add a fallback if STUN to outside server isn't possible

domain-server/src/DomainServer.cpp

@@ -518,6 +518,19 @@ int DomainServer::run() {
                 int numBytesPrivateSocket = unpackSocket(packetData + packetIndex, (sockaddr*) &nodePublicAddress);
                 packetIndex += numBytesPrivateSocket;
                 
+                if (nodePublicAddress.sin_addr.s_addr == 0) {
+                    // this node wants to use us its STUN server
+                    // so set the node public address to whatever we perceive the public address to be
+                    
+                    nodePublicAddress = senderAddress;
+                    
+                    // if the sender is on our box then leave its public address to 0 so that
+                    // other users attempt to reach it on the same address they have for the domain-server
+                    if (senderAddress.sin_addr.s_addr == htonl(INADDR_LOOPBACK)) {
+                        nodePublicAddress.sin_addr.s_addr = 0;
+                    }
+                }
+                
                 int numBytesPublicSocket = unpackSocket(packetData + packetIndex, (sockaddr*) &nodeLocalAddress);
                 packetIndex += numBytesPublicSocket;
                 

libraries/shared/src/NodeList.cpp

@@ -74,7 +74,8 @@ NodeList::NodeList(char newOwnerType, unsigned short int newSocketListenPort) :
     _checkInPacket(NULL),
     _numBytesCheckInPacket(0),
     _publicAddress(),
-    _publicPort(0)
+    _publicPort(0),
+    _shouldUseDomainServerAsSTUN(0)
 {
     
 }
@@ -311,11 +312,15 @@ void NodeList::setNodeTypesOfInterest(const char* nodeTypesOfInterest, int numNo
 
 const uint32_t RFC_5389_MAGIC_COOKIE = 0x2112A442;
 const int NUM_BYTES_STUN_HEADER = 20;
+const int NUM_STUN_REQUESTS_BEFORE_FALLBACK = 5;
 
 void NodeList::sendSTUNRequest() {
     const char STUN_SERVER_HOSTNAME[] = "stun.highfidelity.io";
     const unsigned short STUN_SERVER_PORT = 3478;
     
+    static int failedStunRequests = 0;
+    
+    if (failedStunRequests < NUM_STUN_REQUESTS_BEFORE_FALLBACK) {
         unsigned char stunRequestPacket[NUM_BYTES_STUN_HEADER];
         
         int packetIndex = 0;
@@ -358,6 +363,17 @@ void NodeList::sendSTUNRequest() {
                 break;
             }
         }
+        
+        failedStunRequests++;
+        
+        return;
+    }
+    
+    // if we're here this was the last failed STUN request
+    // use our DS as our stun server
+    qDebug("Failed to lookup public address via STUN server at %s:%hu. Using DS for STUN.\n",
+           STUN_SERVER_HOSTNAME, STUN_SERVER_PORT);
+    _shouldUseDomainServerAsSTUN = true;
 }
 
 void NodeList::processSTUNResponse(unsigned char* packetData, size_t dataBytes) {
@@ -455,7 +471,7 @@ void NodeList::sendDomainServerCheckIn() {
         printedDomainServerIP = true;
     }
     
-    if (_publicAddress.isNull()) {
+    if (_publicAddress.isNull() && !_shouldUseDomainServerAsSTUN) {
         // we don't know our public socket and we need to send it to the domain server
         // send a STUN request to figure it out
         sendSTUNRequest();

libraries/shared/src/NodeList.h

@@ -170,6 +170,7 @@ private:
     int _numBytesCheckInPacket;
     QHostAddress _publicAddress;
     uint16_t _publicPort;
+    bool _shouldUseDomainServerAsSTUN;
     
     void activateSocketFromPingReply(sockaddr *nodeAddress);
     void timePingReply(sockaddr *nodeAddress, unsigned char *packetData);