xref: /freebsd/share/man/man9/vfs_suser.9 (revision 4b9d6057)
1.\"
2.\" Copyright (c) 2004 Alfred Perlstein
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 ``AS IS'' AND ANY EXPRESS OR
15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22.\" 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.Dd April 2, 2004
27.Dt VFS_SUSER 9
28.Os
29.Sh NAME
30.Nm vfs_suser
31.Nd check if credentials have superuser privileges for a mount point
32.Sh SYNOPSIS
33.In sys/param.h
34.In sys/systm.h
35.In sys/mount.h
36.Ft int
37.Fn vfs_suser "struct mount *mp" "struct thread *td"
38.Sh DESCRIPTION
39The
40.Fn vfs_suser
41function checks if the credentials given include superuser powers
42for the given mount point.
43It will check to see if the thread
44passed in has the same credentials as the user that mounted the
45file system.
46If so, it returns 0, otherwise it returns what
47.Xr priv_check 9
48would have returned.
49.Sh RETURN VALUES
50The
51.Fn vfs_suser
52function returns 0 if the user has superuser powers and
53.Er EPERM
54otherwise.
55This is the
56.Em reverse logic
57of some other implementations of
58.Fn suser
59in which a TRUE response indicates superuser powers.
60.Sh SEE ALSO
61.Xr chroot 2 ,
62.Xr jail 2
63.Sh HISTORY
64The
65.Fn vfs_suser
66function was introduced in
67.Fx 5.2 .
68.Sh AUTHORS
69This manual page was written by
70.An Alfred Perlstein .
71