bionic (4) mac_ifoff.4freebsd.gz

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NAME
     mac_ifoff — interface silencing policy


SYNOPSIS
     To compile the interface silencing policy into your kernel, place the following lines in your kernel
     configuration file:

           options MAC
           options MAC_IFOFF

     Alternately, to load the interface silencing policy module at boot time, place the following line in your
     kernel configuration file:

           options MAC

     and in loader.conf(5):

           mac_ifoff_load="YES"


DESCRIPTION
     The mac_ifoff interface silencing module allows administrators to enable and disable incoming and outgoing
     data flow on system network interfaces via the sysctl(8) interface.

     To disable network traffic over the loopback (lo(4)) interface, set the sysctl(8) OID
     security.mac.ifoff.lo_enabled to 0 (default 1).

     To enable network traffic over other interfaces, set the sysctl(8) OID security.mac.ifoff.other_enabled to
     1 (default 0).

     To allow BPF traffic to be received, even while other traffic is disabled, set the sysctl(8) OID
     security.mac.ifoff.bpfrecv_enabled to 1 (default 0).

   Label Format
     No labels are defined.


SEE ALSO
     mac(4), mac_bsdextended(4), mac_lomac(4), mac_mls(4), mac_none(4), mac_partition(4), mac_portacl(4),
     mac_seeotheruids(4), mac_test(4), mac(9)


HISTORY
     The mac_ifoff policy module first appeared in FreeBSD 5.0 and was developed by the TrustedBSD Project.


AUTHORS
     This software was contributed to the FreeBSD Project by Network Associates Labs, the Security Research
     Division of Network Associates Inc.  under DARPA/SPAWAR contract N66001-01-C-8035 (“CBOSS”), as part of the
     DARPA CHATS research program.


BUGS
     While the MAC Framework design is intended to support the containment of the root user, not all attack
     channels are currently protected by entry point checks.  As such, MAC Framework policies should not be
     relied on, in isolation, to protect against a malicious privileged user.