freebsd-nq/lib/libc/posix1e/mac_text.3
Robert Watson d97fcfce27 Introduce support for Mandatory Access Control and extensible
kernel access control.

Extensions to libc to provide basic MAC label manipulation facilities
for userland.  These interface will be replaced in the next month
or two with more flexible interfaces, but provide sufficient support
to allow use of the Biba and MLS policies for user applications.

libc_r wrappers to follow.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-08-02 21:14:42 +00:00

170 lines
4.3 KiB
Groff

.\" Copyright (c) 2001 Networks Associates Technology, Inc.
.\" All rights reserved.
.\"
.\" This software was developed for the FreeBSD Project by Chris
.\" Costello at Safeport Network Services and NAI Labs, the Security
.\" Research Division of Network Associates, Inc. under DARPA/SPAWAR
.\" contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
.\" research program.
.\"
.\" 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. The name of the author may not be used to endorse or promote
.\" products derived from this software without specific prior written
.\" permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.Dd December 21, 2001
.Dt MAC_TEXT 3
.Sh NAME
.Nm mac_from_text ,
.Nm mac_to_text
.Nd convert MAC label to/from text representation
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/mac.h
.Ft mac_t
.Fn mac_from_text "const char *text_p"
.Ft "char *"
.Fn mac_to_text "mac_t label" "size_t *len_p"
.Sh DESCRIPTION
The
.Fn mac_from_text
function converts the text representation of a label
into a
.Vt mac_t ,
which must later be freed with
.Xr mac_free .
The
.Fn mac_to_text
function returns
the text representation of
.Fa label
and sets
.Fa *len_p
to the length of the returned string.
.Pp
.Fx
uses the following format
for MAC policy text representations:
.Pp
.Dl Sy policy Ns No / Ns Sy qualifier
.Pp
Where
.Sy policy
can be one of
.Dq biba ,
.Dq mls ,
or
.Dq te .
.Pp
Valid labels can have the following arguments for
.Sy qualifier ,
depending on the value of
.Sy policy .
.Bl -tag -width "Policy" -offset indent
.It Em Policy
.Em Qualifier
.It biba
.Dq high ,
.Dq low ,
.Dq equal ,
or a numeric grade.
.It mls
.Dq high ,
.Dq low ,
.Dq equal ,
or a numeric level.
.It te
Types for
.Dq te
consist of a type name which must
neither be empty nor exceed the length limit for the label.
.El
.Pp
All policies must be present
in a comma-separated list,
but may be in any order
(see
.Sx EXAMPLES ) .
.Sh RETURN VALUES
The
.Fn mac_from_text
function returns a valid
.Vt mac_t
equivalent to
the MAC label described in
.Fa text_p
upon success, and
.Dv NULL
upon failure, setting
.Va errno
to indicate the error.
.Pp
The
.Fn mac_to_text
function returns a string
containing the text representation of
.Fa label
upon success, and
.Dv NULL
upon failure, setting
.Va errno
to indicate the error.
.Sh EXAMPLES
The following are valid MAC labels:
.Bd -literal -offset indent
biba/high,mls/low,te/none
biba/low,mls/low,te/none
biba/low,mls/3,te/none
.Ed
.Sh COMPATIBILITY
POSIX.1e does not define
a text format for text representations
of MAC labels.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
An invalid policy or qualifier
was specified in
.Fa text_p ,
or an invalid MAC label
was specified in
.Fa label .
.It Bq Er ENOMEM
Insufficient memory was available
to allocate internal storage.
.El
.Sh SEE ALSO
.Xr mac 3 ,
.Xr mac_free 3 ,
.Xr mac_get 3 ,
.Xr mac_set 3
.Sh STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17.
Discussion of the draft
continues on the cross-platform POSIX.1e implementation mailing list.
To join this list, see the
.Fx
POSIX.1e implementation page
for more information.