2 .\" Copyright (c) 2011 Robert N. M. Watson
3 .\" Copyright (c) 2011 Jonathan Anderson
4 .\" All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
15 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 .Dd September 20, 2011
34 .Nd lightweight OS capability and sandbox framework
36 .Cd "options CAPABILITY_MODE"
37 .Cd "options CAPABILITIES"
38 .Cd "options PROCDESC"
41 is a lightweight OS capability and sandbox framework implementing a hybrid
42 capability system model.
44 can be used for application and library compartmentalisation, the
45 decomposition of larger bodies of software into isolated (sandboxed)
46 components in order to implement security policies and limit the impact of
47 software vulnerabilities.
50 provides two core kernel primitives:
51 .Bl -tag -width indent
53 A process mode, entered by invoking
55 in which access to global OS namespaces (such as the file system and PID
56 namespaces) is restricted; only explicitly delegated rights, referenced by
57 memory mappings or file descriptors, may be used.
58 Once set, the flag is inherited by future children processes, and may not be
61 File descriptors that wrap other file descriptors, masking operations that can
62 be called on them; for example, a file descriptor returned by
70 can be called, but not
76 requires use of alternatives to traditional POSIX APIs in order to name
77 objects using capabilities rather than global namespaces:
78 .Bl -tag -width indent
79 .It process descriptors
80 File descriptors representing processes, allowing parent processes to manage
81 child processes without requiring access to the PID namespace.
82 .It anonymous shared memory
83 An extension to the POSIX shared memory API to support anonymous swap objects
84 associated with file descriptors.
104 and was developed at the University of Cambridge.
109 .An "Robert Watson" Aq rwatson@FreeBSD.org
111 .An "Jonathan Anderson" Aq jonathan@FreeBSD.org
112 at the University of Cambridge, and
113 .An "Ben Laurie" Aq benl@FreeBSD.org
115 .An "Kris Kennaway" Aq kris@FreeBSD.org
119 is considered experimental in