HardenedBSD/lib/libposix1e/cap.3

.\"-
.\" Copyright (c) 2000 Robert N. M. Watson
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.\"       $FreeBSD$
.\"
.\" TrustedBSD Project - support for POSIX.1e process capabilities
.\"
.Dd April 1, 2000
.Dt CAP 3
.Os FreeBSD 5.0
.Sh NAME
.Nm cap
.Nd introduction to the POSIX.1e Capability security API
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/cap.h>
.Sh DESCRIPTION
The POSIX.1e Capability interface allows processes to manipulate their
capability set, subject to capability manipulation restrictions imposed
by the kernel.  Using the capability API, a process may request a copy
of its capability state, modify the copy of the state, and resubmit the
state for use, if permitted.
.Pp
A variety of functions are provided for manipulating and managing
process capability state and working store state:
.Bl -tag -width cap_get_flagXX
.It Fn cap_init
This function is described in
.Xr cap_init 3 ,
and may be used to allocate a fresh capability structure with no capability
flags set.
.It Fn cap_clear
This function is described in
.Xr cap_clear 3 ,
and clears all capability flags in a capability structure.
.It Fn cap_dup
This function is described in
.Xr cap_dup 3 ,
and may be used to duplicate a capability structure.
.It Fn cap_free
This function is described in
.Xr cap_free 3 ,
and may be used to free a capability structure.
.It Fn cap_get_flag
This function, described in
.Xr cap_get_flag 3 ,
allows retrieval of a capability flag value from capability state in
working store.
.It Fn cap_get_proc
This function, described in
.Xr cap_get_proc 3 ,
allows retrieval of capability state for the current process.
.It Fn cap_set_flag
This function, described in
.Xr cap_set_flag 3 ,
allows setting of capability flag values in a capability structure held
in the working store.
.It Fn cap_set_proc
This function, described in
.Xr cap_set_proc 3 ,
allows setting of the current process capability state.
.El
.Pp
Documentation of the internal kernel interfaces backing these calls may
be found in
.Xr cap 9 .
The syscalls between the internal interfaces and the public library
routines may change over time, and as such are not documented.  They are
not intended to be called directly without going through the library.
.Sh IMPLEMENTATION NOTES
FreeBSD's support for POSIX.1e interfaces and features is still under
development at this time.
.Pp
POSIX.1e assigns security labels to all objects, extending the security
functionality described in POSIX.1.  These additional labels provide
fine-grained discretionary access control, fine-grained capabilities,
and labels necessary for mandatory access control.  POSIX.2c describes
a set of userland utilities for manipulating these labels.  These userland
utilities are not bundled with
.Fx 5.0
so as to discourage their
use in the short term.
.\" .Sh FILES
.Sh SEE ALSO
.Xr cap_clear 3 ,
.Xr cap_dup 3 ,
.Xr cap_free 3 ,
.Xr cap_get_flag 3 ,
.Xr cap_get_proc 3 ,
.Xr cap_init 3 ,
.Xr cap_set_flag 3 ,
.Xr cap_set_proc 3 ,
.Xr cap 9 ,
.Xr posix1e 3
.Sh STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17.  Discussion
of the draft continues on the cross-platform POSIX.1e implementation
mailing list.  To join this list, see the
.Fx 
POSIX.1e implementation
page for more information.
.Sh HISTORY
Support for POSIX.1e Capabilities was developed as part of the TrustedBSD
Project.
POSIX.1e support was introduced in
.Fx 4.0 ,
and development continues.
.Sh AUTHORS
.An Robert N M Watson
.Sh BUGS
These features are not yet included in the base FreeBSD distribution.