Allow ICEServers to be configured

README.md

@@ -207,7 +207,8 @@ The backend can be configured with the following environment variables.
 - `INCLUDE_PUBLIC_IP_IN_NAT_1_TO_1_IP` - Like `NAT_1_TO_1_IP` but autoconfigured
 - `INTERFACE_FILTER` - Only use a certain interface for UDP traffic
 - `NAT_ICE_CANDIDATE_TYPE` - By default setting a NAT_1_TO_1_IP overrides. Set this to `srflx` to instead append IPs
-- `STUN_SERVERS` - List of STUN servers delineated by '|'. Useful if Broadcast Box is running behind a NAT
+- `CLIENT_ICE_SERVERS` - A JSON array of ICE Servers, same format as browser. These ICE servers will be used by clients.
+- `BACKEND_ICE_SERVERS` - A JSON array of ICE Servers, same format as browser. These ICE servers will be used by server.
 
 - `UDP_MUX_PORT_WHEP` - Like `UDP_MUX_PORT` but only for WHEP traffic
 - `UDP_MUX_PORT_WHIP` - Like `UDP_MUX_PORT` but only for WHIP traffic

internal/webrtc/webrtc.go

@@ -337,11 +337,9 @@ func PopulateMediaEngine(m *webrtc.MediaEngine) error {
 func newPeerConnection(api *webrtc.API) (*webrtc.PeerConnection, error) {
 	cfg := webrtc.Configuration{}
 
-	if stunServers := os.Getenv("STUN_SERVERS"); stunServers != "" {
-		for _, stunServer := range strings.Split(stunServers, "|") {
-			cfg.ICEServers = append(cfg.ICEServers, webrtc.ICEServer{
-				URLs: []string{"stun:" + stunServer},
-			})
+	if iceServers := os.Getenv("BACKEND_ICE_SERVERS"); iceServers != "" {
+		if err := json.Unmarshal([]byte(iceServers), &cfg.ICEServers); err != nil {
+			return nil, err
 		}
 	}
 
@@ -458,3 +456,36 @@ func GetStreamStatuses() []StreamStatus {
 
 	return out
 }
+
+func AddICELinks(res http.ResponseWriter) error {
+	if clientICEServers := os.Getenv("CLIENT_ICE_SERVERS"); clientICEServers != "" {
+		var iceServers []webrtc.ICEServer
+		if err := json.Unmarshal([]byte(clientICEServers), &iceServers); err != nil {
+			return err
+		}
+
+		for _, server := range iceServers {
+			linkValue := ""
+
+			for i, url := range server.URLs {
+				linkValue += "<" + url + ">; rel=\"ice-server\"; "
+				if server.Username != "" {
+					linkValue += "username=\"" + server.Username + "\"; "
+				}
+
+				if cred, ok := server.Credential.(string); ok && cred != "" {
+					linkValue += "credential=\"" + cred + "\"; "
+					linkValue += "credential-type=\"" + server.CredentialType.String() + "\""
+				}
+
+				if i+1 != len(server.URLs) {
+					linkValue += ","
+				}
+			}
+
+			res.Header().Add("Link", linkValue)
+		}
+	}
+
+	return nil
+}

main.go

@@ -28,6 +28,8 @@ const (
 	networkTestIntroMessage   = "\033[0;33mNETWORK_TEST_ON_START is enabled. If the test fails Broadcast Box will exit.\nSee the README for how to debug or disable NETWORK_TEST_ON_START\033[0m"
 	networkTestSuccessMessage = "\033[0;32mNetwork Test passed.\nHave fun using Broadcast Box.\033[0m"
 	networkTestFailedMessage  = "\033[0;31mNetwork Test failed.\n%s\nPlease see the README and join Discord for help\033[0m"
+
+	deprecatedConfigSTUNServers = "\033[0;31mSTUN_SERVERS has been deprecated, use BACKEND_ICE_SERVERS instead\033[0m"
 )
 
 var noBuildDirectoryErr = errors.New("\033[0;31mBuild directory does not exist, run `npm install` and `npm run build` in the web directory.\033[0m")
@@ -87,6 +89,10 @@ func whipHandler(res http.ResponseWriter, r *http.Request) {
 
 	res.Header().Add("Location", "/api/whip")
 	res.Header().Add("Content-Type", "application/sdp")
+	if err = webrtc.AddICELinks(res); err != nil {
+		logHTTPError(res, err.Error(), http.StatusBadRequest)
+		return
+	}
 	res.WriteHeader(http.StatusCreated)
 	fmt.Fprint(res, answer)
 }
@@ -119,6 +125,10 @@ func whepHandler(res http.ResponseWriter, req *http.Request) {
 	apiPath := req.Host + strings.TrimSuffix(req.URL.RequestURI(), "whep")
 	res.Header().Add("Link", `<`+apiPath+"sse/"+whepSessionId+`>; rel="urn:ietf:params:whep:ext:core:server-sent-events"; events="layers"`)
 	res.Header().Add("Link", `<`+apiPath+"layer/"+whepSessionId+`>; rel="urn:ietf:params:whep:ext:core:layer"`)
+	if err = webrtc.AddICELinks(res); err != nil {
+		logHTTPError(res, err.Error(), http.StatusBadRequest)
+		return
+	}
 	res.Header().Add("Location", "/api/whep")
 	res.Header().Add("Content-Type", "application/sdp")
 	res.WriteHeader(http.StatusCreated)
@@ -195,6 +205,13 @@ func corsHandler(next func(w http.ResponseWriter, r *http.Request)) http.Handler
 	}
 }
 
+func checkDeprecatedConfigs() {
+	if os.Getenv("STUN_SERVERS") != "" {
+		fmt.Println(deprecatedConfigSTUNServers)
+		os.Exit(1)
+	}
+}
+
 func main() {
 	loadConfigs := func() error {
 		if os.Getenv("APP_ENV") == "development" {
@@ -231,6 +248,7 @@ func main() {
 		}
 	}
 
+	checkDeprecatedConfigs()
 	webrtc.Configure()
 
 	if os.Getenv("NETWORK_TEST_ON_START") == "true" {