xref: /freebsd/sys/security/mac/mac_inet.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
1 /*-
2  * Copyright (c) 1999-2002, 2007, 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 developed for the FreeBSD Project in part by Network
13  * Associates Laboratories, the Security Research Division of Network
14  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
15  * as part of the DARPA CHATS research program.
16  *
17  * This software was enhanced by SPARTA ISSO under SPAWAR contract
18  * N66001-04-C-6019 ("SEFOS").
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_mac.h"
49 
50 #include <sys/param.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mutex.h>
55 #include <sys/sbuf.h>
56 #include <sys/sdt.h>
57 #include <sys/systm.h>
58 #include <sys/mount.h>
59 #include <sys/file.h>
60 #include <sys/namei.h>
61 #include <sys/protosw.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/sysctl.h>
65 
66 #include <net/if.h>
67 #include <net/if_var.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/in_pcb.h>
71 #include <netinet/ip_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 static struct label *
78 mac_inpcb_label_alloc(int flag)
79 {
80 	struct label *label;
81 	int error;
82 
83 	label = mac_labelzone_alloc(flag);
84 	if (label == NULL)
85 		return (NULL);
86 	if (flag & M_WAITOK)
87 		MAC_POLICY_CHECK(inpcb_init_label, label, flag);
88 	else
89 		MAC_POLICY_CHECK_NOSLEEP(inpcb_init_label, label, flag);
90 	if (error) {
91 		MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
92 		mac_labelzone_free(label);
93 		return (NULL);
94 	}
95 	return (label);
96 }
97 
98 int
99 mac_inpcb_init(struct inpcb *inp, int flag)
100 {
101 
102 	if (mac_labeled & MPC_OBJECT_INPCB) {
103 		inp->inp_label = mac_inpcb_label_alloc(flag);
104 		if (inp->inp_label == NULL)
105 			return (ENOMEM);
106 	} else
107 		inp->inp_label = NULL;
108 	return (0);
109 }
110 
111 static struct label *
112 mac_ipq_label_alloc(int flag)
113 {
114 	struct label *label;
115 	int error;
116 
117 	label = mac_labelzone_alloc(flag);
118 	if (label == NULL)
119 		return (NULL);
120 
121 	if (flag & M_WAITOK)
122 		MAC_POLICY_CHECK(ipq_init_label, label, flag);
123 	else
124 		MAC_POLICY_CHECK_NOSLEEP(ipq_init_label, label, flag);
125 	if (error) {
126 		MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
127 		mac_labelzone_free(label);
128 		return (NULL);
129 	}
130 	return (label);
131 }
132 
133 int
134 mac_ipq_init(struct ipq *q, int flag)
135 {
136 
137 	if (mac_labeled & MPC_OBJECT_IPQ) {
138 		q->ipq_label = mac_ipq_label_alloc(flag);
139 		if (q->ipq_label == NULL)
140 			return (ENOMEM);
141 	} else
142 		q->ipq_label = NULL;
143 	return (0);
144 }
145 
146 static void
147 mac_inpcb_label_free(struct label *label)
148 {
149 
150 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
151 	mac_labelzone_free(label);
152 }
153 
154 void
155 mac_inpcb_destroy(struct inpcb *inp)
156 {
157 
158 	if (inp->inp_label != NULL) {
159 		mac_inpcb_label_free(inp->inp_label);
160 		inp->inp_label = NULL;
161 	}
162 }
163 
164 static void
165 mac_ipq_label_free(struct label *label)
166 {
167 
168 	MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
169 	mac_labelzone_free(label);
170 }
171 
172 void
173 mac_ipq_destroy(struct ipq *q)
174 {
175 
176 	if (q->ipq_label != NULL) {
177 		mac_ipq_label_free(q->ipq_label);
178 		q->ipq_label = NULL;
179 	}
180 }
181 
182 void
183 mac_inpcb_create(struct socket *so, struct inpcb *inp)
184 {
185 
186 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_create, so, so->so_label, inp,
187 	    inp->inp_label);
188 }
189 
190 void
191 mac_ipq_reassemble(struct ipq *q, struct mbuf *m)
192 {
193 	struct label *label;
194 
195 	if (mac_policy_count == 0)
196 		return;
197 
198 	label = mac_mbuf_to_label(m);
199 
200 	MAC_POLICY_PERFORM_NOSLEEP(ipq_reassemble, q, q->ipq_label, m,
201 	    label);
202 }
203 
204 void
205 mac_netinet_fragment(struct mbuf *m, struct mbuf *frag)
206 {
207 	struct label *mlabel, *fraglabel;
208 
209 	if (mac_policy_count == 0)
210 		return;
211 
212 	mlabel = mac_mbuf_to_label(m);
213 	fraglabel = mac_mbuf_to_label(frag);
214 
215 	MAC_POLICY_PERFORM_NOSLEEP(netinet_fragment, m, mlabel, frag,
216 	    fraglabel);
217 }
218 
219 void
220 mac_ipq_create(struct mbuf *m, struct ipq *q)
221 {
222 	struct label *label;
223 
224 	if (mac_policy_count == 0)
225 		return;
226 
227 	label = mac_mbuf_to_label(m);
228 
229 	MAC_POLICY_PERFORM_NOSLEEP(ipq_create, m, label, q, q->ipq_label);
230 }
231 
232 void
233 mac_inpcb_create_mbuf(struct inpcb *inp, struct mbuf *m)
234 {
235 	struct label *mlabel;
236 
237 	INP_LOCK_ASSERT(inp);
238 
239 	if (mac_policy_count == 0)
240 		return;
241 
242 	mlabel = mac_mbuf_to_label(m);
243 
244 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_create_mbuf, inp, inp->inp_label, m,
245 	    mlabel);
246 }
247 
248 int
249 mac_ipq_match(struct mbuf *m, struct ipq *q)
250 {
251 	struct label *label;
252 	int result;
253 
254 	if (mac_policy_count == 0)
255 		return (1);
256 
257 	label = mac_mbuf_to_label(m);
258 
259 	result = 1;
260 	MAC_POLICY_BOOLEAN_NOSLEEP(ipq_match, &&, m, label, q, q->ipq_label);
261 
262 	return (result);
263 }
264 
265 void
266 mac_netinet_arp_send(struct ifnet *ifp, struct mbuf *m)
267 {
268 	struct label *mlabel;
269 
270 	if (mac_policy_count == 0)
271 		return;
272 
273 	mlabel = mac_mbuf_to_label(m);
274 
275 	MAC_IFNET_LOCK(ifp);
276 	MAC_POLICY_PERFORM_NOSLEEP(netinet_arp_send, ifp, ifp->if_label, m,
277 	    mlabel);
278 	MAC_IFNET_UNLOCK(ifp);
279 }
280 
281 void
282 mac_netinet_icmp_reply(struct mbuf *mrecv, struct mbuf *msend)
283 {
284 	struct label *mrecvlabel, *msendlabel;
285 
286 	if (mac_policy_count == 0)
287 		return;
288 
289 	mrecvlabel = mac_mbuf_to_label(mrecv);
290 	msendlabel = mac_mbuf_to_label(msend);
291 
292 	MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_reply, mrecv, mrecvlabel,
293 	    msend, msendlabel);
294 }
295 
296 void
297 mac_netinet_icmp_replyinplace(struct mbuf *m)
298 {
299 	struct label *label;
300 
301 	if (mac_policy_count == 0)
302 		return;
303 
304 	label = mac_mbuf_to_label(m);
305 
306 	MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_replyinplace, m, label);
307 }
308 
309 void
310 mac_netinet_igmp_send(struct ifnet *ifp, struct mbuf *m)
311 {
312 	struct label *mlabel;
313 
314 	if (mac_policy_count == 0)
315 		return;
316 
317 	mlabel = mac_mbuf_to_label(m);
318 
319 	MAC_IFNET_LOCK(ifp);
320 	MAC_POLICY_PERFORM_NOSLEEP(netinet_igmp_send, ifp, ifp->if_label, m,
321 	    mlabel);
322 	MAC_IFNET_UNLOCK(ifp);
323 }
324 
325 void
326 mac_netinet_tcp_reply(struct mbuf *m)
327 {
328 	struct label *label;
329 
330 	if (mac_policy_count == 0)
331 		return;
332 
333 	label = mac_mbuf_to_label(m);
334 
335 	MAC_POLICY_PERFORM_NOSLEEP(netinet_tcp_reply, m, label);
336 }
337 
338 void
339 mac_ipq_update(struct mbuf *m, struct ipq *q)
340 {
341 	struct label *label;
342 
343 	if (mac_policy_count == 0)
344 		return;
345 
346 	label = mac_mbuf_to_label(m);
347 
348 	MAC_POLICY_PERFORM_NOSLEEP(ipq_update, m, label, q, q->ipq_label);
349 }
350 
351 MAC_CHECK_PROBE_DEFINE2(inpcb_check_deliver, "struct inpcb *",
352     "struct mbuf *");
353 
354 int
355 mac_inpcb_check_deliver(struct inpcb *inp, struct mbuf *m)
356 {
357 	struct label *label;
358 	int error;
359 
360 	M_ASSERTPKTHDR(m);
361 
362 	if (mac_policy_count == 0)
363 		return (0);
364 
365 	label = mac_mbuf_to_label(m);
366 
367 	MAC_POLICY_CHECK_NOSLEEP(inpcb_check_deliver, inp, inp->inp_label, m,
368 	    label);
369 	MAC_CHECK_PROBE2(inpcb_check_deliver, error, inp, m);
370 
371 	return (error);
372 }
373 
374 MAC_CHECK_PROBE_DEFINE2(inpcb_check_visible, "struct ucred *",
375     "struct inpcb *");
376 
377 int
378 mac_inpcb_check_visible(struct ucred *cred, struct inpcb *inp)
379 {
380 	int error;
381 
382 	INP_LOCK_ASSERT(inp);
383 
384 	MAC_POLICY_CHECK_NOSLEEP(inpcb_check_visible, cred, inp,
385 	    inp->inp_label);
386 	MAC_CHECK_PROBE2(inpcb_check_visible, error, cred, inp);
387 
388 	return (error);
389 }
390 
391 void
392 mac_inpcb_sosetlabel(struct socket *so, struct inpcb *inp)
393 {
394 
395 	INP_WLOCK_ASSERT(inp);
396 	SOCK_LOCK_ASSERT(so);
397 
398 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_sosetlabel, so, so->so_label, inp,
399 	    inp->inp_label);
400 }
401 
402 void
403 mac_netinet_firewall_reply(struct mbuf *mrecv, struct mbuf *msend)
404 {
405 	struct label *mrecvlabel, *msendlabel;
406 
407 	M_ASSERTPKTHDR(mrecv);
408 	M_ASSERTPKTHDR(msend);
409 
410 	if (mac_policy_count == 0)
411 		return;
412 
413 	mrecvlabel = mac_mbuf_to_label(mrecv);
414 	msendlabel = mac_mbuf_to_label(msend);
415 
416 	MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_reply, mrecv, mrecvlabel,
417 	    msend, msendlabel);
418 }
419 
420 void
421 mac_netinet_firewall_send(struct mbuf *m)
422 {
423 	struct label *label;
424 
425 	M_ASSERTPKTHDR(m);
426 
427 	if (mac_policy_count == 0)
428 		return;
429 
430 	label = mac_mbuf_to_label(m);
431 
432 	MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_send, m, label);
433 }
434 
435 /*
436  * These functions really should be referencing the syncache structure
437  * instead of the label.  However, due to some of the complexities associated
438  * with exposing this syncache structure we operate directly on it's label
439  * pointer.  This should be OK since we aren't making any access control
440  * decisions within this code directly, we are merely allocating and copying
441  * label storage so we can properly initialize mbuf labels for any packets
442  * the syncache code might create.
443  */
444 void
445 mac_syncache_destroy(struct label **label)
446 {
447 
448 	if (*label != NULL) {
449 		MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label, *label);
450 		mac_labelzone_free(*label);
451 		*label = NULL;
452 	}
453 }
454 
455 int
456 mac_syncache_init(struct label **label)
457 {
458 	int error;
459 
460 	if (mac_labeled & MPC_OBJECT_SYNCACHE) {
461 		*label = mac_labelzone_alloc(M_NOWAIT);
462 		if (*label == NULL)
463 			return (ENOMEM);
464 		/*
465 		 * Since we are holding the inpcb locks the policy can not
466 		 * allocate policy specific label storage using M_WAITOK.  So
467 		 * we need to do a MAC_CHECK instead of the typical
468 		 * MAC_PERFORM so we can propagate allocation failures back
469 		 * to the syncache code.
470 		 */
471 		MAC_POLICY_CHECK_NOSLEEP(syncache_init_label, *label,
472 		    M_NOWAIT);
473 		if (error) {
474 			MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label,
475 			    *label);
476 			mac_labelzone_free(*label);
477 		}
478 		return (error);
479 	} else
480 		*label = NULL;
481 	return (0);
482 }
483 
484 void
485 mac_syncache_create(struct label *label, struct inpcb *inp)
486 {
487 
488 	INP_WLOCK_ASSERT(inp);
489 
490 	MAC_POLICY_PERFORM_NOSLEEP(syncache_create, label, inp);
491 }
492 
493 void
494 mac_syncache_create_mbuf(struct label *sc_label, struct mbuf *m)
495 {
496 	struct label *mlabel;
497 
498 	M_ASSERTPKTHDR(m);
499 
500 	if (mac_policy_count == 0)
501 		return;
502 
503 	mlabel = mac_mbuf_to_label(m);
504 
505 	MAC_POLICY_PERFORM_NOSLEEP(syncache_create_mbuf, sc_label, m,
506 	    mlabel);
507 }
508