check_c_source_compiles("#include <linux/filter.h>
#include <sys/socket.h>
#include <stddef.h>
int main(void) {
	setsockopt(0, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, NULL, 0);
}" LWAN_HAVE_SO_ATTACH_REUSEPORT_CBPF)