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 | |
4f0753e7 | 25 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
5778eabd PM |
26 | * |
27 | */ | |
28 | ||
29 | #include <linux/spinlock.h> | |
30 | #include <linux/rcupdate.h> | |
5a0e3ad6 | 31 | #include <linux/gfp.h> |
014ab19a PM |
32 | #include <linux/ip.h> |
33 | #include <linux/ipv6.h> | |
5778eabd PM |
34 | #include <net/sock.h> |
35 | #include <net/netlabel.h> | |
014ab19a PM |
36 | #include <net/ip.h> |
37 | #include <net/ipv6.h> | |
5778eabd PM |
38 | |
39 | #include "objsec.h" | |
40 | #include "security.h" | |
d4ee4231 | 41 | #include "netlabel.h" |
5778eabd | 42 | |
5dbe1eb0 PM |
43 | /** |
44 | * selinux_netlbl_sidlookup_cached - Cache a SID lookup | |
45 | * @skb: the packet | |
46 | * @secattr: the NetLabel security attributes | |
47 | * @sid: the SID | |
48 | * | |
49 | * Description: | |
50 | * Query the SELinux security server to lookup the correct SID for the given | |
51 | * security attributes. If the query is successful, cache the result to speed | |
52 | * up future lookups. Returns zero on success, negative values on failure. | |
53 | * | |
54 | */ | |
55 | static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, | |
4fee5242 | 56 | u16 family, |
5dbe1eb0 PM |
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)) | |
4fee5242 | 66 | netlbl_cache_add(skb, family, secattr); |
5dbe1eb0 PM |
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 | */ | |
a04e71f6 | 154 | void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway) |
dfaebe98 | 155 | { |
a04e71f6 | 156 | netlbl_skbuff_err(skb, family, error, gateway); |
dfaebe98 PM |
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 | 216 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
4fee5242 HD |
217 | rc = selinux_netlbl_sidlookup_cached(skb, family, |
218 | &secattr, sid); | |
5dbe1eb0 | 219 | else |
5778eabd | 220 | *sid = SECSID_NULL; |
220deb96 | 221 | *type = secattr.type; |
5778eabd PM |
222 | netlbl_secattr_destroy(&secattr); |
223 | ||
224 | return rc; | |
225 | } | |
226 | ||
948bf85c PM |
227 | /** |
228 | * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid | |
229 | * @skb: the packet | |
230 | * @family: protocol family | |
231 | * @sid: the SID | |
232 | * | |
233 | * Description | |
234 | * Call the NetLabel mechanism to set the label of a packet using @sid. | |
af901ca1 | 235 | * Returns zero on success, negative values on failure. |
948bf85c PM |
236 | * |
237 | */ | |
238 | int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, | |
239 | u16 family, | |
240 | u32 sid) | |
241 | { | |
242 | int rc; | |
6c5b3fc0 PM |
243 | struct netlbl_lsm_secattr secattr_storage; |
244 | struct netlbl_lsm_secattr *secattr = NULL; | |
948bf85c PM |
245 | struct sock *sk; |
246 | ||
247 | /* if this is a locally generated packet check to see if it is already | |
248 | * being labeled by it's parent socket, if it is just exit */ | |
54abc686 | 249 | sk = skb_to_full_sk(skb); |
948bf85c PM |
250 | if (sk != NULL) { |
251 | struct sk_security_struct *sksec = sk->sk_security; | |
252 | if (sksec->nlbl_state != NLBL_REQSKB) | |
253 | return 0; | |
050d032b | 254 | secattr = selinux_netlbl_sock_getattr(sk, sid); |
6c5b3fc0 PM |
255 | } |
256 | if (secattr == NULL) { | |
257 | secattr = &secattr_storage; | |
258 | netlbl_secattr_init(secattr); | |
259 | rc = security_netlbl_sid_to_secattr(sid, secattr); | |
260 | if (rc != 0) | |
261 | goto skbuff_setsid_return; | |
948bf85c PM |
262 | } |
263 | ||
6c5b3fc0 | 264 | rc = netlbl_skbuff_setattr(skb, family, secattr); |
948bf85c PM |
265 | |
266 | skbuff_setsid_return: | |
6c5b3fc0 PM |
267 | if (secattr == &secattr_storage) |
268 | netlbl_secattr_destroy(secattr); | |
948bf85c PM |
269 | return rc; |
270 | } | |
271 | ||
5778eabd | 272 | /** |
389fb800 PM |
273 | * selinux_netlbl_inet_conn_request - Label an incoming stream connection |
274 | * @req: incoming connection request socket | |
5778eabd PM |
275 | * |
276 | * Description: | |
389fb800 PM |
277 | * A new incoming connection request is represented by @req, we need to label |
278 | * the new request_sock here and the stack will ensure the on-the-wire label | |
279 | * will get preserved when a full sock is created once the connection handshake | |
280 | * is complete. Returns zero on success, negative values on failure. | |
5778eabd PM |
281 | * |
282 | */ | |
389fb800 | 283 | int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) |
5778eabd | 284 | { |
014ab19a | 285 | int rc; |
389fb800 | 286 | struct netlbl_lsm_secattr secattr; |
014ab19a | 287 | |
e1adea92 | 288 | if (family != PF_INET && family != PF_INET6) |
389fb800 | 289 | return 0; |
014ab19a | 290 | |
389fb800 PM |
291 | netlbl_secattr_init(&secattr); |
292 | rc = security_netlbl_sid_to_secattr(req->secid, &secattr); | |
293 | if (rc != 0) | |
294 | goto inet_conn_request_return; | |
295 | rc = netlbl_req_setattr(req, &secattr); | |
296 | inet_conn_request_return: | |
297 | netlbl_secattr_destroy(&secattr); | |
298 | return rc; | |
5778eabd PM |
299 | } |
300 | ||
301 | /** | |
389fb800 PM |
302 | * selinux_netlbl_inet_csk_clone - Initialize the newly created sock |
303 | * @sk: the new sock | |
5778eabd PM |
304 | * |
305 | * Description: | |
389fb800 PM |
306 | * A new connection has been established using @sk, we've already labeled the |
307 | * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but | |
308 | * we need to set the NetLabel state here since we now have a sock structure. | |
5778eabd PM |
309 | * |
310 | */ | |
389fb800 | 311 | void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) |
5778eabd | 312 | { |
389fb800 PM |
313 | struct sk_security_struct *sksec = sk->sk_security; |
314 | ||
315 | if (family == PF_INET) | |
316 | sksec->nlbl_state = NLBL_LABELED; | |
317 | else | |
318 | sksec->nlbl_state = NLBL_UNSET; | |
5778eabd PM |
319 | } |
320 | ||
321 | /** | |
389fb800 PM |
322 | * selinux_netlbl_socket_post_create - Label a socket using NetLabel |
323 | * @sock: the socket to label | |
324 | * @family: protocol family | |
5778eabd PM |
325 | * |
326 | * Description: | |
389fb800 PM |
327 | * Attempt to label a socket using the NetLabel mechanism using the given |
328 | * SID. Returns zero values on success, negative values on failure. | |
5778eabd PM |
329 | * |
330 | */ | |
389fb800 | 331 | int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) |
5778eabd PM |
332 | { |
333 | int rc; | |
389fb800 PM |
334 | struct sk_security_struct *sksec = sk->sk_security; |
335 | struct netlbl_lsm_secattr *secattr; | |
5778eabd | 336 | |
ceba1832 | 337 | if (family != PF_INET && family != PF_INET6) |
5778eabd | 338 | return 0; |
f74af6e8 | 339 | |
389fb800 PM |
340 | secattr = selinux_netlbl_sock_genattr(sk); |
341 | if (secattr == NULL) | |
342 | return -ENOMEM; | |
343 | rc = netlbl_sock_setattr(sk, family, secattr); | |
344 | switch (rc) { | |
345 | case 0: | |
346 | sksec->nlbl_state = NLBL_LABELED; | |
347 | break; | |
348 | case -EDESTADDRREQ: | |
349 | sksec->nlbl_state = NLBL_REQSKB; | |
f74af6e8 | 350 | rc = 0; |
389fb800 PM |
351 | break; |
352 | } | |
5778eabd PM |
353 | |
354 | return rc; | |
355 | } | |
356 | ||
357 | /** | |
358 | * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel | |
359 | * @sksec: the sock's sk_security_struct | |
360 | * @skb: the packet | |
75e22910 | 361 | * @family: protocol family |
5778eabd PM |
362 | * @ad: the audit data |
363 | * | |
364 | * Description: | |
365 | * Fetch the NetLabel security attributes from @skb and perform an access check | |
366 | * against the receiving socket. Returns zero on success, negative values on | |
367 | * error. | |
368 | * | |
369 | */ | |
370 | int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, | |
371 | struct sk_buff *skb, | |
75e22910 | 372 | u16 family, |
2bf49690 | 373 | struct common_audit_data *ad) |
5778eabd PM |
374 | { |
375 | int rc; | |
f36158c4 PM |
376 | u32 nlbl_sid; |
377 | u32 perm; | |
378 | struct netlbl_lsm_secattr secattr; | |
5778eabd | 379 | |
23bcdc1a PM |
380 | if (!netlbl_enabled()) |
381 | return 0; | |
382 | ||
f36158c4 | 383 | netlbl_secattr_init(&secattr); |
75e22910 | 384 | rc = netlbl_skbuff_getattr(skb, family, &secattr); |
5dbe1eb0 | 385 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
4fee5242 HD |
386 | rc = selinux_netlbl_sidlookup_cached(skb, family, |
387 | &secattr, &nlbl_sid); | |
5dbe1eb0 | 388 | else |
f36158c4 PM |
389 | nlbl_sid = SECINITSID_UNLABELED; |
390 | netlbl_secattr_destroy(&secattr); | |
5778eabd PM |
391 | if (rc != 0) |
392 | return rc; | |
8d9107e8 | 393 | |
5778eabd PM |
394 | switch (sksec->sclass) { |
395 | case SECCLASS_UDP_SOCKET: | |
f36158c4 | 396 | perm = UDP_SOCKET__RECVFROM; |
5778eabd PM |
397 | break; |
398 | case SECCLASS_TCP_SOCKET: | |
f36158c4 | 399 | perm = TCP_SOCKET__RECVFROM; |
5778eabd PM |
400 | break; |
401 | default: | |
f36158c4 | 402 | perm = RAWIP_SOCKET__RECVFROM; |
5778eabd PM |
403 | } |
404 | ||
f36158c4 | 405 | rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad); |
5778eabd PM |
406 | if (rc == 0) |
407 | return 0; | |
408 | ||
f36158c4 | 409 | if (nlbl_sid != SECINITSID_UNLABELED) |
a04e71f6 | 410 | netlbl_skbuff_err(skb, family, rc, 0); |
5778eabd PM |
411 | return rc; |
412 | } | |
413 | ||
1f440c99 HD |
414 | /** |
415 | * selinux_netlbl_option - Is this a NetLabel option | |
416 | * @level: the socket level or protocol | |
417 | * @optname: the socket option name | |
418 | * | |
419 | * Description: | |
420 | * Returns true if @level and @optname refer to a NetLabel option. | |
421 | * Helper for selinux_netlbl_socket_setsockopt(). | |
422 | */ | |
423 | static inline int selinux_netlbl_option(int level, int optname) | |
424 | { | |
425 | return (level == IPPROTO_IP && optname == IP_OPTIONS) || | |
426 | (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS); | |
427 | } | |
428 | ||
5778eabd PM |
429 | /** |
430 | * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel | |
431 | * @sock: the socket | |
432 | * @level: the socket level or protocol | |
433 | * @optname: the socket option name | |
434 | * | |
435 | * Description: | |
436 | * Check the setsockopt() call and if the user is trying to replace the IP | |
437 | * options on a socket and a NetLabel is in place for the socket deny the | |
438 | * access; otherwise allow the access. Returns zero when the access is | |
439 | * allowed, -EACCES when denied, and other negative values on error. | |
440 | * | |
441 | */ | |
442 | int selinux_netlbl_socket_setsockopt(struct socket *sock, | |
443 | int level, | |
444 | int optname) | |
445 | { | |
446 | int rc = 0; | |
ba6ff9f2 PM |
447 | struct sock *sk = sock->sk; |
448 | struct sk_security_struct *sksec = sk->sk_security; | |
5778eabd PM |
449 | struct netlbl_lsm_secattr secattr; |
450 | ||
1f440c99 | 451 | if (selinux_netlbl_option(level, optname) && |
014ab19a PM |
452 | (sksec->nlbl_state == NLBL_LABELED || |
453 | sksec->nlbl_state == NLBL_CONNLABELED)) { | |
5778eabd | 454 | netlbl_secattr_init(&secattr); |
ba6ff9f2 | 455 | lock_sock(sk); |
050d032b PM |
456 | /* call the netlabel function directly as we want to see the |
457 | * on-the-wire label that is assigned via the socket's options | |
458 | * and not the cached netlabel/lsm attributes */ | |
ba6ff9f2 PM |
459 | rc = netlbl_sock_getattr(sk, &secattr); |
460 | release_sock(sk); | |
09c50b4a | 461 | if (rc == 0) |
5778eabd | 462 | rc = -EACCES; |
09c50b4a PM |
463 | else if (rc == -ENOMSG) |
464 | rc = 0; | |
5778eabd PM |
465 | netlbl_secattr_destroy(&secattr); |
466 | } | |
5778eabd PM |
467 | |
468 | return rc; | |
469 | } | |
014ab19a PM |
470 | |
471 | /** | |
472 | * selinux_netlbl_socket_connect - Label a client-side socket on connect | |
473 | * @sk: the socket to label | |
474 | * @addr: the destination address | |
475 | * | |
476 | * Description: | |
477 | * Attempt to label a connected socket with NetLabel using the given address. | |
478 | * Returns zero values on success, negative values on failure. | |
479 | * | |
480 | */ | |
481 | int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) | |
482 | { | |
483 | int rc; | |
484 | struct sk_security_struct *sksec = sk->sk_security; | |
6c5b3fc0 | 485 | struct netlbl_lsm_secattr *secattr; |
014ab19a PM |
486 | |
487 | if (sksec->nlbl_state != NLBL_REQSKB && | |
488 | sksec->nlbl_state != NLBL_CONNLABELED) | |
489 | return 0; | |
490 | ||
42d64e1a | 491 | lock_sock(sk); |
014ab19a PM |
492 | |
493 | /* connected sockets are allowed to disconnect when the address family | |
494 | * is set to AF_UNSPEC, if that is what is happening we want to reset | |
495 | * the socket */ | |
496 | if (addr->sa_family == AF_UNSPEC) { | |
497 | netlbl_sock_delattr(sk); | |
498 | sksec->nlbl_state = NLBL_REQSKB; | |
499 | rc = 0; | |
500 | goto socket_connect_return; | |
501 | } | |
6c5b3fc0 PM |
502 | secattr = selinux_netlbl_sock_genattr(sk); |
503 | if (secattr == NULL) { | |
504 | rc = -ENOMEM; | |
014ab19a | 505 | goto socket_connect_return; |
6c5b3fc0 PM |
506 | } |
507 | rc = netlbl_conn_setattr(sk, addr, secattr); | |
508 | if (rc == 0) | |
509 | sksec->nlbl_state = NLBL_CONNLABELED; | |
014ab19a PM |
510 | |
511 | socket_connect_return: | |
42d64e1a | 512 | release_sock(sk); |
014ab19a PM |
513 | return rc; |
514 | } |