Carry raw SDP in the protocol.

rtpconn/webclient.go

@@ -174,8 +174,7 @@ type clientMessage struct {
 	Group            string                   `json:"group,omitempty"`
 	Value            interface{}              `json:"value,omitempty"`
 	Time             int64                    `json:"time,omitempty"`
-	Offer            *webrtc.SessionDescription `json:"offer,omitempty"`
-	Answer           *webrtc.SessionDescription `json:"answer,omitempty"`
+	SDP              string                   `json:"sdp,omitempty"`
 	Candidate        *webrtc.ICECandidateInit `json:"candidate,omitempty"`
 	Labels           map[string]string        `json:"labels,omitempty"`
 	Request          rateMap                  `json:"request,omitempty"`
@@ -464,7 +463,7 @@ func negotiate(c *webClient, down *rtpDownConnection, renegotiate, restartIce bo
 		Id:       down.id,
 		Source:   source,
 		Username: username,
-		Offer:    &offer,
+		SDP:      offer.SDP,
 		Labels:   labels,
 	})
 }
@@ -481,7 +480,7 @@ func sendICE(c *webClient, id string, candidate *webrtc.ICECandidate) error {
 	})
 }
 
-func gotOffer(c *webClient, id string, offer webrtc.SessionDescription, renegotiate bool, labels map[string]string) error {
+func gotOffer(c *webClient, id string, sdp string, renegotiate bool, labels map[string]string) error {
 	if !renegotiate {
 		// unless the client indicates that this is a compatible
 		// renegotiation, tear down the existing connection.
@@ -496,12 +495,15 @@ func gotOffer(c *webClient, id string, offer webrtc.SessionDescription, renegoti
 	up.userId = c.Id()
 	up.username = c.Username()
 
-	err = up.pc.SetRemoteDescription(offer)
+	err = up.pc.SetRemoteDescription(webrtc.SessionDescription{
+		Type: webrtc.SDPTypeOffer,
+		SDP:  sdp,
+	})
 	if err != nil {
 		if renegotiate && !isnew {
 			// create a new PC from scratch
 			log.Printf("SetRemoteDescription(offer): %v", err)
-			return gotOffer(c, id, offer, false, labels)
+			return gotOffer(c, id, sdp, false, labels)
 		}
 		return err
 	}
@@ -524,18 +526,21 @@ func gotOffer(c *webClient, id string, offer webrtc.SessionDescription, renegoti
 	return c.write(clientMessage{
 		Type: "answer",
 		Id:   id,
-		Answer: &answer,
+		SDP:  answer.SDP,
 	})
 }
 
 var ErrUnknownId = errors.New("unknown id")
 
-func gotAnswer(c *webClient, id string, answer webrtc.SessionDescription) error {
+func gotAnswer(c *webClient, id string, sdp string) error {
 	down := getDownConn(c, id)
 	if down == nil {
 		return ErrUnknownId
 	}
-	err := down.pc.SetRemoteDescription(answer)
+	err := down.pc.SetRemoteDescription(webrtc.SessionDescription{
+		Type: webrtc.SDPTypeAnswer,
+		SDP: sdp,
+	})
 	if err != nil {
 		return err
 	}
@@ -1128,21 +1133,15 @@ func handleClientMessage(c *webClient, m clientMessage) error {
 			})
 			return c.error(group.UserError("not authorised"))
 		}
-		if m.Offer == nil {
-			return group.ProtocolError("null offer")
-		}
 		err := gotOffer(
-			c, m.Id, *m.Offer, m.Kind == "renegotiate", m.Labels,
+			c, m.Id, m.SDP, m.Kind == "renegotiate", m.Labels,
 		)
 		if err != nil {
 			log.Printf("gotOffer: %v", err)
 			return failUpConnection(c, m.Id, "negotiation failed")
 		}
 	case "answer":
-		if m.Answer == nil {
-			return group.ProtocolError("null answer")
-		}
-		err := gotAnswer(c, m.Id, *m.Answer)
+		err := gotAnswer(c, m.Id, m.SDP)
 		if err != nil {
 			log.Printf("gotAnswer: %v", err)
 			message := ""

static/protocol.js

@@ -183,8 +183,7 @@ function ServerConnection() {
   * @property {Object<string,boolean>} [permissions]
   * @property {string} [group]
   * @property {unknown} [value]
-  * @property {RTCSessionDescriptionInit} [offer]
-  * @property {RTCSessionDescriptionInit} [answer]
+  * @property {string} [sdp]
   * @property {RTCIceCandidate} [candidate]
   * @property {Object<string,string>} [labels]
   * @property {Object<string,(boolean|number)>} [request]
@@ -265,10 +264,10 @@ ServerConnection.prototype.connect = async function(url) {
                 break;
             case 'offer':
                 sc.gotOffer(m.id, m.labels, m.source, m.username,
-                            m.offer, m.kind === 'renegotiate');
+                            m.sdp, m.kind === 'renegotiate');
                 break;
             case 'answer':
-                sc.gotAnswer(m.id, m.answer);
+                sc.gotAnswer(m.id, m.sdp);
                 break;
             case 'renegotiate':
                 sc.gotRenegotiate(m.id)
@@ -525,11 +524,11 @@ ServerConnection.prototype.groupAction = function(kind, message) {
  * @param {Object<string, string>} labels
  * @param {string} source
  * @param {string} username
- * @param {RTCSessionDescriptionInit} offer
+ * @param {string} sdp
  * @param {boolean} renegotiate
  * @function
  */
-ServerConnection.prototype.gotOffer = async function(id, labels, source, username, offer, renegotiate) {
+ServerConnection.prototype.gotOffer = async function(id, labels, source, username, sdp, renegotiate) {
     let sc = this;
     let c = sc.down[id];
     if(c && !renegotiate) {
@@ -598,7 +597,10 @@ ServerConnection.prototype.gotOffer = async function(id, labels, source, usernam
         sc.ondownstream.call(sc, c);
 
     try {
-        await c.pc.setRemoteDescription(offer);
+        await c.pc.setRemoteDescription({
+            type: 'offer',
+            sdp: sdp,
+        });
 
         await c.flushRemoteIceCandidates();
 
@@ -609,7 +611,7 @@ ServerConnection.prototype.gotOffer = async function(id, labels, source, usernam
         this.send({
             type: 'answer',
             id: id,
-            answer: answer,
+            sdp: answer.sdp,
         });
     } catch(e) {
         try {
@@ -631,15 +633,18 @@ ServerConnection.prototype.gotOffer = async function(id, labels, source, usernam
  * Called when we receive an answer from the server.  Don't call this.
  *
  * @param {string} id
- * @param {RTCSessionDescriptionInit} answer
+ * @param {string} sdp
  * @function
  */
-ServerConnection.prototype.gotAnswer = async function(id, answer) {
+ServerConnection.prototype.gotAnswer = async function(id, sdp) {
     let c = this.up[id];
     if(!c)
         throw new Error('unknown up stream');
     try {
-        await c.pc.setRemoteDescription(answer);
+        await c.pc.setRemoteDescription({
+            type: 'answer',
+            sdp: sdp,
+        });
     } catch(e) {
         try {
             if(c.onerror)
@@ -1038,7 +1043,7 @@ Stream.prototype.negotiate = async function (restartIce) {
         kind: this.localDescriptionSent ? 'renegotiate' : '',
         id: c.id,
         labels: c.labelsByMid,
-        offer: offer,
+        sdp: offer.sdp,
     });
     this.localDescriptionSent = true;
     c.flushLocalIceCandidates();