1995-11-16 01:48:07 +03:00
|
|
|
.\" $NetBSD: 3.t,v 1.2 1995/11/15 22:54:29 pk Exp $
|
1994-05-18 05:12:10 +04:00
|
|
|
.\" Copyright (c) 1983, 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. All advertising materials mentioning features or use of this software
|
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
|
.\" This product includes software developed by the University of
|
|
|
|
|
.\" California, Berkeley and its contributors.
|
|
|
|
|
.\" 4. 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.
|
|
|
|
|
.\"
|
|
|
|
|
.\" @(#)3.t 8.1 (Berkeley) 6/8/93
|
|
|
|
|
.\"
|
|
|
|
|
.NH 1
|
|
|
|
|
Access control
|
|
|
|
|
.PP
|
|
|
|
|
The printer system maintains protected spooling areas so that
|
|
|
|
|
users cannot circumvent printer accounting or
|
|
|
|
|
remove files other than their own.
|
|
|
|
|
The strategy used to maintain protected
|
|
|
|
|
spooling areas is as follows:
|
|
|
|
|
.IP \(bu 3
|
|
|
|
|
The spooling area is writable only by a \fIdaemon\fP user
|
|
|
|
|
and \fIdaemon\fP group.
|
|
|
|
|
.IP \(bu 3
|
|
|
|
|
The \fIlpr\fP program runs set-user-id to \fIroot\fP and
|
|
|
|
|
set-group-id to group \fIdaemon\fP. The \fIroot\fP access permits
|
|
|
|
|
reading any file required. Accessibility is verified
|
|
|
|
|
with an \fIaccess\fP\|(2) call. The group ID
|
|
|
|
|
is used in setting up proper ownership of files
|
|
|
|
|
in the spooling area for \fIlprm\fP.
|
|
|
|
|
.IP \(bu 3
|
|
|
|
|
Control files in a spooling area are made with \fIdaemon\fP
|
|
|
|
|
ownership and group ownership \fIdaemon\fP. Their mode is 0660.
|
|
|
|
|
This insures control files are not modified by a user
|
|
|
|
|
and that no user can remove files except through \fIlprm\fP.
|
|
|
|
|
.IP \(bu 3
|
|
|
|
|
The spooling programs,
|
|
|
|
|
\fIlpd\fP, \fIlpq\fP, and \fIlprm\fP run set-user-id to \fIroot\fP
|
|
|
|
|
and set-group-id to group \fIdaemon\fP to access spool files and printers.
|
|
|
|
|
.IP \(bu 3
|
|
|
|
|
The printer server, \fIlpd\fP,
|
|
|
|
|
uses the same verification procedures as \fIrshd\fP\|(8C)
|
|
|
|
|
in authenticating remote clients. The host on which a client
|
|
|
|
|
resides must be present in the file /etc/hosts.equiv or /etc/hosts.lpd and
|
|
|
|
|
the request message must come from a reserved port number.
|
|
|
|
|
.PP
|
|
|
|
|
In practice, none of \fIlpd\fP, \fIlpq\fP, or
|
|
|
|
|
\fIlprm\fP would have to run as user \fIroot\fP if remote
|
|
|
|
|
spooling were not supported. In previous incarnations of
|
|
|
|
|
the printer system \fIlpd\fP ran set-user-id to \fIdaemon\fP,
|
|
|
|
|
set-group-id to group \fIspooling\fP, and \fIlpq\fP and \fIlprm\fP ran
|
|
|
|
|
set-group-id to group \fIspooling\fP.
|
