Don't close over function

tcp_nat_proxy.py

@@ -1,6 +1,7 @@
 import argparse
 import asyncio
 from collections import namedtuple
+from functools import partial
 
 Route = namedtuple("Route", ["listen_port", "destination_host", "destination_port"])
 
@@ -23,22 +24,25 @@ async def pipe(reader, writer):
         writer.close()
 
 
-async def create_proxy_pipe(route: Route):
-    async def handle_client(local_reader, local_writer):
-        try:
-            remote_reader, remote_writer = await asyncio.open_connection(
-                route.destination_host, route.destination_port
-            )
-            await asyncio.gather(
-                pipe(local_reader, remote_writer), pipe(remote_reader, local_writer)
-            )
-        except ConnectionRefusedError:
-            print("Connection to {} refused".format(destination_host_display(route)))
-            pass
-        finally:
-            local_writer.close()
+async def handle_client(route, local_reader, local_writer):
+    try:
+        remote_reader, remote_writer = await asyncio.open_connection(
+            route.destination_host, route.destination_port
+        )
+        await asyncio.gather(
+            pipe(local_reader, remote_writer), pipe(remote_reader, local_writer)
+        )
+    except ConnectionRefusedError:
+        print("Connection to {} refused".format(destination_host_display(route)))
+        pass
+    finally:
+        local_writer.close()
 
-    server = await asyncio.start_server(handle_client, "0.0.0.0", route.listen_port)
+
+async def create_proxy_pipe(route: Route):
+    server = await asyncio.start_server(
+        partial(handle_client, route), "0.0.0.0", route.listen_port
+    )
     print(
         "Routing from {} to {}".format(
             route.listen_port, destination_host_display(route)
@@ -54,6 +58,7 @@ async def main():
     )
     args = parser.parse_args()
     servers = [create_proxy_pipe(route) for route in args.route]
+    print("Starting servers...")
     await asyncio.gather(*servers)