add connect retrying

mtprotoproxy.py

@@ -154,6 +154,7 @@ TO_TG_BUFSIZE = config.get("TO_TG_BUFSIZE", 65536)
 CLIENT_KEEPALIVE = config.get("CLIENT_KEEPALIVE", 10*60)
 CLIENT_HANDSHAKE_TIMEOUT = config.get("CLIENT_HANDSHAKE_TIMEOUT", 10)
 CLIENT_ACK_TIMEOUT = config.get("CLIENT_ACK_TIMEOUT", 5*60)
+TG_CONNECT_TIMEOUT = config.get("TG_CONNECT_TIMEOUT", 10)
 
 TG_DATACENTER_PORT = 443
 
@@ -591,6 +592,21 @@ def set_bufsizes(sock, recv_buf, send_buf):
     sock.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, send_buf)
 
 
+async def open_connection_tryer(addr, port, limit, timeout, max_attempts=3):
+    for attempt in range(max_attempts-1):
+        try:
+            task = asyncio.open_connection(addr, port, limit=limit)
+            reader_tgt, writer_tgt = await asyncio.wait_for(task, timeout=timeout)
+            return reader_tgt, writer_tgt
+        except (OSError, asyncio.TimeoutError):
+            continue
+
+    # the last attempt
+    task = asyncio.open_connection(addr, port, limit=limit)
+    reader_tgt, writer_tgt = await asyncio.wait_for(task, timeout=timeout)
+    return reader_tgt, writer_tgts
+
+
 async def do_direct_handshake(proto_tag, dc_idx, dec_key_and_iv=None):
     RESERVED_NONCE_FIRST_CHARS = [b"\xef"]
     RESERVED_NONCE_BEGININGS = [b"\x48\x45\x41\x44", b"\x50\x4F\x53\x54",
@@ -609,18 +625,18 @@ async def do_direct_handshake(proto_tag, dc_idx, dec_key_and_iv=None):
         dc = TG_DATACENTERS_V4[dc_idx]
 
     try:
-        reader_tgt, writer_tgt = await asyncio.open_connection(dc, TG_DATACENTER_PORT,
+        reader_tgt, writer_tgt = await open_connection_tryer(
-                                                               limit=TO_CLT_BUFSIZE)
+            dc, TG_DATACENTER_PORT, limit=TO_CLT_BUFSIZE, timeout=TG_CONNECT_TIMEOUT)
-        set_keepalive(writer_tgt.get_extra_info("socket"))
-        set_bufsizes(writer_tgt.get_extra_info("socket"), TO_CLT_BUFSIZE, TO_TG_BUFSIZE)
-
     except ConnectionRefusedError as E:
         print_err("Got connection refused while trying to connect to", dc, TG_DATACENTER_PORT)
         return False
-    except OSError as E:
+    except (OSError, asyncio.TimeoutError) as E:
         print_err("Unable to connect to", dc, TG_DATACENTER_PORT)
         return False
 
+    set_keepalive(writer_tgt.get_extra_info("socket"))
+    set_bufsizes(writer_tgt.get_extra_info("socket"), TO_CLT_BUFSIZE, TO_TG_BUFSIZE)
+
     while True:
         rnd = bytearray([random.randrange(0, 256) for i in range(HANDSHAKE_LEN)])
         if rnd[:1] in RESERVED_NONCE_FIRST_CHARS:
@@ -710,16 +726,18 @@ async def do_middleproxy_handshake(proto_tag, dc_idx, cl_ip, cl_port):
         addr, port = random.choice(TG_MIDDLE_PROXIES_V4[dc_idx])
 
     try:
-        reader_tgt, writer_tgt = await asyncio.open_connection(addr, port, limit=TO_CLT_BUFSIZE)
+        reader_tgt, writer_tgt = await open_connection_tryer(addr, port, limit=TO_CLT_BUFSIZE,
-        set_keepalive(writer_tgt.get_extra_info("socket"))
+                                                             timeout=TG_CONNECT_TIMEOUT)
-        set_bufsizes(writer_tgt.get_extra_info("socket"), TO_CLT_BUFSIZE, TO_TG_BUFSIZE)
     except ConnectionRefusedError as E:
         print_err("Got connection refused while trying to connect to", addr, port)
         return False
-    except OSError as E:
+    except (OSError, asyncio.TimeoutError) as E:
         print_err("Unable to connect to", addr, port)
         return False
 
+    set_keepalive(writer_tgt.get_extra_info("socket"))
+    set_bufsizes(writer_tgt.get_extra_info("socket"), TO_CLT_BUFSIZE, TO_TG_BUFSIZE)
+
     writer_tgt = MTProtoFrameStreamWriter(writer_tgt, START_SEQ_NO)
 
     key_selector = PROXY_SECRET[:4]