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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@paul-moore.com>
8 *
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
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>
32#include <linux/gfp.h>
33#include <linux/ip.h>
34#include <linux/ipv6.h>
35#include <net/sock.h>
36#include <net/netlabel.h>
37#include <net/ip.h>
38#include <net/ipv6.h>
39
40#include "objsec.h"
41#include "security.h"
42#include "netlabel.h"
43
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 */
56static 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
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 */
81static 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
103/**
104 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
105 *
106 * Description:
107 * Invalidate the NetLabel security attribute mapping cache.
108 *
109 */
110void selinux_netlbl_cache_invalidate(void)
111{
112 netlbl_cache_invalidate();
113}
114
115/**
116 * selinux_netlbl_err - Handle a NetLabel packet error
117 * @skb: the packet
118 * @error: the error code
119 * @gateway: true if host is acting as a gateway, false otherwise
120 *
121 * Description:
122 * When a packet is dropped due to a call to avc_has_perm() pass the error
123 * code to the NetLabel subsystem so any protocol specific processing can be
124 * done. This is safe to call even if you are unsure if NetLabel labeling is
125 * present on the packet, NetLabel is smart enough to only act when it should.
126 *
127 */
128void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
129{
130 netlbl_skbuff_err(skb, error, gateway);
131}
132
133/**
134 * selinux_netlbl_sk_security_free - Free the NetLabel fields
135 * @sksec: the sk_security_struct
136 *
137 * Description:
138 * Free all of the memory in the NetLabel fields of a sk_security_struct.
139 *
140 */
141void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
142{
143 if (sksec->nlbl_secattr != NULL)
144 netlbl_secattr_free(sksec->nlbl_secattr);
145}
146
147/**
148 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
149 * @sksec: the sk_security_struct
150 * @family: the socket family
151 *
152 * Description:
153 * Called when the NetLabel state of a sk_security_struct needs to be reset.
154 * The caller is responsible for all the NetLabel sk_security_struct locking.
155 *
156 */
157void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
158{
159 sksec->nlbl_state = NLBL_UNSET;
160}
161
162/**
163 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
164 * @skb: the packet
165 * @family: protocol family
166 * @type: NetLabel labeling protocol type
167 * @sid: the SID
168 *
169 * Description:
170 * Call the NetLabel mechanism to get the security attributes of the given
171 * packet and use those attributes to determine the correct context/SID to
172 * assign to the packet. Returns zero on success, negative values on failure.
173 *
174 */
175int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
176 u16 family,
177 u32 *type,
178 u32 *sid)
179{
180 int rc;
181 struct netlbl_lsm_secattr secattr;
182
183 if (!netlbl_enabled()) {
184 *sid = SECSID_NULL;
185 return 0;
186 }
187
188 netlbl_secattr_init(&secattr);
189 rc = netlbl_skbuff_getattr(skb, family, &secattr);
190 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
191 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
192 else
193 *sid = SECSID_NULL;
194 *type = secattr.type;
195 netlbl_secattr_destroy(&secattr);
196
197 return rc;
198}
199
200/**
201 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
202 * @skb: the packet
203 * @family: protocol family
204 * @sid: the SID
205 *
206 * Description
207 * Call the NetLabel mechanism to set the label of a packet using @sid.
208 * Returns zero on success, negative values on failure.
209 *
210 */
211int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
212 u16 family,
213 u32 sid)
214{
215 int rc;
216 struct netlbl_lsm_secattr secattr_storage;
217 struct netlbl_lsm_secattr *secattr = NULL;
218 struct sock *sk;
219
220 /* if this is a locally generated packet check to see if it is already
221 * being labeled by it's parent socket, if it is just exit */
222 sk = skb->sk;
223 if (sk != NULL) {
224 struct sk_security_struct *sksec = sk->sk_security;
225 if (sksec->nlbl_state != NLBL_REQSKB)
226 return 0;
227 secattr = sksec->nlbl_secattr;
228 }
229 if (secattr == NULL) {
230 secattr = &secattr_storage;
231 netlbl_secattr_init(secattr);
232 rc = security_netlbl_sid_to_secattr(sid, secattr);
233 if (rc != 0)
234 goto skbuff_setsid_return;
235 }
236
237 rc = netlbl_skbuff_setattr(skb, family, secattr);
238
239skbuff_setsid_return:
240 if (secattr == &secattr_storage)
241 netlbl_secattr_destroy(secattr);
242 return rc;
243}
244
245/**
246 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
247 * @req: incoming connection request socket
248 *
249 * Description:
250 * A new incoming connection request is represented by @req, we need to label
251 * the new request_sock here and the stack will ensure the on-the-wire label
252 * will get preserved when a full sock is created once the connection handshake
253 * is complete. Returns zero on success, negative values on failure.
254 *
255 */
256int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
257{
258 int rc;
259 struct netlbl_lsm_secattr secattr;
260
261 if (family != PF_INET)
262 return 0;
263
264 netlbl_secattr_init(&secattr);
265 rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
266 if (rc != 0)
267 goto inet_conn_request_return;
268 rc = netlbl_req_setattr(req, &secattr);
269inet_conn_request_return:
270 netlbl_secattr_destroy(&secattr);
271 return rc;
272}
273
274/**
275 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
276 * @sk: the new sock
277 *
278 * Description:
279 * A new connection has been established using @sk, we've already labeled the
280 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
281 * we need to set the NetLabel state here since we now have a sock structure.
282 *
283 */
284void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
285{
286 struct sk_security_struct *sksec = sk->sk_security;
287
288 if (family == PF_INET)
289 sksec->nlbl_state = NLBL_LABELED;
290 else
291 sksec->nlbl_state = NLBL_UNSET;
292}
293
294/**
295 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
296 * @sock: the socket to label
297 * @family: protocol family
298 *
299 * Description:
300 * Attempt to label a socket using the NetLabel mechanism using the given
301 * SID. Returns zero values on success, negative values on failure.
302 *
303 */
304int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
305{
306 int rc;
307 struct sk_security_struct *sksec = sk->sk_security;
308 struct netlbl_lsm_secattr *secattr;
309
310 if (family != PF_INET)
311 return 0;
312
313 secattr = selinux_netlbl_sock_genattr(sk);
314 if (secattr == NULL)
315 return -ENOMEM;
316 rc = netlbl_sock_setattr(sk, family, secattr);
317 switch (rc) {
318 case 0:
319 sksec->nlbl_state = NLBL_LABELED;
320 break;
321 case -EDESTADDRREQ:
322 sksec->nlbl_state = NLBL_REQSKB;
323 rc = 0;
324 break;
325 }
326
327 return rc;
328}
329
330/**
331 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
332 * @sksec: the sock's sk_security_struct
333 * @skb: the packet
334 * @family: protocol family
335 * @ad: the audit data
336 *
337 * Description:
338 * Fetch the NetLabel security attributes from @skb and perform an access check
339 * against the receiving socket. Returns zero on success, negative values on
340 * error.
341 *
342 */
343int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
344 struct sk_buff *skb,
345 u16 family,
346 struct common_audit_data *ad)
347{
348 int rc;
349 u32 nlbl_sid;
350 u32 perm;
351 struct netlbl_lsm_secattr secattr;
352
353 if (!netlbl_enabled())
354 return 0;
355
356 netlbl_secattr_init(&secattr);
357 rc = netlbl_skbuff_getattr(skb, family, &secattr);
358 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
359 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
360 else
361 nlbl_sid = SECINITSID_UNLABELED;
362 netlbl_secattr_destroy(&secattr);
363 if (rc != 0)
364 return rc;
365
366 switch (sksec->sclass) {
367 case SECCLASS_UDP_SOCKET:
368 perm = UDP_SOCKET__RECVFROM;
369 break;
370 case SECCLASS_TCP_SOCKET:
371 perm = TCP_SOCKET__RECVFROM;
372 break;
373 default:
374 perm = RAWIP_SOCKET__RECVFROM;
375 }
376
377 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
378 if (rc == 0)
379 return 0;
380
381 if (nlbl_sid != SECINITSID_UNLABELED)
382 netlbl_skbuff_err(skb, rc, 0);
383 return rc;
384}
385
386/**
387 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
388 * @sock: the socket
389 * @level: the socket level or protocol
390 * @optname: the socket option name
391 *
392 * Description:
393 * Check the setsockopt() call and if the user is trying to replace the IP
394 * options on a socket and a NetLabel is in place for the socket deny the
395 * access; otherwise allow the access. Returns zero when the access is
396 * allowed, -EACCES when denied, and other negative values on error.
397 *
398 */
399int selinux_netlbl_socket_setsockopt(struct socket *sock,
400 int level,
401 int optname)
402{
403 int rc = 0;
404 struct sock *sk = sock->sk;
405 struct sk_security_struct *sksec = sk->sk_security;
406 struct netlbl_lsm_secattr secattr;
407
408 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
409 (sksec->nlbl_state == NLBL_LABELED ||
410 sksec->nlbl_state == NLBL_CONNLABELED)) {
411 netlbl_secattr_init(&secattr);
412 lock_sock(sk);
413 rc = netlbl_sock_getattr(sk, &secattr);
414 release_sock(sk);
415 if (rc == 0)
416 rc = -EACCES;
417 else if (rc == -ENOMSG)
418 rc = 0;
419 netlbl_secattr_destroy(&secattr);
420 }
421
422 return rc;
423}
424
425/**
426 * selinux_netlbl_socket_connect - Label a client-side socket on connect
427 * @sk: the socket to label
428 * @addr: the destination address
429 *
430 * Description:
431 * Attempt to label a connected socket with NetLabel using the given address.
432 * Returns zero values on success, negative values on failure.
433 *
434 */
435int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
436{
437 int rc;
438 struct sk_security_struct *sksec = sk->sk_security;
439 struct netlbl_lsm_secattr *secattr;
440
441 if (sksec->nlbl_state != NLBL_REQSKB &&
442 sksec->nlbl_state != NLBL_CONNLABELED)
443 return 0;
444
445 local_bh_disable();
446 bh_lock_sock_nested(sk);
447
448 /* connected sockets are allowed to disconnect when the address family
449 * is set to AF_UNSPEC, if that is what is happening we want to reset
450 * the socket */
451 if (addr->sa_family == AF_UNSPEC) {
452 netlbl_sock_delattr(sk);
453 sksec->nlbl_state = NLBL_REQSKB;
454 rc = 0;
455 goto socket_connect_return;
456 }
457 secattr = selinux_netlbl_sock_genattr(sk);
458 if (secattr == NULL) {
459 rc = -ENOMEM;
460 goto socket_connect_return;
461 }
462 rc = netlbl_conn_setattr(sk, addr, secattr);
463 if (rc == 0)
464 sksec->nlbl_state = NLBL_CONNLABELED;
465
466socket_connect_return:
467 bh_unlock_sock(sk);
468 local_bh_enable();
469 return rc;
470}
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@paul-moore.com>
8 *
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
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>
32#include <linux/gfp.h>
33#include <linux/ip.h>
34#include <linux/ipv6.h>
35#include <net/sock.h>
36#include <net/netlabel.h>
37#include <net/ip.h>
38#include <net/ipv6.h>
39
40#include "objsec.h"
41#include "security.h"
42#include "netlabel.h"
43
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 */
56static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
57 u16 family,
58 struct netlbl_lsm_secattr *secattr,
59 u32 *sid)
60{
61 int rc;
62
63 rc = security_netlbl_secattr_to_sid(secattr, sid);
64 if (rc == 0 &&
65 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
66 (secattr->flags & NETLBL_SECATTR_CACHE))
67 netlbl_cache_add(skb, family, secattr);
68
69 return rc;
70}
71
72/**
73 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
74 * @sk: the socket
75 *
76 * Description:
77 * Generate the NetLabel security attributes for a socket, making full use of
78 * the socket's attribute cache. Returns a pointer to the security attributes
79 * on success, NULL on failure.
80 *
81 */
82static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
83{
84 int rc;
85 struct sk_security_struct *sksec = sk->sk_security;
86 struct netlbl_lsm_secattr *secattr;
87
88 if (sksec->nlbl_secattr != NULL)
89 return sksec->nlbl_secattr;
90
91 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
92 if (secattr == NULL)
93 return NULL;
94 rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
95 if (rc != 0) {
96 netlbl_secattr_free(secattr);
97 return NULL;
98 }
99 sksec->nlbl_secattr = secattr;
100
101 return secattr;
102}
103
104/**
105 * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
106 * @sk: the socket
107 * @sid: the SID
108 *
109 * Query the socket's cached secattr and if the SID matches the cached value
110 * return the cache, otherwise return NULL.
111 *
112 */
113static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
114 const struct sock *sk,
115 u32 sid)
116{
117 struct sk_security_struct *sksec = sk->sk_security;
118 struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
119
120 if (secattr == NULL)
121 return NULL;
122
123 if ((secattr->flags & NETLBL_SECATTR_SECID) &&
124 (secattr->attr.secid == sid))
125 return secattr;
126
127 return NULL;
128}
129
130/**
131 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
132 *
133 * Description:
134 * Invalidate the NetLabel security attribute mapping cache.
135 *
136 */
137void selinux_netlbl_cache_invalidate(void)
138{
139 netlbl_cache_invalidate();
140}
141
142/**
143 * selinux_netlbl_err - Handle a NetLabel packet error
144 * @skb: the packet
145 * @error: the error code
146 * @gateway: true if host is acting as a gateway, false otherwise
147 *
148 * Description:
149 * When a packet is dropped due to a call to avc_has_perm() pass the error
150 * code to the NetLabel subsystem so any protocol specific processing can be
151 * done. This is safe to call even if you are unsure if NetLabel labeling is
152 * present on the packet, NetLabel is smart enough to only act when it should.
153 *
154 */
155void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
156{
157 netlbl_skbuff_err(skb, family, error, gateway);
158}
159
160/**
161 * selinux_netlbl_sk_security_free - Free the NetLabel fields
162 * @sksec: the sk_security_struct
163 *
164 * Description:
165 * Free all of the memory in the NetLabel fields of a sk_security_struct.
166 *
167 */
168void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
169{
170 if (sksec->nlbl_secattr != NULL)
171 netlbl_secattr_free(sksec->nlbl_secattr);
172}
173
174/**
175 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
176 * @sksec: the sk_security_struct
177 * @family: the socket family
178 *
179 * Description:
180 * Called when the NetLabel state of a sk_security_struct needs to be reset.
181 * The caller is responsible for all the NetLabel sk_security_struct locking.
182 *
183 */
184void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
185{
186 sksec->nlbl_state = NLBL_UNSET;
187}
188
189/**
190 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
191 * @skb: the packet
192 * @family: protocol family
193 * @type: NetLabel labeling protocol type
194 * @sid: the SID
195 *
196 * Description:
197 * Call the NetLabel mechanism to get the security attributes of the given
198 * packet and use those attributes to determine the correct context/SID to
199 * assign to the packet. Returns zero on success, negative values on failure.
200 *
201 */
202int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
203 u16 family,
204 u32 *type,
205 u32 *sid)
206{
207 int rc;
208 struct netlbl_lsm_secattr secattr;
209
210 if (!netlbl_enabled()) {
211 *sid = SECSID_NULL;
212 return 0;
213 }
214
215 netlbl_secattr_init(&secattr);
216 rc = netlbl_skbuff_getattr(skb, family, &secattr);
217 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
218 rc = selinux_netlbl_sidlookup_cached(skb, family,
219 &secattr, sid);
220 else
221 *sid = SECSID_NULL;
222 *type = secattr.type;
223 netlbl_secattr_destroy(&secattr);
224
225 return rc;
226}
227
228/**
229 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
230 * @skb: the packet
231 * @family: protocol family
232 * @sid: the SID
233 *
234 * Description
235 * Call the NetLabel mechanism to set the label of a packet using @sid.
236 * Returns zero on success, negative values on failure.
237 *
238 */
239int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
240 u16 family,
241 u32 sid)
242{
243 int rc;
244 struct netlbl_lsm_secattr secattr_storage;
245 struct netlbl_lsm_secattr *secattr = NULL;
246 struct sock *sk;
247
248 /* if this is a locally generated packet check to see if it is already
249 * being labeled by it's parent socket, if it is just exit */
250 sk = skb_to_full_sk(skb);
251 if (sk != NULL) {
252 struct sk_security_struct *sksec = sk->sk_security;
253 if (sksec->nlbl_state != NLBL_REQSKB)
254 return 0;
255 secattr = selinux_netlbl_sock_getattr(sk, sid);
256 }
257 if (secattr == NULL) {
258 secattr = &secattr_storage;
259 netlbl_secattr_init(secattr);
260 rc = security_netlbl_sid_to_secattr(sid, secattr);
261 if (rc != 0)
262 goto skbuff_setsid_return;
263 }
264
265 rc = netlbl_skbuff_setattr(skb, family, secattr);
266
267skbuff_setsid_return:
268 if (secattr == &secattr_storage)
269 netlbl_secattr_destroy(secattr);
270 return rc;
271}
272
273/**
274 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
275 * @req: incoming connection request socket
276 *
277 * Description:
278 * A new incoming connection request is represented by @req, we need to label
279 * the new request_sock here and the stack will ensure the on-the-wire label
280 * will get preserved when a full sock is created once the connection handshake
281 * is complete. Returns zero on success, negative values on failure.
282 *
283 */
284int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
285{
286 int rc;
287 struct netlbl_lsm_secattr secattr;
288
289 if (family != PF_INET && family != PF_INET6)
290 return 0;
291
292 netlbl_secattr_init(&secattr);
293 rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
294 if (rc != 0)
295 goto inet_conn_request_return;
296 rc = netlbl_req_setattr(req, &secattr);
297inet_conn_request_return:
298 netlbl_secattr_destroy(&secattr);
299 return rc;
300}
301
302/**
303 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
304 * @sk: the new sock
305 *
306 * Description:
307 * A new connection has been established using @sk, we've already labeled the
308 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
309 * we need to set the NetLabel state here since we now have a sock structure.
310 *
311 */
312void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
313{
314 struct sk_security_struct *sksec = sk->sk_security;
315
316 if (family == PF_INET)
317 sksec->nlbl_state = NLBL_LABELED;
318 else
319 sksec->nlbl_state = NLBL_UNSET;
320}
321
322/**
323 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
324 * @sock: the socket to label
325 * @family: protocol family
326 *
327 * Description:
328 * Attempt to label a socket using the NetLabel mechanism using the given
329 * SID. Returns zero values on success, negative values on failure.
330 *
331 */
332int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
333{
334 int rc;
335 struct sk_security_struct *sksec = sk->sk_security;
336 struct netlbl_lsm_secattr *secattr;
337
338 if (family != PF_INET && family != PF_INET6)
339 return 0;
340
341 secattr = selinux_netlbl_sock_genattr(sk);
342 if (secattr == NULL)
343 return -ENOMEM;
344 rc = netlbl_sock_setattr(sk, family, secattr);
345 switch (rc) {
346 case 0:
347 sksec->nlbl_state = NLBL_LABELED;
348 break;
349 case -EDESTADDRREQ:
350 sksec->nlbl_state = NLBL_REQSKB;
351 rc = 0;
352 break;
353 }
354
355 return rc;
356}
357
358/**
359 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
360 * @sksec: the sock's sk_security_struct
361 * @skb: the packet
362 * @family: protocol family
363 * @ad: the audit data
364 *
365 * Description:
366 * Fetch the NetLabel security attributes from @skb and perform an access check
367 * against the receiving socket. Returns zero on success, negative values on
368 * error.
369 *
370 */
371int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
372 struct sk_buff *skb,
373 u16 family,
374 struct common_audit_data *ad)
375{
376 int rc;
377 u32 nlbl_sid;
378 u32 perm;
379 struct netlbl_lsm_secattr secattr;
380
381 if (!netlbl_enabled())
382 return 0;
383
384 netlbl_secattr_init(&secattr);
385 rc = netlbl_skbuff_getattr(skb, family, &secattr);
386 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
387 rc = selinux_netlbl_sidlookup_cached(skb, family,
388 &secattr, &nlbl_sid);
389 else
390 nlbl_sid = SECINITSID_UNLABELED;
391 netlbl_secattr_destroy(&secattr);
392 if (rc != 0)
393 return rc;
394
395 switch (sksec->sclass) {
396 case SECCLASS_UDP_SOCKET:
397 perm = UDP_SOCKET__RECVFROM;
398 break;
399 case SECCLASS_TCP_SOCKET:
400 perm = TCP_SOCKET__RECVFROM;
401 break;
402 default:
403 perm = RAWIP_SOCKET__RECVFROM;
404 }
405
406 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
407 if (rc == 0)
408 return 0;
409
410 if (nlbl_sid != SECINITSID_UNLABELED)
411 netlbl_skbuff_err(skb, family, rc, 0);
412 return rc;
413}
414
415/**
416 * selinux_netlbl_option - Is this a NetLabel option
417 * @level: the socket level or protocol
418 * @optname: the socket option name
419 *
420 * Description:
421 * Returns true if @level and @optname refer to a NetLabel option.
422 * Helper for selinux_netlbl_socket_setsockopt().
423 */
424static inline int selinux_netlbl_option(int level, int optname)
425{
426 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
427 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
428}
429
430/**
431 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
432 * @sock: the socket
433 * @level: the socket level or protocol
434 * @optname: the socket option name
435 *
436 * Description:
437 * Check the setsockopt() call and if the user is trying to replace the IP
438 * options on a socket and a NetLabel is in place for the socket deny the
439 * access; otherwise allow the access. Returns zero when the access is
440 * allowed, -EACCES when denied, and other negative values on error.
441 *
442 */
443int selinux_netlbl_socket_setsockopt(struct socket *sock,
444 int level,
445 int optname)
446{
447 int rc = 0;
448 struct sock *sk = sock->sk;
449 struct sk_security_struct *sksec = sk->sk_security;
450 struct netlbl_lsm_secattr secattr;
451
452 if (selinux_netlbl_option(level, optname) &&
453 (sksec->nlbl_state == NLBL_LABELED ||
454 sksec->nlbl_state == NLBL_CONNLABELED)) {
455 netlbl_secattr_init(&secattr);
456 lock_sock(sk);
457 /* call the netlabel function directly as we want to see the
458 * on-the-wire label that is assigned via the socket's options
459 * and not the cached netlabel/lsm attributes */
460 rc = netlbl_sock_getattr(sk, &secattr);
461 release_sock(sk);
462 if (rc == 0)
463 rc = -EACCES;
464 else if (rc == -ENOMSG)
465 rc = 0;
466 netlbl_secattr_destroy(&secattr);
467 }
468
469 return rc;
470}
471
472/**
473 * selinux_netlbl_socket_connect - Label a client-side socket on connect
474 * @sk: the socket to label
475 * @addr: the destination address
476 *
477 * Description:
478 * Attempt to label a connected socket with NetLabel using the given address.
479 * Returns zero values on success, negative values on failure.
480 *
481 */
482int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
483{
484 int rc;
485 struct sk_security_struct *sksec = sk->sk_security;
486 struct netlbl_lsm_secattr *secattr;
487
488 if (sksec->nlbl_state != NLBL_REQSKB &&
489 sksec->nlbl_state != NLBL_CONNLABELED)
490 return 0;
491
492 lock_sock(sk);
493
494 /* connected sockets are allowed to disconnect when the address family
495 * is set to AF_UNSPEC, if that is what is happening we want to reset
496 * the socket */
497 if (addr->sa_family == AF_UNSPEC) {
498 netlbl_sock_delattr(sk);
499 sksec->nlbl_state = NLBL_REQSKB;
500 rc = 0;
501 goto socket_connect_return;
502 }
503 secattr = selinux_netlbl_sock_genattr(sk);
504 if (secattr == NULL) {
505 rc = -ENOMEM;
506 goto socket_connect_return;
507 }
508 rc = netlbl_conn_setattr(sk, addr, secattr);
509 if (rc == 0)
510 sksec->nlbl_state = NLBL_CONNLABELED;
511
512socket_connect_return:
513 release_sock(sk);
514 return rc;
515}