check_c_source_compiles("
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
int
main(int argc, char *argv[])
{
	int fd = 0, rv;
	struct accept_filter_arg afa;
	socklen_t afaLen = sizeof(afa);
	afa.af_name[0] = 'A';
	afa.af_arg[0] = 'A';
	rv = setsockopt(fd, SOL_SOCKET, SO_ACCEPTFILTER, &afa, afaLen);
	return (rv != 0);
}
" HAVE_SO_ACCEPTFILTER)