ser is allowed to continue authentication. Either the user is not root, or the root user is trying to log in on an acceptable device.
Authentication is rejected. Either root is attempting to
log in via an unacceptable device, or the
securetty file is world writable or
not a normal file.
Memory buffer error.
The conversation method supplied by the application failed to obtain the username.
The conversation method supplied by the application returned PAM_CONV_AGAIN.
An error occurred while the module was determining the
user's name or tty, or the module could not open
the securetty file.
The module could not find the user name in the
/etc/passwd file to verify whether
the user had a UID of 0. Therefore, the results of running
this module are ignored.