add TCP_REPAIR_WINDOW to netinet/tcp.h from linux v4.8

another kernel internal state exposure for checkpoint-restore.
see linux commit b1ed4c4fa9a5ccf325184fd90edc50978ef6e33a

include/netinet/tcp.h

@@ -30,6 +30,7 @@
 #define TCP_CC_INFO      26
 #define TCP_SAVE_SYN     27
 #define TCP_SAVED_SYN    28
+#define TCP_REPAIR_WINDOW 29
 
 #define TCP_ESTABLISHED  1
 #define TCP_SYN_SENT     2
@@ -199,6 +200,14 @@ struct tcp_md5sig {
 	uint8_t tcpm_key[TCP_MD5SIG_MAXKEYLEN];
 };
 
+struct tcp_repair_window {
+	uint32_t snd_wl1;
+	uint32_t snd_wnd;
+	uint32_t max_window;
+	uint32_t rcv_wnd;
+	uint32_t rcv_wup;
+};
+
 #endif
 
 #endif