Update WebRTC candidates logic

internal/ngrok/ngrok.go

@@ -50,7 +50,7 @@ func Init() {
 
 				log.Info().Str("addr", address).Msg("[ngrok] add external candidate for WebRTC")
 
-				webrtc.AddCandidate(address)
+				webrtc.AddCandidate(address, "tcp")
 			}
 		}
 	})

internal/webrtc/README.md

@@ -1,3 +1,17 @@
+## Config
+
+- supported networks: IPv4 (default), IPv6, both
+- supported TCP: fixed port (default), disabled 
+- supported UDP: random port (default), fixed port
+
+| Config examples              | IPv4 | IPv6 | TCP   | UDP    |
+|------------------------------|------|------|-------|--------|
+| `listen: "0.0.0.0:8555/tcp"` | yes  | no   | fixed | random |
+| `listen: "0.0.0.0:8555/udp"` | yes  | no   | no    | fixed  |
+| `listen: "[::]:8555/tcp"`    | no   | yes  | fixed | random |
+| `listen: ":8555"`            | yes  | yes  | fixed | fixed  |
+| `listen: ""`                 | yes  | yes  | no    | random |
+
 ## Userful links
 
 - https://www.ietf.org/archive/id/draft-ietf-wish-whip-01.html

internal/webrtc/candidates.go

@@ -1,58 +1,66 @@
 package webrtc
 
 import (
+	"net"
+
 	"github.com/AlexxIT/go2rtc/internal/api/ws"
 	"github.com/AlexxIT/go2rtc/pkg/webrtc"
 	"github.com/pion/sdp/v3"
-	"strconv"
-	"strings"
 )
 
 type Address struct {
-	Host string
-	Port int
+	Host    string
+	Port    string
+	Network string
+	Offset  int
 }
 
-var addresses []Address
-
-func AddCandidate(address string) {
-	var port int
-
-	// try to get port from address string
-	if i := strings.LastIndexByte(address, ':'); i > 0 {
-		if v, _ := strconv.Atoi(address[i+1:]); v != 0 {
-			address = address[:i]
-			port = v
+func (a *Address) Marshal() string {
+	host := a.Host
+	if host == "stun" {
+		ip, err := webrtc.GetCachedPublicIP()
+		if err != nil {
+			return ""
 		}
+		host = ip.String()
 	}
 
-	// use default WebRTC port
-	if port == 0 {
-		port, _ = strconv.Atoi(Port)
+	switch a.Network {
+	case "udp":
+		return webrtc.CandidateManualHostUDP(host, a.Port, a.Offset)
+	case "tcp":
+		return webrtc.CandidateManualHostTCPPassive(host, a.Port, a.Offset)
 	}
 
-	addresses = append(addresses, Address{Host: address, Port: port})
+	return ""
+}
+
+var addresses []*Address
+
+func AddCandidate(address, network string) {
+	host, port, err := net.SplitHostPort(address)
+	if err != nil {
+		return
+	}
+
+	offset := -1 - len(addresses) // every next candidate will have a lower priority
+
+	switch network {
+	case "tcp", "udp":
+		addresses = append(addresses, &Address{host, port, network, offset})
+	default:
+		addresses = append(
+			addresses, &Address{host, port, "udp", offset}, &Address{host, port, "tcp", offset},
+		)
+	}
 }
 
 func GetCandidates() (candidates []string) {
 	for _, address := range addresses {
-		// using stun server for receive public IP-address
-		if address.Host == "stun" {
-			ip, err := webrtc.GetCachedPublicIP()
-			if err != nil {
-				continue
-			}
-			// this is a copy, original host unchanged
-			address.Host = ip.String()
+		if candidate := address.Marshal(); candidate != "" {
+			candidates = append(candidates, candidate)
 		}
-
-		candidates = append(
-			candidates,
-			webrtc.CandidateManualHostUDP(address.Host, address.Port),
-			webrtc.CandidateManualHostTCPPassive(address.Host, address.Port),
-		)
 	}
-
 	return
 }
 

internal/webrtc/kinesis.go

@@ -55,7 +55,7 @@ func kinesisClient(rawURL string, query url.Values, desc string) (core.Producer,
 	defer conn.Close()
 
 	// 3. Create Peer Connection
-	api, err := webrtc.NewAPI("")
+	api, err := webrtc.NewAPI()
 	if err != nil {
 		return nil, err
 	}

internal/webrtc/openipc.go

@@ -33,7 +33,7 @@ func openIPCClient(rawURL string, query url.Values) (core.Producer, error) {
 	defer conn.Close()
 
 	// 3. Create Peer Connection
-	api, err := webrtc.NewAPI("")
+	api, err := webrtc.NewAPI()
 	if err != nil {
 		return nil, err
 	}

internal/webrtc/webrtc.go

@@ -2,7 +2,7 @@ package webrtc
 
 import (
 	"errors"
-	"net"
+	"strings"
 
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"github.com/AlexxIT/go2rtc/internal/api/ws"
@@ -32,10 +32,20 @@ func Init() {
 
 	log = app.GetLogger("webrtc")
 
-	address := cfg.Mod.Listen
+	address, network, _ := strings.Cut(cfg.Mod.Listen, "/")
+
+	var candidateHost []string
+	for _, candidate := range cfg.Mod.Candidates {
+		if strings.HasPrefix(candidate, "host:") {
+			candidateHost = append(candidateHost, candidate[5:])
+			continue
+		}
+
+		AddCandidate(candidate, network)
+	}
 
 	// create pionAPI with custom codecs list and custom network settings
-	serverAPI, err := webrtc.NewAPI(address)
+	serverAPI, err := webrtc.NewServerAPI(address, network, candidateHost)
 	if err != nil {
 		log.Error().Err(err).Caller().Send()
 		return
@@ -46,9 +56,8 @@ func Init() {
 
 	if address != "" {
 		log.Info().Str("addr", address).Msg("[webrtc] listen")
-		_, Port, _ = net.SplitHostPort(address)
 
-		clientAPI, _ = webrtc.NewAPI("")
+		clientAPI, _ = webrtc.NewAPI()
 	}
 
 	pionConf := pion.Configuration{
@@ -65,10 +74,6 @@ func Init() {
 		}
 	}
 
-	for _, candidate := range cfg.Mod.Candidates {
-		AddCandidate(candidate)
-	}
-
 	// async WebRTC server (two API versions)
 	ws.HandleFunc("webrtc", asyncHandler)
 	ws.HandleFunc("webrtc/offer", asyncHandler)
@@ -81,7 +86,6 @@ func Init() {
 	streams.HandleFunc("webrtc", streamsHandler)
 }
 
-var Port string
 var log zerolog.Logger
 
 var PeerConnection func(active bool) (*pion.PeerConnection, error)