+@deffn {@code{ioctl} call} UNIOCGMAXIF
+Returns the total number of attachments permitted.
+@end deffn
+
+@deffn {@code{ioctl} call} UNIOCSMAXIF
+Configures the total number of attachments permitted. It is an error to
+reduce this below the number of attachments currently in existence.
+@end deffn
+