xref: /freebsd/share/man/man9/acl.9 (revision c807777a43ef2b59786fa8a1a35c1f154fd069e5)
1.\"-
2.\" Copyright (c) 1999 Robert N. M. Watson
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.\"       $FreeBSD$
27.\"
28.Dd December 23, 1999
29.Os
30.Dt ACL 9
31.Sh NAME
32.Nm acl
33.Nd virtual file system access control lists
34.Sh SYNOPSIS
35.Fd #include <sys/param.h>
36.Fd #include <sys/vnode.h>
37.Fd #include <sys/acl.h>
38.Pp
39.Bd -literal
40typedef int     acl_type_t;
41typedef int     acl_tag_t;
42typedef mode_t  acl_perm_t;
43
44struct acl_entry {
45        acl_tag_t       ae_tag;
46        uid_t           ae_id;
47        acl_perm_t      ae_perm;
48};
49typedef struct acl_entry        *acl_entry_t;
50
51struct acl {
52        int                     acl_cnt;
53        struct acl_entry        acl_entry[MAX_ACL_ENTRIES];
54};
55typedef struct acl      *acl_t;
56
57/*
58 * Possible valid values for a_type of acl_entry_t
59 */
60#define ACL_USER_OBJ    0x00000001
61#define ACL_USER        0x00000002
62#define ACL_GROUP_OBJ   0x00000004
63#define ACL_GROUP       0x00000008
64#define ACL_MASK        0x00000010
65#define ACL_OTHER       0x00000020
66#define ACL_OTHER_OBJ   ACL_OTHER
67#define ACL_AFS_ID      0x00000040
68
69#define ACL_TYPE_ACCESS         0x00000000
70#define ACL_TYPE_DEFAULT        0x00000001
71
72/*
73 * Possible flags in a_perm field
74 */
75#define ACL_PERM_EXEC           0x0001
76#define ACL_PERM_WRITE          0x0002
77#define ACL_PERM_READ           0x0004
78#define ACL_PERM_NONE           0x0000
79#define ACL_PERM_BITS           (ACL_PERM_EXEC | ACL_PERM_WRITE | ACL_PERM_READ)
80#define ACL_POSIX1E_BITS        (ACL_PERM_EXEC | ACL_PERM_WRITE | ACL_PERM_READ)
81.Ed
82.Sh DESCRIPTION
83Access control lists, or ACLs, allow fine-grained specification of rights
84for vnodes representing files and directories.  However, as there are a
85plethora of file systems with differing ACL semantics, the vnode interface
86is aware only of the syntax of ACLs, relying on the underlying file system
87to implement the details.  Depending on the underlying file system, each
88file or directory may have zero or more ACLs associated with it, named using
89the
90.Fa type
91field of the appropriate vnode ACL calls,
92.Xr VOP_ACLCHECK 9 ,
93.Xr VOP_GETACL 9 ,
94and
95.Xr VOP_SETACL 9 .
96
97Currently, each ACL is represented in-kernel by a fixed-size acl structure.
98An ACL is constructed from a fixed size array of ACL entries, each of which
99consists of a set of permissions, principal namespace, and principal
100identifier.  Zero or more of these entries may be "defined", depending on
101the value of the associated acl_cnt field.
102.Sh SEE ALSO
103.Xr VFS 9 ,
104.Xr VOP_ACLCHECK 9 ,
105.Xr VOP_GETACL 9 ,
106.Xr VOP_SETACL 9 .
107.Sh AUTHORS
108This man page was written by
109.An Robert Watson .
110