package yggdrasil import ( "errors" "fmt" "sync" //"sync/atomic" "time" "github.com/yggdrasil-network/yggdrasil-go/src/crypto" "github.com/yggdrasil-network/yggdrasil-go/src/util" ) type link struct { core *Core mutex sync.RWMutex // protects interfaces below interfaces map[linkInfo]*linkInterface } type linkInfo struct { box crypto.BoxPubKey // Their encryption key sig crypto.SigPubKey // Their signing key linkType string // Type of link, e.g. TCP, AWDL local string // Local name or address remote string // Remote name or address } type linkInterfaceMsgIO interface { readMsg() ([]byte, error) writeMsg([]byte) (int, error) close() error // These are temporary workarounds to stream semantics _sendMetaBytes([]byte) error _recvMetaBytes() ([]byte, error) } type linkInterface struct { name string link *link peer *peer msgIO linkInterfaceMsgIO info linkInfo closed chan struct{} } func (l *link) init(c *Core) error { l.core = c l.mutex.Lock() l.interfaces = make(map[linkInfo]*linkInterface) l.mutex.Unlock() if err := l.core.awdl.init(c); err != nil { l.core.log.Println("Failed to start AWDL interface") return err } return nil } func (l *link) create(msgIO linkInterfaceMsgIO, name, linkType, local, remote string) (*linkInterface, error) { // Technically anything unique would work for names, but lets pick something human readable, just for debugging intf := linkInterface{ name: name, link: l, msgIO: msgIO, info: linkInfo{ linkType: linkType, local: local, remote: remote, }, } //l.interfaces[intf.name] = &intf //go intf.start() return &intf, nil } func (intf *linkInterface) handler() error { // TODO split some of this into shorter functions, so it's easier to read, and for the FIXME duplicate peer issue mentioned later myLinkPub, myLinkPriv := crypto.NewBoxKeys() meta := version_getBaseMetadata() meta.box = intf.link.core.boxPub meta.sig = intf.link.core.sigPub meta.link = *myLinkPub metaBytes := meta.encode() // TODO timeouts on send/recv (goroutine for send/recv, channel select w/ timer) err := intf.msgIO._sendMetaBytes(metaBytes) if err != nil { return err } metaBytes, err = intf.msgIO._recvMetaBytes() if err != nil { return err } meta = version_metadata{} if !meta.decode(metaBytes) || !meta.check() { return errors.New("failed to decode metadata") } base := version_getBaseMetadata() if meta.ver > base.ver || meta.ver == base.ver && meta.minorVer > base.minorVer { intf.link.core.log.Println("Failed to connect to node: " + intf.name + " version: " + fmt.Sprintf("%d.%d", meta.ver, meta.minorVer)) return errors.New("failed to connect: wrong version") } // Check if we already have a link to this node intf.info.box = meta.box intf.info.sig = meta.sig intf.link.mutex.Lock() if oldIntf, isIn := intf.link.interfaces[intf.info]; isIn { intf.link.mutex.Unlock() // FIXME we should really return an error and let the caller block instead // That lets them do things like close connections before blocking intf.link.core.log.Println("DEBUG: found existing interface for", intf.name) <-oldIntf.closed return nil } else { intf.closed = make(chan struct{}) intf.link.interfaces[intf.info] = intf defer func() { intf.link.mutex.Lock() delete(intf.link.interfaces, intf.info) intf.link.mutex.Unlock() close(intf.closed) }() intf.link.core.log.Println("DEBUG: registered interface for", intf.name) } intf.link.mutex.Unlock() // Create peer shared := crypto.GetSharedKey(myLinkPriv, &meta.link) intf.peer = intf.link.core.peers.newPeer(&meta.box, &meta.sig, shared, intf.name) if intf.peer == nil { return errors.New("failed to create peer") } defer func() { // More cleanup can go here intf.link.core.peers.removePeer(intf.peer.port) }() // Finish setting up the peer struct out := make(chan []byte, 1) defer close(out) intf.peer.out = func(msg []byte) { defer func() { recover() }() out <- msg } intf.peer.linkOut = make(chan []byte, 1) intf.peer.close = func() { intf.msgIO.close() } go intf.peer.linkLoop() // Start the writer go func() { interval := 4 * time.Second timer := time.NewTimer(interval) clearTimer := func() { if !timer.Stop() { select { case <-timer.C: default: } } } defer clearTimer() for { // First try to send any link protocol traffic select { case msg := <-intf.peer.linkOut: intf.msgIO.writeMsg(msg) continue default: } // No protocol traffic to send, so reset the timer clearTimer() timer.Reset(interval) // Now block until something is ready or the timer triggers keepalive traffic select { case <-timer.C: intf.msgIO.writeMsg(nil) case msg := <-intf.peer.linkOut: intf.msgIO.writeMsg(msg) case msg, ok := <-out: if !ok { return } intf.msgIO.writeMsg(msg) util.PutBytes(msg) if true { // TODO *don't* do this if we're not reading any traffic // In such a case, the reader is responsible for resetting it the next time we read something intf.link.core.switchTable.idleIn <- intf.peer.port } } } }() intf.link.core.switchTable.idleIn <- intf.peer.port // notify switch that we're idle // Run reader loop for { msg, err := intf.msgIO.readMsg() if len(msg) > 0 { intf.peer.handlePacket(msg) } if err != nil { return err } } //////////////////////////////////////////////////////////////////////////////// return nil } /* func (intf *linkInterface) start() { myLinkPub, myLinkPriv := crypto.NewBoxKeys() meta := version_getBaseMetadata() meta.box = intf.link.core.boxPub meta.sig = intf.link.core.sigPub meta.link = *myLinkPub metaBytes := meta.encode() //intf.link.core.log.Println("start: intf.tolink <- metaBytes") intf.tolink <- metaBytes //intf.link.core.log.Println("finish: intf.tolink <- metaBytes") //intf.link.core.log.Println("start: metaBytes = <-intf.fromlink") metaBytes = <-intf.fromlink //intf.link.core.log.Println("finish: metaBytes = <-intf.fromlink") meta = version_metadata{} if !meta.decode(metaBytes) || !meta.check() { intf.link.core.log.Println("Metadata decode failure") return } base := version_getBaseMetadata() if meta.ver > base.ver || meta.ver == base.ver && meta.minorVer > base.minorVer { intf.link.core.log.Println("Failed to connect to node: " + intf.name + " version: " + fmt.Sprintf("%d.%d", meta.ver, meta.minorVer)) return } shared := crypto.GetSharedKey(myLinkPriv, &meta.link) intf.peer = intf.link.core.peers.newPeer(&meta.box, &meta.sig, shared, intf.name) if intf.peer == nil { intf.link.mutex.Lock() delete(intf.link.interfaces, intf.name) intf.link.mutex.Unlock() return } intf.peer.linkOut = make(chan []byte, 1) // protocol traffic intf.peer.out = func(msg []byte) { defer func() { recover() }() intf.tolink <- msg } // called by peer.sendPacket() intf.link.core.switchTable.idleIn <- intf.peer.port // notify switch that we're idle intf.peer.close = func() { close(intf.fromlink) close(intf.tolink) } go intf.handler() go intf.peer.linkLoop() } func (l *link) getInterface(identity string) *linkInterface { l.mutex.RLock() defer l.mutex.RUnlock() if intf, ok := l.interfaces[identity]; ok { return intf } return nil } func (l *link) shutdown(identity string) error { if intf, ok := l.interfaces[identity]; ok { intf.shutdown <- true l.core.peers.removePeer(intf.peer.port) l.mutex.Lock() delete(l.interfaces, identity) l.mutex.Unlock() return nil } else { return fmt.Errorf("interface '%s' doesn't exist or already shutdown", identity) } } func (ai *linkInterface) handler() { send := func(msg []byte) { ai.tolink <- msg atomic.AddUint64(&ai.peer.bytesSent, uint64(len(msg))) util.PutBytes(msg) } for { timerInterval := tcp_ping_interval timer := time.NewTimer(timerInterval) defer timer.Stop() select { case p := <-ai.peer.linkOut: send(p) continue default: } timer.Stop() select { case <-timer.C: default: } timer.Reset(timerInterval) select { case _ = <-timer.C: send([]byte{}) case p := <-ai.peer.linkOut: send(p) continue case r := <-ai.fromlink: ai.peer.handlePacket(r) ai.link.core.switchTable.idleIn <- ai.peer.port case <-ai.shutdown: return } } } */