xref: /freebsd/lib/libc/posix1e/acl_get.3 (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
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28.Dd September 21, 2023
29.Dt ACL_GET 3
30.Os
31.Sh NAME
32.Nm acl_get_fd ,
33.Nm acl_get_fd_np ,
34.Nm acl_get_file ,
35.Nm acl_get_link_np
36.Nd get an ACL for a file
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In sys/types.h
41.In sys/acl.h
42.Ft acl_t
43.Fn acl_get_fd "int fd"
44.Ft acl_t
45.Fn acl_get_fd_np "int fd" "acl_type_t type"
46.Ft acl_t
47.Fn acl_get_file "const char *path_p" "acl_type_t type"
48.Ft acl_t
49.Fn acl_get_link_np "const char *path_p" "acl_type_t type"
50.Sh DESCRIPTION
51The
52.Fn acl_get_fd ,
53.Fn acl_get_file ,
54.Fn acl_get_link_np ,
55and
56.Fn acl_get_fd_np
57each allow the retrieval of an ACL from a file.
58The
59.Fn acl_get_fd
60is a POSIX.1e call that allows the retrieval of an ACL of type
61ACL_TYPE_ACCESS
62from a file descriptor.
63The
64.Fn acl_get_fd_np
65function
66is a non-portable form of
67.Fn acl_get_fd
68that allows the retrieval of any type of ACL from a file descriptor.
69The
70.Fn acl_get_file
71function is a POSIX.1e call that allows the retrieval of a
72specified type of ACL from a file by name;
73.Fn acl_get_link_np
74is a non-portable variation on
75.Fn acl_get_file
76which does not follow a symlink if the target of the call is a
77symlink.
78.Pp
79These functions may cause memory to be allocated.
80The caller should free
81any releasable memory, when the new ACL is no longer required, by calling
82.Xr acl_free 3
83with the
84.Va (void *)acl_t
85as an argument.
86.Pp
87The ACL in the working storage is an independent copy of the ACL associated
88with the object referred to by
89.Va fd .
90The ACL in the working storage shall not participate in any access control
91decisions.
92.Pp
93Valid values for the
94.Va type
95argument are:
96.Bl -column -offset 3n "ACL_TYPE_DEFAULT"
97.It ACL_TYPE_ACCESS	POSIX.1e access ACL
98.It ACL_TYPE_DEFAULT	POSIX.1e default ACL
99.It ACL_TYPE_NFS4	NFSv4 ACL
100.El
101.Pp
102The ACL returned will be branded accordingly.
103.Sh IMPLEMENTATION NOTES
104.Fx Ns 's
105support for POSIX.1e interfaces and features is still under
106development at this time.
107.Sh RETURN VALUES
108Upon successful completion, the function shall return a pointer to the ACL
109that was retrieved.
110Otherwise, a value of
111.Va (acl_t)NULL
112shall be returned, and
113.Va errno
114shall be set to indicate the error.
115.Sh ERRORS
116If any of the following conditions occur, the
117.Fn acl_get_fd
118function shall return a value of
119.Va (acl_t)NULL
120and set
121.Va errno
122to the corresponding value:
123.Bl -tag -width Er
124.It Bq Er EACCES
125Search permission is denied for a component of the path prefix, or the
126object exists and the process does not have appropriate access rights.
127.It Bq Er EBADF
128The
129.Va fd
130argument is not a valid file descriptor.
131.It Bq Er EINVAL
132The ACL type passed is invalid for this file object.
133.It Bq Er ENAMETOOLONG
134A component of a pathname exceeded 255 characters, or an
135entire path name exceeded 1023 characters.
136.It Bq Er ENOENT
137The named object does not exist, or the
138.Va path_p
139argument points to an empty string.
140.It Bq Er ENOMEM
141Insufficient memory available to fulfill request.
142.It Bq Er EOPNOTSUPP
143The file system does not support ACL retrieval.
144.El
145.Sh SEE ALSO
146.Xr acl 3 ,
147.Xr acl_free 3 ,
148.Xr acl_get 3 ,
149.Xr acl_get_brand_np 3 ,
150.Xr acl_set 3 ,
151.Xr posix1e 3
152.Sh STANDARDS
153POSIX.1e is described in IEEE POSIX.1e draft 17.
154.Sh HISTORY
155POSIX.1e support was introduced in
156.Fx 4.0 .
157.Sh AUTHORS
158.An Robert N M Watson
159