Add -stunServer arg for on-premises STUN

common/network/iceip.cxx

@@ -170,10 +170,15 @@ void getPublicIP() {
 		abort();
 
 	unsigned i;
-	for (i = 0; i < sizeof(servers) / sizeof(servers[0]); i++) {
-		if (tryserver(servers[i], sock))
-			break;
-		vlog.info("STUN server %u didn't work, trying next...", i);
+	if (rfb::Server::stunServer[0]) {
+		if (strlen(rfb::Server::stunServer) < PATH_MAX)
+			tryserver(rfb::Server::stunServer, sock);
+	} else {
+		for (i = 0; i < sizeof(servers) / sizeof(servers[0]); i++) {
+			if (tryserver(servers[i], sock))
+				break;
+			vlog.info("STUN server %u didn't work, trying next...", i);
+		}
 	}
 
 	close(sock);

common/rfb/ServerCore.cxx

@@ -221,6 +221,10 @@ rfb::StringParameter rfb::Server::publicIP
 ("publicIP",
  "The server's public IP, for UDP negotiation. If not set, will be queried via the internet.",
  "");
+rfb::StringParameter rfb::Server::stunServer
+("stunServer",
+ "Use this STUN server for querying the server's public IP. If not set, a hardcoded list is used.",
+ "");
 
 rfb::IntParameter rfb::Server::udpFullFrameFrequency
 ("udpFullFrameFrequency",
@@ -236,4 +240,4 @@ static void bandwidthPreset() {
 rfb::PresetParameter rfb::Server::preferBandwidth
 ("PreferBandwidth",
  "Set various options for lower bandwidth use. The default is off, aka to prefer quality.",
- false, bandwidthPreset);
+ false, bandwidthPreset);

common/rfb/ServerCore.h

@@ -63,6 +63,7 @@ namespace rfb {
     static IntParameter udpFullFrameFrequency;
     static StringParameter kasmPasswordFile;
     static StringParameter publicIP;
+    static StringParameter stunServer;
     static BoolParameter printVideoArea;
     static BoolParameter protocol3_3;
     static BoolParameter alwaysShared;