First cut of connection-deduplication

cmd/main.go

@@ -37,6 +37,20 @@ func (ea SimpleApp) Init(connection *tapir.Connection) {
 	}
 }
 
+// CheckConnection is a simple test that GetConnection is working.
+func CheckConnection(service tapir.Service, hostname string) {
+	for {
+		_, err := service.GetConnection(hostname)
+		if err == nil {
+			log.Infof("Authed!")
+			return
+		} else {
+			log.Errorf("Error %v", err)
+		}
+		time.Sleep(time.Second)
+	}
+}
+
 func main() {
 
 	log.SetLevel(log.LevelDebug)
@@ -53,17 +67,18 @@ func main() {
 	id := identity.InitializeV3("server", &sk, &pk)
 
 	// Init a Client to Connect to the Server
-	go client(acn, pubkey)
+	client, clienthostname := genclient(acn)
+	go connectclient(client, pubkey)
 
 	// Init the Server running the Simple App.
 	var service tapir.Service
 	service = new(tor.BaseOnionService)
 	service.Init(acn, sk, id)
+	go CheckConnection(service, clienthostname)
 	service.Listen(SimpleApp{})
 }
 
-// Client will Connect and launch it's own Echo App goroutine.
-func client(acn connectivity.ACN, key ed25519.PublicKey) {
+func genclient(acn connectivity.ACN) (tapir.Service, string) {
 	pubkey, privateKey, _ := ed25519.GenerateKey(rand.Reader)
 	sk := ed25519.PrivateKey(privateKey)
 	pk := ed25519.PublicKey(pubkey)
@@ -71,13 +86,19 @@ func client(acn connectivity.ACN, key ed25519.PublicKey) {
 	var client tapir.Service
 	client = new(tor.BaseOnionService)
 	client.Init(acn, sk, id)
-	cid, _ := client.Connect(utils.GetTorV3Hostname(key), SimpleApp{})
+	return client, utils.GetTorV3Hostname(pk)
+}
+
+// Client will Connect and launch it's own Echo App goroutine.
+func connectclient(client tapir.Service, key ed25519.PublicKey) {
+
+	client.Connect(utils.GetTorV3Hostname(key), SimpleApp{})
 
 	// Once connected, it shouldn't take long to authenticate and run the application. So for the purposes of this demo
 	// we will wait a little while then exit.
 	time.Sleep(time.Second * 5)
 
-	conn, _ := client.GetConnection(cid)
+	conn, _ := client.GetConnection(utils.GetTorV3Hostname(key))
 	log.Debugf("Client has Auth: %v", conn.HasCapability(applications.AuthCapability))
 
 	os.Exit(0)

networks/tor/BaseOnionService.go

@@ -50,23 +50,51 @@ func (s *BaseOnionService) WaitForCapabilityOrClose(cid string, name string) (*t
 }
 
 // GetConnection returns a connection for a given hostname.
-func (s *BaseOnionService) GetConnection(connectionID string) (*tapir.Connection, error) {
-	conn, ok := s.connections.Load(connectionID)
-	if !ok {
+func (s *BaseOnionService) GetConnection(hostname string) (*tapir.Connection, error) {
+	var conn *tapir.Connection
+	s.connections.Range(func(key, value interface{}) bool {
+		connection := value.(*tapir.Connection)
+		if connection.Hostname == hostname {
+			if !connection.Closed {
+				conn = connection
+				return false
+			}
+		}
+		return true
+	})
+	if conn == nil {
 		return nil, errors.New("no connection found")
 	}
-	connection := conn.(*tapir.Connection)
-	return connection, nil
+	return conn, nil
 }
 
 // Connect initializes a new outbound connection to the given peer, using the defined Application
 func (s *BaseOnionService) Connect(hostname string, app tapir.Application) (string, error) {
+	_, err := s.GetConnection(hostname)
+	if err == nil {
+		// Note: This check is not 100% reliable. And we may end up with two connections between peers
+		// This can happen when a client connects to a server as the server is connecting to the client
+		// Because at the start of the connection the server cannot derive the true hostname of the client until it
+		// has auth'd
+		// We mitigate this by performing multiple checks when Connect'ing
+		return "", errors.New("already connected to " + hostname)
+	}
 	// connects to a remote server
 	// spins off to a connection struct
 	log.Debugf("Connecting to %v", hostname)
 	conn, _, err := s.acn.Open(hostname)
 	if err == nil {
 		connectionID := s.getNewConnectionID()
+
+		// Second check. If we didn't catch a double connection attempt before the Open we *should* catch it now because
+		// the auth protocol is quick and Open over onion connections can take some time.
+		// Again this isn't 100% reliable.
+		_, err := s.GetConnection(hostname)
+		if err == nil {
+			conn.Close()
+			return "", errors.New("already connected to " + hostname)
+		}
+
 		log.Debugf("Connected to %v [%v]", hostname, connectionID)
 		s.connections.Store(connectionID, tapir.NewConnection(s.id, hostname, true, conn, app.NewInstance()))
 		return connectionID, nil

notifications/main.go

@@ -162,7 +162,7 @@ func main() {
 	// Init a Client to Connect to the Server
 	go client(acn, pubkey)
 
-rm
+	rm
 }
 
 // Client will Connect and launch it's own Echo App goroutine.

service.go

@@ -24,7 +24,7 @@ type Service interface {
 
 // Connection defines a Tapir Connection
 type Connection struct {
-	hostname     string
+	Hostname     string
 	conn         net.Conn
 	capabilities sync.Map
 	encrypted    bool
@@ -33,13 +33,13 @@ type Connection struct {
 	ID           identity.Identity
 	Outbound     bool
 	Closed       bool
-	MaxLength int
+	MaxLength    int
 }
 
 // NewConnection creates a new Connection
 func NewConnection(id identity.Identity, hostname string, outbound bool, conn net.Conn, app Application) *Connection {
 	connection := new(Connection)
-	connection.hostname = hostname
+	connection.Hostname = hostname
 	connection.conn = conn
 	connection.App = app
 	connection.ID = id
@@ -51,13 +51,13 @@ func NewConnection(id identity.Identity, hostname string, outbound bool, conn ne
 
 // SetHostname sets the hostname on the connection
 func (c *Connection) SetHostname(hostname string) {
-	log.Debugf("[%v -- %v] Asserting Remote Hostname: %v", c.ID.Hostname(), c.hostname, hostname)
-	c.hostname = hostname
+	log.Debugf("[%v -- %v] Asserting Remote Hostname: %v", c.ID.Hostname(), c.Hostname, hostname)
+	c.Hostname = hostname
 }
 
 // SetCapability sets a capability on the connection
 func (c *Connection) SetCapability(name string) {
-	log.Debugf("[%v -- %v] Setting Capability %v", c.ID.Hostname(), c.hostname, name)
+	log.Debugf("[%v -- %v] Setting Capability %v", c.ID.Hostname(), c.Hostname, name)
 	c.capabilities.Store(name, true)
 }
 
@@ -78,7 +78,7 @@ func (c *Connection) Expect() []byte {
 	n, err := io.ReadFull(c.conn, buffer)
 
 	if n != c.MaxLength || err != nil {
-		log.Errorf("[%v -> %v] Wire Error Reading, Read %d bytes, Error: %v", c.hostname, c.ID.Hostname(), n, err)
+		log.Errorf("[%v -> %v] Wire Error Reading, Read %d bytes, Error: %v", c.Hostname, c.ID.Hostname(), n, err)
 		c.conn.Close()
 		c.Closed = true
 		return []byte{}
@@ -91,7 +91,7 @@ func (c *Connection) Expect() []byte {
 		if ok {
 			copy(buffer, decrypted)
 		} else {
-			log.Errorf("[%v -> %v] Error Decrypting Message On Wire", c.hostname, c.ID.Hostname())
+			log.Errorf("[%v -> %v] Error Decrypting Message On Wire", c.Hostname, c.ID.Hostname())
 			c.conn.Close()
 			c.Closed = true
 			return []byte{}
@@ -126,7 +126,7 @@ func (c *Connection) Send(message []byte) {
 		encrypted := secretbox.Seal(nonce[:], buffer[0:c.MaxLength-40], &nonce, &c.key)
 		copy(buffer, encrypted[0:c.MaxLength])
 	}
-	log.Debugf("[%v -> %v] Wire Send %x", c.ID.Hostname(), c.hostname, buffer)
+	log.Debugf("[%v -> %v] Wire Send %x", c.ID.Hostname(), c.Hostname, buffer)
 	_, err := c.conn.Write(buffer)
 	if err != nil {
 		c.conn.Close()