mac_ifoff.c revision 166905
1193323Sed/*- 2193323Sed * Copyright (c) 1999-2002, 2007 Robert N. M. Watson 3193323Sed * Copyright (c) 2001-2002 Networks Associates Technology, Inc. 4193323Sed * All rights reserved. 5193323Sed * 6193323Sed * This software was developed by Robert Watson for the TrustedBSD Project. 7193323Sed * 8193323Sed * This software was developed for the FreeBSD Project in part by Network 9193323Sed * Associates Laboratories, the Security Research Division of Network 10193323Sed * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 11193323Sed * as part of the DARPA CHATS research program. 12193323Sed * 13193323Sed * Redistribution and use in source and binary forms, with or without 14193323Sed * modification, are permitted provided that the following conditions 15193323Sed * are met: 16193323Sed * 1. Redistributions of source code must retain the above copyright 17193323Sed * notice, this list of conditions and the following disclaimer. 18193323Sed * 2. Redistributions in binary form must reproduce the above copyright 19193323Sed * notice, this list of conditions and the following disclaimer in the 20193323Sed * documentation and/or other materials provided with the distribution. 21193323Sed * 22193323Sed * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23198090Srdivacky * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24198090Srdivacky * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25193323Sed * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26193323Sed * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27193323Sed * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28193323Sed * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29193323Sed * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30193323Sed * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31193323Sed * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32193323Sed * SUCH DAMAGE. 33193323Sed * 34193323Sed * $FreeBSD: head/sys/security/mac_ifoff/mac_ifoff.c 166905 2007-02-23 14:39:04Z rwatson $ 35193323Sed */ 36193323Sed 37207618Srdivacky/* 38193323Sed * Developed by the TrustedBSD Project. 39193323Sed * Limit access to interfaces until they are specifically administratively 40193323Sed * enabled. Prevents protocol stack-driven packet leakage in unsafe 41193323Sed * environments. 42193323Sed */ 43193323Sed 44193323Sed#include <sys/param.h> 45193323Sed#include <sys/kernel.h> 46193323Sed#include <sys/module.h> 47193323Sed#include <sys/socket.h> 48193323Sed#include <sys/sysctl.h> 49193323Sed 50193323Sed#include <net/bpfdesc.h> 51193323Sed#include <net/if_types.h> 52193323Sed 53193323Sed#include <security/mac/mac_policy.h> 54193323Sed 55193323SedSYSCTL_DECL(_security_mac); 56193323Sed 57193323SedSYSCTL_NODE(_security_mac, OID_AUTO, ifoff, CTLFLAG_RW, 0, 58193323Sed "TrustedBSD mac_ifoff policy controls"); 59193323Sed 60193323Sedstatic int mac_ifoff_enabled = 1; 61193323SedSYSCTL_INT(_security_mac_ifoff, OID_AUTO, enabled, CTLFLAG_RW, 62193323Sed &mac_ifoff_enabled, 0, "Enforce ifoff policy"); 63193323SedTUNABLE_INT("security.mac.ifoff.enabled", &mac_ifoff_enabled); 64193323Sed 65193323Sedstatic int mac_ifoff_lo_enabled = 1; 66193323SedSYSCTL_INT(_security_mac_ifoff, OID_AUTO, lo_enabled, CTLFLAG_RW, 67193323Sed &mac_ifoff_lo_enabled, 0, "Enable loopback interfaces"); 68193323SedTUNABLE_INT("security.mac.ifoff.lo_enabled", &mac_ifoff_lo_enabled); 69193323Sed 70193323Sedstatic int mac_ifoff_other_enabled = 0; 71193323SedSYSCTL_INT(_security_mac_ifoff, OID_AUTO, other_enabled, CTLFLAG_RW, 72193323Sed &mac_ifoff_other_enabled, 0, "Enable other interfaces"); 73193323SedTUNABLE_INT("security.mac.ifoff.other_enabled", &mac_ifoff_other_enabled); 74193323Sed 75193323Sedstatic int mac_ifoff_bpfrecv_enabled = 0; 76193323SedSYSCTL_INT(_security_mac_ifoff, OID_AUTO, bpfrecv_enabled, CTLFLAG_RW, 77193323Sed &mac_ifoff_bpfrecv_enabled, 0, "Enable BPF reception even when interface " 78193323Sed "is disabled"); 79193323SedTUNABLE_INT("security.mac.ifoff.bpfrecv.enabled", &mac_ifoff_bpfrecv_enabled); 80193323Sed 81193323Sedstatic int 82200581Srdivackycheck_ifnet_outgoing(struct ifnet *ifnet) 83193323Sed{ 84193323Sed 85193323Sed if (!mac_ifoff_enabled) 86193323Sed return (0); 87193323Sed 88193323Sed if (mac_ifoff_lo_enabled && ifnet->if_type == IFT_LOOP) 89193323Sed return (0); 90193323Sed 91193323Sed if (mac_ifoff_other_enabled && ifnet->if_type != IFT_LOOP) 92193323Sed return (0); 93193323Sed 94193323Sed return (EPERM); 95193323Sed} 96193323Sed 97193323Sedstatic int 98193323Sedcheck_ifnet_incoming(struct ifnet *ifnet, int viabpf) 99193323Sed{ 100193323Sed if (!mac_ifoff_enabled) 101193323Sed return (0); 102193323Sed 103193323Sed if (mac_ifoff_lo_enabled && ifnet->if_type == IFT_LOOP) 104193323Sed return (0); 105193323Sed 106193323Sed if (mac_ifoff_other_enabled && ifnet->if_type != IFT_LOOP) 107193323Sed return (0); 108193323Sed 109193323Sed if (viabpf && mac_ifoff_bpfrecv_enabled) 110193323Sed return (0); 111193323Sed 112193323Sed return (EPERM); 113193323Sed} 114193323Sed 115193323Sedstatic int 116193323Sedmac_ifoff_check_bpfdesc_receive(struct bpf_d *bpf_d, struct label *bpflabel, 117193323Sed struct ifnet *ifnet, struct label *ifnetlabel) 118193323Sed{ 119210299Sed 120193323Sed return (check_ifnet_incoming(ifnet, 1)); 121193323Sed} 122193323Sed 123193323Sedstatic int 124193323Sedmac_ifoff_check_ifnet_transmit(struct ifnet *ifnet, struct label *ifnetlabel, 125193323Sed struct mbuf *m, struct label *mbuflabel) 126193323Sed{ 127193323Sed 128193323Sed return (check_ifnet_outgoing(ifnet)); 129198090Srdivacky} 130193323Sed 131193323Sedstatic int 132193323Sedmac_ifoff_check_inpcb_deliver(struct inpcb *inp, struct label *inplabel, 133193323Sed struct mbuf *m, struct label *mlabel) 134193323Sed{ 135193323Sed 136193323Sed M_ASSERTPKTHDR(m); 137193323Sed if (m->m_pkthdr.rcvif != NULL) 138193323Sed return (check_ifnet_incoming(m->m_pkthdr.rcvif, 0)); 139193323Sed 140193323Sed return (0); 141193323Sed} 142193323Sed 143193323Sedstatic int 144193323Sedmac_ifoff_check_socket_deliver(struct socket *so, struct label *socketlabel, 145193323Sed struct mbuf *m, struct label *mbuflabel) 146193323Sed{ 147193323Sed 148193323Sed M_ASSERTPKTHDR(m); 149193323Sed if (m->m_pkthdr.rcvif != NULL) 150193323Sed return (check_ifnet_incoming(m->m_pkthdr.rcvif, 0)); 151193323Sed 152193323Sed return (0); 153193323Sed} 154193323Sed 155193323Sedstatic struct mac_policy_ops mac_ifoff_ops = 156193323Sed{ 157193323Sed .mpo_check_bpfdesc_receive = mac_ifoff_check_bpfdesc_receive, 158193323Sed .mpo_check_ifnet_transmit = mac_ifoff_check_ifnet_transmit, 159193323Sed .mpo_check_inpcb_deliver = mac_ifoff_check_inpcb_deliver, 160193323Sed .mpo_check_socket_deliver = mac_ifoff_check_socket_deliver, 161193323Sed}; 162193323Sed 163193323SedMAC_POLICY_SET(&mac_ifoff_ops, mac_ifoff, "TrustedBSD MAC/ifoff", 164193323Sed MPC_LOADTIME_FLAG_UNLOADOK, NULL); 165193323Sed