Commit | Line | Data |
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5778eabd PM |
1 | /* |
2 | * SELinux NetLabel Support | |
3 | * | |
4 | * This file provides the necessary glue to tie NetLabel into the SELinux | |
5 | * subsystem. | |
6 | * | |
82c21bfa | 7 | * Author: Paul Moore <paul@paul-moore.com> |
5778eabd PM |
8 | * |
9 | */ | |
10 | ||
11 | /* | |
948bf85c | 12 | * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008 |
5778eabd PM |
13 | * |
14 | * This program is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU General Public License as published by | |
16 | * the Free Software Foundation; either version 2 of the License, or | |
17 | * (at your option) any later version. | |
18 | * | |
19 | * This program is distributed in the hope that it will be useful, | |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | |
22 | * the GNU General Public License for more details. | |
23 | * | |
24 | * You should have received a copy of the GNU General Public License | |
25 | * along with this program; if not, write to the Free Software | |
26 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
27 | * | |
28 | */ | |
29 | ||
30 | #include <linux/spinlock.h> | |
31 | #include <linux/rcupdate.h> | |
5a0e3ad6 | 32 | #include <linux/gfp.h> |
014ab19a PM |
33 | #include <linux/ip.h> |
34 | #include <linux/ipv6.h> | |
5778eabd PM |
35 | #include <net/sock.h> |
36 | #include <net/netlabel.h> | |
014ab19a PM |
37 | #include <net/ip.h> |
38 | #include <net/ipv6.h> | |
5778eabd PM |
39 | |
40 | #include "objsec.h" | |
41 | #include "security.h" | |
d4ee4231 | 42 | #include "netlabel.h" |
5778eabd | 43 | |
5dbe1eb0 PM |
44 | /** |
45 | * selinux_netlbl_sidlookup_cached - Cache a SID lookup | |
46 | * @skb: the packet | |
47 | * @secattr: the NetLabel security attributes | |
48 | * @sid: the SID | |
49 | * | |
50 | * Description: | |
51 | * Query the SELinux security server to lookup the correct SID for the given | |
52 | * security attributes. If the query is successful, cache the result to speed | |
53 | * up future lookups. Returns zero on success, negative values on failure. | |
54 | * | |
55 | */ | |
56 | static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, | |
57 | struct netlbl_lsm_secattr *secattr, | |
58 | u32 *sid) | |
59 | { | |
60 | int rc; | |
61 | ||
62 | rc = security_netlbl_secattr_to_sid(secattr, sid); | |
63 | if (rc == 0 && | |
64 | (secattr->flags & NETLBL_SECATTR_CACHEABLE) && | |
65 | (secattr->flags & NETLBL_SECATTR_CACHE)) | |
66 | netlbl_cache_add(skb, secattr); | |
67 | ||
68 | return rc; | |
69 | } | |
70 | ||
6c5b3fc0 PM |
71 | /** |
72 | * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr | |
73 | * @sk: the socket | |
74 | * | |
75 | * Description: | |
76 | * Generate the NetLabel security attributes for a socket, making full use of | |
77 | * the socket's attribute cache. Returns a pointer to the security attributes | |
78 | * on success, NULL on failure. | |
79 | * | |
80 | */ | |
81 | static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) | |
82 | { | |
83 | int rc; | |
84 | struct sk_security_struct *sksec = sk->sk_security; | |
85 | struct netlbl_lsm_secattr *secattr; | |
86 | ||
87 | if (sksec->nlbl_secattr != NULL) | |
88 | return sksec->nlbl_secattr; | |
89 | ||
90 | secattr = netlbl_secattr_alloc(GFP_ATOMIC); | |
91 | if (secattr == NULL) | |
92 | return NULL; | |
93 | rc = security_netlbl_sid_to_secattr(sksec->sid, secattr); | |
94 | if (rc != 0) { | |
95 | netlbl_secattr_free(secattr); | |
96 | return NULL; | |
97 | } | |
98 | sksec->nlbl_secattr = secattr; | |
99 | ||
100 | return secattr; | |
101 | } | |
102 | ||
050d032b PM |
103 | /** |
104 | * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr | |
105 | * @sk: the socket | |
106 | * @sid: the SID | |
107 | * | |
108 | * Query the socket's cached secattr and if the SID matches the cached value | |
109 | * return the cache, otherwise return NULL. | |
110 | * | |
111 | */ | |
112 | static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( | |
113 | const struct sock *sk, | |
114 | u32 sid) | |
115 | { | |
116 | struct sk_security_struct *sksec = sk->sk_security; | |
117 | struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; | |
118 | ||
119 | if (secattr == NULL) | |
120 | return NULL; | |
121 | ||
122 | if ((secattr->flags & NETLBL_SECATTR_SECID) && | |
123 | (secattr->attr.secid == sid)) | |
124 | return secattr; | |
125 | ||
126 | return NULL; | |
127 | } | |
128 | ||
5778eabd PM |
129 | /** |
130 | * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache | |
131 | * | |
132 | * Description: | |
133 | * Invalidate the NetLabel security attribute mapping cache. | |
134 | * | |
135 | */ | |
136 | void selinux_netlbl_cache_invalidate(void) | |
137 | { | |
138 | netlbl_cache_invalidate(); | |
139 | } | |
140 | ||
dfaebe98 PM |
141 | /** |
142 | * selinux_netlbl_err - Handle a NetLabel packet error | |
143 | * @skb: the packet | |
144 | * @error: the error code | |
145 | * @gateway: true if host is acting as a gateway, false otherwise | |
146 | * | |
147 | * Description: | |
148 | * When a packet is dropped due to a call to avc_has_perm() pass the error | |
149 | * code to the NetLabel subsystem so any protocol specific processing can be | |
150 | * done. This is safe to call even if you are unsure if NetLabel labeling is | |
151 | * present on the packet, NetLabel is smart enough to only act when it should. | |
152 | * | |
153 | */ | |
154 | void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway) | |
155 | { | |
156 | netlbl_skbuff_err(skb, error, gateway); | |
157 | } | |
158 | ||
6c5b3fc0 PM |
159 | /** |
160 | * selinux_netlbl_sk_security_free - Free the NetLabel fields | |
dd3e7836 | 161 | * @sksec: the sk_security_struct |
6c5b3fc0 PM |
162 | * |
163 | * Description: | |
164 | * Free all of the memory in the NetLabel fields of a sk_security_struct. | |
165 | * | |
166 | */ | |
dd3e7836 | 167 | void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec) |
6c5b3fc0 | 168 | { |
dd3e7836 EP |
169 | if (sksec->nlbl_secattr != NULL) |
170 | netlbl_secattr_free(sksec->nlbl_secattr); | |
6c5b3fc0 PM |
171 | } |
172 | ||
5778eabd PM |
173 | /** |
174 | * selinux_netlbl_sk_security_reset - Reset the NetLabel fields | |
dd3e7836 | 175 | * @sksec: the sk_security_struct |
5778eabd PM |
176 | * @family: the socket family |
177 | * | |
178 | * Description: | |
179 | * Called when the NetLabel state of a sk_security_struct needs to be reset. | |
25985edc | 180 | * The caller is responsible for all the NetLabel sk_security_struct locking. |
5778eabd PM |
181 | * |
182 | */ | |
dd3e7836 | 183 | void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec) |
5778eabd | 184 | { |
dd3e7836 | 185 | sksec->nlbl_state = NLBL_UNSET; |
5778eabd PM |
186 | } |
187 | ||
5778eabd PM |
188 | /** |
189 | * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel | |
190 | * @skb: the packet | |
75e22910 | 191 | * @family: protocol family |
220deb96 | 192 | * @type: NetLabel labeling protocol type |
5778eabd PM |
193 | * @sid: the SID |
194 | * | |
195 | * Description: | |
196 | * Call the NetLabel mechanism to get the security attributes of the given | |
197 | * packet and use those attributes to determine the correct context/SID to | |
198 | * assign to the packet. Returns zero on success, negative values on failure. | |
199 | * | |
200 | */ | |
75e22910 PM |
201 | int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, |
202 | u16 family, | |
220deb96 | 203 | u32 *type, |
75e22910 | 204 | u32 *sid) |
5778eabd PM |
205 | { |
206 | int rc; | |
207 | struct netlbl_lsm_secattr secattr; | |
208 | ||
23bcdc1a PM |
209 | if (!netlbl_enabled()) { |
210 | *sid = SECSID_NULL; | |
211 | return 0; | |
212 | } | |
213 | ||
5778eabd | 214 | netlbl_secattr_init(&secattr); |
75e22910 | 215 | rc = netlbl_skbuff_getattr(skb, family, &secattr); |
5dbe1eb0 PM |
216 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
217 | rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid); | |
218 | else | |
5778eabd | 219 | *sid = SECSID_NULL; |
220deb96 | 220 | *type = secattr.type; |
5778eabd PM |
221 | netlbl_secattr_destroy(&secattr); |
222 | ||
223 | return rc; | |
224 | } | |
225 | ||
948bf85c PM |
226 | /** |
227 | * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid | |
228 | * @skb: the packet | |
229 | * @family: protocol family | |
230 | * @sid: the SID | |
231 | * | |
232 | * Description | |
233 | * Call the NetLabel mechanism to set the label of a packet using @sid. | |
af901ca1 | 234 | * Returns zero on success, negative values on failure. |
948bf85c PM |
235 | * |
236 | */ | |
237 | int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, | |
238 | u16 family, | |
239 | u32 sid) | |
240 | { | |
241 | int rc; | |
6c5b3fc0 PM |
242 | struct netlbl_lsm_secattr secattr_storage; |
243 | struct netlbl_lsm_secattr *secattr = NULL; | |
948bf85c PM |
244 | struct sock *sk; |
245 | ||
246 | /* if this is a locally generated packet check to see if it is already | |
247 | * being labeled by it's parent socket, if it is just exit */ | |
248 | sk = skb->sk; | |
249 | if (sk != NULL) { | |
250 | struct sk_security_struct *sksec = sk->sk_security; | |
251 | if (sksec->nlbl_state != NLBL_REQSKB) | |
252 | return 0; | |
050d032b | 253 | secattr = selinux_netlbl_sock_getattr(sk, sid); |
6c5b3fc0 PM |
254 | } |
255 | if (secattr == NULL) { | |
256 | secattr = &secattr_storage; | |
257 | netlbl_secattr_init(secattr); | |
258 | rc = security_netlbl_sid_to_secattr(sid, secattr); | |
259 | if (rc != 0) | |
260 | goto skbuff_setsid_return; | |
948bf85c PM |
261 | } |
262 | ||
6c5b3fc0 | 263 | rc = netlbl_skbuff_setattr(skb, family, secattr); |
948bf85c PM |
264 | |
265 | skbuff_setsid_return: | |
6c5b3fc0 PM |
266 | if (secattr == &secattr_storage) |
267 | netlbl_secattr_destroy(secattr); | |
948bf85c PM |
268 | return rc; |
269 | } | |
270 | ||
5778eabd | 271 | /** |
389fb800 PM |
272 | * selinux_netlbl_inet_conn_request - Label an incoming stream connection |
273 | * @req: incoming connection request socket | |
5778eabd PM |
274 | * |
275 | * Description: | |
389fb800 PM |
276 | * A new incoming connection request is represented by @req, we need to label |
277 | * the new request_sock here and the stack will ensure the on-the-wire label | |
278 | * will get preserved when a full sock is created once the connection handshake | |
279 | * is complete. Returns zero on success, negative values on failure. | |
5778eabd PM |
280 | * |
281 | */ | |
389fb800 | 282 | int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) |
5778eabd | 283 | { |
014ab19a | 284 | int rc; |
389fb800 | 285 | struct netlbl_lsm_secattr secattr; |
014ab19a | 286 | |
389fb800 PM |
287 | if (family != PF_INET) |
288 | return 0; | |
014ab19a | 289 | |
389fb800 PM |
290 | netlbl_secattr_init(&secattr); |
291 | rc = security_netlbl_sid_to_secattr(req->secid, &secattr); | |
292 | if (rc != 0) | |
293 | goto inet_conn_request_return; | |
294 | rc = netlbl_req_setattr(req, &secattr); | |
295 | inet_conn_request_return: | |
296 | netlbl_secattr_destroy(&secattr); | |
297 | return rc; | |
5778eabd PM |
298 | } |
299 | ||
300 | /** | |
389fb800 PM |
301 | * selinux_netlbl_inet_csk_clone - Initialize the newly created sock |
302 | * @sk: the new sock | |
5778eabd PM |
303 | * |
304 | * Description: | |
389fb800 PM |
305 | * A new connection has been established using @sk, we've already labeled the |
306 | * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but | |
307 | * we need to set the NetLabel state here since we now have a sock structure. | |
5778eabd PM |
308 | * |
309 | */ | |
389fb800 | 310 | void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) |
5778eabd | 311 | { |
389fb800 PM |
312 | struct sk_security_struct *sksec = sk->sk_security; |
313 | ||
314 | if (family == PF_INET) | |
315 | sksec->nlbl_state = NLBL_LABELED; | |
316 | else | |
317 | sksec->nlbl_state = NLBL_UNSET; | |
5778eabd PM |
318 | } |
319 | ||
320 | /** | |
389fb800 PM |
321 | * selinux_netlbl_socket_post_create - Label a socket using NetLabel |
322 | * @sock: the socket to label | |
323 | * @family: protocol family | |
5778eabd PM |
324 | * |
325 | * Description: | |
389fb800 PM |
326 | * Attempt to label a socket using the NetLabel mechanism using the given |
327 | * SID. Returns zero values on success, negative values on failure. | |
5778eabd PM |
328 | * |
329 | */ | |
389fb800 | 330 | int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) |
5778eabd PM |
331 | { |
332 | int rc; | |
389fb800 PM |
333 | struct sk_security_struct *sksec = sk->sk_security; |
334 | struct netlbl_lsm_secattr *secattr; | |
5778eabd | 335 | |
389fb800 | 336 | if (family != PF_INET) |
5778eabd | 337 | return 0; |
f74af6e8 | 338 | |
389fb800 PM |
339 | secattr = selinux_netlbl_sock_genattr(sk); |
340 | if (secattr == NULL) | |
341 | return -ENOMEM; | |
342 | rc = netlbl_sock_setattr(sk, family, secattr); | |
343 | switch (rc) { | |
344 | case 0: | |
345 | sksec->nlbl_state = NLBL_LABELED; | |
346 | break; | |
347 | case -EDESTADDRREQ: | |
348 | sksec->nlbl_state = NLBL_REQSKB; | |
f74af6e8 | 349 | rc = 0; |
389fb800 PM |
350 | break; |
351 | } | |
5778eabd PM |
352 | |
353 | return rc; | |
354 | } | |
355 | ||
356 | /** | |
357 | * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel | |
358 | * @sksec: the sock's sk_security_struct | |
359 | * @skb: the packet | |
75e22910 | 360 | * @family: protocol family |
5778eabd PM |
361 | * @ad: the audit data |
362 | * | |
363 | * Description: | |
364 | * Fetch the NetLabel security attributes from @skb and perform an access check | |
365 | * against the receiving socket. Returns zero on success, negative values on | |
366 | * error. | |
367 | * | |
368 | */ | |
369 | int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, | |
370 | struct sk_buff *skb, | |
75e22910 | 371 | u16 family, |
2bf49690 | 372 | struct common_audit_data *ad) |
5778eabd PM |
373 | { |
374 | int rc; | |
f36158c4 PM |
375 | u32 nlbl_sid; |
376 | u32 perm; | |
377 | struct netlbl_lsm_secattr secattr; | |
5778eabd | 378 | |
23bcdc1a PM |
379 | if (!netlbl_enabled()) |
380 | return 0; | |
381 | ||
f36158c4 | 382 | netlbl_secattr_init(&secattr); |
75e22910 | 383 | rc = netlbl_skbuff_getattr(skb, family, &secattr); |
5dbe1eb0 PM |
384 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
385 | rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid); | |
386 | else | |
f36158c4 PM |
387 | nlbl_sid = SECINITSID_UNLABELED; |
388 | netlbl_secattr_destroy(&secattr); | |
5778eabd PM |
389 | if (rc != 0) |
390 | return rc; | |
8d9107e8 | 391 | |
5778eabd PM |
392 | switch (sksec->sclass) { |
393 | case SECCLASS_UDP_SOCKET: | |
f36158c4 | 394 | perm = UDP_SOCKET__RECVFROM; |
5778eabd PM |
395 | break; |
396 | case SECCLASS_TCP_SOCKET: | |
f36158c4 | 397 | perm = TCP_SOCKET__RECVFROM; |
5778eabd PM |
398 | break; |
399 | default: | |
f36158c4 | 400 | perm = RAWIP_SOCKET__RECVFROM; |
5778eabd PM |
401 | } |
402 | ||
f36158c4 | 403 | rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad); |
5778eabd PM |
404 | if (rc == 0) |
405 | return 0; | |
406 | ||
f36158c4 | 407 | if (nlbl_sid != SECINITSID_UNLABELED) |
dfaebe98 | 408 | netlbl_skbuff_err(skb, rc, 0); |
5778eabd PM |
409 | return rc; |
410 | } | |
411 | ||
412 | /** | |
413 | * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel | |
414 | * @sock: the socket | |
415 | * @level: the socket level or protocol | |
416 | * @optname: the socket option name | |
417 | * | |
418 | * Description: | |
419 | * Check the setsockopt() call and if the user is trying to replace the IP | |
420 | * options on a socket and a NetLabel is in place for the socket deny the | |
421 | * access; otherwise allow the access. Returns zero when the access is | |
422 | * allowed, -EACCES when denied, and other negative values on error. | |
423 | * | |
424 | */ | |
425 | int selinux_netlbl_socket_setsockopt(struct socket *sock, | |
426 | int level, | |
427 | int optname) | |
428 | { | |
429 | int rc = 0; | |
ba6ff9f2 PM |
430 | struct sock *sk = sock->sk; |
431 | struct sk_security_struct *sksec = sk->sk_security; | |
5778eabd PM |
432 | struct netlbl_lsm_secattr secattr; |
433 | ||
5778eabd | 434 | if (level == IPPROTO_IP && optname == IP_OPTIONS && |
014ab19a PM |
435 | (sksec->nlbl_state == NLBL_LABELED || |
436 | sksec->nlbl_state == NLBL_CONNLABELED)) { | |
5778eabd | 437 | netlbl_secattr_init(&secattr); |
ba6ff9f2 | 438 | lock_sock(sk); |
050d032b PM |
439 | /* call the netlabel function directly as we want to see the |
440 | * on-the-wire label that is assigned via the socket's options | |
441 | * and not the cached netlabel/lsm attributes */ | |
ba6ff9f2 PM |
442 | rc = netlbl_sock_getattr(sk, &secattr); |
443 | release_sock(sk); | |
09c50b4a | 444 | if (rc == 0) |
5778eabd | 445 | rc = -EACCES; |
09c50b4a PM |
446 | else if (rc == -ENOMSG) |
447 | rc = 0; | |
5778eabd PM |
448 | netlbl_secattr_destroy(&secattr); |
449 | } | |
5778eabd PM |
450 | |
451 | return rc; | |
452 | } | |
014ab19a PM |
453 | |
454 | /** | |
455 | * selinux_netlbl_socket_connect - Label a client-side socket on connect | |
456 | * @sk: the socket to label | |
457 | * @addr: the destination address | |
458 | * | |
459 | * Description: | |
460 | * Attempt to label a connected socket with NetLabel using the given address. | |
461 | * Returns zero values on success, negative values on failure. | |
462 | * | |
463 | */ | |
464 | int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) | |
465 | { | |
466 | int rc; | |
467 | struct sk_security_struct *sksec = sk->sk_security; | |
6c5b3fc0 | 468 | struct netlbl_lsm_secattr *secattr; |
014ab19a PM |
469 | |
470 | if (sksec->nlbl_state != NLBL_REQSKB && | |
471 | sksec->nlbl_state != NLBL_CONNLABELED) | |
472 | return 0; | |
473 | ||
42d64e1a | 474 | lock_sock(sk); |
014ab19a PM |
475 | |
476 | /* connected sockets are allowed to disconnect when the address family | |
477 | * is set to AF_UNSPEC, if that is what is happening we want to reset | |
478 | * the socket */ | |
479 | if (addr->sa_family == AF_UNSPEC) { | |
480 | netlbl_sock_delattr(sk); | |
481 | sksec->nlbl_state = NLBL_REQSKB; | |
482 | rc = 0; | |
483 | goto socket_connect_return; | |
484 | } | |
6c5b3fc0 PM |
485 | secattr = selinux_netlbl_sock_genattr(sk); |
486 | if (secattr == NULL) { | |
487 | rc = -ENOMEM; | |
014ab19a | 488 | goto socket_connect_return; |
6c5b3fc0 PM |
489 | } |
490 | rc = netlbl_conn_setattr(sk, addr, secattr); | |
491 | if (rc == 0) | |
492 | sksec->nlbl_state = NLBL_CONNLABELED; | |
014ab19a PM |
493 | |
494 | socket_connect_return: | |
42d64e1a | 495 | release_sock(sk); |
014ab19a PM |
496 | return rc; |
497 | } |