Refactor (De)SerializeSessionDescription as common utils

client/lib/lib_test.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"testing"
 
+	"git.torproject.org/pluggable-transports/snowflake.git/common/util"
 	"github.com/pion/webrtc/v2"
 	. "github.com/smartystreets/goconvey/convey"
 )
@@ -230,7 +231,7 @@ func TestSnowflakeClient(t *testing.T) {
 				So(err, ShouldBeNil)
 
 				c.offerChannel <- nil
-				answer := deserializeSessionDescription(sampleAnswer)
+				answer := util.DeserializeSessionDescription(sampleAnswer)
 				So(answer, ShouldNotBeNil)
 				c.answerChannel <- answer
 				err = c.exchangeSDP()
@@ -255,7 +256,7 @@ func TestSnowflakeClient(t *testing.T) {
 					ctx.So(err, ShouldBeNil)
 					wg.Done()
 				}()
-				answer := deserializeSessionDescription(sampleAnswer)
+				answer := util.DeserializeSessionDescription(sampleAnswer)
 				c.answerChannel <- answer
 				wg.Wait()
 			})
@@ -285,7 +286,7 @@ func TestSnowflakeClient(t *testing.T) {
 			http.StatusOK,
 			[]byte(`{"type":"answer","sdp":"fake"}`),
 		}
-		fakeOffer := deserializeSessionDescription(`{"type":"offer","sdp":"test"}`)
+		fakeOffer := util.DeserializeSessionDescription(`{"type":"offer","sdp":"test"}`)
 
 		Convey("Construct BrokerChannel with no front domain", func() {
 			b, err := NewBrokerChannel("test.broker", "", transport, false)

client/lib/rendezvous.go

@@ -18,6 +18,7 @@ import (
 	"net/http"
 	"net/url"
 
+	"git.torproject.org/pluggable-transports/snowflake.git/common/util"
 	"github.com/pion/sdp/v2"
 	"github.com/pion/webrtc/v2"
 )
@@ -140,7 +141,7 @@ func (bc *BrokerChannel) Negotiate(offer *webrtc.SessionDescription) (
 			SDP:  stripLocalAddresses(offer.SDP),
 		}
 	}
-	data := bytes.NewReader([]byte(serializeSessionDescription(offer)))
+	data := bytes.NewReader([]byte(util.SerializeSessionDescription(offer)))
 	// Suffix with broker's client registration handler.
 	clientURL := bc.url.ResolveReference(&url.URL{Path: "client"})
 	request, err := http.NewRequest("POST", clientURL.String(), data)
@@ -163,7 +164,7 @@ func (bc *BrokerChannel) Negotiate(offer *webrtc.SessionDescription) (
 		if nil != err {
 			return nil, err
 		}
-		answer := deserializeSessionDescription(string(body))
+		answer := util.DeserializeSessionDescription(string(body))
 		return answer, nil
 	case http.StatusServiceUnavailable:
 		return nil, errors.New(BrokerError503)

client/lib/util.go

@@ -1,11 +1,8 @@
 package lib
 
 import (
-	"encoding/json"
 	"log"
 	"time"
-
-	"github.com/pion/webrtc/v2"
 )
 
 const (
@@ -86,52 +83,3 @@ func (b *BytesSyncLogger) AddInbound(amount int) {
 	}
 	b.InboundChan <- amount
 }
-func deserializeSessionDescription(msg string) *webrtc.SessionDescription {
-	var parsed map[string]interface{}
-	err := json.Unmarshal([]byte(msg), &parsed)
-	if nil != err {
-		log.Println(err)
-		return nil
-	}
-	if _, ok := parsed["type"]; !ok {
-		log.Println("Cannot deserialize SessionDescription without type field.")
-		return nil
-	}
-	if _, ok := parsed["sdp"]; !ok {
-		log.Println("Cannot deserialize SessionDescription without sdp field.")
-		return nil
-	}
-
-	var stype webrtc.SDPType
-	switch parsed["type"].(string) {
-	default:
-		log.Println("Unknown SDP type")
-		return nil
-	case "offer":
-		stype = webrtc.SDPTypeOffer
-	case "pranswer":
-		stype = webrtc.SDPTypePranswer
-	case "answer":
-		stype = webrtc.SDPTypeAnswer
-	case "rollback":
-		stype = webrtc.SDPTypeRollback
-	}
-
-	if err != nil {
-		log.Println(err)
-		return nil
-	}
-	return &webrtc.SessionDescription{
-		Type: stype,
-		SDP:  parsed["sdp"].(string),
-	}
-}
-
-func serializeSessionDescription(desc *webrtc.SessionDescription) string {
-	bytes, err := json.Marshal(*desc)
-	if nil != err {
-		log.Println(err)
-		return ""
-	}
-	return string(bytes)
-}

common/util/util.go

@@ -0,0 +1,58 @@
+package util
+
+import (
+	"encoding/json"
+	"log"
+
+	"github.com/pion/webrtc/v2"
+)
+
+func SerializeSessionDescription(desc *webrtc.SessionDescription) string {
+	bytes, err := json.Marshal(*desc)
+	if nil != err {
+		log.Println(err)
+		return ""
+	}
+	return string(bytes)
+}
+
+func DeserializeSessionDescription(msg string) *webrtc.SessionDescription {
+	var parsed map[string]interface{}
+	err := json.Unmarshal([]byte(msg), &parsed)
+	if nil != err {
+		log.Println(err)
+		return nil
+	}
+	if _, ok := parsed["type"]; !ok {
+		log.Println("Cannot deserialize SessionDescription without type field.")
+		return nil
+	}
+	if _, ok := parsed["sdp"]; !ok {
+		log.Println("Cannot deserialize SessionDescription without sdp field.")
+		return nil
+	}
+
+	var stype webrtc.SDPType
+	switch parsed["type"].(string) {
+	default:
+		log.Println("Unknown SDP type")
+		return nil
+	case "offer":
+		stype = webrtc.SDPTypeOffer
+	case "pranswer":
+		stype = webrtc.SDPTypePranswer
+	case "answer":
+		stype = webrtc.SDPTypeAnswer
+	case "rollback":
+		stype = webrtc.SDPTypeRollback
+	}
+
+	if err != nil {
+		log.Println(err)
+		return nil
+	}
+	return &webrtc.SessionDescription{
+		Type: stype,
+		SDP:  parsed["sdp"].(string),
+	}
+}

proxy-go/proxy-go_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"git.torproject.org/pluggable-transports/snowflake.git/common/messages"
+	"git.torproject.org/pluggable-transports/snowflake.git/common/util"
 	"github.com/pion/webrtc/v2"
 	. "github.com/smartystreets/goconvey/convey"
 )
@@ -197,7 +198,7 @@ func TestSessionDescriptions(t *testing.T) {
 				},
 			},
 		} {
-			desc := deserializeSessionDescription(test.msg)
+			desc := util.DeserializeSessionDescription(test.msg)
 			So(desc, ShouldResemble, test.ret)
 		}
 	})
@@ -214,7 +215,7 @@ func TestSessionDescriptions(t *testing.T) {
 				`{"type":"offer","sdp":"test"}`,
 			},
 		} {
-			msg := serializeSessionDescription(test.desc)
+			msg := util.SerializeSessionDescription(test.desc)
 			So(msg, ShouldResemble, test.ret)
 		}
 	})
@@ -239,7 +240,7 @@ func TestBrokerInteractions(t *testing.T) {
 			},
 		}
 		pc, _ := webrtc.NewPeerConnection(config)
-		offer := deserializeSessionDescription(sampleOffer)
+		offer := util.DeserializeSessionDescription(sampleOffer)
 		pc.SetRemoteDescription(*offer)
 		answer, _ := pc.CreateAnswer(nil)
 		pc.SetLocalDescription(answer)

proxy-go/snowflake.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"crypto/rand"
 	"encoding/base64"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"io"
@@ -21,6 +20,7 @@ import (
 
 	"git.torproject.org/pluggable-transports/snowflake.git/common/messages"
 	"git.torproject.org/pluggable-transports/snowflake.git/common/safelog"
+	"git.torproject.org/pluggable-transports/snowflake.git/common/util"
 	"git.torproject.org/pluggable-transports/snowflake.git/common/websocketconn"
 	"github.com/gorilla/websocket"
 	"github.com/pion/webrtc/v2"
@@ -199,7 +199,7 @@ func (b *Broker) pollOffer(sid string) *webrtc.SessionDescription {
 						return nil
 					}
 					if offer != "" {
-						return deserializeSessionDescription(offer)
+						return util.DeserializeSessionDescription(offer)
 					}
 				}
 			}
@@ -209,7 +209,7 @@ func (b *Broker) pollOffer(sid string) *webrtc.SessionDescription {
 
 func (b *Broker) sendAnswer(sid string, pc *webrtc.PeerConnection) error {
 	brokerPath := b.url.ResolveReference(&url.URL{Path: "answer"})
-	answer := string([]byte(serializeSessionDescription(pc.LocalDescription())))
+	answer := string([]byte(util.SerializeSessionDescription(pc.LocalDescription())))
 	body, err := messages.EncodeAnswerRequest(answer, sid)
 	if err != nil {
 		return err
@@ -465,49 +465,3 @@ func main() {
 		runSession(sessionID)
 	}
 }
-
-func deserializeSessionDescription(msg string) *webrtc.SessionDescription {
-	var parsed map[string]interface{}
-	err := json.Unmarshal([]byte(msg), &parsed)
-	if nil != err {
-		log.Println(err)
-		return nil
-	}
-	if _, ok := parsed["type"]; !ok {
-		log.Println("Cannot deserialize SessionDescription without type field.")
-		return nil
-	}
-	if _, ok := parsed["sdp"]; !ok {
-		log.Println("Cannot deserialize SessionDescription without sdp field.")
-		return nil
-	}
-
-	var stype webrtc.SDPType
-	switch parsed["type"].(string) {
-	default:
-		log.Println("Unknown SDP type")
-		return nil
-	case "offer":
-		stype = webrtc.SDPTypeOffer
-	case "pranswer":
-		stype = webrtc.SDPTypePranswer
-	case "answer":
-		stype = webrtc.SDPTypeAnswer
-	case "rollback":
-		stype = webrtc.SDPTypeRollback
-	}
-
-	return &webrtc.SessionDescription{
-		Type: stype,
-		SDP:  parsed["sdp"].(string),
-	}
-}
-
-func serializeSessionDescription(desc *webrtc.SessionDescription) string {
-	bytes, err := json.Marshal(*desc)
-	if nil != err {
-		log.Println(err)
-		return ""
-	}
-	return string(bytes)
-}