Refactor handshaker loop

client/internal/peer/conn.go

@@ -125,7 +125,6 @@ func NewConn(engineCtx context.Context, config ConnConfig, statusRecorder *Statu
 		wgProxyFactory: wgProxyFactory,
 		signaler:       signaler,
 		allowedIPsIP:   allowedIPsIP.String(),
-		handshaker:     NewHandshaker(ctx, connLog, config, signaler),
 		statusRelay:    StatusDisconnected,
 		statusICE:      StatusDisconnected,
 	}
@@ -133,7 +132,6 @@ func NewConn(engineCtx context.Context, config ConnConfig, statusRecorder *Statu
 	rFns := WorkerRelayCallbacks{
 		OnConnReady:     conn.relayConnectionIsReady,
 		OnStatusChanged: conn.onWorkerRelayStateChanged,
-		DoHandshake:     conn.doHandshake,
 	}
 
 	wFns := WorkerICECallbacks{
@@ -142,8 +140,13 @@ func NewConn(engineCtx context.Context, config ConnConfig, statusRecorder *Statu
 		DoHandshake:     conn.doHandshake,
 	}
 
+	conn.handshaker = NewHandshaker(ctx, connLog, config, signaler, conn.onNewOffer)
+	go conn.handshaker.Listen()
 	conn.workerRelay = NewWorkerRelay(ctx, connLog, relayManager, config, rFns)
-	conn.workerICE = NewWorkerICE(ctx, connLog, config, config.ICEConfig, signaler, iFaceDiscover, statusRecorder, wFns)
+	conn.workerICE, err = NewWorkerICE(ctx, connLog, config, config.ICEConfig, signaler, iFaceDiscover, statusRecorder, wFns)
+	if err != nil {
+		return nil, err
+	}
 	return conn, nil
 }
 
@@ -525,25 +528,21 @@ func (conn *Conn) updateStatus(peerState State, remoteRosenpassPubKey []byte, re
 	return
 }
 
-func (conn *Conn) doHandshake() (*OfferAnswer, error) {
+func (conn *Conn) doHandshake() error {
 	if !conn.signaler.Ready() {
-		return nil, ErrSignalIsNotReady
+		return ErrSignalIsNotReady
 	}
 
 	var (
 		ha  HandshakeArgs
 		err error
 	)
-	ha.IceUFrag, ha.IcePwd, err = conn.workerICE.GetLocalUserCredentials()
+	ha.IceUFrag, ha.IcePwd = conn.workerICE.GetLocalUserCredentials()
-	if err != nil {
-		conn.log.Errorf("failed to get local user credentials: %v", err)
-	}
-
 	addr, err := conn.workerRelay.RelayAddress()
 	if err == nil {
 		ha.RelayAddr = addr.String()
 	}
-	return conn.handshaker.Handshake(ha)
+	return conn.handshaker.SendOffer(ha)
 }
 
 func (conn *Conn) evalStatus() ConnStatus {
@@ -558,6 +557,12 @@ func (conn *Conn) evalStatus() ConnStatus {
 	return StatusDisconnected
 }
 
+func (conn *Conn) onNewOffer(answer *OfferAnswer) {
+	// todo move to this callback into handshaker
+	go conn.workerRelay.OnNewOffer(answer)
+	go conn.workerICE.OnNewOffer(answer)
+}
+
 func isRosenpassEnabled(remoteRosenpassPubKey []byte) bool {
 	return remoteRosenpassPubKey != nil
 }

client/internal/peer/handshaker.go

@@ -54,12 +54,27 @@ type HandshakeArgs struct {
 	RelayAddr string
 }
 
+func (a HandshakeArgs) Equal(args HandshakeArgs) bool {
+	if a.IceUFrag != args.IceUFrag {
+		return false
+	}
+
+	if a.IcePwd != args.IcePwd {
+		return false
+	}
+	if a.RelayAddr != args.RelayAddr {
+		return false
+	}
+	return true
+}
+
 type Handshaker struct {
-	mu       sync.Mutex
+	mu                 sync.Mutex
-	ctx      context.Context
+	ctx                context.Context
-	log      *log.Entry
+	log                *log.Entry
-	config   ConnConfig
+	config             ConnConfig
-	signaler *Signaler
+	signaler           *Signaler
+	onNewOfferListener func(*OfferAnswer)
 
 	// remoteOffersCh is a channel used to wait for remote credentials to proceed with the connection
 	remoteOffersCh chan OfferAnswer
@@ -69,50 +84,54 @@ type Handshaker struct {
 	remoteOfferAnswer        *OfferAnswer
 	remoteOfferAnswerCreated time.Time
 
-	handshakeArgs HandshakeArgs
+	lastSentOffer time.Time
+	lastOfferArgs HandshakeArgs
 }
 
-func NewHandshaker(ctx context.Context, log *log.Entry, config ConnConfig, signaler *Signaler) *Handshaker {
+func NewHandshaker(ctx context.Context, log *log.Entry, config ConnConfig, signaler *Signaler, onNewOfferListener func(*OfferAnswer)) *Handshaker {
 	return &Handshaker{
-		ctx:            ctx,
+		ctx:                ctx,
-		log:            log,
+		log:                log,
-		config:         config,
+		config:             config,
-		signaler:       signaler,
+		signaler:           signaler,
-		remoteOffersCh: make(chan OfferAnswer),
+		remoteOffersCh:     make(chan OfferAnswer),
-		remoteAnswerCh: make(chan OfferAnswer),
+		remoteAnswerCh:     make(chan OfferAnswer),
+		onNewOfferListener: onNewOfferListener,
 	}
 }
 
-func (h *Handshaker) Handshake(args HandshakeArgs) (*OfferAnswer, error) {
+func (h *Handshaker) Listen() {
+	for {
+		remoteOfferAnswer, err := h.waitForRemoteOfferConfirmation()
+		if err != nil {
+			if _, ok := err.(*ConnectionClosedError); ok {
+				return
+			}
+			log.Errorf("failed to received remote offer confirmation: %s", err)
+			continue
+		}
+
+		h.log.Debugf("received connection confirmation, running version %s and with remote WireGuard listen port %d", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort)
+		go h.onNewOfferListener(remoteOfferAnswer)
+	}
+}
+
+func (h *Handshaker) SendOffer(args HandshakeArgs) error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
-	h.log.Infof("start handshake with remote peer")
+	if h.lastOfferArgs.Equal(args) && h.lastSentOffer.After(time.Now().Add(-time.Second)) {
-	h.handshakeArgs = args
+		return nil
-
-	cachedOfferAnswer, ok := h.cachedHandshake()
-	if ok {
-		return cachedOfferAnswer, nil
 	}
 
 	err := h.sendOffer(args)
 	if err != nil {
-		return nil, err
+		return err
 	}
 
-	// Only continue once we got a connection confirmation from the remote peer.
+	h.lastOfferArgs = args
-	// The connection timeout could have happened before a confirmation received from the remote.
+	h.lastSentOffer = time.Now()
-	// The connection could have also been closed externally (e.g. when we received an update from the management that peer shouldn't be connected)
+	return nil
-	remoteOfferAnswer, err := h.waitForRemoteOfferConfirmation()
-	if err != nil {
-		return nil, err
-	}
-	h.storeRemoteOfferAnswer(remoteOfferAnswer)
-
-	h.log.Debugf("received connection confirmation, running version %s and with remote WireGuard listen port %d",
-		remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort)
-
-	return remoteOfferAnswer, nil
 }
 
 // OnRemoteOffer handles an offer from the remote peer and returns true if the message was accepted, false otherwise
@@ -149,6 +168,23 @@ func (h *Handshaker) OnRemoteAnswer(answer OfferAnswer) bool {
 	}
 }
 
+func (h *Handshaker) waitForRemoteOfferConfirmation() (*OfferAnswer, error) {
+	select {
+	case remoteOfferAnswer := <-h.remoteOffersCh:
+		// received confirmation from the remote peer -> ready to proceed
+		err := h.sendAnswer()
+		if err != nil {
+			return nil, err
+		}
+		return &remoteOfferAnswer, nil
+	case remoteOfferAnswer := <-h.remoteAnswerCh:
+		return &remoteOfferAnswer, nil
+	case <-h.ctx.Done():
+		// closed externally
+		return nil, NewConnectionClosedError(h.config.Key)
+	}
+}
+
 // sendOffer prepares local user credentials and signals them to the remote peer
 func (h *Handshaker) sendOffer(args HandshakeArgs) error {
 	offer := OfferAnswer{
@@ -166,12 +202,12 @@ func (h *Handshaker) sendOffer(args HandshakeArgs) error {
 func (h *Handshaker) sendAnswer() error {
 	h.log.Debugf("sending answer")
 	answer := OfferAnswer{
-		IceCredentials:  IceCredentials{h.handshakeArgs.IceUFrag, h.handshakeArgs.IcePwd},
+		IceCredentials:  IceCredentials{h.lastOfferArgs.IceUFrag, h.lastOfferArgs.IcePwd},
 		WgListenPort:    h.config.LocalWgPort,
 		Version:         version.NetbirdVersion(),
 		RosenpassPubKey: h.config.RosenpassPubKey,
 		RosenpassAddr:   h.config.RosenpassAddr,
-		RelaySrvAddress: h.handshakeArgs.RelayAddr,
+		RelaySrvAddress: h.lastOfferArgs.RelayAddr,
 	}
 	err := h.signaler.SignalAnswer(answer, h.config.Key)
 	if err != nil {
@@ -180,43 +216,3 @@ func (h *Handshaker) sendAnswer() error {
 
 	return nil
 }
-
-func (h *Handshaker) waitForRemoteOfferConfirmation() (*OfferAnswer, error) {
-	timeout := time.NewTimer(h.config.Timeout)
-	defer timeout.Stop()
-
-	select {
-	case remoteOfferAnswer := <-h.remoteOffersCh:
-		// received confirmation from the remote peer -> ready to proceed
-		err := h.sendAnswer()
-		if err != nil {
-			return nil, err
-		}
-		return &remoteOfferAnswer, nil
-	case remoteOfferAnswer := <-h.remoteAnswerCh:
-		return &remoteOfferAnswer, nil
-	case <-timeout.C:
-		h.log.Debugf("handshake timeout")
-		return nil, NewConnectionTimeoutError(h.config.Key, h.config.Timeout)
-	case <-h.ctx.Done():
-		// closed externally
-		return nil, NewConnectionClosedError(h.config.Key)
-	}
-}
-
-func (h *Handshaker) storeRemoteOfferAnswer(answer *OfferAnswer) {
-	h.remoteOfferAnswer = answer
-	h.remoteOfferAnswerCreated = time.Now()
-}
-
-func (h *Handshaker) cachedHandshake() (*OfferAnswer, bool) {
-	if h.remoteOfferAnswer == nil {
-		return nil, false
-	}
-
-	if time.Since(h.remoteOfferAnswerCreated) > handshakeCacheTimeout {
-		return nil, false
-	}
-
-	return h.remoteOfferAnswer, true
-}

client/internal/peer/worker_ice.go

@@ -2,7 +2,6 @@ package peer
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"math/rand"
 	"net"
@@ -69,7 +68,7 @@ type ICEConnInfo struct {
 type WorkerICECallbacks struct {
 	OnConnReady     func(ConnPriority, ICEConnInfo)
 	OnStatusChanged func(ConnStatus)
-	DoHandshake     func() (*OfferAnswer, error)
+	DoHandshake     func() error
 }
 
 type WorkerICE struct {
@@ -90,12 +89,19 @@ type WorkerICE struct {
 	StunTurn []*stun.URI
 
 	sentExtraSrflx bool
-	localUfrag     string
+
-	localPwd       string
+	localUfrag         string
+	localPwd           string
+	creadantialHasUsed bool
+	hasRelayOnLocally  bool
+	onDisconnected     context.CancelFunc
+	onOfferReceived    context.CancelFunc
+	tickerCancel       context.CancelFunc
+	ticker             *time.Ticker
 }
 
-func NewWorkerICE(ctx context.Context, log *log.Entry, config ConnConfig, configICE ICEConfig, signaler *Signaler, ifaceDiscover stdnet.ExternalIFaceDiscover, statusRecorder *Status, callBacks WorkerICECallbacks) *WorkerICE {
+func NewWorkerICE(ctx context.Context, log *log.Entry, config ConnConfig, configICE ICEConfig, signaler *Signaler, ifaceDiscover stdnet.ExternalIFaceDiscover, statusRecorder *Status, callBacks WorkerICECallbacks) (*WorkerICE, error) {
-	cice := &WorkerICE{
+	w := &WorkerICE{
 		ctx:            ctx,
 		log:            log,
 		config:         config,
@@ -105,113 +111,141 @@ func NewWorkerICE(ctx context.Context, log *log.Entry, config ConnConfig, config
 		statusRecorder: statusRecorder,
 		conn:           callBacks,
 	}
-	return cice
+
+	localUfrag, localPwd, err := generateICECredentials()
+	if err != nil {
+		return nil, err
+	}
+	w.localUfrag = localUfrag
+	w.localPwd = localPwd
+	return w, nil
 }
 
-// SetupICEConnection sets up an ICE connection with the remote peer.
-// If the relay mode is supported then try to connect in p2p way only.
-// It is trying to reconnection in a loop until the context is canceled.
-// In case of success connection it will call the onICEConnReady callback.
 func (w *WorkerICE) SetupICEConnection(hasRelayOnLocally bool) {
-	time.Sleep(20 * time.Second)
+	w.muxAgent.Lock()
+	defer w.muxAgent.Unlock()
+	if w.agent != nil {
+		return
+	}
+
+	w.hasRelayOnLocally = hasRelayOnLocally
+	go w.sendOffer()
+}
+
+func (w *WorkerICE) sendOffer() {
+	w.ticker = time.NewTicker(w.config.Timeout)
+	defer w.ticker.Stop()
+
+	tickerCtx, tickerCancel := context.WithCancel(w.ctx)
+	w.tickerCancel = tickerCancel
+	w.conn.OnStatusChanged(StatusConnecting)
+
+	w.log.Debugf("ICE trigger a new handshake")
+	err := w.conn.DoHandshake()
+	if err != nil {
+		w.log.Errorf("%s", err)
+	}
+
 	for {
-		if !w.waitForReconnectTry() {
+		w.log.Debugf("ICE trigger new reconnect handshake")
+		select {
+		case <-w.ticker.C:
+			err := w.conn.DoHandshake()
+			if err != nil {
+				w.log.Errorf("%s", err)
+			}
+		case <-tickerCtx.Done():
+			w.log.Debugf("left reconnect loop")
+			return
+		case <-w.ctx.Done():
 			return
 		}
-
-		w.conn.OnStatusChanged(StatusConnecting)
-
-		w.log.Debugf("trying to establish ICE connection with peer %s", w.config.Key)
-
-		remoteOfferAnswer, err := w.conn.DoHandshake()
-		if err != nil {
-			if errors.Is(err, ErrSignalIsNotReady) {
-				w.log.Infof("signal client isn't ready, skipping connection attempt")
-			}
-			continue
-		}
-
-		var preferredCandidateTypes []ice.CandidateType
-		if hasRelayOnLocally && remoteOfferAnswer.RelaySrvAddress != "" {
-			w.selectedPriority = connPriorityICEP2P
-			preferredCandidateTypes = candidateTypesP2P()
-		} else {
-			w.selectedPriority = connPriorityICETurn
-			preferredCandidateTypes = candidateTypes()
-		}
-
-		ctx, ctxCancel := context.WithCancel(w.ctx)
-		w.muxAgent.Lock()
-		agent, err := w.reCreateAgent(ctxCancel, preferredCandidateTypes)
-		if err != nil {
-			ctxCancel()
-			w.muxAgent.Unlock()
-			continue
-		}
-		w.agent = agent
-		// generate credentials for the next loop. Important the credentials are generated before handshake, because
-		// the handshake could provide a cached offer-answer
-		w.localUfrag, w.localPwd, err = generateICECredentials()
-		if err != nil {
-			ctxCancel()
-			w.muxAgent.Unlock()
-			continue
-		}
-		w.muxAgent.Unlock()
-
-		err = w.agent.GatherCandidates()
-		if err != nil {
-			ctxCancel()
-			continue
-		}
-
-		// will block until connection succeeded
-		// but it won't release if ICE Agent went into Disconnected or Failed state,
-		// so we have to cancel it with the provided context once agent detected a broken connection
-		remoteConn, err := w.turnAgentDial(remoteOfferAnswer)
-		if err != nil {
-			ctxCancel()
-			continue
-		}
-
-		pair, err := w.agent.GetSelectedCandidatePair()
-		if err != nil {
-			ctxCancel()
-			continue
-		}
-
-		if !isRelayCandidate(pair.Local) {
-			// dynamically set remote WireGuard port if other side specified a different one from the default one
-			remoteWgPort := iface.DefaultWgPort
-			if remoteOfferAnswer.WgListenPort != 0 {
-				remoteWgPort = remoteOfferAnswer.WgListenPort
-			}
-
-			// To support old version's with direct mode we attempt to punch an additional role with the remote WireGuard port
-			go w.punchRemoteWGPort(pair, remoteWgPort)
-		}
-
-		ci := ICEConnInfo{
-			RemoteConn:                 remoteConn,
-			RosenpassPubKey:            remoteOfferAnswer.RosenpassPubKey,
-			RosenpassAddr:              remoteOfferAnswer.RosenpassAddr,
-			LocalIceCandidateType:      pair.Local.Type().String(),
-			RemoteIceCandidateType:     pair.Remote.Type().String(),
-			LocalIceCandidateEndpoint:  fmt.Sprintf("%s:%d", pair.Local.Address(), pair.Local.Port()),
-			RemoteIceCandidateEndpoint: fmt.Sprintf("%s:%d", pair.Remote.Address(), pair.Remote.Port()),
-			Direct:                     !isRelayCandidate(pair.Local),
-			Relayed:                    isRelayed(pair),
-			RelayedOnLocal:             isRelayCandidate(pair.Local),
-		}
-		go w.conn.OnConnReady(w.selectedPriority, ci)
-
-		<-ctx.Done()
-		ctxCancel()
-		_ = w.agent.Close()
-		w.conn.OnStatusChanged(StatusDisconnected)
 	}
 }
 
+func (w *WorkerICE) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
+	log.Debugf("OnNewOffer for ICE")
+	w.muxAgent.Lock()
+
+	if w.agent != nil {
+		log.Debugf("agent already exists, skipping the offer")
+		w.muxAgent.Unlock()
+		return
+	}
+
+	// cancel reconnection loop
+	w.log.Debugf("canceling reconnection loop")
+	w.tickerCancel()
+
+	var preferredCandidateTypes []ice.CandidateType
+	if w.hasRelayOnLocally && remoteOfferAnswer.RelaySrvAddress != "" {
+		w.selectedPriority = connPriorityICEP2P
+		preferredCandidateTypes = candidateTypesP2P()
+	} else {
+		w.selectedPriority = connPriorityICETurn
+		preferredCandidateTypes = candidateTypes()
+	}
+
+	w.log.Debugf("recreate agent")
+	agentCtx, agentCancel := context.WithCancel(w.ctx)
+	agent, err := w.reCreateAgent(agentCancel, preferredCandidateTypes)
+	if err != nil {
+		w.log.Errorf("failed to recreate ICE Agent: %s", err)
+		return
+	}
+	w.agent = agent
+	w.muxAgent.Unlock()
+
+	w.log.Debugf("gather candidates")
+	err = w.agent.GatherCandidates()
+	if err != nil {
+		w.log.Debugf("failed to gather candidates: %s", err)
+		return
+	}
+
+	// will block until connection succeeded
+	// but it won't release if ICE Agent went into Disconnected or Failed state,
+	// so we have to cancel it with the provided context once agent detected a broken connection
+	w.log.Debugf("turnAgentDial")
+	remoteConn, err := w.turnAgentDial(agentCtx, remoteOfferAnswer)
+	if err != nil {
+		w.log.Debugf("failed to dial the remote peer: %s", err)
+		return
+	}
+
+	w.log.Debugf("GetSelectedCandidatePair")
+	pair, err := w.agent.GetSelectedCandidatePair()
+	if err != nil {
+		return
+	}
+
+	if !isRelayCandidate(pair.Local) {
+		// dynamically set remote WireGuard port if other side specified a different one from the default one
+		remoteWgPort := iface.DefaultWgPort
+		if remoteOfferAnswer.WgListenPort != 0 {
+			remoteWgPort = remoteOfferAnswer.WgListenPort
+		}
+
+		// To support old version's with direct mode we attempt to punch an additional role with the remote WireGuard port
+		go w.punchRemoteWGPort(pair, remoteWgPort)
+	}
+
+	ci := ICEConnInfo{
+		RemoteConn:                 remoteConn,
+		RosenpassPubKey:            remoteOfferAnswer.RosenpassPubKey,
+		RosenpassAddr:              remoteOfferAnswer.RosenpassAddr,
+		LocalIceCandidateType:      pair.Local.Type().String(),
+		RemoteIceCandidateType:     pair.Remote.Type().String(),
+		LocalIceCandidateEndpoint:  fmt.Sprintf("%s:%d", pair.Local.Address(), pair.Local.Port()),
+		RemoteIceCandidateEndpoint: fmt.Sprintf("%s:%d", pair.Remote.Address(), pair.Remote.Port()),
+		Direct:                     !isRelayCandidate(pair.Local),
+		Relayed:                    isRelayed(pair),
+		RelayedOnLocal:             isRelayCandidate(pair.Local),
+	}
+	w.log.Debugf("on conn ready")
+	go w.conn.OnConnReady(w.selectedPriority, ci)
+}
+
 // OnRemoteCandidate Handles ICE connection Candidate provided by the remote peer.
 func (w *WorkerICE) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HAMap) {
 	w.muxAgent.Lock()
@@ -233,19 +267,14 @@ func (w *WorkerICE) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HA
 	}
 }
 
-func (w *WorkerICE) GetLocalUserCredentials() (frag string, pwd string, err error) {
+func (w *WorkerICE) GetLocalUserCredentials() (frag string, pwd string) {
 	w.muxAgent.Lock()
 	defer w.muxAgent.Unlock()
-
+	return w.localUfrag, w.localPwd
-	if w.localUfrag != "" && w.localPwd != "" {
-		return w.localUfrag, w.localPwd, nil
-	}
-
-	w.localUfrag, w.localPwd, err = generateICECredentials()
-	return w.localUfrag, w.localPwd, err
 }
 
-func (w *WorkerICE) reCreateAgent(ctxCancel context.CancelFunc, relaySupport []ice.CandidateType) (*ice.Agent, error) {
+func (w *WorkerICE) reCreateAgent(agentCancel context.CancelFunc, relaySupport []ice.CandidateType) (*ice.Agent, error) {
+	log.Debugf("--RECREATE AGENT-----")
 	transportNet, err := w.newStdNet()
 	if err != nil {
 		w.log.Errorf("failed to create pion's stdnet: %s", err)
@@ -256,9 +285,9 @@ func (w *WorkerICE) reCreateAgent(ctxCancel context.CancelFunc, relaySupport []i
 	iceRelayAcceptanceMinWait := iceRelayAcceptanceMinWait()
 
 	agentConfig := &ice.AgentConfig{
-		MulticastDNSMode:       ice.MulticastDNSModeDisabled,
+		MulticastDNSMode: ice.MulticastDNSModeDisabled,
-		NetworkTypes:           []ice.NetworkType{ice.NetworkTypeUDP4, ice.NetworkTypeUDP6},
+		NetworkTypes:     []ice.NetworkType{ice.NetworkTypeUDP4, ice.NetworkTypeUDP6},
-		Urls:                   w.configICE.StunTurn.Load().([]*stun.URI),
+		//Urls:                   w.configICE.StunTurn.Load().([]*stun.URI),
 		CandidateTypes:         relaySupport,
 		InterfaceFilter:        stdnet.InterfaceFilter(w.configICE.InterfaceBlackList),
 		UDPMux:                 w.configICE.UDPMux,
@@ -291,7 +320,23 @@ func (w *WorkerICE) reCreateAgent(ctxCancel context.CancelFunc, relaySupport []i
 	err = agent.OnConnectionStateChange(func(state ice.ConnectionState) {
 		w.log.Debugf("ICE ConnectionState has changed to %s", state.String())
 		if state == ice.ConnectionStateFailed || state == ice.ConnectionStateDisconnected {
-			ctxCancel()
+			w.conn.OnStatusChanged(StatusDisconnected)
+
+			w.muxAgent.Lock()
+			agentCancel()
+			_ = agent.Close()
+			w.agent = nil
+
+			// generate credentials for the next agent creation loop
+			localUfrag, localPwd, err := generateICECredentials()
+			if err != nil {
+				log.Errorf("failed to generate new ICE credentials: %s", err)
+			}
+			w.localUfrag = localUfrag
+			w.localPwd = localPwd
+
+			w.muxAgent.Unlock()
+			go w.sendOffer()
 		}
 	})
 	if err != nil {
@@ -387,12 +432,12 @@ func (w *WorkerICE) shouldSendExtraSrflxCandidate(candidate ice.Candidate) bool
 	return false
 }
 
-func (w *WorkerICE) turnAgentDial(remoteOfferAnswer *OfferAnswer) (*ice.Conn, error) {
+func (w *WorkerICE) turnAgentDial(ctx context.Context, remoteOfferAnswer *OfferAnswer) (*ice.Conn, error) {
 	isControlling := w.config.LocalKey > w.config.Key
 	if isControlling {
-		return w.agent.Dial(w.ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
+		return w.agent.Dial(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
 	} else {
-		return w.agent.Accept(w.ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
+		return w.agent.Accept(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
 	}
 }
 
@@ -465,7 +510,7 @@ func candidateTypes() []ice.CandidateType {
 }
 
 func candidateTypesP2P() []ice.CandidateType {
-	return []ice.CandidateType{ice.CandidateTypeHost, ice.CandidateTypeServerReflexive}
+	return []ice.CandidateType{ice.CandidateTypeHost}
 }
 
 func isRelayCandidate(candidate ice.Candidate) bool {
@@ -480,6 +525,7 @@ func isRelayed(pair *ice.CandidatePair) bool {
 }
 
 func generateICECredentials() (string, string, error) {
+	log.Debugf("-----GENERATE CREDENTIALS------")
 	ufrag, err := randutil.GenerateCryptoRandomString(lenUFrag, runesAlpha)
 	if err != nil {
 		return "", "", err

client/internal/peer/worker_relay.go

@@ -2,10 +2,7 @@ package peer
 
 import (
 	"context"
-	"errors"
-	"math/rand"
 	"net"
-	"time"
 
 	log "github.com/sirupsen/logrus"
 
@@ -21,7 +18,6 @@ type RelayConnInfo struct {
 type WorkerRelayCallbacks struct {
 	OnConnReady     func(RelayConnInfo)
 	OnStatusChanged func(ConnStatus)
-	DoHandshake     func() (*OfferAnswer, error)
 }
 
 type WorkerRelay struct {
@@ -44,52 +40,37 @@ func NewWorkerRelay(ctx context.Context, log *log.Entry, relayManager *relayClie
 
 // SetupRelayConnection todo: this function is not completed. Make no sense to put it in a for loop because we are not waiting for any event
 func (w *WorkerRelay) SetupRelayConnection() {
-	for {
-		if !w.waitForReconnectTry() {
-			return
-		}
 
-		w.log.Debugf("trying to establish Relay connection with peer %s", w.config.Key)
+}
 
-		remoteOfferAnswer, err := w.conn.DoHandshake()
+func (w *WorkerRelay) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
-		if err != nil {
+	if !w.isRelaySupported(remoteOfferAnswer) {
-			if errors.Is(err, ErrSignalIsNotReady) {
+		w.log.Infof("Relay is not supported by remote peer")
-				w.log.Infof("signal client isn't ready, skipping connection attempt")
+		// todo should we retry?
-			}
+		// if the remote peer doesn't support relay make no sense to retry infinity
-			w.log.Errorf("%s", err)
+		// but if the remote peer supports relay just the connection is lost we should retry
-			continue
+		return
-		}
-
-		if !w.isRelaySupported(remoteOfferAnswer) {
-			w.log.Infof("Relay is not supported by remote peer")
-			// todo should we retry?
-			// if the remote peer doesn't support relay make no sense to retry infinity
-			// but if the remote peer supports relay just the connection is lost we should retry
-			continue
-		}
-
-		// the relayManager will return with error in case if the connection has lost with relay server
-		currentRelayAddress, err := w.relayManager.RelayAddress()
-		if err != nil {
-			w.log.Infof("local Relay connection is lost, skipping connection attempt")
-			continue
-		}
-
-		srv := w.preferredRelayServer(currentRelayAddress.String(), remoteOfferAnswer.RelaySrvAddress)
-		relayedConn, err := w.relayManager.OpenConn(srv, w.config.Key)
-		if err != nil {
-			w.log.Infof("failed to open relay connection: %s", err)
-			continue
-		}
-
-		go w.conn.OnConnReady(RelayConnInfo{
-			relayedConn:     relayedConn,
-			rosenpassPubKey: remoteOfferAnswer.RosenpassPubKey,
-			rosenpassAddr:   remoteOfferAnswer.RosenpassAddr,
-		})
-
-		<-w.ctx.Done()
 	}
+
+	// the relayManager will return with error in case if the connection has lost with relay server
+	currentRelayAddress, err := w.relayManager.RelayAddress()
+	if err != nil {
+		w.log.Infof("local Relay connection is lost, skipping connection attempt")
+		return
+	}
+
+	srv := w.preferredRelayServer(currentRelayAddress.String(), remoteOfferAnswer.RelaySrvAddress)
+	relayedConn, err := w.relayManager.OpenConn(srv, w.config.Key)
+	if err != nil {
+		w.log.Infof("do not need to reopen relay connection: %s", err)
+		return
+	}
+
+	go w.conn.OnConnReady(RelayConnInfo{
+		relayedConn:     relayedConn,
+		rosenpassPubKey: remoteOfferAnswer.RosenpassPubKey,
+		rosenpassAddr:   remoteOfferAnswer.RosenpassAddr,
+	})
 }
 
 func (w *WorkerRelay) RelayAddress() (net.Addr, error) {
@@ -113,20 +94,3 @@ func (w *WorkerRelay) preferredRelayServer(myRelayAddress, remoteRelayAddress st
 func (w *WorkerRelay) RelayIsSupportedLocally() bool {
 	return w.relayManager.HasRelayAddress()
 }
-
-// waitForReconnectTry waits for a random duration before trying to reconnect
-func (w *WorkerRelay) waitForReconnectTry() bool {
-	minWait := 500
-	maxWait := 2000
-	duration := time.Duration(rand.Intn(maxWait-minWait)+minWait) * time.Millisecond
-
-	timeout := time.NewTimer(duration)
-	defer timeout.Stop()
-
-	select {
-	case <-w.ctx.Done():
-		return false
-	case <-timeout.C:
-		return true
-	}
-}