Fix restricted/symmetric nat pairing

Author: cpacia

net/rpcudp.py

@@ -202,7 +202,8 @@ def func(node, *args):
 
             address = (node.ip, node.port)
             relay_addr = None
-            if node.nat_type == SYMMETRIC:
+            if node.nat_type == SYMMETRIC or \
+                    (node.nat_type == RESTRICTED and self.sourceNode.nat_type == SYMMETRIC):
                 relay_addr = node.relay_node
 
             d = defer.Deferred()
@@ -213,7 +214,9 @@ def func(node, *args):
 
             self.multiplexer.send_message(data, address, relay_addr)
 
-            if self.multiplexer[address].state != State.CONNECTED and node.nat_type == RESTRICTED:
+            if self.multiplexer[address].state != State.CONNECTED and \
+                            node.nat_type == RESTRICTED and \
+                            self.sourceNode.nat_type != SYMMETRIC:
                 self.hole_punch(Node(digest("null"), node.relay_node[0], node.relay_node[1], nat_type=FULL_CONE),
                                 address[0], address[1], "True")
                 self.log.debug("sending hole punch message to %s" % address[0] + ":" + str(address[1]))