From c6ad7ac39f3d8e973db8e1cae65dba1500a94f11 Mon Sep 17 00:00:00 2001
From: Alexey Khit <alexey.khit@gmail.com>
Date: Fri, 13 Jan 2023 20:34:18 +0300
Subject: [PATCH] Add single UDP port for WebRTC Server

---
 cmd/debug/stack.go       |  1 +
 cmd/webrtc/candidates.go | 33 +++++++++++++++++++--------------
 pkg/webrtc/api.go        | 16 ++++++++++------
 pkg/webrtc/helper.go     |  4 ++--
 4 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/cmd/debug/stack.go b/cmd/debug/stack.go
index cbd36647..048ed77e 100644
--- a/cmd/debug/stack.go
+++ b/cmd/debug/stack.go
@@ -25,6 +25,7 @@ var stackSkip = [][]byte{
 
 	// webrtc/api.go
 	[]byte("created by github.com/pion/ice/v2.NewTCPMuxDefault"),
+	[]byte("created by github.com/pion/ice/v2.NewUDPMuxDefault"),
 }
 
 func stackHandler(w http.ResponseWriter, r *http.Request) {
diff --git a/cmd/webrtc/candidates.go b/cmd/webrtc/candidates.go
index 677c0a15..50f0c52f 100644
--- a/cmd/webrtc/candidates.go
+++ b/cmd/webrtc/candidates.go
@@ -7,6 +7,7 @@ import (
 )
 
 var candidates []string
+var networks = []string{"udp", "tcp"}
 
 func AddCandidate(address string) {
 	candidates = append(candidates, address)
@@ -20,15 +21,17 @@ func asyncCandidates(tr *api.Transport) {
 			continue
 		}
 
-		cand, err := webrtc.NewCandidate(address)
-		if err != nil {
-			log.Warn().Err(err).Caller().Send()
-			continue
+		for _, network := range networks {
+			cand, err := webrtc.NewCandidate(network, address)
+			if err != nil {
+				log.Warn().Err(err).Caller().Send()
+				continue
+			}
+
+			log.Trace().Str("candidate", cand).Msg("[webrtc] config")
+
+			tr.Write(&api.Message{Type: "webrtc/candidate", Value: cand})
 		}
-
-		log.Trace().Str("candidate", cand).Msg("[webrtc] config")
-
-		tr.Write(&api.Message{Type: "webrtc/candidate", Value: cand})
 	}
 }
 
@@ -57,13 +60,15 @@ func syncCanditates(answer string) (string, error) {
 			continue
 		}
 
-		cand, err := webrtc.NewCandidate(address)
-		if err != nil {
-			log.Warn().Err(err).Msg("[webrtc] candidate")
-			continue
-		}
+		for _, network := range networks {
+			cand, err := webrtc.NewCandidate(network, address)
+			if err != nil {
+				log.Warn().Err(err).Msg("[webrtc] candidate")
+				continue
+			}
 
-		md.WithPropertyAttribute(cand)
+			md.WithPropertyAttribute(cand)
+		}
 	}
 
 	if end {
diff --git a/pkg/webrtc/api.go b/pkg/webrtc/api.go
index 5a968045..2012d580 100644
--- a/pkg/webrtc/api.go
+++ b/pkg/webrtc/api.go
@@ -35,13 +35,17 @@ func NewAPI(address string) (*webrtc.API, error) {
 	s.SetICEMulticastDNSMode(ice.MulticastDNSModeDisabled)
 
 	if address != "" {
-		ln, err := net.Listen("tcp", address)
-		if err == nil {
-			s.SetNetworkTypes([]webrtc.NetworkType{
-				webrtc.NetworkTypeUDP4, webrtc.NetworkTypeUDP6,
-				webrtc.NetworkTypeTCP4, webrtc.NetworkTypeTCP6,
-			})
+		s.SetNetworkTypes([]webrtc.NetworkType{
+			webrtc.NetworkTypeUDP4, webrtc.NetworkTypeUDP6,
+			webrtc.NetworkTypeTCP4, webrtc.NetworkTypeTCP6,
+		})
 
+		if ln, err := net.ListenPacket("udp", address); err == nil {
+			udpMux := webrtc.NewICEUDPMux(nil, ln)
+			s.SetICEUDPMux(udpMux)
+		}
+
+		if ln, err := net.Listen("tcp", address); err == nil {
 			tcpMux := webrtc.NewICETCPMux(nil, ln, 8)
 			s.SetICETCPMux(tcpMux)
 		}
diff --git a/pkg/webrtc/helper.go b/pkg/webrtc/helper.go
index 8a94feab..17eaca5b 100644
--- a/pkg/webrtc/helper.go
+++ b/pkg/webrtc/helper.go
@@ -13,7 +13,7 @@ import (
 	"time"
 )
 
-func NewCandidate(address string) (string, error) {
+func NewCandidate(network, address string) (string, error) {
 	i := strings.LastIndexByte(address, ':')
 	if i < 0 {
 		return "", errors.New("wrong candidate: " + address)
@@ -26,7 +26,7 @@ func NewCandidate(address string) (string, error) {
 	}
 
 	cand, err := ice.NewCandidateHost(&ice.CandidateHostConfig{
-		Network:   "tcp",
+		Network:   network,
 		Address:   host,
 		Port:      i,
 		Component: ice.ComponentRTP,