From 6ef144c3b97e197283a0b5f9019393cbfe93c4cc Mon Sep 17 00:00:00 2001
From: Pierre Hubert <pierre.git@communiquons.org>
Date: Sun, 17 Oct 2021 20:01:42 +0200
Subject: [PATCH] Can specify custom IP & port access

---
 config.go   |  7 +++++++
 config.yaml |  7 +++++++
 main.go     |  8 ++++++++
 relay.go    | 34 +++++++++++++++++++---------------
 ws.go       |  6 +++---
 5 files changed, 44 insertions(+), 18 deletions(-)

diff --git a/config.go b/config.go
index 32602f0..706dd38 100644
--- a/config.go
+++ b/config.go
@@ -17,6 +17,13 @@ type Config struct {
 	Path     string
 	Token    string
 
+	// Optional information to inject proxy reachability (can be left empty)
+	AccessIP string
+
+	// Optionaly restrict Ports range (can be left to 0)
+	PortStart int
+	PortEnd   int
+
 	// Amount of time to wait before automatically
 	//quitting the application when the websocket
 	// connection was interrupted
diff --git a/config.yaml b/config.yaml
index fab1894..ed073b2 100644
--- a/config.yaml
+++ b/config.yaml
@@ -8,6 +8,13 @@ port: 3000
 path: /rtc_proxy/ws
 token: SecretToken
 
+# Set the IP this relay can be reached (optional)
+# accessip: 
+
+# Limit UDP ports this server will listen to
+portstart: 0
+portend: 0
+
 # Number of seconds to wait before automatically 
 # closing the proxy (if WebSocket connection was
 # interrupted)
diff --git a/main.go b/main.go
index b0faf52..b711415 100644
--- a/main.go
+++ b/main.go
@@ -19,6 +19,14 @@ func main() {
 	// First, load the config
 	conf := loadConfig(os.Args[1])
 
+	if len(conf.AccessIP) > 0 {
+		fmt.Printf("RTC reachable at %s\n", conf.AccessIP)
+	}
+
+	if conf.PortStart > 0 && conf.PortEnd > conf.PortStart {
+		fmt.Printf("Will listen only on these ports: %d to %d\n", conf.PortStart, conf.PortEnd)
+	}
+
 	/// Avoid to quick restart loop
 	defer timeBeforeQuit(&conf)
 
diff --git a/relay.go b/relay.go
index a530b23..0587ec5 100644
--- a/relay.go
+++ b/relay.go
@@ -52,7 +52,7 @@ var connections = make(map[string]*activeRelay)
 var currID uint = 0
 
 /// Process incoming messages
-func onSignal(callHash, peerID string, data map[string]interface{}) {
+func onSignal(config *Config, callHash, peerID string, data map[string]interface{}) {
 
 	// Close all the channels that requested so
 	processCloseRequests()
@@ -134,7 +134,7 @@ func onSignal(callHash, peerID string, data map[string]interface{}) {
 		}
 		currID++
 		connections[callHash] = &newRelay
-		go newCall(newSignal, &newRelay)
+		go newCall(config, newSignal, &newRelay)
 
 	} else {
 		// Forward the message to the channel
@@ -143,15 +143,15 @@ func onSignal(callHash, peerID string, data map[string]interface{}) {
 }
 
 /// Request an offer for a client of a broadcast
-func onRequestOffer(callHash, peerID string) {
-	onSignal(callHash, peerID, map[string]interface{}{
+func onRequestOffer(c *Config, callHash, peerID string) {
+	onSignal(c, callHash, peerID, map[string]interface{}{
 		"type": "REQUEST_OFFER",
 	})
 }
 
 /// Request connections to be closed
-func onCloseConnection(callHash, peerID string) {
-	onSignal(callHash, peerID, map[string]interface{}{
+func onCloseConnection(c *Config, callHash, peerID string) {
+	onSignal(c, callHash, peerID, map[string]interface{}{
 		"type": "CLOSE_CONN",
 	})
 }
@@ -191,7 +191,7 @@ func processCloseRequests() {
 }
 
 /// Start new call
-func newCall(mainOffer receivedSignal, r *activeRelay) {
+func newCall(config *Config, mainOffer receivedSignal, r *activeRelay) {
 
 	// I am not sure this is a strong way to determine whether we are having
 	// a video call or not, but I have not found any better way yet...
@@ -220,16 +220,20 @@ func newCall(mainOffer receivedSignal, r *activeRelay) {
 	s := webrtc.SettingEngine{}
 	s.SetTrickle(false) // I did not manage to make the connection trickling, sorry...
 
-	// TODO : remove hardcoded ports
-	if err := s.SetEphemeralUDPPortRange(5000, 5001); err != nil {
-		log.Println("Error: faild to set ephemeral UDP Port range!", err)
-		askForClose(r)
-		return
+	// Optional : restrict ports
+	if config.PortStart > 0 && config.PortEnd > config.PortStart {
+		if err := s.SetEphemeralUDPPortRange(uint16(config.PortStart), uint16(config.PortEnd)); err != nil {
+			log.Println("Error: faild to set ephemeral UDP Port range!", err)
+			askForClose(r)
+			return
+		}
 	}
 
-	// TODO : remove hardcoded ips
-	ips := []string{"127.0.0.1"}
-	s.SetNAT1To1IPs(ips, webrtc.ICECandidateTypeHost)
+	// Optional : set access IP
+	if len(config.AccessIP) > 0 {
+		ips := []string{config.AccessIP}
+		s.SetNAT1To1IPs(ips, webrtc.ICECandidateTypeHost)
+	}
 
 	// Create the API object with the MediaEngine
 	api := webrtc.NewAPI(webrtc.WithMediaEngine(mediaEngine),
diff --git a/ws.go b/ws.go
index fdc694f..8421a66 100644
--- a/ws.go
+++ b/ws.go
@@ -82,17 +82,17 @@ func openWs(conf *Config) {
 
 		// Remote signal
 		case "signal":
-			onSignal(msg.CallHash, msg.PeerID, msg.Data.(map[string]interface{}))
+			onSignal(conf, msg.CallHash, msg.PeerID, msg.Data.(map[string]interface{}))
 			break
 
 		// Request an offer
 		case "request_offer":
-			onRequestOffer(msg.CallHash, msg.PeerID)
+			onRequestOffer(conf, msg.CallHash, msg.PeerID)
 			break
 
 		// Close a connection
 		case "close_conn":
-			onCloseConnection(msg.CallHash, msg.PeerID)
+			onCloseConnection(conf, msg.CallHash, msg.PeerID)
 			break
 
 		default: