1.\"- 2.\" Copyright (c) 2000, 2001, 2002 Robert N. M. Watson 3.\" All rights reserved. 4.\" 5.\" This software was developed by Robert Watson for the TrustedBSD Project. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd December 18, 2002 31.Dt ACL 3 32.Os 33.Sh NAME 34.Nm acl 35.Nd introduction to the POSIX.1e ACL security API 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/types.h 40.In sys/acl.h 41.Sh DESCRIPTION 42.Fx 43permits file systems to export Access Control Lists via the VFS, and 44provides a library for userland access to and manipulation of these ACLs. 45Not all file systems provide support for ACLs, and some may require that 46ACL support be explicitly enabled by the administrator. 47The library calls include routines to allocate, duplicate, retrieve, set, 48and validate ACLs associated with file objects. 49As well as the POSIX.1e routines, there are a number of non-portable 50extensions defined that allow for alternative ACL semantics than the 51POSIX.1e semantics, such as AFS, NTFS, Coda, and NWFS semantics. 52Where routines are non-standard, they are suffixed with _np to indicate that 53they are not portable. 54.Pp 55POSIX.1e describes a set of ACL manipulation routines to manage the 56contents of ACLs, as well as their relationships with files; almost 57all of these support routines are implemented in 58.Fx . 59.Pp 60Available functions, sorted by behavior, include: 61.Bl -tag -width indent 62.It Fn acl_add_perm 63This function is described in 64.Xr acl_add_perm 3 , 65and may be used to add permissions to a permission set. 66.It Fn acl_calc_mask 67This function is described in 68.Xr acl_calc_mask 3 , 69and may be used to calculate and set the permissions associated with 70the 71.Dv ACL_MASK 72entry. 73.It Fn acl_clear_perms 74This function is described in 75.Xr acl_clear_perms 3 , 76and may be used to clear all permissions from a permission set. 77.It Fn acl_copy_entry 78This function is described in 79.Xr acl_copy_entry 3 , 80and may be used to copy the contents of an ACL entry. 81.It Fn acl_create_entry 82This function is described in 83.Xr acl_create_entry 3 , 84and may be used to create an empty entry in an ACL. 85.It Xo 86.Fn acl_delete_def_file , 87.Fn acl_delete_def_link_np , 88.Fn acl_delete_fd_np , 89.Fn acl_delete_file_np , 90.Fn acl_delete_link_np 91.Xc 92These functions are described in 93.Xr acl_delete 3 , 94and may be used to delete ACLs from file system objects. 95.It Fn acl_delete_entry 96This function is described in 97.Xr acl_delete_entry 3 , 98and may be used to delete an entry from an ACL. 99.It Fn acl_delete_perm 100This function is described in 101.Xr acl_delete_perm 3 , 102and may be used to delete permissions from a permset. 103.It Fn acl_dup 104This function is described in 105.Xr acl_dup 3 , 106and may be used to duplicate an ACL structure. 107.It Fn acl_free 108This function is described in 109.Xr acl_free 3 , 110and may be used to free userland working ACL storage. 111.It Fn acl_from_text 112This function is described in 113.Xr acl_from_text 3 , 114and may be used to convert a text-form ACL into working ACL state, if 115the ACL has POSIX.1e semantics. 116.It Fn acl_get_entry 117This function is described in 118.Xr acl_get_entry 3 , 119and may be used to retrieve a designated ACL entry from an ACL. 120.It Xo 121.Fn acl_get_fd , 122.Fn acl_get_fd_np , 123.Fn acl_get_file , 124.Fn acl_get_link_np 125.Xc 126These functions are described in 127.Xr acl_get 3 , 128and may be used to retrieve ACLs from file system objects. 129.It Fn acl_get_permset 130This function is described in 131.Xr acl_get_permset 3 , 132and may be used to retrieve a permset from an ACL entry. 133.It Fn acl_get_qualifier 134This function is described in 135.Xr acl_get_qualifier 3 , 136and may be used to retrieve the qualifier from an ACL entry. 137.It Fn acl_get_tag_type 138This function is described in 139.Xr acl_get_tag_type 3 , 140and may be used to retrieve the tag type from an ACL entry. 141.It Fn acl_init 142This function is described in 143.Xr acl_init 3 , 144and may be used to allocate a fresh (empty) ACL structure. 145.It Xo 146.Fn acl_set_fd , 147.Fn acl_set_fd_np , 148.Fn acl_set_file , 149.Fn acl_set_link_np 150.Xc 151These functions are described in 152.Xr acl_set 3 , 153and may be used to assign an ACL to a file system object. 154.It Fn acl_set_permset 155This function is described in 156.Xr acl_set_permset 3 , 157and may be used to set the permissions of an ACL entry from a permset. 158.It Fn acl_set_qualifier 159This function is described in 160.Xr acl_set_qualifier 3 , 161and may be used to set the qualifier of an ACL. 162.It Fn acl_set_tag_type 163This function is described in 164.Xr acl_set_tag_type 3 , 165and may be used to set the tag type of an ACL. 166.It Fn acl_to_text 167This function is described in 168.Xr acl_to_text 3 , 169and may be used to generate a text-form of a POSIX.1e semantics ACL. 170.It Xo 171.Fn acl_valid , 172.Fn acl_valid_fd_np , 173.Fn acl_valid_file_np , 174.Fn acl_valid_link_np 175.Xc 176These functions are described in 177.Xr acl_valid 3 , 178and may be used to validate an ACL as correct POSIX.1e-semantics, or 179as appropriate for a particular file system object regardless of semantics. 180.El 181.Pp 182Documentation of the internal kernel interfaces backing these calls may 183be found in 184.Xr acl 9 . 185The syscalls between the internal interfaces and the public library 186routines may change over time, and as such are not documented. 187They are not intended to be called directly without going through the 188library. 189.Sh SEE ALSO 190.Xr getfacl 1 , 191.Xr setfacl 1 , 192.Xr acl_add_perm 3 , 193.Xr acl_calc_mask 3 , 194.Xr acl_clear_perms 3 , 195.Xr acl_copy_entry 3 , 196.Xr acl_create_entry 3 , 197.Xr acl_delete_entry 3 , 198.Xr acl_delete_perm 3 , 199.Xr acl_dup 3 , 200.Xr acl_free 3 , 201.Xr acl_from_text 3 , 202.Xr acl_get 3 , 203.Xr acl_get_permset 3 , 204.Xr acl_get_qualifier 3 , 205.Xr acl_get_tag_type 3 , 206.Xr acl_init 3 , 207.Xr acl_set 3 , 208.Xr acl_set_permset 3 , 209.Xr acl_set_qualifier 3 , 210.Xr acl_set_tag_type 3 , 211.Xr acl_to_text 3 , 212.Xr acl_valid 3 , 213.Xr posix1e 3 , 214.Xr acl 9 215.Sh STANDARDS 216POSIX.1e assigns security labels to all objects, extending the security 217functionality described in POSIX.1. 218These additional labels provide fine-grained discretionary access control, 219fine-grained capabilities, and labels necessary for mandatory access 220control. 221POSIX.2c describes a set of userland utilities for manipulating these 222labels. 223.Pp 224POSIX.1e is described in IEEE POSIX.1e draft 17. 225Discussion of the draft continues on the cross-platform POSIX.1e 226implementation mailing list. 227To join this list, see the 228.Fx 229POSIX.1e implementation page for more information. 230.Sh HISTORY 231POSIX.1e support was introduced in 232.Fx 4.0 ; 233.Fx 5.0 234was the first version to include a complete ACL implementation based 235on extended attributes for the UFS and UFS2 file systems. 236.Pp 237The 238.Xr getfacl 1 239and 240.Xr setfacl 1 241utilities describe the user tools that permit direct manipulation of complete 242file ACLs. 243.Sh AUTHORS 244.An Robert N M Watson 245