1 /*-
2 * Copyright (c) 1999-2002, 2007 Robert N. M. Watson
3 * Copyright (c) 2001-2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed by Robert Watson for the TrustedBSD Project.
7 *
8 * This software was developed for the FreeBSD Project in part by Network
9 * Associates Laboratories, the Security Research Division of Network
10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
11 * as part of the DARPA CHATS research program.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $FreeBSD$
35 */
36
37 /*
38 * Developed by the TrustedBSD Project.
39 *
40 * Limit access to interfaces until they are specifically administratively
41 * enabled. Prevents protocol stack-driven packet leakage in unsafe
42 * environments.
43 */
44
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/module.h>
48 #include <sys/socket.h>
49 #include <sys/sysctl.h>
50
51 #include <net/bpfdesc.h>
52 #include <net/if_types.h>
53
54 #include <security/mac/mac_policy.h>
55
56 SYSCTL_DECL(_security_mac);
57
58 SYSCTL_NODE(_security_mac, OID_AUTO, ifoff, CTLFLAG_RW, 0,
59 "TrustedBSD mac_ifoff policy controls");
60
61 static int ifoff_enabled = 1;
62 SYSCTL_INT(_security_mac_ifoff, OID_AUTO, enabled, CTLFLAG_RW,
63 &ifoff_enabled, 0, "Enforce ifoff policy");
64 TUNABLE_INT("security.mac.ifoff.enabled", &ifoff_enabled);
65
66 static int ifoff_lo_enabled = 1;
67 SYSCTL_INT(_security_mac_ifoff, OID_AUTO, lo_enabled, CTLFLAG_RW,
68 &ifoff_lo_enabled, 0, "Enable loopback interfaces");
69 TUNABLE_INT("security.mac.ifoff.lo_enabled", &ifoff_lo_enabled);
70
71 static int ifoff_other_enabled = 0;
72 SYSCTL_INT(_security_mac_ifoff, OID_AUTO, other_enabled, CTLFLAG_RW,
73 &ifoff_other_enabled, 0, "Enable other interfaces");
74 TUNABLE_INT("security.mac.ifoff.other_enabled", &ifoff_other_enabled);
75
76 static int ifoff_bpfrecv_enabled = 0;
77 SYSCTL_INT(_security_mac_ifoff, OID_AUTO, bpfrecv_enabled, CTLFLAG_RW,
78 &ifoff_bpfrecv_enabled, 0, "Enable BPF reception even when interface "
79 "is disabled");
80 TUNABLE_INT("security.mac.ifoff.bpfrecv.enabled", &ifoff_bpfrecv_enabled);
81
82 static int
83 check_ifnet_outgoing(struct ifnet *ifp)
84 {
85
86 if (!ifoff_enabled)
87 return (0);
88
89 if (ifoff_lo_enabled && ifp->if_type == IFT_LOOP)
90 return (0);
91
92 if (ifoff_other_enabled && ifp->if_type != IFT_LOOP)
93 return (0);
94
95 return (EPERM);
96 }
97
98 static int
99 check_ifnet_incoming(struct ifnet *ifp, int viabpf)
100 {
101 if (!ifoff_enabled)
102 return (0);
103
104 if (ifoff_lo_enabled && ifp->if_type == IFT_LOOP)
105 return (0);
106
107 if (ifoff_other_enabled && ifp->if_type != IFT_LOOP)
108 return (0);
109
110 if (viabpf && ifoff_bpfrecv_enabled)
111 return (0);
112
113 return (EPERM);
114 }
115
116 static int
117 ifoff_check_bpfdesc_receive(struct bpf_d *d, struct label *dlabel,
118 struct ifnet *ifp, struct label *ifplabel)
119 {
120
121 return (check_ifnet_incoming(ifp, 1));
122 }
123
124 static int
125 ifoff_check_ifnet_transmit(struct ifnet *ifp, struct label *ifplabel,
126 struct mbuf *m, struct label *mlabel)
127 {
128
129 return (check_ifnet_outgoing(ifp));
130 }
131
132 static int
133 ifoff_check_inpcb_deliver(struct inpcb *inp, struct label *inplabel,
134 struct mbuf *m, struct label *mlabel)
135 {
136
137 M_ASSERTPKTHDR(m);
138 if (m->m_pkthdr.rcvif != NULL)
139 return (check_ifnet_incoming(m->m_pkthdr.rcvif, 0));
140
141 return (0);
142 }
143
144 static int
145 ifoff_check_socket_deliver(struct socket *so, struct label *solabel,
146 struct mbuf *m, struct label *mlabel)
147 {
148
149 M_ASSERTPKTHDR(m);
150 if (m->m_pkthdr.rcvif != NULL)
151 return (check_ifnet_incoming(m->m_pkthdr.rcvif, 0));
152
153 return (0);
154 }
155
156 static struct mac_policy_ops ifoff_ops =
157 {
158 .mpo_check_bpfdesc_receive = ifoff_check_bpfdesc_receive,
159 .mpo_check_ifnet_transmit = ifoff_check_ifnet_transmit,
160 .mpo_check_inpcb_deliver = ifoff_check_inpcb_deliver,
161 .mpo_check_socket_deliver = ifoff_check_socket_deliver,
162 };
163
164 MAC_POLICY_SET(&ifoff_ops, mac_ifoff, "TrustedBSD MAC/ifoff",
165 MPC_LOADTIME_FLAG_UNLOADOK, NULL);
Cache object: fcc46905f7a033fe32b85833b4958826
|