blob: 2e984413c7b2daaa5313e7bf8fa1b3b193064252 [file] [log] [blame]
Paul Moore5778eab2007-02-28 15:14:22 -05001/*
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/*
Paul Moore948bf852008-10-10 10:16:32 -040012 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
Paul Moore5778eab2007-02-28 15:14:22 -050013 *
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>
Paul Moore014ab192008-10-10 10:16:33 -040032#include <linux/ip.h>
33#include <linux/ipv6.h>
Paul Moore5778eab2007-02-28 15:14:22 -050034#include <net/sock.h>
35#include <net/netlabel.h>
Paul Moore014ab192008-10-10 10:16:33 -040036#include <net/ip.h>
37#include <net/ipv6.h>
Paul Moore5778eab2007-02-28 15:14:22 -050038
39#include "objsec.h"
40#include "security.h"
Adrian Bunkd4ee4232008-02-27 23:20:42 +020041#include "netlabel.h"
Paul Moore5778eab2007-02-28 15:14:22 -050042
43/**
Paul Moore5dbe1eb2008-01-29 08:44:18 -050044 * 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 */
55static 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
70/**
Paul Moore6c5b3fc2008-10-10 10:16:33 -040071 * 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 */
80static 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
102/**
Paul Moore5778eab2007-02-28 15:14:22 -0500103 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
104 *
105 * Description:
106 * Invalidate the NetLabel security attribute mapping cache.
107 *
108 */
109void selinux_netlbl_cache_invalidate(void)
110{
111 netlbl_cache_invalidate();
112}
113
114/**
Paul Mooredfaebe92008-10-10 10:16:31 -0400115 * 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 */
127void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
128{
129 netlbl_skbuff_err(skb, error, gateway);
130}
131
132/**
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400133 * 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 */
140void 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
146/**
Paul Moore5778eab2007-02-28 15:14:22 -0500147 * 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 */
Paul Moore389fb8002009-03-27 17:10:34 -0400156void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec)
Paul Moore5778eab2007-02-28 15:14:22 -0500157{
Paul Moore389fb8002009-03-27 17:10:34 -0400158 ssec->nlbl_state = NLBL_UNSET;
Paul Moore5778eab2007-02-28 15:14:22 -0500159}
160
161/**
Paul Moore5778eab2007-02-28 15:14:22 -0500162 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
163 * @skb: the packet
Paul Moore75e22912008-01-29 08:38:04 -0500164 * @family: protocol family
Paul Moore220deb92008-01-29 08:38:23 -0500165 * @type: NetLabel labeling protocol type
Paul Moore5778eab2007-02-28 15:14:22 -0500166 * @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 */
Paul Moore75e22912008-01-29 08:38:04 -0500174int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
175 u16 family,
Paul Moore220deb92008-01-29 08:38:23 -0500176 u32 *type,
Paul Moore75e22912008-01-29 08:38:04 -0500177 u32 *sid)
Paul Moore5778eab2007-02-28 15:14:22 -0500178{
179 int rc;
180 struct netlbl_lsm_secattr secattr;
181
Paul Moore23bcdc12007-07-18 12:28:45 -0400182 if (!netlbl_enabled()) {
183 *sid = SECSID_NULL;
184 return 0;
185 }
186
Paul Moore5778eab2007-02-28 15:14:22 -0500187 netlbl_secattr_init(&secattr);
Paul Moore75e22912008-01-29 08:38:04 -0500188 rc = netlbl_skbuff_getattr(skb, family, &secattr);
Paul Moore5dbe1eb2008-01-29 08:44:18 -0500189 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
190 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
191 else
Paul Moore5778eab2007-02-28 15:14:22 -0500192 *sid = SECSID_NULL;
Paul Moore220deb92008-01-29 08:38:23 -0500193 *type = secattr.type;
Paul Moore5778eab2007-02-28 15:14:22 -0500194 netlbl_secattr_destroy(&secattr);
195
196 return rc;
197}
198
199/**
Paul Moore948bf852008-10-10 10:16:32 -0400200 * 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.
207 * Returns zero on auccess, negative values on failure.
208 *
209 */
210int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
211 u16 family,
212 u32 sid)
213{
214 int rc;
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400215 struct netlbl_lsm_secattr secattr_storage;
216 struct netlbl_lsm_secattr *secattr = NULL;
Paul Moore948bf852008-10-10 10:16:32 -0400217 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;
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400226 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;
Paul Moore948bf852008-10-10 10:16:32 -0400234 }
235
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400236 rc = netlbl_skbuff_setattr(skb, family, secattr);
Paul Moore948bf852008-10-10 10:16:32 -0400237
238skbuff_setsid_return:
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400239 if (secattr == &secattr_storage)
240 netlbl_secattr_destroy(secattr);
Paul Moore948bf852008-10-10 10:16:32 -0400241 return rc;
242}
243
244/**
Paul Moore389fb8002009-03-27 17:10:34 -0400245 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
246 * @req: incoming connection request socket
Paul Moore5778eab2007-02-28 15:14:22 -0500247 *
248 * Description:
Paul Moore389fb8002009-03-27 17:10:34 -0400249 * 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.
Paul Moore5778eab2007-02-28 15:14:22 -0500253 *
254 */
Paul Moore389fb8002009-03-27 17:10:34 -0400255int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
Paul Moore5778eab2007-02-28 15:14:22 -0500256{
Paul Moore014ab192008-10-10 10:16:33 -0400257 int rc;
Paul Moore389fb8002009-03-27 17:10:34 -0400258 struct netlbl_lsm_secattr secattr;
259
260 if (family != PF_INET)
261 return 0;
262
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);
268inet_conn_request_return:
269 netlbl_secattr_destroy(&secattr);
270 return rc;
271}
272
273/**
274 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
275 * @sk: the new sock
276 *
277 * Description:
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.
281 *
282 */
283void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
284{
Paul Moore014ab192008-10-10 10:16:33 -0400285 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore014ab192008-10-10 10:16:33 -0400286
Paul Moore389fb8002009-03-27 17:10:34 -0400287 if (family == PF_INET)
Paul Moore014ab192008-10-10 10:16:33 -0400288 sksec->nlbl_state = NLBL_LABELED;
Paul Moore389fb8002009-03-27 17:10:34 -0400289 else
290 sksec->nlbl_state = NLBL_UNSET;
Paul Moore5778eab2007-02-28 15:14:22 -0500291}
292
293/**
294 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
295 * @sock: the socket to label
Paul Moore389fb8002009-03-27 17:10:34 -0400296 * @family: protocol family
Paul Moore5778eab2007-02-28 15:14:22 -0500297 *
298 * Description:
299 * Attempt to label a socket using the NetLabel mechanism using the given
300 * SID. Returns zero values on success, negative values on failure.
301 *
302 */
Paul Moore389fb8002009-03-27 17:10:34 -0400303int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
Paul Moore5778eab2007-02-28 15:14:22 -0500304{
305 int rc;
Paul Moore389fb8002009-03-27 17:10:34 -0400306 struct sk_security_struct *sksec = sk->sk_security;
307 struct netlbl_lsm_secattr *secattr;
Paul Moore5778eab2007-02-28 15:14:22 -0500308
Paul Moore389fb8002009-03-27 17:10:34 -0400309 if (family != PF_INET)
Paul Moore5778eab2007-02-28 15:14:22 -0500310 return 0;
Paul Mooref74af6e2008-02-25 11:40:33 -0500311
Paul Moore389fb8002009-03-27 17:10:34 -0400312 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;
Paul Mooref74af6e2008-02-25 11:40:33 -0500322 rc = 0;
Paul Moore389fb8002009-03-27 17:10:34 -0400323 break;
324 }
Paul Moore5778eab2007-02-28 15:14:22 -0500325
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
Paul Moore75e22912008-01-29 08:38:04 -0500333 * @family: protocol family
Paul Moore5778eab2007-02-28 15:14:22 -0500334 * @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 */
342int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
343 struct sk_buff *skb,
Paul Moore75e22912008-01-29 08:38:04 -0500344 u16 family,
Paul Moore5778eab2007-02-28 15:14:22 -0500345 struct avc_audit_data *ad)
346{
347 int rc;
Paul Mooref36158c2007-07-18 12:28:46 -0400348 u32 nlbl_sid;
349 u32 perm;
350 struct netlbl_lsm_secattr secattr;
Paul Moore5778eab2007-02-28 15:14:22 -0500351
Paul Moore23bcdc12007-07-18 12:28:45 -0400352 if (!netlbl_enabled())
353 return 0;
354
Paul Mooref36158c2007-07-18 12:28:46 -0400355 netlbl_secattr_init(&secattr);
Paul Moore75e22912008-01-29 08:38:04 -0500356 rc = netlbl_skbuff_getattr(skb, family, &secattr);
Paul Moore5dbe1eb2008-01-29 08:44:18 -0500357 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
358 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
359 else
Paul Mooref36158c2007-07-18 12:28:46 -0400360 nlbl_sid = SECINITSID_UNLABELED;
361 netlbl_secattr_destroy(&secattr);
Paul Moore5778eab2007-02-28 15:14:22 -0500362 if (rc != 0)
363 return rc;
Linus Torvalds8d9107e2007-07-13 16:53:18 -0700364
Paul Moore5778eab2007-02-28 15:14:22 -0500365 switch (sksec->sclass) {
366 case SECCLASS_UDP_SOCKET:
Paul Mooref36158c2007-07-18 12:28:46 -0400367 perm = UDP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500368 break;
369 case SECCLASS_TCP_SOCKET:
Paul Mooref36158c2007-07-18 12:28:46 -0400370 perm = TCP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500371 break;
372 default:
Paul Mooref36158c2007-07-18 12:28:46 -0400373 perm = RAWIP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500374 }
375
Paul Mooref36158c2007-07-18 12:28:46 -0400376 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
Paul Moore5778eab2007-02-28 15:14:22 -0500377 if (rc == 0)
378 return 0;
379
Paul Mooref36158c2007-07-18 12:28:46 -0400380 if (nlbl_sid != SECINITSID_UNLABELED)
Paul Mooredfaebe92008-10-10 10:16:31 -0400381 netlbl_skbuff_err(skb, rc, 0);
Paul Moore5778eab2007-02-28 15:14:22 -0500382 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 */
398int selinux_netlbl_socket_setsockopt(struct socket *sock,
399 int level,
400 int optname)
401{
402 int rc = 0;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700403 struct sock *sk = sock->sk;
404 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore5778eab2007-02-28 15:14:22 -0500405 struct netlbl_lsm_secattr secattr;
406
Paul Moore5778eab2007-02-28 15:14:22 -0500407 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
Paul Moore014ab192008-10-10 10:16:33 -0400408 (sksec->nlbl_state == NLBL_LABELED ||
409 sksec->nlbl_state == NLBL_CONNLABELED)) {
Paul Moore5778eab2007-02-28 15:14:22 -0500410 netlbl_secattr_init(&secattr);
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700411 lock_sock(sk);
412 rc = netlbl_sock_getattr(sk, &secattr);
413 release_sock(sk);
Paul Moore09c50b42009-02-20 16:33:02 -0500414 if (rc == 0)
Paul Moore5778eab2007-02-28 15:14:22 -0500415 rc = -EACCES;
Paul Moore09c50b42009-02-20 16:33:02 -0500416 else if (rc == -ENOMSG)
417 rc = 0;
Paul Moore5778eab2007-02-28 15:14:22 -0500418 netlbl_secattr_destroy(&secattr);
419 }
Paul Moore5778eab2007-02-28 15:14:22 -0500420
421 return rc;
422}
Paul Moore014ab192008-10-10 10:16:33 -0400423
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 */
434int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
435{
436 int rc;
437 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400438 struct netlbl_lsm_secattr *secattr;
Paul Moore014ab192008-10-10 10:16:33 -0400439
440 if (sksec->nlbl_state != NLBL_REQSKB &&
441 sksec->nlbl_state != NLBL_CONNLABELED)
442 return 0;
443
Paul Moore014ab192008-10-10 10:16:33 -0400444 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 }
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400456 secattr = selinux_netlbl_sock_genattr(sk);
457 if (secattr == NULL) {
458 rc = -ENOMEM;
Paul Moore014ab192008-10-10 10:16:33 -0400459 goto socket_connect_return;
Paul Moore6c5b3fc2008-10-10 10:16:33 -0400460 }
461 rc = netlbl_conn_setattr(sk, addr, secattr);
462 if (rc == 0)
463 sksec->nlbl_state = NLBL_CONNLABELED;
Paul Moore014ab192008-10-10 10:16:33 -0400464
465socket_connect_return:
466 bh_unlock_sock(sk);
467 local_bh_enable();
Paul Moore014ab192008-10-10 10:16:33 -0400468 return rc;
469}