1/*-
2 * Copyright (c) 1999-2002, 2009 Robert N. M. Watson
3 * Copyright (c) 2001 Ilmar S. Habibulin
4 * Copyright (c) 2001-2004 Networks Associates Technology, Inc.
5 * Copyright (c) 2006 SPARTA, Inc.
6 * Copyright (c) 2008 Apple Inc.
7 * All rights reserved.
8 *
9 * This software was developed by Robert Watson and Ilmar Habibulin for the
10 * TrustedBSD Project.
11 *
12 * This software was enhanced by SPARTA ISSO under SPAWAR contract
13 * N66001-04-C-6019 ("SEFOS").
14 *
15 * This software was developed for the FreeBSD Project in part by Network
16 * Associates Laboratories, the Security Research Division of Network
17 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
18 * as part of the DARPA CHATS research program.
19 *
20 * This software was developed at the University of Cambridge Computer
21 * Laboratory with support from a grant from Google, Inc.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the above copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * SUCH DAMAGE.
43 */
44
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD$");
47
48#include "opt_kdtrace.h"
49#include "opt_mac.h"
50
51#include <sys/param.h>
52#include <sys/kernel.h>
53#include <sys/lock.h>
54#include <sys/malloc.h>
55#include <sys/mutex.h>
56#include <sys/mac.h>
57#include <sys/priv.h>
58#include <sys/sbuf.h>
59#include <sys/sdt.h>
60#include <sys/systm.h>
61#include <sys/mount.h>
62#include <sys/file.h>
63#include <sys/namei.h>
64#include <sys/protosw.h>
65#include <sys/socket.h>
66#include <sys/socketvar.h>
67#include <sys/sysctl.h>
68
69#include <net/bpfdesc.h>
70#include <net/if.h>
71#include <net/if_var.h>
72
73#include <security/mac/mac_framework.h>
74#include <security/mac/mac_internal.h>
75#include <security/mac/mac_policy.h>
76
77/*
78 * XXXRW: struct ifnet locking is incomplete in the network code, so we use
79 * our own global mutex for struct ifnet.  Non-ideal, but should help in the
80 * SMP environment.
81 */
82struct mtx mac_ifnet_mtx;
83MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
84
85/*
86 * Retrieve the label associated with an mbuf by searching for the tag.
87 * Depending on the value of mac_labelmbufs, it's possible that a label will
88 * not be present, in which case NULL is returned.  Policies must handle the
89 * possibility of an mbuf not having label storage if they do not enforce
90 * early loading.
91 */
92struct label *
93mac_mbuf_to_label(struct mbuf *m)
94{
95	struct m_tag *tag;
96	struct label *label;
97
98	if (m == NULL)
99		return (NULL);
100	tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL);
101	if (tag == NULL)
102		return (NULL);
103	label = (struct label *)(tag+1);
104	return (label);
105}
106
107static struct label *
108mac_bpfdesc_label_alloc(void)
109{
110	struct label *label;
111
112	label = mac_labelzone_alloc(M_WAITOK);
113	MAC_POLICY_PERFORM(bpfdesc_init_label, label);
114	return (label);
115}
116
117void
118mac_bpfdesc_init(struct bpf_d *d)
119{
120
121	if (mac_labeled & MPC_OBJECT_BPFDESC)
122		d->bd_label = mac_bpfdesc_label_alloc();
123	else
124		d->bd_label = NULL;
125}
126
127static struct label *
128mac_ifnet_label_alloc(void)
129{
130	struct label *label;
131
132	label = mac_labelzone_alloc(M_WAITOK);
133	MAC_POLICY_PERFORM(ifnet_init_label, label);
134	return (label);
135}
136
137void
138mac_ifnet_init(struct ifnet *ifp)
139{
140
141	if (mac_labeled & MPC_OBJECT_IFNET)
142		ifp->if_label = mac_ifnet_label_alloc();
143	else
144		ifp->if_label = NULL;
145}
146
147int
148mac_mbuf_tag_init(struct m_tag *tag, int flag)
149{
150	struct label *label;
151	int error;
152
153	label = (struct label *) (tag + 1);
154	mac_init_label(label);
155
156	if (flag & M_WAITOK)
157		MAC_POLICY_CHECK(mbuf_init_label, label, flag);
158	else
159		MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag);
160	if (error) {
161		MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
162		mac_destroy_label(label);
163	}
164	return (error);
165}
166
167int
168mac_mbuf_init(struct mbuf *m, int flag)
169{
170	struct m_tag *tag;
171	int error;
172
173	M_ASSERTPKTHDR(m);
174
175	if (mac_labeled & MPC_OBJECT_MBUF) {
176		tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
177		    flag);
178		if (tag == NULL)
179			return (ENOMEM);
180		error = mac_mbuf_tag_init(tag, flag);
181		if (error) {
182			m_tag_free(tag);
183			return (error);
184		}
185		m_tag_prepend(m, tag);
186	}
187	return (0);
188}
189
190static void
191mac_bpfdesc_label_free(struct label *label)
192{
193
194	MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label);
195	mac_labelzone_free(label);
196}
197
198void
199mac_bpfdesc_destroy(struct bpf_d *d)
200{
201
202	if (d->bd_label != NULL) {
203		mac_bpfdesc_label_free(d->bd_label);
204		d->bd_label = NULL;
205	}
206}
207
208static void
209mac_ifnet_label_free(struct label *label)
210{
211
212	MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label);
213	mac_labelzone_free(label);
214}
215
216void
217mac_ifnet_destroy(struct ifnet *ifp)
218{
219
220	if (ifp->if_label != NULL) {
221		mac_ifnet_label_free(ifp->if_label);
222		ifp->if_label = NULL;
223	}
224}
225
226void
227mac_mbuf_tag_destroy(struct m_tag *tag)
228{
229	struct label *label;
230
231	label = (struct label *)(tag+1);
232
233	MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
234	mac_destroy_label(label);
235}
236
237/*
238 * mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which
239 * case the labels must also be duplicated.
240 */
241void
242mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest)
243{
244	struct label *src_label, *dest_label;
245
246	src_label = (struct label *)(src+1);
247	dest_label = (struct label *)(dest+1);
248
249	/*
250	 * mac_mbuf_tag_init() is called on the target tag in m_tag_copy(),
251	 * so we don't need to call it here.
252	 */
253	MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
254}
255
256void
257mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to)
258{
259	struct label *src_label, *dest_label;
260
261	if (mac_policy_count == 0)
262		return;
263
264	src_label = mac_mbuf_to_label(m_from);
265	dest_label = mac_mbuf_to_label(m_to);
266
267	MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
268}
269
270static void
271mac_ifnet_copy_label(struct label *src, struct label *dest)
272{
273
274	MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest);
275}
276
277static int
278mac_ifnet_externalize_label(struct label *label, char *elements,
279    char *outbuf, size_t outbuflen)
280{
281	int error;
282
283	MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
284
285	return (error);
286}
287
288static int
289mac_ifnet_internalize_label(struct label *label, char *string)
290{
291	int error;
292
293	MAC_POLICY_INTERNALIZE(ifnet, label, string);
294
295	return (error);
296}
297
298void
299mac_ifnet_create(struct ifnet *ifp)
300{
301
302	if (mac_policy_count == 0)
303		return;
304
305	MAC_IFNET_LOCK(ifp);
306	MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, ifp->if_label);
307	MAC_IFNET_UNLOCK(ifp);
308}
309
310void
311mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d)
312{
313
314	MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label);
315}
316
317void
318mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m)
319{
320	struct label *label;
321
322	/* Assume reader lock is enough. */
323	BPFD_LOCK_ASSERT(d);
324
325	if (mac_policy_count == 0)
326		return;
327
328	label = mac_mbuf_to_label(m);
329
330	MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m,
331	    label);
332}
333
334void
335mac_ifnet_create_mbuf(struct ifnet *ifp, struct mbuf *m)
336{
337	struct label *label;
338
339	if (mac_policy_count == 0)
340		return;
341
342	label = mac_mbuf_to_label(m);
343
344	MAC_IFNET_LOCK(ifp);
345	MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, ifp->if_label, m,
346	    label);
347	MAC_IFNET_UNLOCK(ifp);
348}
349
350MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *",
351    "struct ifnet *");
352
353int
354mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp)
355{
356	int error;
357
358	/* Assume reader lock is enough. */
359	BPFD_LOCK_ASSERT(d);
360
361	if (mac_policy_count == 0)
362		return (0);
363
364	MAC_IFNET_LOCK(ifp);
365	MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp,
366	    ifp->if_label);
367	MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp);
368	MAC_IFNET_UNLOCK(ifp);
369
370	return (error);
371}
372
373MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *",
374    "struct mbuf *");
375
376int
377mac_ifnet_check_transmit(struct ifnet *ifp, struct mbuf *m)
378{
379	struct label *label;
380	int error;
381
382	M_ASSERTPKTHDR(m);
383
384	if (mac_policy_count == 0)
385		return (0);
386
387	label = mac_mbuf_to_label(m);
388
389	MAC_IFNET_LOCK(ifp);
390	MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, ifp->if_label, m,
391	    label);
392	MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m);
393	MAC_IFNET_UNLOCK(ifp);
394
395	return (error);
396}
397
398int
399mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr,
400    struct ifnet *ifp)
401{
402	char *elements, *buffer;
403	struct label *intlabel;
404	struct mac mac;
405	int error;
406
407	if (!(mac_labeled & MPC_OBJECT_IFNET))
408		return (EINVAL);
409
410	error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
411	if (error)
412		return (error);
413
414	error = mac_check_structmac_consistent(&mac);
415	if (error)
416		return (error);
417
418	elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
419	error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
420	if (error) {
421		free(elements, M_MACTEMP);
422		return (error);
423	}
424
425	buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
426	intlabel = mac_ifnet_label_alloc();
427	MAC_IFNET_LOCK(ifp);
428	mac_ifnet_copy_label(ifp->if_label, intlabel);
429	MAC_IFNET_UNLOCK(ifp);
430	error = mac_ifnet_externalize_label(intlabel, elements, buffer,
431	    mac.m_buflen);
432	mac_ifnet_label_free(intlabel);
433	if (error == 0)
434		error = copyout(buffer, mac.m_string, strlen(buffer)+1);
435
436	free(buffer, M_MACTEMP);
437	free(elements, M_MACTEMP);
438
439	return (error);
440}
441
442int
443mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp)
444{
445	struct label *intlabel;
446	struct mac mac;
447	char *buffer;
448	int error;
449
450	if (!(mac_labeled & MPC_OBJECT_IFNET))
451		return (EINVAL);
452
453	error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
454	if (error)
455		return (error);
456
457	error = mac_check_structmac_consistent(&mac);
458	if (error)
459		return (error);
460
461	buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
462	error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
463	if (error) {
464		free(buffer, M_MACTEMP);
465		return (error);
466	}
467
468	intlabel = mac_ifnet_label_alloc();
469	error = mac_ifnet_internalize_label(intlabel, buffer);
470	free(buffer, M_MACTEMP);
471	if (error) {
472		mac_ifnet_label_free(intlabel);
473		return (error);
474	}
475
476	/*
477	 * XXX: Note that this is a redundant privilege check, since policies
478	 * impose this check themselves if required by the policy
479	 * Eventually, this should go away.
480	 */
481	error = priv_check_cred(cred, PRIV_NET_SETIFMAC, 0);
482	if (error) {
483		mac_ifnet_label_free(intlabel);
484		return (error);
485	}
486
487	MAC_IFNET_LOCK(ifp);
488	MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp,
489	    ifp->if_label, intlabel);
490	if (error) {
491		MAC_IFNET_UNLOCK(ifp);
492		mac_ifnet_label_free(intlabel);
493		return (error);
494	}
495
496	MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, ifp->if_label,
497	    intlabel);
498	MAC_IFNET_UNLOCK(ifp);
499
500	mac_ifnet_label_free(intlabel);
501	return (0);
502}
503