package eth import ( "container/list" "fmt" "github.com/ethereum/eth-go/ethchain" "github.com/ethereum/eth-go/ethdb" "github.com/ethereum/eth-go/ethrpc" "github.com/ethereum/eth-go/ethutil" "github.com/ethereum/eth-go/ethwire" "github.com/ethereum/eth-go/ethlog" "io/ioutil" "math/rand" "net" "net/http" "strconv" "strings" "sync" "sync/atomic" "time" ) var ethlogger = ethlog.NewLogger("SERV") func eachPeer(peers *list.List, callback func(*Peer, *list.Element)) { // Loop thru the peers and close them (if we had them) for e := peers.Front(); e != nil; e = e.Next() { if peer, ok := e.Value.(*Peer); ok { callback(peer, e) } } } const ( processReapingTimeout = 60 // TODO increase ) type Ethereum struct { // Channel for shutting down the ethereum shutdownChan chan bool quit chan bool // DB interface //db *ethdb.LDBDatabase db ethutil.Database // State manager for processing new blocks and managing the over all states stateManager *ethchain.StateManager // The transaction pool. Transaction can be pushed on this pool // for later including in the blocks txPool *ethchain.TxPool // The canonical chain blockChain *ethchain.BlockChain // Peers (NYI) peers *list.List // Nonce Nonce uint64 Addr net.Addr Port string peerMut sync.Mutex // Capabilities for outgoing peers serverCaps Caps nat NAT // Specifies the desired amount of maximum peers MaxPeers int Mining bool listening bool reactor *ethutil.ReactorEngine RpcServer *ethrpc.JsonRpcServer } func New(caps Caps, usePnp bool) (*Ethereum, error) { db, err := ethdb.NewLDBDatabase("database") //db, err := ethdb.NewMemDatabase() if err != nil { return nil, err } var nat NAT if usePnp { nat, err = Discover() if err != nil { ethlogger.Debugln("UPnP failed", err) } } ethutil.Config.Db = db nonce, _ := ethutil.RandomUint64() ethereum := &Ethereum{ shutdownChan: make(chan bool), quit: make(chan bool), db: db, peers: list.New(), Nonce: nonce, serverCaps: caps, nat: nat, } ethereum.reactor = ethutil.NewReactorEngine() ethereum.txPool = ethchain.NewTxPool(ethereum) ethereum.blockChain = ethchain.NewBlockChain(ethereum) ethereum.stateManager = ethchain.NewStateManager(ethereum) // Start the tx pool ethereum.txPool.Start() return ethereum, nil } // Replay block func (self *Ethereum) BlockDo(hash []byte) error { block := self.blockChain.GetBlock(hash) if block == nil { return fmt.Errorf("unknown block %x", hash) } parent := self.blockChain.GetBlock(block.PrevHash) _, err := self.stateManager.ApplyDiff(parent.State(), parent, block) if err != nil { return err } return nil } func (s *Ethereum) Reactor() *ethutil.ReactorEngine { return s.reactor } func (s *Ethereum) BlockChain() *ethchain.BlockChain { return s.blockChain } func (s *Ethereum) StateManager() *ethchain.StateManager { return s.stateManager } func (s *Ethereum) TxPool() *ethchain.TxPool { return s.txPool } func (s *Ethereum) ServerCaps() Caps { return s.serverCaps } func (s *Ethereum) IsMining() bool { return s.Mining } func (s *Ethereum) PeerCount() int { return s.peers.Len() } func (s *Ethereum) IsUpToDate() bool { upToDate := true eachPeer(s.peers, func(peer *Peer, e *list.Element) { if atomic.LoadInt32(&peer.connected) == 1 { if peer.catchingUp == true { upToDate = false } } }) return upToDate } func (s *Ethereum) PushPeer(peer *Peer) { s.peers.PushBack(peer) } func (s *Ethereum) IsListening() bool { return s.listening } func (s *Ethereum) AddPeer(conn net.Conn) { peer := NewPeer(conn, s, true) if peer != nil { if s.peers.Len() < s.MaxPeers { peer.Start() } else { ethlogger.Debugf("Max connected peers reached. Not adding incoming peer.") } } } func (s *Ethereum) ProcessPeerList(addrs []string) { for _, addr := range addrs { // TODO Probably requires some sanity checks s.ConnectToPeer(addr) } } func (s *Ethereum) ConnectToPeer(addr string) error { if s.peers.Len() < s.MaxPeers { var alreadyConnected bool ahost, _, _ := net.SplitHostPort(addr) var chost string ips, err := net.LookupIP(ahost) if err != nil { return err } else { // If more then one ip is available try stripping away the ipv6 ones if len(ips) > 1 { var ipsv4 []net.IP // For now remove the ipv6 addresses for _, ip := range ips { if strings.Contains(ip.String(), "::") { continue } else { ipsv4 = append(ipsv4, ip) } } if len(ipsv4) == 0 { return fmt.Errorf("[SERV] No IPV4 addresses available for hostname") } // Pick a random ipv4 address, simulating round-robin DNS. rand.Seed(time.Now().UTC().UnixNano()) i := rand.Intn(len(ipsv4)) chost = ipsv4[i].String() } else { if len(ips) == 0 { return fmt.Errorf("[SERV] No IPs resolved for the given hostname") return nil } chost = ips[0].String() } } eachPeer(s.peers, func(p *Peer, v *list.Element) { if p.conn == nil { return } phost, _, _ := net.SplitHostPort(p.conn.RemoteAddr().String()) if phost == chost { alreadyConnected = true //ethlogger.Debugf("Peer %s already added.\n", chost) return } }) if alreadyConnected { return nil } NewOutboundPeer(addr, s, s.serverCaps) } return nil } func (s *Ethereum) OutboundPeers() []*Peer { // Create a new peer slice with at least the length of the total peers outboundPeers := make([]*Peer, s.peers.Len()) length := 0 eachPeer(s.peers, func(p *Peer, e *list.Element) { if !p.inbound && p.conn != nil { outboundPeers[length] = p length++ } }) return outboundPeers[:length] } func (s *Ethereum) InboundPeers() []*Peer { // Create a new peer slice with at least the length of the total peers inboundPeers := make([]*Peer, s.peers.Len()) length := 0 eachPeer(s.peers, func(p *Peer, e *list.Element) { if p.inbound { inboundPeers[length] = p length++ } }) return inboundPeers[:length] } func (s *Ethereum) InOutPeers() []*Peer { // Reap the dead peers first s.reapPeers() // Create a new peer slice with at least the length of the total peers inboundPeers := make([]*Peer, s.peers.Len()) length := 0 eachPeer(s.peers, func(p *Peer, e *list.Element) { // Only return peers with an actual ip if len(p.host) > 0 { inboundPeers[length] = p length++ } }) return inboundPeers[:length] } func (s *Ethereum) Broadcast(msgType ethwire.MsgType, data []interface{}) { msg := ethwire.NewMessage(msgType, data) s.BroadcastMsg(msg) } func (s *Ethereum) BroadcastMsg(msg *ethwire.Msg) { eachPeer(s.peers, func(p *Peer, e *list.Element) { p.QueueMessage(msg) }) } func (s *Ethereum) Peers() *list.List { return s.peers } func (s *Ethereum) reapPeers() { eachPeer(s.peers, func(p *Peer, e *list.Element) { if atomic.LoadInt32(&p.disconnect) == 1 || (p.inbound && (time.Now().Unix()-p.lastPong) > int64(5*time.Minute)) { s.removePeerElement(e) } }) } func (s *Ethereum) removePeerElement(e *list.Element) { s.peerMut.Lock() defer s.peerMut.Unlock() s.peers.Remove(e) s.reactor.Post("peerList", s.peers) } func (s *Ethereum) RemovePeer(p *Peer) { eachPeer(s.peers, func(peer *Peer, e *list.Element) { if peer == p { s.removePeerElement(e) } }) } func (s *Ethereum) ReapDeadPeerHandler() { reapTimer := time.NewTicker(processReapingTimeout * time.Second) for { select { case <-reapTimer.C: s.reapPeers() } } } // Start the ethereum func (s *Ethereum) Start(seed bool) { // Bind to addr and port ln, err := net.Listen("tcp", ":"+s.Port) if err != nil { ethlogger.Warnln("Connection listening disabled. Acting as client") s.listening = false } else { s.listening = true // Starting accepting connections ethlogger.Infoln("Ready and accepting connections") // Start the peer handler go s.peerHandler(ln) } if s.nat != nil { go s.upnpUpdateThread() } // Start the reaping processes go s.ReapDeadPeerHandler() if seed { s.Seed() } } func (s *Ethereum) Seed() { ethlogger.Debugln("Retrieving seed nodes") // Eth-Go Bootstrapping ips, er := net.LookupIP("seed.bysh.me") if er == nil { peers := []string{} for _, ip := range ips { node := fmt.Sprintf("%s:%d", ip.String(), 30303) ethlogger.Debugln("Found DNS Go Peer:", node) peers = append(peers, node) } s.ProcessPeerList(peers) } // Official DNS Bootstrapping _, nodes, err := net.LookupSRV("eth", "tcp", "ethereum.org") if err == nil { peers := []string{} // Iterate SRV nodes for _, n := range nodes { target := n.Target port := strconv.Itoa(int(n.Port)) // Resolve target to ip (Go returns list, so may resolve to multiple ips?) addr, err := net.LookupHost(target) if err == nil { for _, a := range addr { // Build string out of SRV port and Resolved IP peer := net.JoinHostPort(a, port) ethlogger.Debugln("Found DNS Bootstrap Peer:", peer) peers = append(peers, peer) } } else { ethlogger.Debugln("Couldn't resolve :", target) } } // Connect to Peer list s.ProcessPeerList(peers) } else { // Fallback to servers.poc3.txt resp, err := http.Get("http://www.ethereum.org/servers.poc3.txt") if err != nil { ethlogger.Warnln("Fetching seed failed:", err) return } defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) if err != nil { ethlogger.Warnln("Reading seed failed:", err) return } s.ConnectToPeer(string(body)) } } func (s *Ethereum) peerHandler(listener net.Listener) { for { conn, err := listener.Accept() if err != nil { ethlogger.Debugln(err) continue } go s.AddPeer(conn) } } func (s *Ethereum) Stop() { // Close the database defer s.db.Close() eachPeer(s.peers, func(p *Peer, e *list.Element) { p.Stop() }) close(s.quit) if s.RpcServer != nil { s.RpcServer.Stop() } s.txPool.Stop() s.stateManager.Stop() close(s.shutdownChan) } // This function will wait for a shutdown and resumes main thread execution func (s *Ethereum) WaitForShutdown() { <-s.shutdownChan } func (s *Ethereum) upnpUpdateThread() { // Go off immediately to prevent code duplication, thereafter we renew // lease every 15 minutes. timer := time.NewTimer(5 * time.Minute) lport, _ := strconv.ParseInt(s.Port, 10, 16) first := true out: for { select { case <-timer.C: var err error _, err = s.nat.AddPortMapping("TCP", int(lport), int(lport), "eth listen port", 20*60) if err != nil { ethlogger.Debugln("can't add UPnP port mapping:", err) break out } if first && err == nil { _, err = s.nat.GetExternalAddress() if err != nil { ethlogger.Debugln("UPnP can't get external address:", err) continue out } first = false } timer.Reset(time.Minute * 15) case <-s.quit: break out } } timer.Stop() if err := s.nat.DeletePortMapping("TCP", int(lport), int(lport)); err != nil { ethlogger.Debugln("unable to remove UPnP port mapping:", err) } else { ethlogger.Debugln("succesfully disestablished UPnP port mapping") } }