Faster, async local ip discovery

src/util/UpnpPunch.py

@@ -17,6 +17,7 @@ import gevent
 
 logger = logging.getLogger("Upnp")
 
+
 class UpnpError(Exception):
     pass
 
@@ -128,8 +129,7 @@ def _parse_igd_profile(profile_xml):
 
 # add description
 def _get_local_ips():
-    local_ips = []
-
+    def method1():
         try:
             # get local ip using UDP and a  broadcast address
             s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
@@ -138,24 +138,39 @@ def _get_local_ips():
             # using port 1 as per hobbldygoop's comment about port 0 not working on osx:
             # https://github.com/sirMackk/ZeroNet/commit/fdcd15cf8df0008a2070647d4d28ffedb503fba2#commitcomment-9863928
             s.connect(('239.255.255.250', 1))
-        local_ips.append(s.getsockname()[0])
+            return [s.getsockname()[0]]
         except:
             pass
 
+    def method2():
         # Get ip by using UDP and a normal address (google dns ip)
         try:
             s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
             s.connect(('8.8.8.8', 0))
-        local_ips.append(s.getsockname()[0])
+            return [s.getsockname()[0]]
         except:
             pass
 
+    def method3():
         # Get ip by '' hostname . Not supported on all platforms.
         try:
-        local_ips += socket.gethostbyname_ex('')[2]
+            return socket.gethostbyname_ex('')[2]
         except:
             pass
 
+    threads = [
+        gevent.spawn(method1),
+        gevent.spawn(method2),
+        gevent.spawn(method3)
+    ]
+
+    gevent.joinall(threads, timeout=5)
+
+    local_ips = []
+    for thread in threads:
+        if thread.value:
+            local_ips += thread.value
+
     # Delete duplicates
     local_ips = list(set(local_ips))
 
@@ -373,8 +388,6 @@ if __name__ == "__main__":
     print("Success:", ask_to_open_port(15443, "ZeroNet", protos=["TCP"]))
     print("Done in", time.time() - s)
 
-
     print("Closing port...")
     print("Success:", ask_to_close_port(15443, "ZeroNet", protos=["TCP"]))
     print("Done in", time.time() - s)
-