add handling of some unknown new rpc

mtprotoproxy.py

@@ -868,6 +868,7 @@ class ProxyReqStreamReader(LayeredStreamReaderBase):
         RPC_PROXY_ANS = b"\x0d\xda\x03\x44"
         RPC_CLOSE_EXT = b"\xa2\x34\xb6\x5e"
         RPC_SIMPLE_ACK = b"\x9b\x40\xac\x3b"
+        RPC_UNKNOWN = b'\xdf\xa2\x30\x57'
 
         data = await self.upstream.read(1)
 
@@ -886,6 +887,9 @@ class ProxyReqStreamReader(LayeredStreamReaderBase):
             conn_id, confirm = data[4:12], data[12:16]
             return confirm, {"SIMPLE_ACK": True}
 
+        if ans_type == RPC_UNKNOWN:
+            return b"", {"SKIP_SEND": True}
+
         print_err("unknown rpc ans type:", ans_type)
         return b""
 
@@ -1570,6 +1574,9 @@ async def tg_connect_reader_to_writer(rd, wr, user, rd_buf_size, is_upstream):
             else:
                 extra = {}
 
+            if extra.get("SKIP_SEND"):
+                continue
+
             if not data:
                 wr.write_eof()
                 await wr.drain()