process DNS

shadowsocks/udprelay.py

@@ -902,7 +902,7 @@ class UDPRelay(object):
         self._cache_dns_client = lru_cache.LRUCache(timeout=10,
                                          close_callback=self._close_client_pair)
         self._client_fd_to_server_addr = {}
-        self._dns_cache = lru_cache.LRUCache(timeout=300)
+        self._dns_cache = lru_cache.LRUCache(timeout=1800)
         self._eventloop = None
         self._closed = False
         self.server_transfer_ul = 0
@@ -1158,10 +1158,12 @@ class UDPRelay(object):
         connecttype, dest_addr, dest_port, header_length = header_result
 
         if self._is_local:
+            connecttype = 3
             server_addr, server_port = self._get_a_server()
         else:
             server_addr, server_port = dest_addr, dest_port
 
+        if (connecttype & 7) == 3:
             addrs = self._dns_cache.get(server_addr, None)
             if addrs is None:
                 # TODO async getaddrinfo
@@ -1172,6 +1174,12 @@ class UDPRelay(object):
                     return
                 else:
                     self._dns_cache[server_addr] = addrs
+        else:
+            addrs = socket.getaddrinfo(server_addr, server_port, 0,
+                                       socket.SOCK_DGRAM, socket.SOL_UDP)
+            if not addrs:
+                # drop
+                return
 
         af, socktype, proto, canonname, sa = addrs[0]
         key = client_key(r_addr, af)