diff options
Diffstat (limited to 'usr.sbin/lpr/SMM.doc/3.t')
-rw-r--r-- | usr.sbin/lpr/SMM.doc/3.t | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/usr.sbin/lpr/SMM.doc/3.t b/usr.sbin/lpr/SMM.doc/3.t new file mode 100644 index 0000000..8c950a9 --- /dev/null +++ b/usr.sbin/lpr/SMM.doc/3.t @@ -0,0 +1,73 @@ +.\" 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. |