Section: Linux-PAM Manual (8)
:pam_nologin.so [file=/path/nologin] [successok]
The suggested usage for /etc/pam.d/login is:
auth required pam_nologin.so
In order to make this module effective, all login methods should be secured by it. It should be used as a required method listed before any sufficient methods in order to get standard Unix nologin semantics. Note, the use of successok module argument causes the module to return PAM_SUCCESS and as such would break such a configuration - failing sufficient modules would lead to a successful login because the nologin module succeeded.
pam_nologin was written by Michael K. Johnson <firstname.lastname@example.org>.
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