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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, see <http://www.gnu.org/licenses/>.
26 *
27 */
28
29#include <linux/spinlock.h>
30#include <linux/rcupdate.h>
31#include <linux/gfp.h>
32#include <linux/ip.h>
33#include <linux/ipv6.h>
34#include <net/sock.h>
35#include <net/netlabel.h>
36#include <net/ip.h>
37#include <net/ipv6.h>
38
39#include "objsec.h"
40#include "security.h"
41#include "netlabel.h"
42
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 */
55static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
56 u16 family,
57 struct netlbl_lsm_secattr *secattr,
58 u32 *sid)
59{
60 int rc;
61
62 rc = security_netlbl_secattr_to_sid(&selinux_state, secattr, sid);
63 if (rc == 0 &&
64 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
65 (secattr->flags & NETLBL_SECATTR_CACHE))
66 netlbl_cache_add(skb, family, 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(&selinux_state, sksec->sid,
94 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
254 if (sksec->nlbl_state != NLBL_REQSKB)
255 return 0;
256 secattr = selinux_netlbl_sock_getattr(sk, sid);
257 }
258 if (secattr == NULL) {
259 secattr = &secattr_storage;
260 netlbl_secattr_init(secattr);
261 rc = security_netlbl_sid_to_secattr(&selinux_state, sid,
262 secattr);
263 if (rc != 0)
264 goto skbuff_setsid_return;
265 }
266
267 rc = netlbl_skbuff_setattr(skb, family, secattr);
268
269skbuff_setsid_return:
270 if (secattr == &secattr_storage)
271 netlbl_secattr_destroy(secattr);
272 return rc;
273}
274
275/**
276 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
277 * @ep: incoming association endpoint.
278 * @skb: the packet.
279 *
280 * Description:
281 * A new incoming connection is represented by @ep, ......
282 * Returns zero on success, negative values on failure.
283 *
284 */
285int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
286 struct sk_buff *skb)
287{
288 int rc;
289 struct netlbl_lsm_secattr secattr;
290 struct sk_security_struct *sksec = ep->base.sk->sk_security;
291 struct sockaddr *addr;
292 struct sockaddr_in addr4;
293#if IS_ENABLED(CONFIG_IPV6)
294 struct sockaddr_in6 addr6;
295#endif
296
297 if (ep->base.sk->sk_family != PF_INET &&
298 ep->base.sk->sk_family != PF_INET6)
299 return 0;
300
301 netlbl_secattr_init(&secattr);
302 rc = security_netlbl_sid_to_secattr(&selinux_state,
303 ep->secid, &secattr);
304 if (rc != 0)
305 goto assoc_request_return;
306
307 /* Move skb hdr address info to a struct sockaddr and then call
308 * netlbl_conn_setattr().
309 */
310 if (ip_hdr(skb)->version == 4) {
311 addr4.sin_family = AF_INET;
312 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
313 addr = (struct sockaddr *)&addr4;
314#if IS_ENABLED(CONFIG_IPV6)
315 } else {
316 addr6.sin6_family = AF_INET6;
317 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
318 addr = (struct sockaddr *)&addr6;
319#endif
320 }
321
322 rc = netlbl_conn_setattr(ep->base.sk, addr, &secattr);
323 if (rc == 0)
324 sksec->nlbl_state = NLBL_LABELED;
325
326assoc_request_return:
327 netlbl_secattr_destroy(&secattr);
328 return rc;
329}
330
331/**
332 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
333 * @req: incoming connection request socket
334 *
335 * Description:
336 * A new incoming connection request is represented by @req, we need to label
337 * the new request_sock here and the stack will ensure the on-the-wire label
338 * will get preserved when a full sock is created once the connection handshake
339 * is complete. Returns zero on success, negative values on failure.
340 *
341 */
342int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
343{
344 int rc;
345 struct netlbl_lsm_secattr secattr;
346
347 if (family != PF_INET && family != PF_INET6)
348 return 0;
349
350 netlbl_secattr_init(&secattr);
351 rc = security_netlbl_sid_to_secattr(&selinux_state, req->secid,
352 &secattr);
353 if (rc != 0)
354 goto inet_conn_request_return;
355 rc = netlbl_req_setattr(req, &secattr);
356inet_conn_request_return:
357 netlbl_secattr_destroy(&secattr);
358 return rc;
359}
360
361/**
362 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
363 * @sk: the new sock
364 *
365 * Description:
366 * A new connection has been established using @sk, we've already labeled the
367 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
368 * we need to set the NetLabel state here since we now have a sock structure.
369 *
370 */
371void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
372{
373 struct sk_security_struct *sksec = sk->sk_security;
374
375 if (family == PF_INET)
376 sksec->nlbl_state = NLBL_LABELED;
377 else
378 sksec->nlbl_state = NLBL_UNSET;
379}
380
381/**
382 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
383 * @sk: current sock
384 * @newsk: the new sock
385 *
386 * Description:
387 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
388 */
389void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
390{
391 struct sk_security_struct *sksec = sk->sk_security;
392 struct sk_security_struct *newsksec = newsk->sk_security;
393
394 newsksec->nlbl_state = sksec->nlbl_state;
395}
396
397/**
398 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
399 * @sock: the socket to label
400 * @family: protocol family
401 *
402 * Description:
403 * Attempt to label a socket using the NetLabel mechanism using the given
404 * SID. Returns zero values on success, negative values on failure.
405 *
406 */
407int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
408{
409 int rc;
410 struct sk_security_struct *sksec = sk->sk_security;
411 struct netlbl_lsm_secattr *secattr;
412
413 if (family != PF_INET && family != PF_INET6)
414 return 0;
415
416 secattr = selinux_netlbl_sock_genattr(sk);
417 if (secattr == NULL)
418 return -ENOMEM;
419 rc = netlbl_sock_setattr(sk, family, secattr);
420 switch (rc) {
421 case 0:
422 sksec->nlbl_state = NLBL_LABELED;
423 break;
424 case -EDESTADDRREQ:
425 sksec->nlbl_state = NLBL_REQSKB;
426 rc = 0;
427 break;
428 }
429
430 return rc;
431}
432
433/**
434 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
435 * @sksec: the sock's sk_security_struct
436 * @skb: the packet
437 * @family: protocol family
438 * @ad: the audit data
439 *
440 * Description:
441 * Fetch the NetLabel security attributes from @skb and perform an access check
442 * against the receiving socket. Returns zero on success, negative values on
443 * error.
444 *
445 */
446int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
447 struct sk_buff *skb,
448 u16 family,
449 struct common_audit_data *ad)
450{
451 int rc;
452 u32 nlbl_sid;
453 u32 perm;
454 struct netlbl_lsm_secattr secattr;
455
456 if (!netlbl_enabled())
457 return 0;
458
459 netlbl_secattr_init(&secattr);
460 rc = netlbl_skbuff_getattr(skb, family, &secattr);
461 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
462 rc = selinux_netlbl_sidlookup_cached(skb, family,
463 &secattr, &nlbl_sid);
464 else
465 nlbl_sid = SECINITSID_UNLABELED;
466 netlbl_secattr_destroy(&secattr);
467 if (rc != 0)
468 return rc;
469
470 switch (sksec->sclass) {
471 case SECCLASS_UDP_SOCKET:
472 perm = UDP_SOCKET__RECVFROM;
473 break;
474 case SECCLASS_TCP_SOCKET:
475 perm = TCP_SOCKET__RECVFROM;
476 break;
477 default:
478 perm = RAWIP_SOCKET__RECVFROM;
479 }
480
481 rc = avc_has_perm(&selinux_state,
482 sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
483 if (rc == 0)
484 return 0;
485
486 if (nlbl_sid != SECINITSID_UNLABELED)
487 netlbl_skbuff_err(skb, family, rc, 0);
488 return rc;
489}
490
491/**
492 * selinux_netlbl_option - Is this a NetLabel option
493 * @level: the socket level or protocol
494 * @optname: the socket option name
495 *
496 * Description:
497 * Returns true if @level and @optname refer to a NetLabel option.
498 * Helper for selinux_netlbl_socket_setsockopt().
499 */
500static inline int selinux_netlbl_option(int level, int optname)
501{
502 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
503 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
504}
505
506/**
507 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
508 * @sock: the socket
509 * @level: the socket level or protocol
510 * @optname: the socket option name
511 *
512 * Description:
513 * Check the setsockopt() call and if the user is trying to replace the IP
514 * options on a socket and a NetLabel is in place for the socket deny the
515 * access; otherwise allow the access. Returns zero when the access is
516 * allowed, -EACCES when denied, and other negative values on error.
517 *
518 */
519int selinux_netlbl_socket_setsockopt(struct socket *sock,
520 int level,
521 int optname)
522{
523 int rc = 0;
524 struct sock *sk = sock->sk;
525 struct sk_security_struct *sksec = sk->sk_security;
526 struct netlbl_lsm_secattr secattr;
527
528 if (selinux_netlbl_option(level, optname) &&
529 (sksec->nlbl_state == NLBL_LABELED ||
530 sksec->nlbl_state == NLBL_CONNLABELED)) {
531 netlbl_secattr_init(&secattr);
532 lock_sock(sk);
533 /* call the netlabel function directly as we want to see the
534 * on-the-wire label that is assigned via the socket's options
535 * and not the cached netlabel/lsm attributes */
536 rc = netlbl_sock_getattr(sk, &secattr);
537 release_sock(sk);
538 if (rc == 0)
539 rc = -EACCES;
540 else if (rc == -ENOMSG)
541 rc = 0;
542 netlbl_secattr_destroy(&secattr);
543 }
544
545 return rc;
546}
547
548/**
549 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
550 * connect
551 * @sk: the socket to label
552 * @addr: the destination address
553 *
554 * Description:
555 * Attempt to label a connected socket with NetLabel using the given address.
556 * Returns zero values on success, negative values on failure.
557 *
558 */
559static int selinux_netlbl_socket_connect_helper(struct sock *sk,
560 struct sockaddr *addr)
561{
562 int rc;
563 struct sk_security_struct *sksec = sk->sk_security;
564 struct netlbl_lsm_secattr *secattr;
565
566 /* connected sockets are allowed to disconnect when the address family
567 * is set to AF_UNSPEC, if that is what is happening we want to reset
568 * the socket */
569 if (addr->sa_family == AF_UNSPEC) {
570 netlbl_sock_delattr(sk);
571 sksec->nlbl_state = NLBL_REQSKB;
572 rc = 0;
573 return rc;
574 }
575 secattr = selinux_netlbl_sock_genattr(sk);
576 if (secattr == NULL) {
577 rc = -ENOMEM;
578 return rc;
579 }
580 rc = netlbl_conn_setattr(sk, addr, secattr);
581 if (rc == 0)
582 sksec->nlbl_state = NLBL_CONNLABELED;
583
584 return rc;
585}
586
587/**
588 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
589 * connect
590 * @sk: the socket to label
591 * @addr: the destination address
592 *
593 * Description:
594 * Attempt to label a connected socket that already has the socket locked
595 * with NetLabel using the given address.
596 * Returns zero values on success, negative values on failure.
597 *
598 */
599int selinux_netlbl_socket_connect_locked(struct sock *sk,
600 struct sockaddr *addr)
601{
602 struct sk_security_struct *sksec = sk->sk_security;
603
604 if (sksec->nlbl_state != NLBL_REQSKB &&
605 sksec->nlbl_state != NLBL_CONNLABELED)
606 return 0;
607
608 return selinux_netlbl_socket_connect_helper(sk, addr);
609}
610
611/**
612 * selinux_netlbl_socket_connect - Label a client-side socket on connect
613 * @sk: the socket to label
614 * @addr: the destination address
615 *
616 * Description:
617 * Attempt to label a connected socket with NetLabel using the given address.
618 * Returns zero values on success, negative values on failure.
619 *
620 */
621int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
622{
623 int rc;
624
625 lock_sock(sk);
626 rc = selinux_netlbl_socket_connect_locked(sk, addr);
627 release_sock(sk);
628
629 return rc;
630}
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}