Add option to drop remote ICE candidates. (#3118)

Defaults to OFF.

pkg/rtc/participant.go

@@ -158,6 +158,7 @@ type ParticipantParams struct {
 	ForwardStats                   *sfu.ForwardStats
 	DisableSenderReportPassThrough bool
 	MetricConfig                   metric.MetricConfig
+	DropRemoteICECandidates        bool
 }
 
 type ParticipantImpl struct {
@@ -1448,6 +1449,7 @@ func (p *ParticipantImpl) setupTransportManager() error {
 		PublisherHandler:             pth,
 		SubscriberHandler:            sth,
 		DataChannelStats:             p.dataChannelStats,
+		DropRemoteICECandidates:      p.params.DropRemoteICECandidates,
 	}
 	if p.params.SyncStreams && p.params.PlayoutDelay.GetEnabled() && p.params.ClientInfo.isFirefox() {
 		// we will disable playout delay for Firefox if the user is expecting

pkg/rtc/transport.go

@@ -248,6 +248,7 @@ type TransportParams struct {
 	IsSendSide                   bool
 	AllowPlayoutDelay            bool
 	DataChannelMaxBufferedAmount uint64
+	DropRemoteICECandidates      bool
 }
 
 func newPeerConnection(params TransportParams, onBandwidthEstimator func(estimator cc.BandwidthEstimator)) (*webrtc.PeerConnection, *webrtc.MediaEngine, error) {
@@ -1400,7 +1401,7 @@ func (t *PCTransport) handleRemoteICECandidate(e event) error {
 	c := e.data.(*webrtc.ICECandidateInit)
 
 	filtered := false
-	if t.preferTCP.Load() && !strings.Contains(c.Candidate, "tcp") {
+	if t.params.DropRemoteICECandidates || (t.preferTCP.Load() && !strings.Contains(c.Candidate, "tcp")) {
 		t.params.Logger.Debugw("filtering out remote candidate", "candidate", c.Candidate)
 		filtered = true
 	}
@@ -1454,7 +1455,7 @@ func (t *PCTransport) filterCandidates(sd webrtc.SessionDescription, preferTCP,
 					filteredAttrs = append(filteredAttrs, a)
 					continue
 				}
-				excluded := preferTCP && !c.NetworkType().IsTCP()
+				excluded := (!isLocal && t.params.DropRemoteICECandidates) || (preferTCP && !c.NetworkType().IsTCP())
 				if !excluded {
 					if !t.params.Config.UseMDNS && types.IsICECandidateMDNS(c) {
 						excluded = true

pkg/rtc/transportmanager.go

@@ -93,6 +93,7 @@ type TransportManagerParams struct {
 	PublisherHandler             transport.Handler
 	SubscriberHandler            transport.Handler
 	DataChannelStats             *telemetry.BytesTrackStats
+	DropRemoteICECandidates      bool
 }
 
 type TransportManager struct {
@@ -146,6 +147,7 @@ func NewTransportManager(params TransportManagerParams) (*TransportManager, erro
 		ClientInfo:              params.ClientInfo,
 		Transport:               livekit.SignalTarget_PUBLISHER,
 		Handler:                 TransportManagerPublisherTransportHandler{TransportManagerTransportHandler{params.PublisherHandler, t}},
+		DropRemoteICECandidates: params.DropRemoteICECandidates,
 	})
 	if err != nil {
 		return nil, err
@@ -168,6 +170,7 @@ func NewTransportManager(params TransportManagerParams) (*TransportManager, erro
 		DataChannelMaxBufferedAmount: params.DataChannelMaxBufferedAmount,
 		Transport:                    livekit.SignalTarget_SUBSCRIBER,
 		Handler:                      TransportManagerTransportHandler{params.SubscriberHandler, t},
+		DropRemoteICECandidates:      params.DropRemoteICECandidates,
 	})
 	if err != nil {
 		return nil, err