+AC_CHECK_HEADERS([sys/types.h sys/socket.h sys/uio.h])
+AC_CHECK_MEMBERS([struct msghdr.msg_control, struct msghdr.msg_accrights], [], [], [#if HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#if HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#if HAVE_SYS_UIO_H
+# include <sys/uio.h>
+#endif])