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.\"
.\" Copyright (c) 2012 The FreeBSD Foundation
.\" All rights reserved.
.\"
.\" This documentation was written by Pawel Jakub Dawidek under sponsorship
.\" 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_FCNTLS_LIMIT 2
.Os
.Sh NAME
.Nm cap_fcntls_limit ,
.Nm cap_fcntls_get
.Nd manage allowed fcntl commands
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/capsicum.h
.Ft int
.Fn cap_fcntls_limit "int fd" "uint32_t fcntlrights"
.Ft int
.Fn cap_fcntls_get "int fd" "uint32_t *fcntlrightsp"
.Sh DESCRIPTION
If a file descriptor is granted the
.Dv CAP_FCNTL
capability right, the list of allowed
.Xr fcntl 2
commands can be selectively reduced (but never expanded) with the
.Fn cap_fcntls_limit
system call.
.Pp
A bitmask of allowed fcntls commands for a given file descriptor can be obtained
with the
.Fn cap_fcntls_get
system call.
.Sh FLAGS
The following flags may be specified in the
.Fa fcntlrights
argument or returned in the
.Fa fcntlrightsp
argument:
.Bl -tag -width CAP_FCNTL_GETOWN
.It Dv CAP_FCNTL_GETFL
Permit
.Dv F_GETFL
command.
.It Dv CAP_FCNTL_SETFL
Permit
.Dv F_SETFL
command.
.It Dv CAP_FCNTL_GETOWN
Permit
.Dv F_GETOWN
command.
.It Dv CAP_FCNTL_SETOWN
Permit
.Dv F_SETOWN
command.
.El
.Sh RETURN VALUES
.Rv -std
.Sh ERRORS
.Fn cap_fcntls_limit
succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid descriptor.
.It Bq Er EINVAL
An invalid flag has been passed in
.Fa fcntlrights .
.It Bq Er ENOTCAPABLE
.Fa fcntlrights
would expand the list of allowed
.Xr fcntl 2
commands.
.El
.Pp
.Fn cap_fcntls_get
succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid descriptor.
.It Bq Er EFAULT
The
.Fa fcntlrightsp
argument points at an invalid address.
.El
.Sh SEE ALSO
.Xr cap_ioctls_limit 2 ,
.Xr cap_rights_limit 2 ,
.Xr fcntl 2
.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 Mt pawel@dawidek.net
under sponsorship of the FreeBSD Foundation.
|
