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 June 25, 2009 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 NFSv4, 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_flag_np 63This function is described in 64.Xr acl_add_flag_np 3 , 65and may be used to add flags to a flagset. 66.It Fn acl_add_perm 67This function is described in 68.Xr acl_add_perm 3 , 69and may be used to add permissions to a permission set. 70.It Fn acl_calc_mask 71This function is described in 72.Xr acl_calc_mask 3 , 73and may be used to calculate and set the permissions associated with 74the 75.Dv ACL_MASK 76entry. 77.It Fn acl_clear_flags_np 78This function is described in 79.Xr acl_clear_flags_np 3 , 80and may be used to clear all flags from a flagset. 81.It Fn acl_clear_perms 82This function is described in 83.Xr acl_clear_perms 3 , 84and may be used to clear all permissions from a permission set. 85.It Fn acl_copy_entry 86This function is described in 87.Xr acl_copy_entry 3 , 88and may be used to copy the contents of an ACL entry. 89.It Xo 90.Fn acl_create_entry , 91.Fn acl_create_entry_np 92.Xc 93These functions are described in 94.Xr acl_create_entry 3 , 95and may be used to create an empty entry in an ACL. 96.It Xo 97.Fn acl_delete_def_file , 98.Fn acl_delete_def_link_np , 99.Fn acl_delete_fd_np , 100.Fn acl_delete_file_np , 101.Fn acl_delete_link_np 102.Xc 103These functions are described in 104.Xr acl_delete 3 , 105and may be used to delete ACLs from file system objects. 106.It Xo 107.Fn acl_delete_entry , 108.Fn acl_delete_entry_np , 109.Xc 110This functions are described in 111.Xr acl_delete_entry 3 , 112and may be used to delete an entry from an ACL. 113.It Fn acl_delete_flag_np 114This function is described in 115.Xr acl_delete_flag_np 3 , 116and may be used to delete flags from a flagset. 117.It Fn acl_delete_perm 118This function is described in 119.Xr acl_delete_perm 3 , 120and may be used to delete permissions from a permset. 121.It Fn acl_dup 122This function is described in 123.Xr acl_dup 3 , 124and may be used to duplicate an ACL structure. 125.It Fn acl_free 126This function is described in 127.Xr acl_free 3 , 128and may be used to free userland working ACL storage. 129.It Fn acl_from_text 130This function is described in 131.Xr acl_from_text 3 , 132and may be used to convert a text-form ACL into working ACL state, if 133the ACL has POSIX.1e or NFSv4 semantics. 134.It Fn acl_get_entry 135This function is described in 136.Xr acl_get_entry 3 , 137and may be used to retrieve a designated ACL entry from an ACL. 138.It Xo 139.Fn acl_get_fd , 140.Fn acl_get_fd_np , 141.Fn acl_get_file , 142.Fn acl_get_link_np 143.Xc 144These functions are described in 145.Xr acl_get 3 , 146and may be used to retrieve ACLs from file system objects. 147.It Fn acl_get_entry_type_np 148This function is described in 149.Xr acl_get_entry_type_np 3 , 150and may be used to retrieve an ACL type from an ACL entry. 151.It Fn acl_get_flagset_np 152This function is described in 153.Xr acl_get_flagset_np 3 , 154and may be used to retrieve a flagset from an ACL entry. 155.It Fn acl_get_permset 156This function is described in 157.Xr acl_get_permset 3 , 158and may be used to retrieve a permset from an ACL entry. 159.It Fn acl_get_qualifier 160This function is described in 161.Xr acl_get_qualifier 3 , 162and may be used to retrieve the qualifier from an ACL entry. 163.It Fn acl_get_tag_type 164This function is described in 165.Xr acl_get_tag_type 3 , 166and may be used to retrieve the tag type from an ACL entry. 167.It Fn acl_init 168This function is described in 169.Xr acl_init 3 , 170and may be used to allocate a fresh (empty) ACL structure. 171.It Fn acl_is_trivial_np 172This function is described in 173.Xr acl_is_trivial_np 3 , 174and may be used to find out whether ACL is trivial. 175.It Xo 176.Fn acl_set_fd , 177.Fn acl_set_fd_np , 178.Fn acl_set_file , 179.Fn acl_set_link_np 180.Xc 181These functions are described in 182.Xr acl_set 3 , 183and may be used to assign an ACL to a file system object. 184.It Fn acl_set_entry_type_np 185This function is described in 186.Xr acl_set_entry_type_np 3 , 187and may be used to set the ACL type of an ACL entry. 188.It Fn acl_set_flagset_np 189This function is described in 190.Xr acl_set_flagset_np 3 , 191and may be used to set the flags of an ACL entry from a flagset. 192.It Fn acl_set_permset 193This function is described in 194.Xr acl_set_permset 3 , 195and may be used to set the permissions of an ACL entry from a permset. 196.It Fn acl_set_qualifier 197This function is described in 198.Xr acl_set_qualifier 3 , 199and may be used to set the qualifier of an ACL. 200.It Fn acl_set_tag_type 201This function is described in 202.Xr acl_set_tag_type 3 , 203and may be used to set the tag type of an ACL. 204.It Fn acl_strip_np 205This function is describe din 206.Xr acl-strip_np 3 , 207and may be used to remove extended entries from an ACL. 208.It Xo 209.Fn acl_to_text , 210.Fn acl_to_text_np 211.Xc 212These functions are described in 213.Xr acl_to_text 3 , 214and may be used to generate a text-form of a POSIX.1e or NFSv4 semantics ACL. 215.It Xo 216.Fn acl_valid , 217.Fn acl_valid_fd_np , 218.Fn acl_valid_file_np , 219.Fn acl_valid_link_np 220.Xc 221These functions are described in 222.Xr acl_valid 3 , 223and may be used to validate an ACL as correct POSIX.1e-semantics, or 224as appropriate for a particular file system object regardless of semantics. 225.El 226.Pp 227Documentation of the internal kernel interfaces backing these calls may 228be found in 229.Xr acl 9 . 230The syscalls between the internal interfaces and the public library 231routines may change over time, and as such are not documented. 232They are not intended to be called directly without going through the 233library. 234.Sh SEE ALSO 235.Xr getfacl 1 , 236.Xr setfacl 1 , 237.Xr acl_add_flag_np 3 , 238.Xr acl_add_perm 3 , 239.Xr acl_calc_mask 3 , 240.Xr acl_clear_flags_np 3 , 241.Xr acl_clear_perms 3 , 242.Xr acl_copy_entry 3 , 243.Xr acl_create_entry 3 , 244.Xr acl_delete_entry 3 , 245.Xr acl_delete_flag_np 3 , 246.Xr acl_delete_perm 3 , 247.Xr acl_dup 3 , 248.Xr acl_free 3 , 249.Xr acl_from_text 3 , 250.Xr acl_get 3 , 251.Xr acl_get_entry_type_np 3 , 252.Xr acl_get_flagset_np 3 , 253.Xr acl_get_permset 3 , 254.Xr acl_get_qualifier 3 , 255.Xr acl_get_tag_type 3 , 256.Xr acl_init 3 , 257.Xr acl_is_trivial_np 3 , 258.Xr acl_set 3 , 259.Xr acl_set_entry_type_np 3 , 260.Xr acl_set_flagset_np 3 , 261.Xr acl_set_permset 3 , 262.Xr acl_set_qualifier 3 , 263.Xr acl_set_tag_type 3 , 264.Xr acl_strip_np 3 , 265.Xr acl_to_text 3 , 266.Xr acl_valid 3 , 267.Xr posix1e 3 , 268.Xr acl 9 269.Sh STANDARDS 270POSIX.1e assigns security labels to all objects, extending the security 271functionality described in POSIX.1. 272These additional labels provide fine-grained discretionary access control, 273fine-grained capabilities, and labels necessary for mandatory access 274control. 275POSIX.2c describes a set of userland utilities for manipulating these 276labels. 277.Pp 278POSIX.1e is described in IEEE POSIX.1e draft 17. 279Discussion of the draft continues on the cross-platform POSIX.1e 280implementation mailing list. 281To join this list, see the 282.Fx 283POSIX.1e implementation page for more information. 284.Sh HISTORY 285POSIX.1e support was introduced in 286.Fx 4.0 ; 287.Fx 5.0 288was the first version to include a complete ACL implementation based 289on extended attributes for the UFS and UFS2 file systems. 290.Pp 291The 292.Xr getfacl 1 293and 294.Xr setfacl 1 295utilities describe the user tools that permit direct manipulation of complete 296file ACLs. 297.Sh AUTHORS 298.An Robert N M Watson 299