extern BOOL system_filtering; /* TRUE when running system filter */
extern BOOL tcp_fastopen_ok; /* appears to be supported by kernel */
+extern blob tcp_fastopen_nodata; /* for zero-data TFO connect requests */
extern BOOL tcp_in_fastopen; /* conn used fastopen */
extern BOOL tcp_in_fastopen_logged; /* one-time logging */
extern BOOL tcp_nodelay; /* Controls TCP_NODELAY on daemon */