package p2p import ( "errors" "fmt" "net" "sync/atomic" "time" . "github.com/tendermint/tendermint/common" ) type Reactor interface { Start(sw *Switch) Stop() GetChannels() []*ChannelDescriptor AddPeer(peer *Peer) RemovePeer(peer *Peer, reason interface{}) Receive(chId byte, peer *Peer, msgBytes []byte) } //-------------------------------------- type BaseReactor struct{} func (_ BaseReactor) Start(sw *Switch) {} func (_ BaseReactor) Stop() {} func (_ BaseReactor) GetChannels() []*ChannelDescriptor { return nil } func (_ BaseReactor) AddPeer(peer *Peer) {} func (_ BaseReactor) RemovePeer(peer *Peer, reason interface{}) {} func (_ BaseReactor) Receive(chId byte, peer *Peer, msgBytes []byte) {} //----------------------------------------------------------------------------- /* The `Switch` handles peer connections and exposes an API to receive incoming messages on `Reactors`. Each `Reactor` is responsible for handling incoming messages of one or more `Channels`. So while sending outgoing messages is typically performed on the peer, incoming messages are received on the reactor. */ type Switch struct { network string listeners []Listener reactors map[string]Reactor chDescs []*ChannelDescriptor reactorsByCh map[byte]Reactor peers *PeerSet dialing *CMap running uint32 } var ( ErrSwitchDuplicatePeer = errors.New("Duplicate peer") ) const ( peerDialTimeoutSeconds = 3 ) func NewSwitch() *Switch { sw := &Switch{ network: "", reactors: make(map[string]Reactor), chDescs: make([]*ChannelDescriptor, 0), reactorsByCh: make(map[byte]Reactor), peers: NewPeerSet(), dialing: NewCMap(), running: 0, } return sw } // Not goroutine safe. func (sw *Switch) SetNetwork(network string) { sw.network = network } // Not goroutine safe. func (sw *Switch) AddReactor(name string, reactor Reactor) Reactor { // Validate the reactor. // No two reactors can share the same channel. reactorChannels := reactor.GetChannels() for _, chDesc := range reactorChannels { chId := chDesc.Id if sw.reactorsByCh[chId] != nil { panic(fmt.Sprintf("Channel %X has multiple reactors %v & %v", chId, sw.reactorsByCh[chId], reactor)) } sw.chDescs = append(sw.chDescs, chDesc) sw.reactorsByCh[chId] = reactor } sw.reactors[name] = reactor return reactor } // Not goroutine safe. func (sw *Switch) Reactors() map[string]Reactor { return sw.reactors } // Not goroutine safe. func (sw *Switch) Reactor(name string) Reactor { return sw.reactors[name] } // Not goroutine safe. func (sw *Switch) AddListener(l Listener) { sw.listeners = append(sw.listeners, l) } func (sw *Switch) Listeners() []Listener { return sw.listeners } // Not goroutine safe. func (sw *Switch) IsListening() bool { return len(sw.listeners) > 0 } func (sw *Switch) Start() { if atomic.CompareAndSwapUint32(&sw.running, 0, 1) { // Start reactors for _, reactor := range sw.reactors { reactor.Start(sw) } // Start peers for _, peer := range sw.peers.List() { sw.startInitPeer(peer) } // Start listeners for _, listener := range sw.listeners { go sw.listenerRoutine(listener) } } } func (sw *Switch) Stop() { if atomic.CompareAndSwapUint32(&sw.running, 1, 0) { // Stop listeners for _, listener := range sw.listeners { listener.Stop() } sw.listeners = nil // Stop peers for _, peer := range sw.peers.List() { peer.stop() } sw.peers = NewPeerSet() // Stop reactors for _, reactor := range sw.reactors { reactor.Stop() } } } func (sw *Switch) AddPeerWithConnection(conn net.Conn, outbound bool) (*Peer, error) { peer := newPeer(conn, outbound, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError) // Add the peer to .peers if sw.peers.Add(peer) { log.Info("Added peer", "peer", peer) } else { log.Info("Ignoring duplicate peer", "peer", peer) return nil, ErrSwitchDuplicatePeer } if atomic.LoadUint32(&sw.running) == 1 { sw.startInitPeer(peer) } return peer, nil } func (sw *Switch) startInitPeer(peer *Peer) { // Start the peer peer.start() // Notify reactors sw.doAddPeer(peer) // Send handshake msg := &pexHandshakeMessage{Network: sw.network} peer.Send(PexChannel, msg) } func (sw *Switch) DialPeerWithAddress(addr *NetAddress) (*Peer, error) { log.Debug("Dialing address", "address", addr) sw.dialing.Set(addr.String(), addr) conn, err := addr.DialTimeout(peerDialTimeoutSeconds * time.Second) sw.dialing.Delete(addr.String()) if err != nil { log.Debug("Failed dialing address", "address", addr, "error", err) return nil, err } peer, err := sw.AddPeerWithConnection(conn, true) if err != nil { log.Debug("Failed adding peer", "address", addr, "conn", conn, "error", err) return nil, err } log.Info("Dialed and added peer", "address", addr, "peer", peer) return peer, nil } func (sw *Switch) IsDialing(addr *NetAddress) bool { return sw.dialing.Has(addr.String()) } // Broadcast runs a go routine for each attempted send, which will block // trying to send for defaultSendTimeoutSeconds. Returns a channel // which receives success values for each attempted send (false if times out) func (sw *Switch) Broadcast(chId byte, msg interface{}) chan bool { successChan := make(chan bool, len(sw.peers.List())) log.Debug("Broadcast", "channel", chId, "msg", msg) for _, peer := range sw.peers.List() { go func(peer *Peer) { success := peer.Send(chId, msg) successChan <- success }(peer) } return successChan } // Returns the count of outbound/inbound and outbound-dialing peers. func (sw *Switch) NumPeers() (outbound, inbound, dialing int) { peers := sw.peers.List() for _, peer := range peers { if peer.outbound { outbound++ } else { inbound++ } } dialing = sw.dialing.Size() return } func (sw *Switch) Peers() IPeerSet { return sw.peers } // Disconnect from a peer due to external error. // TODO: make record depending on reason. func (sw *Switch) StopPeerForError(peer *Peer, reason interface{}) { log.Info("Stopping peer for error", "peer", peer, "error", reason) sw.peers.Remove(peer) peer.stop() // Notify reactors sw.doRemovePeer(peer, reason) } // Disconnect from a peer gracefully. // TODO: handle graceful disconnects. func (sw *Switch) StopPeerGracefully(peer *Peer) { log.Info("Stopping peer gracefully") sw.peers.Remove(peer) peer.stop() // Notify reactors sw.doRemovePeer(peer, nil) } func (sw *Switch) doAddPeer(peer *Peer) { for _, reactor := range sw.reactors { reactor.AddPeer(peer) } } func (sw *Switch) doRemovePeer(peer *Peer, reason interface{}) { for _, reactor := range sw.reactors { reactor.RemovePeer(peer, reason) } } func (sw *Switch) listenerRoutine(l Listener) { for { inConn, ok := <-l.Connections() if !ok { break } // New inbound connection! peer, err := sw.AddPeerWithConnection(inConn, false) if err != nil { log.Info("Ignoring error from inbound connection: %v\n%v", peer, err) continue } // NOTE: We don't yet have the external address of the // remote (if they have a listener at all). // PEXReactor's pexRoutine will handle that. } // cleanup } //----------------------------------------------------------------------------- type SwitchEventNewPeer struct { Peer *Peer } type SwitchEventDonePeer struct { Peer *Peer Error interface{} }