xref: /freebsd/lib/libc/gen/cap_rights_get.3 (revision cf321a51b19bb685eb0bb536b62a429e6866e872)

.\"
.\" Copyright (c) 2013 The FreeBSD Foundation
.\" All rights reserved.
.\"
.\" This documentation was written by Pawel Jakub Dawidek under sponsorship
.\" from the FreeBSD Foundation.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd March 27, 2014
.Dt CAP_RIGHTS_GET 3
.Os
.Sh NAME
.Nm cap_rights_get
.Nd obtain capability rights
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/capsicum.h
.Ft int
.Fn cap_rights_get "int fd" "cap_rights_t *rights"
.Sh DESCRIPTION
The
.Nm cap_rights_get
function allows to obtain current capability rights for the given descriptor.
The function will fill the
.Fa rights
argument with all capability rights if they were not limited or capability
rights configured during the last successful call of
.Xr cap_rights_limit 2
on the given descriptor.
.Pp
The
.Fa rights
argument can be inspected using
.Xr cap_rights_init 3
family of functions.
.Pp
The complete list of the capability rights can be found in the
.Xr rights 4
manual page.
.Sh RETURN VALUES
.Rv -std
.Sh EXAMPLES
The following example demonstrates how to limit file descriptor capability
rights and how to obtain them.
.Bd -literal
cap_rights_t setrights, getrights;
int fd;

memset(&setrights, 0, sizeof(setrights));
memset(&getrights, 0, sizeof(getrights));

fd = open("/tmp/foo", O_RDONLY);
if (fd < 0)
	err(1, "open() failed");

cap_rights_init(&setrights, CAP_FSTAT, CAP_READ);
if (cap_rights_limit(fd, &setrights) < 0 && errno != ENOSYS)
	err(1, "cap_rights_limit() failed");

if (cap_rights_get(fd, &getrights) < 0 && errno != ENOSYS)
	err(1, "cap_rights_get() failed");

assert(memcmp(&setrights, &getrights, sizeof(setrights)) == 0);
.Ed
.Sh ERRORS
.Fn cap_rights_get
succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid active descriptor.
.It Bq Er EFAULT
The
.Fa rights
argument points at an invalid address.
.El
.Sh SEE ALSO
.Xr cap_rights_limit 2 ,
.Xr cap_rights_init 3 ,
.Xr errno 2 ,
.Xr open 2 ,
.Xr assert 3 ,
.Xr err 3 ,
.Xr memcmp 3 ,
.Xr memset 3 ,
.Xr capsicum 4 ,
.Xr rights 4
.Sh HISTORY
Support for capabilities and capabilities mode was developed as part of the
.Tn TrustedBSD
Project.
.Sh AUTHORS
This function was created by
.An Pawel Jakub Dawidek Aq pawel@dawidek.net
under sponsorship of the FreeBSD Foundation.