Add ToJSON ICECandidate method

With this change we can always exchange ICECandidateInit when signaling

Author: Hugo Arregui

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/pion/rtcp v1.2.1
 	github.com/pion/rtp v1.1.3
 	github.com/pion/sctp v1.6.4
-	github.com/pion/sdp/v2 v2.2.0
+	github.com/pion/sdp/v2 v2.3.0
 	github.com/pion/srtp v1.2.6
 	github.com/pion/transport v0.8.6
 	github.com/stretchr/testify v1.3.0

go.sum

@@ -40,8 +40,8 @@ github.com/pion/rtp v1.1.3/go.mod h1:/l4cvcKd0D3u9JLs2xSVI95YkfXW87a3br3nqmVtSlE
 github.com/pion/sctp v1.6.3/go.mod h1:cCqpLdYvgEUdl715+qbWtgT439CuQrAgy8BZTp0aEfA=
 github.com/pion/sctp v1.6.4 h1:edUNxTabSErLWOdeUUAxds8gwx5kGnFam4zL5DWpILk=
 github.com/pion/sctp v1.6.4/go.mod h1:cCqpLdYvgEUdl715+qbWtgT439CuQrAgy8BZTp0aEfA=
-github.com/pion/sdp/v2 v2.2.0 h1:JiixCEU8g6LbSsh1Bg5SOk0TPnJrn2HBOA1yJ+mRYhI=
-github.com/pion/sdp/v2 v2.2.0/go.mod h1:idSlWxhfWQDtTy9J05cgxpHBu/POwXN2VDRGYxT/EjU=
+github.com/pion/sdp/v2 v2.3.0 h1:5EhwPh1xKWYYjjvMuubHoMLy6M0B9U26Hh7q3f7vEGk=
+github.com/pion/sdp/v2 v2.3.0/go.mod h1:idSlWxhfWQDtTy9J05cgxpHBu/POwXN2VDRGYxT/EjU=
 github.com/pion/srtp v1.2.6 h1:mHQuAMh0P67R7/j1F260u3O+fbRWLyjKLRPZYYvODFM=
 github.com/pion/srtp v1.2.6/go.mod h1:rd8imc5htjfs99XiEoOjLMEOcVjME63UHx9Ek9IGst0=
 github.com/pion/stun v0.3.1 h1:d09JJzOmOS8ZzIp8NppCMgrxGZpJ4Ix8qirfNYyI3BA=

ice_go.go

@@ -53,17 +53,3 @@ func newICECandidateFromSDP(c sdp.ICECandidate) (ICECandidate, error) {
 		RelatedPort:    c.RelatedPort,
 	}, nil
 }
-
-func iceCandidateToSDP(c ICECandidate) sdp.ICECandidate {
-	return sdp.ICECandidate{
-		Foundation:     c.Foundation,
-		Priority:       c.Priority,
-		Address:        c.Address,
-		Protocol:       c.Protocol.String(),
-		Port:           c.Port,
-		Component:      c.Component,
-		Typ:            c.Typ.String(),
-		RelatedAddress: c.RelatedAddress,
-		RelatedPort:    c.RelatedPort,
-	}
-}

icecandidate.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"github.com/pion/ice"
+	"github.com/pion/sdp/v2"
 )
 
 // ICECandidate represents a ice candidate
@@ -137,3 +138,24 @@ func (c ICECandidate) String() string {
 	}
 	return ic.String()
 }
+
+func iceCandidateToSDP(c ICECandidate) sdp.ICECandidate {
+	return sdp.ICECandidate{
+		Foundation:     c.Foundation,
+		Priority:       c.Priority,
+		Address:        c.Address,
+		Protocol:       c.Protocol.String(),
+		Port:           c.Port,
+		Component:      c.Component,
+		Typ:            c.Typ.String(),
+		RelatedAddress: c.RelatedAddress,
+		RelatedPort:    c.RelatedPort,
+	}
+}
+
+// ToJSON returns an ICECandidateInit
+// as indicated by the spec https://w3c.github.io/webrtc-pc/#dom-rtcicecandidate-tojson
+func (c ICECandidate) ToJSON() ICECandidateInit {
+	var sdpmLineIndex uint16
+	return ICECandidateInit{Candidate: iceCandidateToSDP(c).Marshal(), SDPMLineIndex: &sdpmLineIndex}
+}

peerconnection.go

@@ -825,17 +825,21 @@ func (pc *PeerConnection) SetLocalDescription(desc SessionDescription) error {
 		return err
 	}
 
+	// To support all unittests which are following the future trickle=true
+	// setup while also support the old trickle=false synchronous gathering
+	// process this is necessary to avoid calling Garther() in multiple
+	// pleces; which causes race conditions. (issue-707)
 	if !pc.iceGatherer.agentIsTrickle {
-		// To support all unittests which are following the future trickle=true
-		// setup while also support the old trickle=false synchronous gathering
-		// process this is necessary to avoid calling Garther() in multiple
-		// pleces; which causes race conditions. (issue-707)
 		if err := pc.iceGatherer.SignalCandidates(); err != nil {
 			return err
 		}
 		return nil
 	}
-	return pc.iceGatherer.Gather()
+
+	if desc.Type == SDPTypeAnswer {
+		return pc.iceGatherer.Gather()
+	}
+	return nil
 }
 
 // LocalDescription returns pendingLocalDescription if it is not null and
@@ -850,7 +854,7 @@ func (pc *PeerConnection) LocalDescription() *SessionDescription {
 }
 
 // SetRemoteDescription sets the SessionDescription of the remote peer
-func (pc *PeerConnection) SetRemoteDescription(desc SessionDescription) error {
+func (pc *PeerConnection) SetRemoteDescription(desc SessionDescription) error { //nolint pion/webrtc#614
 	if pc.currentRemoteDescription != nil { // pion/webrtc#207
 		return fmt.Errorf("remoteDescription is already defined, SetRemoteDescription can only be called once")
 	}
@@ -1027,6 +1031,9 @@ func (pc *PeerConnection) SetRemoteDescription(desc SessionDescription) error {
 		pc.mu.Unlock()
 	}()
 
+	if (desc.Type == SDPTypeAnswer || desc.Type == SDPTypePranswer) && pc.iceGatherer.agentIsTrickle {
+		return pc.iceGatherer.Gather()
+	}
 	return nil
 }