package eth import ( "bytes" "container/list" "fmt" "github.com/ethereum/eth-go/ethchain" "github.com/ethereum/eth-go/ethlog" "github.com/ethereum/eth-go/ethutil" "github.com/ethereum/eth-go/ethwire" "net" "strconv" "strings" "sync/atomic" "time" ) var peerlogger = ethlog.NewLogger("PEER") const ( // The size of the output buffer for writing messages outputBufferSize = 50 // Current protocol version ProtocolVersion = 23 // 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 // Last received pong message lastPong int64 // Indicates whether a MsgGetPeersTy was requested of the peer // this to prevent receiving false peers. requestedPeerList bool host []byte port uint16 caps Caps // 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, 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 := net.DialTimeout("tcp", addr, 10*time.Second) if err != nil { peerlogger.Debugln("Connection to peer failed", 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 } // 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 } } peerlogger.DebugDetailf("(%v) <= %v %v\n", p.conn.RemoteAddr(), msg.Type, msg.Data) 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 } } } // 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 %v\n", p.conn.RemoteAddr(), msg.Type, msg.Data) 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.Now().Sub(p.pingStartTime) case ethwire.MsgBlockTy: // Get all blocks and process them var block, lastBlock *ethchain.Block var err error // Make sure we are actually receiving anything if msg.Data.Len()-1 > 1 && p.diverted { // We requested blocks and now we need to make sure we have a common ancestor somewhere in these blocks so we can find // common ground to start syncing from lastBlock = ethchain.NewBlockFromRlpValue(msg.Data.Get(msg.Data.Len() - 1)) if p.lastRequestedBlock != nil && bytes.Compare(lastBlock.Hash(), p.lastRequestedBlock.Hash()) == 0 { p.catchingUp = false continue } p.lastRequestedBlock = lastBlock peerlogger.Infof("Last block: %x. Checking if we have it locally.\n", lastBlock.Hash()) for i := msg.Data.Len() - 1; i >= 0; i-- { block = ethchain.NewBlockFromRlpValue(msg.Data.Get(i)) // Do we have this block on our chain? If so we can continue if !p.ethereum.StateManager().BlockChain().HasBlock(block.Hash()) { // We don't have this block, but we do have a block with the same prevHash, diversion time! if p.ethereum.StateManager().BlockChain().HasBlockWithPrevHash(block.PrevHash) { p.diverted = false if !p.ethereum.StateManager().BlockChain().FindCanonicalChainFromMsg(msg, block.PrevHash) { p.SyncWithPeerToLastKnown() } break } } } if !p.ethereum.StateManager().BlockChain().HasBlock(lastBlock.Hash()) { // If we can't find a common ancenstor we need to request more blocks. // FIXME: At one point this won't scale anymore since we are not asking for an offset // we just keep increasing the amount of blocks. p.blocksRequested = p.blocksRequested * 2 peerlogger.Infof("No common ancestor found, requesting %d more blocks.\n", p.blocksRequested) p.catchingUp = false p.FindCommonParentBlock() break } } for i := msg.Data.Len() - 1; i >= 0; i-- { block = ethchain.NewBlockFromRlpValue(msg.Data.Get(i)) //p.ethereum.StateManager().PrepareDefault(block) //state := p.ethereum.StateManager().CurrentState() err = p.ethereum.StateManager().Process(block, false) if err != nil { if ethutil.Config.Debug { peerlogger.Infof("Block %x failed\n", block.Hash()) peerlogger.Infof("%v\n", err) peerlogger.Debugln(block) } break } else { lastBlock = block } } if msg.Data.Len() == 0 { // Set catching up to false if // the peer has nothing left to give p.catchingUp = false } if err != nil { // If the parent is unknown try to catch up with this peer if ethchain.IsParentErr(err) { /* b := ethchain.NewBlockFromRlpValue(msg.Data.Get(0)) peerlogger.Infof("Attempting to catch (%x). Parent known\n", b.Hash()) p.catchingUp = false p.CatchupWithPeer(b.Hash()) peerlogger.Infoln(b) */ peerlogger.Infoln("Attempting to catch. Parent known") p.catchingUp = false p.CatchupWithPeer(p.ethereum.BlockChain().CurrentBlock.Hash()) } else if ethchain.IsValidationErr(err) { fmt.Println("Err:", err) p.catchingUp = false } } else { // If we're catching up, try to catch up further. if p.catchingUp && msg.Data.Len() > 1 { if lastBlock != nil { blockInfo := lastBlock.BlockInfo() peerlogger.DebugDetailf("Synced chain to #%d %x %x\n", blockInfo.Number, lastBlock.Hash(), blockInfo.Hash) } p.catchingUp = false hash := p.ethereum.BlockChain().CurrentBlock.Hash() p.CatchupWithPeer(hash) } } 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: // Flag this peer as a 'requested of new peers' this to // prevent malicious peers being forced. p.requestedPeerList = true // Peer asked for list of connected peers p.pushPeers() case ethwire.MsgPeersTy: // Received a list of peers (probably because MsgGetPeersTy was send) // Only act on message if we actually requested for a peers list if p.requestedPeerList { 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) // Mark unrequested again p.requestedPeerList = false } case ethwire.MsgGetChainTy: var parent *ethchain.Block // Length minus one since the very last element in the array is a count l := msg.Data.Len() - 1 // Ignore empty get chains if l == 0 { break } // Amount of parents in the canonical chain //amountOfBlocks := msg.Data.Get(l).AsUint() amountOfBlocks := uint64(100) // Check each SHA block hash from the message and determine whether // the SHA is in the database for i := 0; i < l; i++ { if data := msg.Data.Get(i).Bytes(); p.ethereum.StateManager().BlockChain().HasBlock(data) { parent = p.ethereum.BlockChain().GetBlock(data) break } } // If a parent is found send back a reply if parent != nil { peerlogger.DebugDetailf("Found canonical block, returning chain from: %x ", parent.Hash()) chain := p.ethereum.BlockChain().GetChainFromHash(parent.Hash(), amountOfBlocks) if len(chain) > 0 { //peerlogger.Debugf("Returning %d blocks: %x ", len(chain), parent.Hash()) p.QueueMessage(ethwire.NewMessage(ethwire.MsgBlockTy, chain)) } else { p.QueueMessage(ethwire.NewMessage(ethwire.MsgBlockTy, []interface{}{})) } } else { //peerlogger.Debugf("Could not find a similar block") // If no blocks are found we send back a reply with msg not in chain // and the last hash from get chain if l > 0 { lastHash := msg.Data.Get(l - 1) //log.Printf("Sending not in chain with hash %x\n", lastHash.AsRaw()) p.QueueMessage(ethwire.NewMessage(ethwire.MsgNotInChainTy, []interface{}{lastHash.Raw()})) } } case ethwire.MsgNotInChainTy: peerlogger.DebugDetailf("Not in chain: %x\n", msg.Data.Get(0).Bytes()) if p.diverted == true { // If were already looking for a common parent and we get here again we need to go deeper p.blocksRequested = p.blocksRequested * 2 } p.diverted = true p.catchingUp = false p.FindCommonParentBlock() 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)) // Unofficial but fun nonetheless case ethwire.MsgTalkTy: peerlogger.Infoln("%v says: %s\n", p.conn.RemoteAddr(), msg.Data.Str()) } } } p.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() // 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) pushHandshake() error { pubkey := p.ethereum.KeyManager().PublicKey() msg := ethwire.NewMessage(ethwire.MsgHandshakeTy, []interface{}{ uint32(ProtocolVersion), uint32(0), []byte(p.version), byte(p.caps), p.port, pubkey[1:], }) p.QueueMessage(msg) return nil } 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 (p *Peer) handleHandshake(msg *ethwire.Msg) { c := msg.Data // Set pubkey p.pubkey = c.Get(5).Bytes() if p.pubkey == nil { 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(p.pubkey, peer.pubkey) == 0 { usedPub++ } }) if usedPub > 0 { peerlogger.Debugf("Pubkey %x found more then once. Already connected to client.", p.pubkey) p.Stop() return } if c.Get(0).Uint() != ProtocolVersion { peerlogger.Debugf("Invalid peer version. Require protocol: %d. Received: %d\n", ProtocolVersion, c.Get(0).Uint()) p.Stop() return } // [PROTOCOL_VERSION, NETWORK_ID, CLIENT_ID, CAPS, PORT, PUBKEY] p.versionKnown = true // If this is an inbound connection send an ack back if p.inbound { p.port = uint16(c.Get(4).Uint()) // Self connect detection pubkey := p.ethereum.KeyManager().PublicKey() if bytes.Compare(pubkey, p.pubkey) == 0 { p.Stop() return } } // Set the peer's caps p.caps = Caps(c.Get(3).Byte()) // Get a reference to the peers version versionString := c.Get(2).Str() if len(versionString) > 0 { p.SetVersion(c.Get(2).Str()) } p.ethereum.PushPeer(p) p.ethereum.reactor.Post("peerList", p.ethereum.Peers()) ethlogger.Infof("Added peer (%s) %d / %d\n", p.conn.RemoteAddr(), p.ethereum.Peers().Len(), p.ethereum.MaxPeers) // Catch up with the connected peer if !p.ethereum.IsUpToDate() { peerlogger.Debugln("Already syncing up with a peer; sleeping") time.Sleep(10 * time.Second) } p.SyncWithPeerToLastKnown() 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) SyncWithPeerToLastKnown() { p.catchingUp = false p.CatchupWithPeer(p.ethereum.BlockChain().CurrentBlock.Hash()) } func (p *Peer) FindCommonParentBlock() { if p.catchingUp { return } p.catchingUp = true if p.blocksRequested == 0 { p.blocksRequested = 20 } blocks := p.ethereum.BlockChain().GetChain(p.ethereum.BlockChain().CurrentBlock.Hash(), p.blocksRequested) var hashes []interface{} for _, block := range blocks { hashes = append(hashes, block.Hash()) } msgInfo := append(hashes, uint64(len(hashes))) peerlogger.DebugDetailf("Asking for block from %x (%d total) from %s\n", p.ethereum.BlockChain().CurrentBlock.Hash(), len(hashes), p.conn.RemoteAddr().String()) msg := ethwire.NewMessage(ethwire.MsgGetChainTy, msgInfo) p.QueueMessage(msg) } func (p *Peer) CatchupWithPeer(blockHash []byte) { if !p.catchingUp { // Make sure nobody else is catching up when you want to do this p.catchingUp = true msg := ethwire.NewMessage(ethwire.MsgGetChainTy, []interface{}{blockHash, uint64(30)}) p.QueueMessage(msg) peerlogger.DebugDetailf("Requesting blockchain %x... from peer %s\n", p.ethereum.BlockChain().CurrentBlock.Hash()[:4], p.conn.RemoteAddr()) msg = ethwire.NewMessage(ethwire.MsgGetTxsTy, []interface{}{}) p.QueueMessage(msg) } } 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) }