233 lines
7.5 KiB
Groff
233 lines
7.5 KiB
Groff
.\"-
|
|
.\" Copyright (c) 2000, 2001 Robert N. M. Watson
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 28, 2000
|
|
.Dt ACL 3
|
|
.Os FreeBSD
|
|
.Sh NAME
|
|
.Nm acl
|
|
.Nd introduction to the POSIX.1e ACL security API
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sys/types.h>
|
|
.Fd #include <sys/acl.h>
|
|
.Sh DESCRIPTION
|
|
.Fx
|
|
permits file systems to export Access Control Lists via the VFS, and
|
|
provides a library for userland access to and manipulation of these ACLs.
|
|
Not all file systems provide support for ACLs, and some may require that
|
|
ACL support be explicitely enabled by the administrator.
|
|
The library calls include routines to allocate, duplicate, retrieve, set,
|
|
and validate ACLs associated with file objects.
|
|
As well as the POSIX.1e routines, there are a number of non-portable
|
|
extensions defined that allow for alternative ACL semantics than the
|
|
POSIX.1e semantics, such as AFS, NTFS, Coda, and NWFS semantics.
|
|
Where routines are non-standard, they are suffixed with _np to indicate that
|
|
they are not portable.
|
|
.Pp
|
|
POSIX.1e describes a set of ACL manipulation routines to manage the
|
|
contents of ACLs, as well as their relationships with files; almost
|
|
all of these support routines are implemented in
|
|
.Fx .
|
|
.Pp
|
|
Available functions, sorted by behavior, include:
|
|
.Bl -tag -width indent
|
|
.It Fn acl_add_perm
|
|
This function is described in
|
|
.Xr acl_add_perm 3 ,
|
|
and may be used to add permissions to a permission set.
|
|
.It Fn acl_calc_mask
|
|
This function is described in
|
|
.Xr acl_calc_mask 3 ,
|
|
and may be used to calculate and set the permissions associated with
|
|
the
|
|
.Dv ACL_MASK
|
|
entry.
|
|
.It Fn acl_clear_perms
|
|
This function is described in
|
|
.Xr acl_clear_perms 3 ,
|
|
and may be used to clear all permissions from a permission set.
|
|
.It Fn acl_copy_entry
|
|
This function is described in
|
|
.Xr acl_copy_entry 3 ,
|
|
and may be used to copy the contents of an ACL entry.
|
|
.It Fn acl_create_entry
|
|
This function is described in
|
|
.Xr acl_create_entry 3 ,
|
|
and may be used to create an empty entry in an ACL.
|
|
.It Xo
|
|
.Fn acl_delete_def_file ,
|
|
.Fn acl_delete_file_np ,
|
|
.Fn acl_delete_fd_np
|
|
.Xc
|
|
These functions are described in
|
|
.Xr acl_delete 3 ,
|
|
and may be used to delete ACLs from file system objects.
|
|
.It Fn acl_delete_entry
|
|
This function is described in
|
|
.Xr acl_delete_entry 3 ,
|
|
and may be used to delete an entry from an ACL.
|
|
.It Fn acl_delete_perm
|
|
This function is described in
|
|
.Xr acl_delete_perm 3 ,
|
|
and may be used to delete permissions from a permset.
|
|
.It Fn acl_dup
|
|
This function is described in
|
|
.Xr acl_dup 3 ,
|
|
and may be used to duplicate an ACL structure.
|
|
.It Fn acl_free
|
|
This function is described in
|
|
.Xr acl_free 3 ,
|
|
and may be used to free userland working ACL storage.
|
|
.It Fn acl_from_text
|
|
This function is described in
|
|
.Xr acl_from_text 3 ,
|
|
and may be used to convert a text-form ACL into working ACL state, if
|
|
the ACL has POSIX.1e semantics.
|
|
.It Fn acl_get_entry
|
|
This function is described in
|
|
.Xr acl_get_entry 3 ,
|
|
and may be used to retrieve a designated ACL entry from an ACL.
|
|
.It Xo
|
|
.Fn acl_get_file ,
|
|
.Fn acl_get_fd ,
|
|
.Fn acl_get_fd_np
|
|
.Xc
|
|
These functions are described in
|
|
.Xr acl_get 3 ,
|
|
and may be used to retrieve ACLs from file system objects.
|
|
.It Fn acl_get_permset
|
|
This function is described in
|
|
.Xr acl_get_permset 3 ,
|
|
and may be used to retrieve a permset from an ACL entry.
|
|
.It Fn acl_get_qualifier
|
|
This function is described in
|
|
.Xr acl_get_qualifier 3 ,
|
|
and may be used to retrieve the qualifier from an ACL entry.
|
|
.It Fn acl_get_tag_type
|
|
This function is described in
|
|
.Xr acl_get_tag_type 3 ,
|
|
and may be used to retrieve the tag type from an ACL entry.
|
|
.It Fn acl_init
|
|
This function is described in
|
|
.Xr acl_init 3 ,
|
|
and may be used to allocate a fresh (empty) ACL structure.
|
|
.It Xo
|
|
.Fn acl_set_file ,
|
|
.Fn acl_set_fd ,
|
|
.Fn acl_set_fd_np
|
|
.Xc
|
|
These functions are described in
|
|
.Xr acl_set 3 ,
|
|
and may be used to assign an ACL to a file system object.
|
|
.It Fn acl_set_permset
|
|
This function is described in
|
|
.Xr acl_set_permset 3 ,
|
|
and may be used to set the permissions of an ACL entry from a permset.
|
|
.It Fn acl_set_qualifier
|
|
This function is described in
|
|
.Xr acl_set_qualifier 3 ,
|
|
and may be used to set the qualifier of an ACL.
|
|
.It Fn acl_set_tag_type
|
|
This function is described in
|
|
.Xr acl_set_tag_type 3 ,
|
|
and may be used to set the tag type of an ACL.
|
|
.It Fn acl_to_text
|
|
This function is described in
|
|
.Xr acl_to_text 3 ,
|
|
and may be used to generate a text-form of a POSIX.1e semantics ACL.
|
|
.It Xo
|
|
.Fn acl_valid ,
|
|
.Fn acl_valid_file_np ,
|
|
.Fn acl_valid_fd_np
|
|
.Xc
|
|
These functions are described in
|
|
.Xr acl_valid 3 ,
|
|
and may be used to validate an ACL as correct POSIX.1e-semantics, or
|
|
as appropriate for a particular file system object regardless of semantics.
|
|
.El
|
|
.Pp
|
|
Documentation of the internal kernel interfaces backing these calls may
|
|
be found in
|
|
.Xr acl 9 .
|
|
The syscalls between the internal interfaces and the public library
|
|
routines may change over time, and as such are not documented.
|
|
They are not intended to be called directly without going through the
|
|
library.
|
|
.Sh IMPLEMENTATION NOTES
|
|
.Fx Ns 's
|
|
support for POSIX.1e interfaces and features is still under
|
|
development at this time.
|
|
.Sh SEE ALSO
|
|
.Xr acl_add_perm 3 ,
|
|
.Xr acl_calc_mask 3 ,
|
|
.Xr acl_clear_perms 3 ,
|
|
.Xr acl_copy_entry 3 ,
|
|
.Xr acl_create_entry 3 ,
|
|
.Xr acl_delete_entry 3 ,
|
|
.Xr acl_delete_perm 3 ,
|
|
.Xr acl_dup 3 ,
|
|
.Xr acl_free 3 ,
|
|
.Xr acl_from_text 3 ,
|
|
.Xr acl_get 3 ,
|
|
.Xr acl_get_permset 3 ,
|
|
.Xr acl_get_qualifier 3 ,
|
|
.Xr acl_get_tag_type 3 ,
|
|
.Xr acl_init 3 ,
|
|
.Xr acl_set 3 ,
|
|
.Xr acl_set_permset 3 ,
|
|
.Xr acl_set_qualifier 3 ,
|
|
.Xr acl_set_tag_type 3 ,
|
|
.Xr acl_to_text 3 ,
|
|
.Xr acl_valid 3 ,
|
|
.Xr acl 9 ,
|
|
.Xr posix1e 3
|
|
.Sh STANDARDS
|
|
POSIX.1e assigns security labels to all objects, extending the security
|
|
functionality described in POSIX.1.
|
|
These additional labels provide fine-grained discretionary access control,
|
|
fine-grained capabilities, and labels necessary for mandatory access
|
|
control.
|
|
POSIX.2c describes a set of userland utilities for manipulating these
|
|
labels.
|
|
.Pp
|
|
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.
|
|
.Sh HISTORY
|
|
POSIX.1e support was introduced in
|
|
.Fx 4.0 ;
|
|
.Fx 5.0
|
|
was the first version to include a complete ACL implementation based
|
|
on extended attributes.
|
|
.Sh AUTHORS
|
|
.An Robert N M Watson
|