x03 DiscTooManyPeers = 0x04 DiscConnDup = 0x05 DiscGenesisErr = 0x06 DiscProtoErr = 0x07 DiscQuitting = 0x08 ) var discReasonToString = []string{ "requested", "TCP sys error", "bad protocol", "useless peer", "too many peers", "already connected", "wrong genesis block", "incompatible network", "quitting", } func (d DiscReason) String() string { if len(discReasonToString) < int(d) { return "Unknown" } return discReasonToString[d] } // Peer capabilities type Caps byte const ( CapPeerDiscTy = 1 << iota CapTxTy CapChainTy CapDefault = CapChainTy | CapTxTy | CapPeerDiscTy ) var capsToString = map[Caps]string{ CapPeerDiscTy: "Peer discovery", CapTxTy: "Transaction relaying", CapChainTy: "Block chain relaying", } func (c Caps) IsCap(cap Caps) bool { return c&cap > 0 } func (c Caps) String() string { var caps []string if c.IsCap(CapPeerDiscTy) { caps = append(caps, capsToString[CapPeerDiscTy]) } if c.IsCap(CapChainTy) { caps = append(caps, capsToString[CapChainTy]) } if c.IsCap(CapTxTy) { caps = append(caps, capsToString[CapTxTy]) } return strings.Join(caps, " | ") } type Peer struct { // Ethereum interface ethereum *Ethereum // Net connection conn net.Conn // Output queue which is used to communicate and handle messages outputQueue chan *ethwire.Msg // Quit channel quit chan bool // Determines whether it's an inbound or outbound peer inbound bool // Flag for checking the peer's connectivity state connected int32 disconnect int32 // Last known message send lastSend time.Time // Indicated whether a verack has been send or not // This flag is used by writeMessage to check if messages are allowed // to be send or not. If no version is known all messages are ignored. versionKnown bool statusKnown bool // Last received pong message lastPong int64 lastBlockReceived time.Time host []byte port uint16 caps Caps td *big.Int bestHash []byte lastReceivedHash []byte requestedHashes [][]byte // This peer's public key pubkey []byte // Indicated whether the node is catching up or not catchingUp bool diverted bool blocksRequested int version string // We use this to give some kind of pingtime to a node, not very accurate, could be improved. pingTime time.Duration pingStartTime time.Time lastRequestedBlock *ethchain.Block } func NewPeer(conn net.Conn, ethereum *Ethereum, inbound bool) *Peer { pubkey := ethereum.KeyManager().PublicKey()[1:] return &Peer{ outputQueue: make(chan *ethwire.Msg, outputBufferSize), quit: make(chan bool), ethereum: ethereum, conn: conn, inbound: inbound, disconnect: 0, connected: 1, port: 30303, pubkey: pubkey, blocksRequested: 10, caps: ethereum.ServerCaps(), version: ethereum.ClientIdentity().String(), } } func NewOutboundPeer(addr string, ethereum *Ethereum, caps Caps) *Peer { p := &Peer{ outputQueue: make(chan *ethwire.Msg, outputBufferSize), quit: make(chan bool), ethereum: ethereum, inbound: false, connected: 0, disconnect: 0, port: 30303, caps: caps, version: ethereum.ClientIdentity().String(), } // Set up the connection in another goroutine so we don't block the main thread go func() { conn, err := p.Connect(addr) if err != nil { peerlogger.Debugln("Connection to peer failed. Giving up.", err) p.Stop() return } p.conn = conn // Atomically set the connection state atomic.StoreInt32(&p.connected, 1) atomic.StoreInt32(&p.disconnect, 0) p.Start() }() return p } func (self *Peer) Connect(addr string) (conn net.Conn, err error) { const maxTries = 3 for attempts := 0; attempts < maxTries; attempts++ { conn, err = net.DialTimeout("tcp", addr, 10*time.Second) if err != nil { //peerlogger.Debugf("Peer connection failed. Retrying (%d/%d) (%s)\n", attempts+1, maxTries, addr) time.Sleep(time.Duration(attempts*20) * time.Second) continue } // Success return } return } // Getters func (p *Peer) PingTime() string { return p.pingTime.String() } func (p *Peer) Inbound() bool { return p.inbound } func (p *Peer) LastSend() time.Time { return p.lastSend } func (p *Peer) LastPong() int64 { return p.lastPong } func (p *Peer) Host() []byte { return p.host } func (p *Peer) Port() uint16 { return p.port } func (p *Peer) Version() string { return p.version } func (p *Peer) Connected() *int32 { return &p.connected } // Setters func (p *Peer) SetVersion(version string) { p.version = version } // Outputs any RLP encoded data to the peer func (p *Peer) QueueMessage(msg *ethwire.Msg) { if atomic.LoadInt32(&p.connected) != 1 { return } p.outputQueue <- msg } func (p *Peer) writeMessage(msg *ethwire.Msg) { // Ignore the write if we're not connected if atomic.LoadInt32(&p.connected) != 1 { return } if !p.versionKnown { switch msg.Type { case ethwire.MsgHandshakeTy: // Ok default: // Anything but ack is allowed return } } else { /* if !p.statusKnown { switch msg.Type { case ethwire.MsgStatusTy: // Ok default: // Anything but ack is allowed return } } */ } peerlogger.DebugDetailf("(%v) <= %v\n", p.conn.RemoteAddr(), formatMessage(msg)) err := ethwire.WriteMessage(p.conn, msg) if err != nil { peerlogger.Debugln(" Can't send message:", err) // Stop the client if there was an error writing to it p.Stop() return } } // Outbound message handler. Outbound messages are handled here func (p *Peer) HandleOutbound() { // The ping timer. Makes sure that every 2 minutes a ping is send to the peer pingTimer := time.NewTicker(pingPongTimer) serviceTimer := time.NewTicker(5 * time.Minute) out: for { select { // Main message queue. All outbound messages are processed through here case msg := <-p.outputQueue: p.writeMessage(msg) p.lastSend = time.Now() // Ping timer case <-pingTimer.C: /* timeSince := time.Since(time.Unix(p.lastPong, 0)) if !p.pingStartTime.IsZero() && p.lastPong != 0 && timeSince > (pingPongTimer+30*time.Second) { peerlogger.Infof("Peer did not respond to latest pong fast enough, it took %s, disconnecting.\n", timeSince) p.Stop() return } */ p.writeMessage(ethwire.NewMessage(ethwire.MsgPingTy, "")) p.pingStartTime = time.Now() // Service timer takes care of peer broadcasting, transaction // posting or block posting case <-serviceTimer.C: if p.caps&CapPeerDiscTy > 0 { msg := p.peersMessage() p.ethereum.BroadcastMsg(msg) } case <-p.quit: // Break out of the for loop if a quit message is posted break out } } clean: // This loop is for draining the output queue and anybody waiting for us for { select { case <-p.outputQueue: // TODO default: break clean } } } func formatMessage(msg *ethwire.Msg) (ret string) { ret = fmt.Sprintf("%v ", msg.Type) /* XXX Commented out because I need the log level here to determine if i should or shouldn't generate this message */ switch msg.Type { case ethwire.MsgPeersTy: ret += fmt.Sprintf("(%d entries)", msg.Data.Len()) case ethwire.MsgBlockTy: b1, b2 := ethchain.NewBlockFromRlpValue(msg.Data.Get(0)), ethchain.NewBlockFromRlpValue(msg.Data.Get(msg.Data.Len()-1)) ret += fmt.Sprintf("(%d entries) %x - %x", msg.Data.Len(), b1.Hash()[0:4], b2.Hash()[0:4]) case ethwire.MsgBlockHashesTy: h1, h2 := msg.Data.Get(0).Bytes(), msg.Data.Get(msg.Data.Len()-1).Bytes() ret += fmt.Sprintf("(%d entries) %x - %x", msg.Data.Len(), h1[0:4], h2[0:4]) } return } // Inbound handler. Inbound messages are received here and passed to the appropriate methods func (p *Peer) HandleInbound() { for atomic.LoadInt32(&p.disconnect) == 0 { // HMM? time.Sleep(50 * time.Millisecond) // Wait for a message from the peer msgs, err := ethwire.ReadMessages(p.conn) if err != nil { peerlogger.Debugln(err) } for _, msg := range msgs { peerlogger.DebugDetailf("(%v) => %v\n", p.conn.RemoteAddr(), formatMessage(msg)) switch msg.Type { case ethwire.MsgHandshakeTy: // Version message p.handleHandshake(msg) //if p.caps.IsCap(CapPeerDiscTy) { p.QueueMessage(ethwire.NewMessage(ethwire.MsgGetPeersTy, "")) //} case ethwire.MsgDiscTy: p.Stop() peerlogger.Infoln("Disconnect peer: ", DiscReason(msg.Data.Get(0).Uint())) case ethwire.MsgPingTy: // Respond back with pong p.QueueMessage(ethwire.NewMessage(ethwire.MsgPongTy, "")) case ethwire.MsgPongTy: // If we received a pong back from a peer we set the // last pong so the peer handler knows this peer is still // active. p.lastPong = time.Now().Unix() p.pingTime = time.Since(p.pingStartTime) case ethwire.MsgTxTy: // If the message was a transaction queue the transaction // in the TxPool where it will undergo validation and // processing when a new block is found for i := 0; i < msg.Data.Len(); i++ { tx := ethchain.NewTransactionFromValue(msg.Data.Get(i)) p.ethereum.TxPool().QueueTransaction(tx) } case ethwire.MsgGetPeersTy: // Peer asked for list of connected peers p.pushPeers() case ethwire.MsgPeersTy: // Received a list of peers (probably because MsgGetPeersTy was send) data := msg.Data // Create new list of possible peers for the ethereum to process peers := make([]string, data.Len()) // Parse each possible peer for i := 0; i < data.Len(); i++ { value := data.Get(i) peers[i] = unpackAddr(value.Get(0), value.Get(1).Uint()) } // Connect to the list of peers p.ethereum.ProcessPeerList(peers) case ethwire.MsgStatusTy: // Handle peer's status msg p.handleStatus(msg) case ethwire.MsgGetTxsTy: // Get the current transactions of the pool txs := p.ethereum.TxPool().CurrentTransactions() // Get the RlpData values from the txs txsInterface := make([]interface{}, len(txs)) for i, tx := range txs { txsInterface[i] = tx.RlpData() } // Broadcast it back to the peer p.QueueMessage(ethwire.NewMessage(ethwire.MsgTxTy, txsInterface)) case ethwire.MsgGetBlockHashesTy: if msg.Data.Len() < 2 { peerlogger.Debugln("err: argument length invalid ", msg.Data.Len()) } hash := msg.Data.Get(0).Bytes() amount := msg.Data.Get(1).Uint() hashes := p.ethereum.BlockChain().GetChainHashesFromHash(hash, amount) p.QueueMessage(ethwire.NewMessage(ethwire.MsgBlockHashesTy, ethutil.ByteSliceToInterface(hashes))) case ethwire.MsgGetBlocksTy: // Limit to max 300 blocks max := int(math.Min(float64(msg.Data.Len()), 300.0)) var blocks []interface{} for i := 0; i < max; i++ { hash := msg.Data.Get(i).Bytes() block := p.ethereum.BlockChain().GetBlock(hash) if block != nil { blocks = append(blocks, block.Value().Raw()) } } p.QueueMessage(ethwire.NewMessage(ethwire.MsgBlockTy, blocks)) case ethwire.MsgBlockHashesTy: p.catchingUp = true blockPool := p.ethereum.blockPool foundCommonHash := false it := msg.Data.NewIterator() for it.Next() { hash := it.Value().Bytes() if blockPool.HasCommonHash(hash) { foundCommonHash = true break } blockPool.AddHash(hash) p.lastReceivedHash = hash p.lastBlockReceived = time.Now() } if foundCommonHash { p.FetchBlocks() } else { p.FetchHashes() } case ethwire.MsgBlockTy: p.catchingUp = true blockPool := p.ethereum.blockPool it := msg.Data.NewIterator() for it.Next() { block := ethchain.NewBlockFromRlpValue(it.Value()) //fmt.Printf("%v %x - %x\n", block.Number, block.Hash()[0:4], block.PrevHash[0:4]) blockPool.SetBlock(block, p) p.lastBlockReceived = time.Now() } var err error blockPool.CheckLinkAndProcess(func(block *ethchain.Block) { err = p.ethereum.StateManager().Process(block, false) }) if err != nil { peerlogger.Infoln(err) } else { // Don't trigger if there's just one block. if blockPool.Len() != 0 && msg.Data.Len() > 1 { p.FetchBlocks() } } } } } p.Stop() } func (self *Peer) FetchBlocks() { blockPool := self.ethereum.blockPool hashes := blockPool.Take(100, self) if len(hashes) > 0 { self.QueueMessage(ethwire.NewMessage(ethwire.MsgGetBlocksTy, ethutil.ByteSliceToInterface(hashes))) } } func (self *Peer) FetchHashes() { blockPool := self.ethereum.blockPool if self.td.Cmp(blockPool.td) >= 0 { blockPool.td = self.td if !blockPool.HasLatestHash() { self.QueueMessage(ethwire.NewMessage(ethwire.MsgGetBlockHashesTy, []interface{}{self.lastReceivedHash, uint32(256)})) } } } // General update method func (self *Peer) update() { serviceTimer := time.NewTicker(5 * time.Second) out: for { select { case <-serviceTimer.C: if time.Since(self.lastBlockReceived) > 10*time.Second { self.catchingUp = false } case <-self.quit: break out } } serviceTimer.Stop() } func (p *Peer) Start() { peerHost, peerPort, _ := net.SplitHostPort(p.conn.LocalAddr().String()) servHost, servPort, _ := net.SplitHostPort(p.conn.RemoteAddr().String()) if p.inbound { p.host, p.port = packAddr(peerHost, peerPort) } else { p.host, p.port = packAddr(servHost, servPort) } err := p.pushHandshake() if err != nil { peerlogger.Debugln("Peer can't send outbound version ack", err) p.Stop() return } go p.HandleOutbound() // Run the inbound handler in a new goroutine go p.HandleInbound() // Run the general update handler go p.update() // Wait a few seconds for startup and then ask for an initial ping time.Sleep(2 * time.Second) p.writeMessage(ethwire.NewMessage(ethwire.MsgPingTy, "")) p.pingStartTime = time.Now() } func (p *Peer) Stop() { if atomic.AddInt32(&p.disconnect, 1) != 1 { return } close(p.quit) if atomic.LoadInt32(&p.connected) != 0 { p.writeMessage(ethwire.NewMessage(ethwire.MsgDiscTy, "")) p.conn.Close() } // Pre-emptively remove the peer; don't wait for reaping. We already know it's dead if we are here p.ethereum.RemovePeer(p) } func (p *Peer) peersMessage() *ethwire.Msg { outPeers := make([]interface{}, len(p.ethereum.InOutPeers())) // Serialise each peer for i, peer := range p.ethereum.InOutPeers() { // Don't return localhost as valid peer if !net.ParseIP(peer.conn.RemoteAddr().String()).IsLoopback() { outPeers[i] = peer.RlpData() } } // Return the message to the peer with the known list of connected clients return ethwire.NewMessage(ethwire.MsgPeersTy, outPeers) } // Pushes the list of outbound peers to the client when requested func (p *Peer) pushPeers() { p.QueueMessage(p.peersMessage()) } func (self *Peer) pushStatus() { const netVersion = 0 msg := ethwire.NewMessage(ethwire.MsgStatusTy, []interface{}{ uint32(ProtocolVersion), uint32(netVersion), self.ethereum.BlockChain().TD, self.ethereum.BlockChain().CurrentBlock.Hash(), self.ethereum.BlockChain().Genesis().Hash(), }) self.QueueMessage(msg) } func (self *Peer) handleStatus(msg *ethwire.Msg) { c := msg.Data var ( protoVersion = c.Get(0).Uint() netVersion = c.Get(1).Uint() td = c.Get(2).BigInt() bestHash = c.Get(3).Bytes() genesis = c.Get(4).Bytes() ) if bytes.Compare(self.ethereum.BlockChain().Genesis().Hash(), genesis) != 0 { ethlogger.Warnf("Invalid genisis hash %x. Disabling [ETH]\n", genesis) return } // Get the td and last hash self.td = td self.bestHash = bestHash self.lastReceivedHash = bestHash self.statusKnown = true // Compare the total TD with the blockchain TD. If remote is higher // fetch hashes from highest TD node. if self.td.Cmp(self.ethereum.BlockChain().TD) > 0 { self.ethereum.blockPool.AddHash(self.lastReceivedHash) self.FetchHashes() } ethlogger.Infof("Peer is [ETH] capable. (TD = %v ~ %x) %d / %d", self.td, self.bestHash, protoVersion, netVersion) } func (p *Peer) pushHandshake() error { pubkey := p.ethereum.KeyManager().PublicKey() msg := ethwire.NewMessage(ethwire.MsgHandshakeTy, []interface{}{ P2PVersion, []byte(p.version), []interface{}{"eth"}, p.port, pubkey[1:], }) p.QueueMessage(msg) return nil } func (p *Peer) handleHandshake(msg *ethwire.Msg) { c := msg.Data var ( p2pVersion = c.Get(0).Uint() clientId = c.Get(1).Str() caps = c.Get(2) port = c.Get(3).Uint() pub = c.Get(4).Bytes() ) // Check correctness of p2p protocol version if p2pVersion != P2PVersion { peerlogger.Debugf("Invalid P2P version. Require protocol %d, received %d\n", P2PVersion, p2pVersion) p.Stop() return } // Handle the pub key (validation, uniqueness) if len(pub) == 0 { peerlogger.Warnln("Pubkey required, not supplied in handshake.") p.Stop() return } usedPub := 0 // This peer is already added to the peerlist so we expect to find a double pubkey at least once eachPeer(p.ethereum.Peers(), func(peer *Peer, e *list.Element) { if bytes.Compare(pub, peer.pubkey) == 0 { usedPub++ } }) if usedPub > 0 { peerlogger.Debugf("Pubkey %x found more then once. Already connected to client.", p.pubkey) p.Stop() return } p.pubkey = pub // If this is an inbound connection send an ack back if p.inbound { p.port = uint16(port) // Self connect detection pubkey := p.ethereum.KeyManager().PublicKey() if bytes.Compare(pubkey, p.pubkey) == 0 { p.Stop() return } } p.SetVersion(clientId) p.versionKnown = true p.ethereum.PushPeer(p) p.ethereum.reactor.Post("peerList", p.ethereum.Peers()) capsIt := caps.NewIterator() var capsStrs []string for capsIt.Next() { cap := capsIt.Value().Str() switch cap { case "eth": p.pushStatus() } capsStrs = append(capsStrs, cap) } ethlogger.Infof("Added peer (%s) %d / %d (%v)\n", p.conn.RemoteAddr(), p.ethereum.Peers().Len(), p.ethereum.MaxPeers, capsStrs) peerlogger.Debugln(p) } func (p *Peer) String() string { var strBoundType string if p.inbound { strBoundType = "inbound" } else { strBoundType = "outbound" } var strConnectType string if atomic.LoadInt32(&p.disconnect) == 0 { strConnectType = "connected" } else { strConnectType = "disconnected" } return fmt.Sprintf("[%s] (%s) %v %s [%s]", strConnectType, strBoundType, p.conn.RemoteAddr(), p.version, p.caps) } func (p *Peer) RlpData() []interface{} { return []interface{}{p.host, p.port, p.pubkey} } func packAddr(address, port string) ([]byte, uint16) { addr := strings.Split(address, ".") a, _ := strconv.Atoi(addr[0]) b, _ := strconv.Atoi(addr[1]) c, _ := strconv.Atoi(addr[2]) d, _ := strconv.Atoi(addr[3]) host := []byte{byte(a), byte(b), byte(c), byte(d)} prt, _ := strconv.Atoi(port) return host, uint16(prt) } func unpackAddr(value *ethutil.Value, p uint64) string { byts := value.Bytes() a := strconv.Itoa(int(byts[0])) b := strconv.Itoa(int(byts[1])) c := strconv.Itoa(int(byts[2])) d := strconv.Itoa(int(byts[3])) host := strings.Join([]string{a, b, c, d}, ".") port := strconv.Itoa(int(p)) return net.JoinHostPort(host, port) }