1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)nologin.8 8.1 (Berkeley) 6/19/93 29.\" $FreeBSD: head/usr.sbin/nologin/nologin.5 314436 2017-02-28 23:42:47Z imp $ 30.\" 31.Dd October 5, 2017 32.Dt NOLOGIN 5 33.Os 34.Sh NAME 35.Nm nologin 36.Nd disallow logins 37.Sh DESCRIPTION 38Programs such as 39.Xr login 1 40disallow logins if the 41.Nm 42file exists. 43The programs display the contents of 44.Nm 45to the user if possible and interrupt the login sequence. 46This makes it simple to temporarily prevent incoming logins systemwide. 47.Pp 48To disable logins on a per-account basis, 49investigate 50.Xr nologin 8 . 51.Sh SECURITY 52The 53.Nm 54file is ignored for user root by default. 55.Sh IMPLEMENTATION NOTES 56The 57.Nm 58feature is implemented through 59.Xr login.conf 5 , 60which allows to change the pathname of the 61file and to extend the list of users 62exempt from temporary login restriction. 63.Pp 64PAM-aware programs can be selectively configured to respect 65.Nm 66using the 67.Xr pam_nologin 8 68module via 69.Xr pam.conf 5 . 70.Pp 71The 72.Nm 73file will be removed at system boot if it resides in 74.Pa /var/run 75and 76.Va cleanvar_enable 77is set to 78.Dq Li YES 79in 80.Xr rc.conf 5 , 81which is default. 82Therefore system reboot can effectively re-enable logins. 83.Sh FILES 84.Bl -tag -width ".Pa /var/run/nologin" -compact 85.It Pa /var/run/nologin 86default location of 87.Nm 88.El 89.Sh SEE ALSO 90.Xr login 1 , 91.Xr login.conf 5 , 92.Xr pam.conf 5 , 93.Xr rc.conf 5 , 94.Xr nologin 8 , 95.Xr pam_nologin 8 , 96.Xr shutdown 8 97