V_tcp_fastopen_psk_enable
if (V_tcp_fastopen_psk_enable) {
new = V_tcp_fastopen_psk_enable;
if (V_tcp_fastopen_psk_enable && !new) {
V_tcp_fastopen_psk_enable = 0;
} else if (!V_tcp_fastopen_psk_enable && new) {
V_tcp_fastopen_psk_enable = 1;