freebsd-nq/usr.sbin/nologin/nologin.5
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

97 lines
2.9 KiB
Groff

.\" Copyright (c) 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)nologin.8 8.1 (Berkeley) 6/19/93
.\" $FreeBSD$
.\"
.Dd May 10, 2007
.Dt NOLOGIN 5
.Os
.Sh NAME
.Nm nologin
.Nd disallow logins
.Sh DESCRIPTION
Programs such as
.Xr login 1
disallow logins if the
.Nm
file exists.
The programs display the contents of
.Nm
to the user if possible and interrupt the login sequence.
This makes it simple to temporarily prevent incoming logins systemwide.
.Pp
To disable logins on a per-account basis,
investigate
.Xr nologin 8 .
.Sh SECURITY
The
.Nm
file is ignored for user root by default.
.Sh IMPLEMENTATION NOTES
The
.Nm
feature is implemented through
.Xr login.conf 5 ,
which allows to change the pathname of the
file and to extend the list of users
exempt from temporary login restriction.
.Pp
PAM-aware programs can be selectively configured to respect
.Nm
using the
.Xr pam_nologin 8
module via
.Xr pam.conf 5 .
.Pp
The
.Nm
file will be removed at system boot if it resides in
.Pa /var/run
and
.Va cleanvar_enable
is set to
.Dq Li YES
in
.Xr rc.conf 5 ,
which is default.
Therefore system reboot can effectively re-enable logins.
.Sh FILES
.Bl -tag -width ".Pa /var/run/nologin" -compact
.It Pa /var/run/nologin
default location of
.Nm
.El
.Sh SEE ALSO
.Xr login 1 ,
.Xr login.conf 5 ,
.Xr pam.conf 5 ,
.Xr rc.conf 5 ,
.Xr nologin 8 ,
.Xr pam_nologin 8 ,
.Xr shutdown 8