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/*-
* Copyright (c) 1999-2002, 2007 Robert N. M. Watson
* Copyright (c) 2001-2002 Networks Associates Technology, Inc.
* Copyright (c) 2006 SPARTA, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, 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.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* 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.
*
* $FreeBSD$
*/
/*
* Developed by the TrustedBSD Project.
*
* Limit access to interfaces until they are specifically administratively
* enabled. Prevents protocol stack-driven packet leakage in unsafe
* environments.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/bpfdesc.h>
#include <net/if_types.h>
#include <security/mac/mac_policy.h>
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, ifoff, CTLFLAG_RW, 0,
"TrustedBSD mac_ifoff policy controls");
static int ifoff_enabled = 1;
SYSCTL_INT(_security_mac_ifoff, OID_AUTO, enabled, CTLFLAG_RW,
&ifoff_enabled, 0, "Enforce ifoff policy");
TUNABLE_INT("security.mac.ifoff.enabled", &ifoff_enabled);
static int ifoff_lo_enabled = 1;
SYSCTL_INT(_security_mac_ifoff, OID_AUTO, lo_enabled, CTLFLAG_RW,
&ifoff_lo_enabled, 0, "Enable loopback interfaces");
TUNABLE_INT("security.mac.ifoff.lo_enabled", &ifoff_lo_enabled);
static int ifoff_other_enabled = 0;
SYSCTL_INT(_security_mac_ifoff, OID_AUTO, other_enabled, CTLFLAG_RW,
&ifoff_other_enabled, 0, "Enable other interfaces");
TUNABLE_INT("security.mac.ifoff.other_enabled", &ifoff_other_enabled);
static int ifoff_bpfrecv_enabled = 0;
SYSCTL_INT(_security_mac_ifoff, OID_AUTO, bpfrecv_enabled, CTLFLAG_RW,
&ifoff_bpfrecv_enabled, 0, "Enable BPF reception even when interface "
"is disabled");
TUNABLE_INT("security.mac.ifoff.bpfrecv.enabled", &ifoff_bpfrecv_enabled);
static int
ifnet_check_outgoing(struct ifnet *ifp)
{
if (!ifoff_enabled)
return (0);
if (ifoff_lo_enabled && ifp->if_type == IFT_LOOP)
return (0);
if (ifoff_other_enabled && ifp->if_type != IFT_LOOP)
return (0);
return (EPERM);
}
static int
ifnet_check_incoming(struct ifnet *ifp, int viabpf)
{
if (!ifoff_enabled)
return (0);
if (ifoff_lo_enabled && ifp->if_type == IFT_LOOP)
return (0);
if (ifoff_other_enabled && ifp->if_type != IFT_LOOP)
return (0);
if (viabpf && ifoff_bpfrecv_enabled)
return (0);
return (EPERM);
}
/*
* Object-specific entry point implementations are sorted alphabetically by
* object type and then by operation.
*/
static int
ifoff_bpfdesc_check_receive(struct bpf_d *d, struct label *dlabel,
struct ifnet *ifp, struct label *ifplabel)
{
return (ifnet_check_incoming(ifp, 1));
}
static int
ifoff_ifnet_check_transmit(struct ifnet *ifp, struct label *ifplabel,
struct mbuf *m, struct label *mlabel)
{
return (ifnet_check_outgoing(ifp));
}
static int
ifoff_inpcb_check_deliver(struct inpcb *inp, struct label *inplabel,
struct mbuf *m, struct label *mlabel)
{
M_ASSERTPKTHDR(m);
if (m->m_pkthdr.rcvif != NULL)
return (ifnet_check_incoming(m->m_pkthdr.rcvif, 0));
return (0);
}
static int
ifoff_socket_check_deliver(struct socket *so, struct label *solabel,
struct mbuf *m, struct label *mlabel)
{
M_ASSERTPKTHDR(m);
if (m->m_pkthdr.rcvif != NULL)
return (ifnet_check_incoming(m->m_pkthdr.rcvif, 0));
return (0);
}
static struct mac_policy_ops ifoff_ops =
{
.mpo_bpfdesc_check_receive = ifoff_bpfdesc_check_receive,
.mpo_ifnet_check_transmit = ifoff_ifnet_check_transmit,
.mpo_inpcb_check_deliver = ifoff_inpcb_check_deliver,
.mpo_socket_check_deliver = ifoff_socket_check_deliver,
};
MAC_POLICY_SET(&ifoff_ops, mac_ifoff, "TrustedBSD MAC/ifoff",
MPC_LOADTIME_FLAG_UNLOADOK, NULL);
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