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 | * | |
7 | * Author: Paul Moore <paul.moore@hp.com> | |
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> | |
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, | |
56 | struct netlbl_lsm_secattr *secattr, | |
57 | u32 *sid) | |
58 | { | |
59 | int rc; | |
60 | ||
61 | rc = security_netlbl_secattr_to_sid(secattr, sid); | |
62 | if (rc == 0 && | |
63 | (secattr->flags & NETLBL_SECATTR_CACHEABLE) && | |
64 | (secattr->flags & NETLBL_SECATTR_CACHE)) | |
65 | netlbl_cache_add(skb, secattr); | |
66 | ||
67 | return rc; | |
68 | } | |
69 | ||
6c5b3fc0 PM |
70 | /** |
71 | * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr | |
72 | * @sk: the socket | |
73 | * | |
74 | * Description: | |
75 | * Generate the NetLabel security attributes for a socket, making full use of | |
76 | * the socket's attribute cache. Returns a pointer to the security attributes | |
77 | * on success, NULL on failure. | |
78 | * | |
79 | */ | |
80 | static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) | |
81 | { | |
82 | int rc; | |
83 | struct sk_security_struct *sksec = sk->sk_security; | |
84 | struct netlbl_lsm_secattr *secattr; | |
85 | ||
86 | if (sksec->nlbl_secattr != NULL) | |
87 | return sksec->nlbl_secattr; | |
88 | ||
89 | secattr = netlbl_secattr_alloc(GFP_ATOMIC); | |
90 | if (secattr == NULL) | |
91 | return NULL; | |
92 | rc = security_netlbl_sid_to_secattr(sksec->sid, secattr); | |
93 | if (rc != 0) { | |
94 | netlbl_secattr_free(secattr); | |
95 | return NULL; | |
96 | } | |
97 | sksec->nlbl_secattr = secattr; | |
98 | ||
99 | return secattr; | |
100 | } | |
101 | ||
5778eabd PM |
102 | /** |
103 | * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache | |
104 | * | |
105 | * Description: | |
106 | * Invalidate the NetLabel security attribute mapping cache. | |
107 | * | |
108 | */ | |
109 | void selinux_netlbl_cache_invalidate(void) | |
110 | { | |
111 | netlbl_cache_invalidate(); | |
112 | } | |
113 | ||
dfaebe98 PM |
114 | /** |
115 | * selinux_netlbl_err - Handle a NetLabel packet error | |
116 | * @skb: the packet | |
117 | * @error: the error code | |
118 | * @gateway: true if host is acting as a gateway, false otherwise | |
119 | * | |
120 | * Description: | |
121 | * When a packet is dropped due to a call to avc_has_perm() pass the error | |
122 | * code to the NetLabel subsystem so any protocol specific processing can be | |
123 | * done. This is safe to call even if you are unsure if NetLabel labeling is | |
124 | * present on the packet, NetLabel is smart enough to only act when it should. | |
125 | * | |
126 | */ | |
127 | void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway) | |
128 | { | |
129 | netlbl_skbuff_err(skb, error, gateway); | |
130 | } | |
131 | ||
6c5b3fc0 PM |
132 | /** |
133 | * selinux_netlbl_sk_security_free - Free the NetLabel fields | |
134 | * @sssec: the sk_security_struct | |
135 | * | |
136 | * Description: | |
137 | * Free all of the memory in the NetLabel fields of a sk_security_struct. | |
138 | * | |
139 | */ | |
140 | void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec) | |
141 | { | |
142 | if (ssec->nlbl_secattr != NULL) | |
143 | netlbl_secattr_free(ssec->nlbl_secattr); | |
144 | } | |
145 | ||
5778eabd PM |
146 | /** |
147 | * selinux_netlbl_sk_security_reset - Reset the NetLabel fields | |
148 | * @ssec: the sk_security_struct | |
149 | * @family: the socket family | |
150 | * | |
151 | * Description: | |
152 | * Called when the NetLabel state of a sk_security_struct needs to be reset. | |
153 | * The caller is responsibile for all the NetLabel sk_security_struct locking. | |
154 | * | |
155 | */ | |
389fb800 | 156 | void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec) |
5778eabd | 157 | { |
389fb800 | 158 | ssec->nlbl_state = NLBL_UNSET; |
5778eabd PM |
159 | } |
160 | ||
5778eabd PM |
161 | /** |
162 | * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel | |
163 | * @skb: the packet | |
75e22910 | 164 | * @family: protocol family |
220deb96 | 165 | * @type: NetLabel labeling protocol type |
5778eabd PM |
166 | * @sid: the SID |
167 | * | |
168 | * Description: | |
169 | * Call the NetLabel mechanism to get the security attributes of the given | |
170 | * packet and use those attributes to determine the correct context/SID to | |
171 | * assign to the packet. Returns zero on success, negative values on failure. | |
172 | * | |
173 | */ | |
75e22910 PM |
174 | int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, |
175 | u16 family, | |
220deb96 | 176 | u32 *type, |
75e22910 | 177 | u32 *sid) |
5778eabd PM |
178 | { |
179 | int rc; | |
180 | struct netlbl_lsm_secattr secattr; | |
181 | ||
23bcdc1a PM |
182 | if (!netlbl_enabled()) { |
183 | *sid = SECSID_NULL; | |
184 | return 0; | |
185 | } | |
186 | ||
5778eabd | 187 | netlbl_secattr_init(&secattr); |
75e22910 | 188 | rc = netlbl_skbuff_getattr(skb, family, &secattr); |
5dbe1eb0 PM |
189 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
190 | rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid); | |
191 | else | |
5778eabd | 192 | *sid = SECSID_NULL; |
220deb96 | 193 | *type = secattr.type; |
5778eabd PM |
194 | netlbl_secattr_destroy(&secattr); |
195 | ||
196 | return rc; | |
197 | } | |
198 | ||
948bf85c PM |
199 | /** |
200 | * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid | |
201 | * @skb: the packet | |
202 | * @family: protocol family | |
203 | * @sid: the SID | |
204 | * | |
205 | * Description | |
206 | * Call the NetLabel mechanism to set the label of a packet using @sid. | |
af901ca1 | 207 | * Returns zero on success, negative values on failure. |
948bf85c PM |
208 | * |
209 | */ | |
210 | int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, | |
211 | u16 family, | |
212 | u32 sid) | |
213 | { | |
214 | int rc; | |
6c5b3fc0 PM |
215 | struct netlbl_lsm_secattr secattr_storage; |
216 | struct netlbl_lsm_secattr *secattr = NULL; | |
948bf85c PM |
217 | struct sock *sk; |
218 | ||
219 | /* if this is a locally generated packet check to see if it is already | |
220 | * being labeled by it's parent socket, if it is just exit */ | |
221 | sk = skb->sk; | |
222 | if (sk != NULL) { | |
223 | struct sk_security_struct *sksec = sk->sk_security; | |
224 | if (sksec->nlbl_state != NLBL_REQSKB) | |
225 | return 0; | |
6c5b3fc0 PM |
226 | secattr = sksec->nlbl_secattr; |
227 | } | |
228 | if (secattr == NULL) { | |
229 | secattr = &secattr_storage; | |
230 | netlbl_secattr_init(secattr); | |
231 | rc = security_netlbl_sid_to_secattr(sid, secattr); | |
232 | if (rc != 0) | |
233 | goto skbuff_setsid_return; | |
948bf85c PM |
234 | } |
235 | ||
6c5b3fc0 | 236 | rc = netlbl_skbuff_setattr(skb, family, secattr); |
948bf85c PM |
237 | |
238 | skbuff_setsid_return: | |
6c5b3fc0 PM |
239 | if (secattr == &secattr_storage) |
240 | netlbl_secattr_destroy(secattr); | |
948bf85c PM |
241 | return rc; |
242 | } | |
243 | ||
5778eabd | 244 | /** |
389fb800 PM |
245 | * selinux_netlbl_inet_conn_request - Label an incoming stream connection |
246 | * @req: incoming connection request socket | |
5778eabd PM |
247 | * |
248 | * Description: | |
389fb800 PM |
249 | * A new incoming connection request is represented by @req, we need to label |
250 | * the new request_sock here and the stack will ensure the on-the-wire label | |
251 | * will get preserved when a full sock is created once the connection handshake | |
252 | * is complete. Returns zero on success, negative values on failure. | |
5778eabd PM |
253 | * |
254 | */ | |
389fb800 | 255 | int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) |
5778eabd | 256 | { |
014ab19a | 257 | int rc; |
389fb800 | 258 | struct netlbl_lsm_secattr secattr; |
014ab19a | 259 | |
389fb800 PM |
260 | if (family != PF_INET) |
261 | return 0; | |
014ab19a | 262 | |
389fb800 PM |
263 | netlbl_secattr_init(&secattr); |
264 | rc = security_netlbl_sid_to_secattr(req->secid, &secattr); | |
265 | if (rc != 0) | |
266 | goto inet_conn_request_return; | |
267 | rc = netlbl_req_setattr(req, &secattr); | |
268 | inet_conn_request_return: | |
269 | netlbl_secattr_destroy(&secattr); | |
270 | return rc; | |
5778eabd PM |
271 | } |
272 | ||
273 | /** | |
389fb800 PM |
274 | * selinux_netlbl_inet_csk_clone - Initialize the newly created sock |
275 | * @sk: the new sock | |
5778eabd PM |
276 | * |
277 | * Description: | |
389fb800 PM |
278 | * A new connection has been established using @sk, we've already labeled the |
279 | * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but | |
280 | * we need to set the NetLabel state here since we now have a sock structure. | |
5778eabd PM |
281 | * |
282 | */ | |
389fb800 | 283 | void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) |
5778eabd | 284 | { |
389fb800 PM |
285 | struct sk_security_struct *sksec = sk->sk_security; |
286 | ||
287 | if (family == PF_INET) | |
288 | sksec->nlbl_state = NLBL_LABELED; | |
289 | else | |
290 | sksec->nlbl_state = NLBL_UNSET; | |
5778eabd PM |
291 | } |
292 | ||
293 | /** | |
389fb800 PM |
294 | * selinux_netlbl_socket_post_create - Label a socket using NetLabel |
295 | * @sock: the socket to label | |
296 | * @family: protocol family | |
5778eabd PM |
297 | * |
298 | * Description: | |
389fb800 PM |
299 | * Attempt to label a socket using the NetLabel mechanism using the given |
300 | * SID. Returns zero values on success, negative values on failure. | |
5778eabd PM |
301 | * |
302 | */ | |
389fb800 | 303 | int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) |
5778eabd PM |
304 | { |
305 | int rc; | |
389fb800 PM |
306 | struct sk_security_struct *sksec = sk->sk_security; |
307 | struct netlbl_lsm_secattr *secattr; | |
5778eabd | 308 | |
389fb800 | 309 | if (family != PF_INET) |
5778eabd | 310 | return 0; |
f74af6e8 | 311 | |
389fb800 PM |
312 | secattr = selinux_netlbl_sock_genattr(sk); |
313 | if (secattr == NULL) | |
314 | return -ENOMEM; | |
315 | rc = netlbl_sock_setattr(sk, family, secattr); | |
316 | switch (rc) { | |
317 | case 0: | |
318 | sksec->nlbl_state = NLBL_LABELED; | |
319 | break; | |
320 | case -EDESTADDRREQ: | |
321 | sksec->nlbl_state = NLBL_REQSKB; | |
f74af6e8 | 322 | rc = 0; |
389fb800 PM |
323 | break; |
324 | } | |
5778eabd PM |
325 | |
326 | return rc; | |
327 | } | |
328 | ||
329 | /** | |
330 | * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel | |
331 | * @sksec: the sock's sk_security_struct | |
332 | * @skb: the packet | |
75e22910 | 333 | * @family: protocol family |
5778eabd PM |
334 | * @ad: the audit data |
335 | * | |
336 | * Description: | |
337 | * Fetch the NetLabel security attributes from @skb and perform an access check | |
338 | * against the receiving socket. Returns zero on success, negative values on | |
339 | * error. | |
340 | * | |
341 | */ | |
342 | int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, | |
343 | struct sk_buff *skb, | |
75e22910 | 344 | u16 family, |
2bf49690 | 345 | struct common_audit_data *ad) |
5778eabd PM |
346 | { |
347 | int rc; | |
f36158c4 PM |
348 | u32 nlbl_sid; |
349 | u32 perm; | |
350 | struct netlbl_lsm_secattr secattr; | |
5778eabd | 351 | |
23bcdc1a PM |
352 | if (!netlbl_enabled()) |
353 | return 0; | |
354 | ||
f36158c4 | 355 | netlbl_secattr_init(&secattr); |
75e22910 | 356 | rc = netlbl_skbuff_getattr(skb, family, &secattr); |
5dbe1eb0 PM |
357 | if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
358 | rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid); | |
359 | else | |
f36158c4 PM |
360 | nlbl_sid = SECINITSID_UNLABELED; |
361 | netlbl_secattr_destroy(&secattr); | |
5778eabd PM |
362 | if (rc != 0) |
363 | return rc; | |
8d9107e8 | 364 | |
5778eabd PM |
365 | switch (sksec->sclass) { |
366 | case SECCLASS_UDP_SOCKET: | |
f36158c4 | 367 | perm = UDP_SOCKET__RECVFROM; |
5778eabd PM |
368 | break; |
369 | case SECCLASS_TCP_SOCKET: | |
f36158c4 | 370 | perm = TCP_SOCKET__RECVFROM; |
5778eabd PM |
371 | break; |
372 | default: | |
f36158c4 | 373 | perm = RAWIP_SOCKET__RECVFROM; |
5778eabd PM |
374 | } |
375 | ||
f36158c4 | 376 | rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad); |
5778eabd PM |
377 | if (rc == 0) |
378 | return 0; | |
379 | ||
f36158c4 | 380 | if (nlbl_sid != SECINITSID_UNLABELED) |
dfaebe98 | 381 | netlbl_skbuff_err(skb, rc, 0); |
5778eabd PM |
382 | return rc; |
383 | } | |
384 | ||
385 | /** | |
386 | * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel | |
387 | * @sock: the socket | |
388 | * @level: the socket level or protocol | |
389 | * @optname: the socket option name | |
390 | * | |
391 | * Description: | |
392 | * Check the setsockopt() call and if the user is trying to replace the IP | |
393 | * options on a socket and a NetLabel is in place for the socket deny the | |
394 | * access; otherwise allow the access. Returns zero when the access is | |
395 | * allowed, -EACCES when denied, and other negative values on error. | |
396 | * | |
397 | */ | |
398 | int selinux_netlbl_socket_setsockopt(struct socket *sock, | |
399 | int level, | |
400 | int optname) | |
401 | { | |
402 | int rc = 0; | |
ba6ff9f2 PM |
403 | struct sock *sk = sock->sk; |
404 | struct sk_security_struct *sksec = sk->sk_security; | |
5778eabd PM |
405 | struct netlbl_lsm_secattr secattr; |
406 | ||
5778eabd | 407 | if (level == IPPROTO_IP && optname == IP_OPTIONS && |
014ab19a PM |
408 | (sksec->nlbl_state == NLBL_LABELED || |
409 | sksec->nlbl_state == NLBL_CONNLABELED)) { | |
5778eabd | 410 | netlbl_secattr_init(&secattr); |
ba6ff9f2 PM |
411 | lock_sock(sk); |
412 | rc = netlbl_sock_getattr(sk, &secattr); | |
413 | release_sock(sk); | |
09c50b4a | 414 | if (rc == 0) |
5778eabd | 415 | rc = -EACCES; |
09c50b4a PM |
416 | else if (rc == -ENOMSG) |
417 | rc = 0; | |
5778eabd PM |
418 | netlbl_secattr_destroy(&secattr); |
419 | } | |
5778eabd PM |
420 | |
421 | return rc; | |
422 | } | |
014ab19a PM |
423 | |
424 | /** | |
425 | * selinux_netlbl_socket_connect - Label a client-side socket on connect | |
426 | * @sk: the socket to label | |
427 | * @addr: the destination address | |
428 | * | |
429 | * Description: | |
430 | * Attempt to label a connected socket with NetLabel using the given address. | |
431 | * Returns zero values on success, negative values on failure. | |
432 | * | |
433 | */ | |
434 | int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) | |
435 | { | |
436 | int rc; | |
437 | struct sk_security_struct *sksec = sk->sk_security; | |
6c5b3fc0 | 438 | struct netlbl_lsm_secattr *secattr; |
014ab19a PM |
439 | |
440 | if (sksec->nlbl_state != NLBL_REQSKB && | |
441 | sksec->nlbl_state != NLBL_CONNLABELED) | |
442 | return 0; | |
443 | ||
014ab19a PM |
444 | local_bh_disable(); |
445 | bh_lock_sock_nested(sk); | |
446 | ||
447 | /* connected sockets are allowed to disconnect when the address family | |
448 | * is set to AF_UNSPEC, if that is what is happening we want to reset | |
449 | * the socket */ | |
450 | if (addr->sa_family == AF_UNSPEC) { | |
451 | netlbl_sock_delattr(sk); | |
452 | sksec->nlbl_state = NLBL_REQSKB; | |
453 | rc = 0; | |
454 | goto socket_connect_return; | |
455 | } | |
6c5b3fc0 PM |
456 | secattr = selinux_netlbl_sock_genattr(sk); |
457 | if (secattr == NULL) { | |
458 | rc = -ENOMEM; | |
014ab19a | 459 | goto socket_connect_return; |
6c5b3fc0 PM |
460 | } |
461 | rc = netlbl_conn_setattr(sk, addr, secattr); | |
462 | if (rc == 0) | |
463 | sksec->nlbl_state = NLBL_CONNLABELED; | |
014ab19a PM |
464 | |
465 | socket_connect_return: | |
466 | bh_unlock_sock(sk); | |
467 | local_bh_enable(); | |
014ab19a PM |
468 | return rc; |
469 | } |