Finish ICE implementation

ice_helper.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/pions/pkg/stun"
+	"golang.org/x/net/ipv4"
+)
+
+func packetHandler(relaySocket *ipv4.PacketConn, remoteKey [16]byte) {
+	const MTU = 1500
+	buffer := make([]byte, MTU)
+
+	for {
+		n, _, srcAddr, _ := relaySocket.ReadFrom(buffer)
+
+		if packetType, err := stun.GetPacketType(buffer[:n]); err == nil && packetType == stun.PacketTypeSTUN {
+			if m, err := stun.NewMessage(buffer[:n]); err == nil && m.Class == stun.ClassRequest && m.Method == stun.MethodBinding {
+				dstAddr := &stun.TransportAddr{IP: srcAddr.(*net.UDPAddr).IP, Port: srcAddr.(*net.UDPAddr).Port}
+				err := stun.BuildAndSend(relaySocket, dstAddr, stun.ClassSuccessResponse, stun.MethodBinding, m.TransactionID,
+					&stun.XorMappedAddress{
+						XorAddress: stun.XorAddress{
+							IP:   dstAddr.IP,
+							Port: dstAddr.Port,
+						},
+					},
+					&stun.MessageIntegrity{
+						Key: remoteKey,
+					},
+
+					&stun.Fingerprint{},
+				)
+				if err != nil {
+					fmt.Println(err)
+				}
+
+			}
+		}
+
+	}
+
+}
+
+func udpListener(ip string, remoteKey [16]byte) (int, error) {
+	listener, err := net.ListenPacket("udp4", ip+":0")
+	if err != nil {
+		return 0, err
+	}
+
+	relaySocket := ipv4.NewPacketConn(listener)
+	err = relaySocket.SetControlMessage(ipv4.FlagDst, true)
+	if err != nil {
+		return 0, err
+	}
+
+	addr, err := stun.NewTransportAddr(listener.LocalAddr())
+	go packetHandler(relaySocket, remoteKey)
+	return addr.Port, err
+}

main.go

@@ -1,12 +1,19 @@
 package main
 
 import (
+	"bufio"
 	"encoding/base64"
 	"fmt"
+	"os"
 )
 
 func main() {
+	fmt.Print("base64 encoded Session Description: ")
+	text, _ := bufio.NewReader(os.Stdin).ReadString('\n')
+	fmt.Println(text)
+
 	a := generateVP8OnlyAnswer().Marshal()
 	fmt.Println(a)
 	fmt.Println(base64.StdEncoding.EncodeToString([]byte(a)))
+	select {}
 }

sdp_helper.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"crypto/md5"
 	"fmt"
 	"math/rand"
 	"net"
@@ -13,6 +14,9 @@ import (
 // TODO RTCPeerConnection.localDescription()
 func generateVP8OnlyAnswer() *sdp.SessionDescription {
 
+	iceUsername := randSeq(16)
+	icePassword := randSeq(32)
+
 	videoMediaDescription := &sdp.MediaDescription{
 		MediaName:      "video 7 RTP/SAVPF 96 97",
 		ConnectionData: "IN IP4 127.0.0.1",
@@ -30,8 +34,8 @@ func generateVP8OnlyAnswer() *sdp.SessionDescription {
 			"setup:active",
 			"mid:video",
 			"recvonly",
-			"ice-ufrag:" + randSeq(16),
-			"ice-pwd:" + randSeq(32),
+			"ice-ufrag:" + iceUsername,
+			"ice-pwd:" + icePassword,
 			"ice-options:renomination",
 			"rtcp-mux",
 			"rtcp-rsize",
@@ -40,8 +44,13 @@ func generateVP8OnlyAnswer() *sdp.SessionDescription {
 
 	// Generate only UDP host candidates for ICE
 	basePriority := uint16(rand.Uint32() & (1<<16 - 1))
-	dstPort := 1816
+	remoteKey := md5.Sum([]byte(iceUsername + ":" + icePassword))
 	for id, c := range hostCandidates() {
+		dstPort, err := udpListener(c, remoteKey)
+		if err != nil {
+			panic(err)
+		}
+
 		videoMediaDescription.Attributes = append(videoMediaDescription.Attributes, fmt.Sprintf("candidate:udpcandidate %d udp %d %s %d typ host", id, basePriority, c, dstPort))
 
 		basePriority = basePriority + 1