1.\" Copyright (c) 2002 Networks Associates Technology, Inc. 2.\" All rights reserved. 3.\" 4.\" This software was developed for the FreeBSD Project by Chris Costello 5.\" at Safeport Network Services and Network Associates Laboratories, the 6.\" Security Research Division of Network Associates, Inc. under 7.\" DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 8.\" DARPA CHATS research program. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" $FreeBSD$ 32.Dd DECEMBER 10, 2002 33.Os 34.Dt MAC_IFOFF 4 35.Sh NAME 36.Nm mac_ifoff 37.Nd interface silencing policy 38.Sh SYNOPSIS 39To compile the interface silencing policy into your kernel, 40place the following lines in your kernel 41configuration file: 42.Cd "options MAC" 43.Cd "options MAC_IFOFF" 44.Pp 45Alternately, to load the interface silencing policy module at boot time, 46place the following line in your kernel configuration file: 47.Cd "options MAC" 48.Pp 49and in 50.Xr loader.conf 5 : 51.Cd mac_ifoff_load= Ns \&"YES" 52.Sh DESCRIPTION 53The 54.Nm 55interface silencing module allows administrators to enable and disable 56incoming and outgoing data flow on system network interfaces 57via the 58.Xr sysctl 8 59interface. 60.Pp 61To disable network traffic over the loopback 62.Xr ( lo 4 ) 63interface, set the 64.Xr sysctl 8 65OID 66.Va security.mac.ifoff.lo_enabled 67to 68.Li 0 69(default 70.Li 1 ) . 71.Pp 72To enable network traffic over other interfaces, 73set the 74.Xr sysctl 8 75OID 76.Va security.mac.ifoff.other_enabled 77to 78.Li 1 79(default 80.Li 0 ) . 81.Pp 82To allow BPF traffic to be received, 83even while other traffic is disabled, 84set the 85.Xr sysctl 8 86OID 87.Va security.mac.ifoff.bpfrecv_enabled 88to 89.Li 1 90(default 91.Li 0 ) . 92.Ss Label Format 93No labels are defined. 94.Sh SEE ALSO 95.Xr lomac 4 , 96.Xr mac 4 , 97.Xr mac_bsdextended 4 , 98.Xr mac_lomac 4 , 99.Xr mac_mls 4 , 100.Xr mac_none 4 , 101.Xr mac_partition 4 , 102.Xr mac_portacl 4 , 103.Xr mac_seeotheruids 4 , 104.Xr mac_test 4 , 105.Xr mac 9 106.Sh HISTORY 107The 108.Nm 109policy module first appeared in 110.Fx 5.0 111and was developed by the TrustedBSD Project. 112.Sh AUTHORS 113This software was contributed to the 114.Fx 115Project by Network Associates Labs, 116the Security Research Division of Network Associates 117Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 118as part of the DARPA CHATS research program. 119.Sh BUGS 120See 121.Xr mac 9 122concerning appropriateness for production use. 123The TrustedBSD MAC Framework is considered experimental in 124.Fx . 125.Pp 126While the MAC Framework design is intended to support the containment of 127the root user, not all attack channels are currently protected by entry 128point checks. 129As such, MAC Framework policies should not be relied on, in isolation, 130to protect against a malicious privileged user. 131