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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_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 */
112static 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
129/**
130 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
131 *
132 * Description:
133 * Invalidate the NetLabel security attribute mapping cache.
134 *
135 */
136void selinux_netlbl_cache_invalidate(void)
137{
138 netlbl_cache_invalidate();
139}
140
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 */
154void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
155{
156 netlbl_skbuff_err(skb, error, gateway);
157}
158
159/**
160 * selinux_netlbl_sk_security_free - Free the NetLabel fields
161 * @sksec: the sk_security_struct
162 *
163 * Description:
164 * Free all of the memory in the NetLabel fields of a sk_security_struct.
165 *
166 */
167void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
168{
169 if (sksec->nlbl_secattr != NULL)
170 netlbl_secattr_free(sksec->nlbl_secattr);
171}
172
173/**
174 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
175 * @sksec: the sk_security_struct
176 * @family: the socket family
177 *
178 * Description:
179 * Called when the NetLabel state of a sk_security_struct needs to be reset.
180 * The caller is responsible for all the NetLabel sk_security_struct locking.
181 *
182 */
183void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
184{
185 sksec->nlbl_state = NLBL_UNSET;
186}
187
188/**
189 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
190 * @skb: the packet
191 * @family: protocol family
192 * @type: NetLabel labeling protocol type
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 */
201int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
202 u16 family,
203 u32 *type,
204 u32 *sid)
205{
206 int rc;
207 struct netlbl_lsm_secattr secattr;
208
209 if (!netlbl_enabled()) {
210 *sid = SECSID_NULL;
211 return 0;
212 }
213
214 netlbl_secattr_init(&secattr);
215 rc = netlbl_skbuff_getattr(skb, family, &secattr);
216 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
217 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
218 else
219 *sid = SECSID_NULL;
220 *type = secattr.type;
221 netlbl_secattr_destroy(&secattr);
222
223 return rc;
224}
225
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.
234 * Returns zero on success, negative values on failure.
235 *
236 */
237int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
238 u16 family,
239 u32 sid)
240{
241 int rc;
242 struct netlbl_lsm_secattr secattr_storage;
243 struct netlbl_lsm_secattr *secattr = NULL;
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_to_full_sk(skb);
249 if (sk != NULL) {
250 struct sk_security_struct *sksec = sk->sk_security;
251 if (sksec->nlbl_state != NLBL_REQSKB)
252 return 0;
253 secattr = selinux_netlbl_sock_getattr(sk, sid);
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;
261 }
262
263 rc = netlbl_skbuff_setattr(skb, family, secattr);
264
265skbuff_setsid_return:
266 if (secattr == &secattr_storage)
267 netlbl_secattr_destroy(secattr);
268 return rc;
269}
270
271/**
272 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
273 * @req: incoming connection request socket
274 *
275 * Description:
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.
280 *
281 */
282int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
283{
284 int rc;
285 struct netlbl_lsm_secattr secattr;
286
287 if (family != PF_INET)
288 return 0;
289
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);
295inet_conn_request_return:
296 netlbl_secattr_destroy(&secattr);
297 return rc;
298}
299
300/**
301 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
302 * @sk: the new sock
303 *
304 * Description:
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.
308 *
309 */
310void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
311{
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;
318}
319
320/**
321 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
322 * @sock: the socket to label
323 * @family: protocol family
324 *
325 * Description:
326 * Attempt to label a socket using the NetLabel mechanism using the given
327 * SID. Returns zero values on success, negative values on failure.
328 *
329 */
330int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
331{
332 int rc;
333 struct sk_security_struct *sksec = sk->sk_security;
334 struct netlbl_lsm_secattr *secattr;
335
336 if (family != PF_INET)
337 return 0;
338
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;
349 rc = 0;
350 break;
351 }
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
360 * @family: protocol family
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 */
369int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
370 struct sk_buff *skb,
371 u16 family,
372 struct common_audit_data *ad)
373{
374 int rc;
375 u32 nlbl_sid;
376 u32 perm;
377 struct netlbl_lsm_secattr secattr;
378
379 if (!netlbl_enabled())
380 return 0;
381
382 netlbl_secattr_init(&secattr);
383 rc = netlbl_skbuff_getattr(skb, family, &secattr);
384 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
385 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
386 else
387 nlbl_sid = SECINITSID_UNLABELED;
388 netlbl_secattr_destroy(&secattr);
389 if (rc != 0)
390 return rc;
391
392 switch (sksec->sclass) {
393 case SECCLASS_UDP_SOCKET:
394 perm = UDP_SOCKET__RECVFROM;
395 break;
396 case SECCLASS_TCP_SOCKET:
397 perm = TCP_SOCKET__RECVFROM;
398 break;
399 default:
400 perm = RAWIP_SOCKET__RECVFROM;
401 }
402
403 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
404 if (rc == 0)
405 return 0;
406
407 if (nlbl_sid != SECINITSID_UNLABELED)
408 netlbl_skbuff_err(skb, rc, 0);
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 */
425int selinux_netlbl_socket_setsockopt(struct socket *sock,
426 int level,
427 int optname)
428{
429 int rc = 0;
430 struct sock *sk = sock->sk;
431 struct sk_security_struct *sksec = sk->sk_security;
432 struct netlbl_lsm_secattr secattr;
433
434 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
435 (sksec->nlbl_state == NLBL_LABELED ||
436 sksec->nlbl_state == NLBL_CONNLABELED)) {
437 netlbl_secattr_init(&secattr);
438 lock_sock(sk);
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 */
442 rc = netlbl_sock_getattr(sk, &secattr);
443 release_sock(sk);
444 if (rc == 0)
445 rc = -EACCES;
446 else if (rc == -ENOMSG)
447 rc = 0;
448 netlbl_secattr_destroy(&secattr);
449 }
450
451 return rc;
452}
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 */
464int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
465{
466 int rc;
467 struct sk_security_struct *sksec = sk->sk_security;
468 struct netlbl_lsm_secattr *secattr;
469
470 if (sksec->nlbl_state != NLBL_REQSKB &&
471 sksec->nlbl_state != NLBL_CONNLABELED)
472 return 0;
473
474 lock_sock(sk);
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 }
485 secattr = selinux_netlbl_sock_genattr(sk);
486 if (secattr == NULL) {
487 rc = -ENOMEM;
488 goto socket_connect_return;
489 }
490 rc = netlbl_conn_setattr(sk, addr, secattr);
491 if (rc == 0)
492 sksec->nlbl_state = NLBL_CONNLABELED;
493
494socket_connect_return:
495 release_sock(sk);
496 return rc;
497}
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}