Add ICE Trickle support

Resolves pion/ice#51

Co-authored-by: Konstantin Itskov <konstantin.itskov@kovits.com>

go.mod

@@ -5,7 +5,7 @@ go 1.12
 require (
 	github.com/pion/datachannel v1.4.3
 	github.com/pion/dtls v1.3.5
-	github.com/pion/ice v0.3.2
+	github.com/pion/ice v0.3.3
 	github.com/pion/logging v0.2.1
 	github.com/pion/quic v0.1.1
 	github.com/pion/rtcp v1.2.0

go.sum

@@ -26,8 +26,8 @@ github.com/pion/datachannel v1.4.3 h1:tqS6YiqqAiFCxGGhvn1K7fHEzemK9Aov025dE/isGF
 github.com/pion/datachannel v1.4.3/go.mod h1:SpMJbuu8v+qbA94m6lWQwSdCf8JKQvgmdSHDNtcbe+w=
 github.com/pion/dtls v1.3.5 h1:mBioifvh6JSE9pD4FtJh5WoizygoqkOJNJyS5Ns+y1U=
 github.com/pion/dtls v1.3.5/go.mod h1:CjlPLfQdsTg3G4AEXjJp8FY5bRweBlxHrgoFrN+fQsk=
-github.com/pion/ice v0.3.2 h1:wBm0F9an2y+mpIlmn2sC4sHVjZnCl0K9zY23R3ijYmA=
-github.com/pion/ice v0.3.2/go.mod h1:T57BaxW8oBC+CuV1+ZAAVm8/UsnpQB/S/hII+Y2Nyn0=
+github.com/pion/ice v0.3.3 h1:ysSx7pDczIJx8XyYpFI2zoqtYhFD+B1cQdtY2ol5lT4=
+github.com/pion/ice v0.3.3/go.mod h1:T57BaxW8oBC+CuV1+ZAAVm8/UsnpQB/S/hII+Y2Nyn0=
 github.com/pion/logging v0.2.1 h1:LwASkBKZ+2ysGJ+jLv1E/9H1ge0k1nTfi1X+5zirkDk=
 github.com/pion/logging v0.2.1/go.mod h1:k0/tDVsRCX2Mb2ZEmTqNa7CWsQPc+YYCB7Q+5pahoms=
 github.com/pion/quic v0.1.1 h1:D951FV+TOqI9A0rTF7tHx0Loooqz+nyzjEyj8o3PuMA=

icegatherer.go

@@ -21,15 +21,20 @@ type ICEGatherer struct {
 
 	validatedServers []*ice.URL
 
-	agent *ice.Agent
+	agentIsTrickle bool
+	agent          *ice.Agent
 
 	portMin           uint16
 	portMax           uint16
 	candidateTypes    []ice.CandidateType
 	connectionTimeout *time.Duration
 	keepaliveInterval *time.Duration
 	loggerFactory     logging.LoggerFactory
+	log               logging.LeveledLogger
 	networkTypes      []NetworkType
+
+	onLocalCandidateHdlr func(candidate *ICECandidate)
+	onStateChangeHdlr    func(state ICEGathererState)
 }
 
 // NewICEGatherer creates a new NewICEGatherer.
@@ -66,24 +71,27 @@ func NewICEGatherer(
 		connectionTimeout: connectionTimeout,
 		keepaliveInterval: keepaliveInterval,
 		loggerFactory:     loggerFactory,
+		log:               loggerFactory.NewLogger("ice"),
 		networkTypes:      networkTypes,
 		candidateTypes:    candidateTypes,
 	}, nil
 }
 
-// State indicates the current state of the ICE gatherer.
-func (g *ICEGatherer) State() ICEGathererState {
-	g.lock.RLock()
-	defer g.lock.RUnlock()
-	return g.state
-}
-
-// Gather ICE candidates.
-func (g *ICEGatherer) Gather() error {
+func (g *ICEGatherer) createAgent() error {
 	g.lock.Lock()
 	defer g.lock.Unlock()
+	agentIsTrickle := g.onLocalCandidateHdlr != nil || g.onStateChangeHdlr != nil
+
+	if g.agent != nil {
+		if !g.agentIsTrickle && agentIsTrickle {
+			return errors.New("ICEAgent created without OnCandidate or StateChange handler, but now has one set")
+		}
+
+		return nil
+	}
 
 	config := &ice.AgentConfig{
+		Trickle:           agentIsTrickle,
 		Urls:              g.validatedServers,
 		PortMin:           g.portMin,
 		PortMax:           g.portMax,
@@ -108,11 +116,49 @@ func (g *ICEGatherer) Gather() error {
 	}
 
 	g.agent = agent
-	g.state = ICEGathererStateComplete
+	g.agentIsTrickle = agentIsTrickle
+	if agentIsTrickle {
+		g.state = ICEGathererStateComplete
+	}
 
 	return nil
 }
 
+// Gather ICE candidates.
+func (g *ICEGatherer) Gather() error {
+	if err := g.createAgent(); err != nil {
+		return err
+	}
+
+	g.lock.Lock()
+	onLocalCandidateHdlr := g.onLocalCandidateHdlr
+	isTrickle := g.agentIsTrickle
+	agent := g.agent
+	g.lock.Unlock()
+
+	if !isTrickle {
+		return nil
+	}
+
+	g.setState(ICEGathererStateGathering)
+	if err := agent.OnCandidate(func(candidate ice.Candidate) {
+		if candidate != nil {
+			c, err := newICECandidateFromICE(candidate)
+			if err != nil {
+				g.log.Warnf("Failed to convert ice.Candidate: %s", err)
+				return
+			}
+			onLocalCandidateHdlr(&c)
+		} else {
+			g.setState(ICEGathererStateComplete)
+			onLocalCandidateHdlr(nil)
+		}
+	}); err != nil {
+		return err
+	}
+	return agent.GatherCandidates()
+}
+
 // Close prunes all local candidates, and closes the ports.
 func (g *ICEGatherer) Close() error {
 	g.lock.Lock()
@@ -133,14 +179,11 @@ func (g *ICEGatherer) Close() error {
 
 // GetLocalParameters returns the ICE parameters of the ICEGatherer.
 func (g *ICEGatherer) GetLocalParameters() (ICEParameters, error) {
-	g.lock.RLock()
-	defer g.lock.RUnlock()
-	if g.agent == nil {
-		return ICEParameters{}, errors.New("gatherer not started")
+	if err := g.createAgent(); err != nil {
+		return ICEParameters{}, err
 	}
 
 	frag, pwd := g.agent.GetLocalUserCredentials()
-
 	return ICEParameters{
 		UsernameFragment: frag,
 		Password:         pwd,
@@ -150,17 +193,51 @@ func (g *ICEGatherer) GetLocalParameters() (ICEParameters, error) {
 
 // GetLocalCandidates returns the sequence of valid local candidates associated with the ICEGatherer.
 func (g *ICEGatherer) GetLocalCandidates() ([]ICECandidate, error) {
-	g.lock.RLock()
-	defer g.lock.RUnlock()
-
-	if g.agent == nil {
-		return nil, errors.New("gatherer not started")
+	if err := g.createAgent(); err != nil {
+		return nil, err
 	}
-
 	iceCandidates, err := g.agent.GetLocalCandidates()
 	if err != nil {
 		return nil, err
 	}
 
 	return newICECandidatesFromICE(iceCandidates)
 }
+
+// OnLocalCandidate sets an event handler which fires when a new local ICE candidate is available
+func (g *ICEGatherer) OnLocalCandidate(f func(*ICECandidate)) {
+	g.lock.Lock()
+	defer g.lock.Unlock()
+	g.onLocalCandidateHdlr = f
+}
+
+// OnStateChange fires any time the ICEGatherer changes
+func (g *ICEGatherer) OnStateChange(f func(ICEGathererState)) {
+	g.lock.Lock()
+	defer g.lock.Unlock()
+	g.onStateChangeHdlr = f
+}
+
+// State indicates the current state of the ICE gatherer.
+func (g *ICEGatherer) State() ICEGathererState {
+	g.lock.RLock()
+	defer g.lock.RUnlock()
+	return g.state
+}
+
+func (g *ICEGatherer) setState(s ICEGathererState) {
+	g.lock.Lock()
+	g.state = s
+	hdlr := g.onStateChangeHdlr
+	g.lock.Unlock()
+
+	if hdlr != nil {
+		go hdlr(s)
+	}
+}
+
+func (g *ICEGatherer) getAgent() *ice.Agent {
+	g.lock.RLock()
+	defer g.lock.RUnlock()
+	return g.agent
+}

icetransport.go

@@ -260,8 +260,7 @@ func (t *ICETransport) NewEndpoint(f mux.MatchFunc) *mux.Endpoint {
 }
 
 func (t *ICETransport) ensureGatherer() error {
-	if t.gatherer == nil ||
-		t.gatherer.agent == nil {
+	if t.gatherer == nil || t.gatherer.getAgent() == nil {
 		return errors.New("gatherer not started")
 	}