Always use public STUN servers

ice-adapter/src/main/java/com/faforever/iceadapter/ice/GameSession.java

@@ -37,6 +37,11 @@ public class GameSession {
     private static final String STUN = "stun";
     private static final String TURN = "turn";
 
+    private static final List<TransportAddress> PUBLIC_STUN_SERVERS = List.of(
+            new TransportAddress("stun.cloudflare.com", 3478, Transport.UDP),
+            new TransportAddress("stun.l.google.com", 19302, Transport.UDP),
+            new TransportAddress("stun.sipgate.net", 3478, Transport.UDP));
+
     @Getter
     private final Map<Integer, Peer> peers = new ConcurrentHashMap<>();
 
@@ -104,7 +109,13 @@ public void close() {
      * Called by the client via jsonRPC
      */
     public static void setIceServers(List<Map<String, Object>> iceServersData) {
-        GameSession.iceServers.clear();
+        iceServers.clear();
+
+        PUBLIC_STUN_SERVERS.forEach(stunServer -> {
+            var iceServer = new IceServer();
+            iceServer.getStunAddresses().add(stunServer);
+            iceServers.add(iceServer);
+        });
 
         if (iceServersData.isEmpty()) {
             return;

ice-adapter/src/main/java/com/faforever/iceadapter/ice/PeerIceModule.java

@@ -78,6 +78,7 @@ public PeerIceModule(Peer peer) {
 
     /**
      * Updates the current iceState and informs the client via RPC
+     *
      * @param newState the new State
      */
     private void setState(IceState newState) {
@@ -124,16 +125,22 @@ private void createAgent() {
     private void gatherCandidates() {
         log.info(getLogPrefix() + "Gathering ice candidates");
 
-        List<IceServer> iceServers = getViableIceServers();
-
-        iceServers.stream()
+        // For STUN all servers are relevant (latency is not an issue)
+        GameSession.getIceServers().stream()
                 .flatMap(s -> s.getStunAddresses().stream())
-                .map(StunCandidateHarvester::new)
-                .forEach(agent::addCandidateHarvester);
-        iceServers.forEach(iceServer -> iceServer.getTurnAddresses().stream()
-                .map(a -> new TurnCandidateHarvester(
-                        a, new LongTermCredential(iceServer.getTurnUsername(), iceServer.getTurnCredential())))
-                .forEach(agent::addCandidateHarvester));
+                .forEach(address -> {
+                    log.info("Add STUN harvester for {}", address.getHostName());
+                    agent.addCandidateHarvester(new StunCandidateHarvester(address));
+                });
+
+        // TURN is latency sensitive
+        List<IceServer> iceServers = getViableIceServers();
+        iceServers.forEach(iceServer -> iceServer.getTurnAddresses().forEach(address -> {
+            var harvester = new TurnCandidateHarvester(
+                    address, new LongTermCredential(iceServer.getTurnUsername(), iceServer.getTurnCredential()));
+            log.info("Add TURN harvester for {}", address.getHostName());
+            agent.addCandidateHarvester(harvester);
+        }));
 
         CompletableFuture<Void> gatheringFuture = CompletableFuture.runAsync(() -> {
             try {
@@ -238,6 +245,7 @@ private List<IceServer> getViableIceServers() {
 
     /**
      * Starts harvesting local candidates if in answer mode, then initiates the actual ICE process
+     *
      * @param remoteCandidatesMessage
      */
     public synchronized void onIceMessageReceived(CandidatesMessage remoteCandidatesMessage) {
@@ -418,6 +426,7 @@ private synchronized void reinitIce() {
 
     /**
      * Data received from FA, prepends prefix and sends it via ICE to the other peer
+     *
      * @param faData
      * @param length
      */
@@ -430,6 +439,7 @@ void onFaDataReceived(byte[] faData, int length) {
 
     /**
      * Send date via ice to the other peer
+     *
      * @param data
      * @param offset
      * @param length