implement read timeout, if server sends nothing for 1 min, connection drops

mtprotoproxy.py

@@ -139,8 +139,8 @@ def init_config():
     # use middle proxy, necessary to show ad
     conf_dict.setdefault("USE_MIDDLE_PROXY", len(conf_dict["AD_TAG"]) == 16)
 
-    # if IPv6 available, use it by default
-    conf_dict.setdefault("PREFER_IPV6", socket.has_ipv6)
+    # if IPv6 available, use it by default, IPv6 with middle proxies is unstable now
+    conf_dict.setdefault("PREFER_IPV6", socket.has_ipv6 and not conf_dict["USE_MIDDLE_PROXY"])
 
     # disables tg->client traffic reencryption, faster but less secure
     conf_dict.setdefault("FAST_MODE", True)
@@ -264,6 +264,9 @@ def init_config():
     # telegram servers connect timeout in seconds
     conf_dict.setdefault("TG_CONNECT_TIMEOUT", 10)
 
+    # drop connection if no data from telegram server for this many seconds
+    conf_dict.setdefault("TG_READ_TIMEOUT", 60)
+
     # listen address for IPv4
     conf_dict.setdefault("LISTEN_ADDR_IPV4", "0.0.0.0")
 
@@ -1584,7 +1587,11 @@ async def do_middleproxy_handshake(proto_tag, dc_idx, cl_ip, cl_port):
 async def tg_connect_reader_to_writer(rd, wr, user, rd_buf_size, is_upstream):
     try:
         while True:
-            data = await rd.read(rd_buf_size)
+            if not is_upstream:
+                data = await asyncio.wait_for(rd.read(rd_buf_size),
+                                              timeout=config.TG_READ_TIMEOUT)
+            else:
+                data = await rd.read(rd_buf_size)
             if isinstance(data, tuple):
                 data, extra = data
             else:
@@ -1605,7 +1612,7 @@ async def tg_connect_reader_to_writer(rd, wr, user, rd_buf_size, is_upstream):
 
                 wr.write(data, extra)
                 await wr.drain()
-    except (OSError, asyncio.IncompleteReadError) as e:
+    except (OSError, asyncio.IncompleteReadError, asyncio.TimeoutError) as e:
         # print_err(e)
         pass
 
@@ -2011,6 +2018,7 @@ async def get_srv_time():
                     continue
                 line = line[len("Date: "):].decode()
                 srv_time = datetime.datetime.strptime(line, "%a, %d %b %Y %H:%M:%S %Z")
+                srv_time = srv_time.replace(tzinfo=datetime.timezone.utc)
                 now_time = datetime.datetime.now(datetime.timezone.utc)
                 is_time_skewed = (now_time-srv_time).total_seconds() > MAX_TIME_SKEW
                 if is_time_skewed and config.USE_MIDDLE_PROXY and not disable_middle_proxy: