CHECK_C_SOURCE_COMPILES("
#include <sys/socket.h>
#include <linux/tcp.h>
#include <linux/tls.h>
int main (void) {
    return TCP_ULP + SOL_TLS + TLS_TX + TLS_1_2_VERSION + TLS_CIPHER_AES_GCM_128 + TLS_CIPHER_AES_GCM_256;
}
" SYSTEM_HAS_KTLS)