--- linux-4.9.37/include/net/tcp.h	2017-07-12 16:42:41.000000000 +0300
+++ linux-4.9.y/include/net/tcp.h	2021-06-07 13:01:34.000000000 +0300
@@ -53,6 +53,8 @@
 
 #define MAX_TCP_HEADER	(128 + MAX_HEADER)
 #define MAX_TCP_OPTION_SPACE 40
+#define TCP_MIN_SND_MSS		48
+#define TCP_MIN_GSO_SIZE	(TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE)
 
 /*
  * Never offer a window over 32767 without using window scaling. Some