Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * SELinux NetLabel Support
4 *
5 * This file provides the necessary glue to tie NetLabel into the SELinux
6 * subsystem.
7 *
8 * Author: Paul Moore <paul@paul-moore.com>
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
13 */
14
15#include <linux/spinlock.h>
16#include <linux/rcupdate.h>
17#include <linux/gfp.h>
18#include <linux/ip.h>
19#include <linux/ipv6.h>
20#include <net/sock.h>
21#include <net/netlabel.h>
22#include <net/ip.h>
23#include <net/ipv6.h>
24
25#include "objsec.h"
26#include "security.h"
27#include "netlabel.h"
28
29/**
30 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
31 * @skb: the packet
32 * @secattr: the NetLabel security attributes
33 * @sid: the SID
34 *
35 * Description:
36 * Query the SELinux security server to lookup the correct SID for the given
37 * security attributes. If the query is successful, cache the result to speed
38 * up future lookups. Returns zero on success, negative values on failure.
39 *
40 */
41static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
42 u16 family,
43 struct netlbl_lsm_secattr *secattr,
44 u32 *sid)
45{
46 int rc;
47
48 rc = security_netlbl_secattr_to_sid(&selinux_state, secattr, sid);
49 if (rc == 0 &&
50 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
51 (secattr->flags & NETLBL_SECATTR_CACHE))
52 netlbl_cache_add(skb, family, secattr);
53
54 return rc;
55}
56
57/**
58 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
59 * @sk: the socket
60 *
61 * Description:
62 * Generate the NetLabel security attributes for a socket, making full use of
63 * the socket's attribute cache. Returns a pointer to the security attributes
64 * on success, NULL on failure.
65 *
66 */
67static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
68{
69 int rc;
70 struct sk_security_struct *sksec = sk->sk_security;
71 struct netlbl_lsm_secattr *secattr;
72
73 if (sksec->nlbl_secattr != NULL)
74 return sksec->nlbl_secattr;
75
76 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
77 if (secattr == NULL)
78 return NULL;
79 rc = security_netlbl_sid_to_secattr(&selinux_state, sksec->sid,
80 secattr);
81 if (rc != 0) {
82 netlbl_secattr_free(secattr);
83 return NULL;
84 }
85 sksec->nlbl_secattr = secattr;
86
87 return secattr;
88}
89
90/**
91 * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
92 * @sk: the socket
93 * @sid: the SID
94 *
95 * Query the socket's cached secattr and if the SID matches the cached value
96 * return the cache, otherwise return NULL.
97 *
98 */
99static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
100 const struct sock *sk,
101 u32 sid)
102{
103 struct sk_security_struct *sksec = sk->sk_security;
104 struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
105
106 if (secattr == NULL)
107 return NULL;
108
109 if ((secattr->flags & NETLBL_SECATTR_SECID) &&
110 (secattr->attr.secid == sid))
111 return secattr;
112
113 return NULL;
114}
115
116/**
117 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
118 *
119 * Description:
120 * Invalidate the NetLabel security attribute mapping cache.
121 *
122 */
123void selinux_netlbl_cache_invalidate(void)
124{
125 netlbl_cache_invalidate();
126}
127
128/**
129 * selinux_netlbl_err - Handle a NetLabel packet error
130 * @skb: the packet
131 * @error: the error code
132 * @gateway: true if host is acting as a gateway, false otherwise
133 *
134 * Description:
135 * When a packet is dropped due to a call to avc_has_perm() pass the error
136 * code to the NetLabel subsystem so any protocol specific processing can be
137 * done. This is safe to call even if you are unsure if NetLabel labeling is
138 * present on the packet, NetLabel is smart enough to only act when it should.
139 *
140 */
141void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
142{
143 netlbl_skbuff_err(skb, family, error, gateway);
144}
145
146/**
147 * selinux_netlbl_sk_security_free - Free the NetLabel fields
148 * @sksec: the sk_security_struct
149 *
150 * Description:
151 * Free all of the memory in the NetLabel fields of a sk_security_struct.
152 *
153 */
154void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
155{
156 if (sksec->nlbl_secattr != NULL)
157 netlbl_secattr_free(sksec->nlbl_secattr);
158}
159
160/**
161 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
162 * @sksec: the sk_security_struct
163 * @family: the socket family
164 *
165 * Description:
166 * Called when the NetLabel state of a sk_security_struct needs to be reset.
167 * The caller is responsible for all the NetLabel sk_security_struct locking.
168 *
169 */
170void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
171{
172 sksec->nlbl_state = NLBL_UNSET;
173}
174
175/**
176 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
177 * @skb: the packet
178 * @family: protocol family
179 * @type: NetLabel labeling protocol type
180 * @sid: the SID
181 *
182 * Description:
183 * Call the NetLabel mechanism to get the security attributes of the given
184 * packet and use those attributes to determine the correct context/SID to
185 * assign to the packet. Returns zero on success, negative values on failure.
186 *
187 */
188int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
189 u16 family,
190 u32 *type,
191 u32 *sid)
192{
193 int rc;
194 struct netlbl_lsm_secattr secattr;
195
196 if (!netlbl_enabled()) {
197 *sid = SECSID_NULL;
198 return 0;
199 }
200
201 netlbl_secattr_init(&secattr);
202 rc = netlbl_skbuff_getattr(skb, family, &secattr);
203 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
204 rc = selinux_netlbl_sidlookup_cached(skb, family,
205 &secattr, sid);
206 else
207 *sid = SECSID_NULL;
208 *type = secattr.type;
209 netlbl_secattr_destroy(&secattr);
210
211 return rc;
212}
213
214/**
215 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
216 * @skb: the packet
217 * @family: protocol family
218 * @sid: the SID
219 *
220 * Description
221 * Call the NetLabel mechanism to set the label of a packet using @sid.
222 * Returns zero on success, negative values on failure.
223 *
224 */
225int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
226 u16 family,
227 u32 sid)
228{
229 int rc;
230 struct netlbl_lsm_secattr secattr_storage;
231 struct netlbl_lsm_secattr *secattr = NULL;
232 struct sock *sk;
233
234 /* if this is a locally generated packet check to see if it is already
235 * being labeled by it's parent socket, if it is just exit */
236 sk = skb_to_full_sk(skb);
237 if (sk != NULL) {
238 struct sk_security_struct *sksec = sk->sk_security;
239
240 if (sksec->nlbl_state != NLBL_REQSKB)
241 return 0;
242 secattr = selinux_netlbl_sock_getattr(sk, sid);
243 }
244 if (secattr == NULL) {
245 secattr = &secattr_storage;
246 netlbl_secattr_init(secattr);
247 rc = security_netlbl_sid_to_secattr(&selinux_state, sid,
248 secattr);
249 if (rc != 0)
250 goto skbuff_setsid_return;
251 }
252
253 rc = netlbl_skbuff_setattr(skb, family, secattr);
254
255skbuff_setsid_return:
256 if (secattr == &secattr_storage)
257 netlbl_secattr_destroy(secattr);
258 return rc;
259}
260
261/**
262 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
263 * @ep: incoming association endpoint.
264 * @skb: the packet.
265 *
266 * Description:
267 * A new incoming connection is represented by @ep, ......
268 * Returns zero on success, negative values on failure.
269 *
270 */
271int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
272 struct sk_buff *skb)
273{
274 int rc;
275 struct netlbl_lsm_secattr secattr;
276 struct sk_security_struct *sksec = ep->base.sk->sk_security;
277 struct sockaddr_in addr4;
278 struct sockaddr_in6 addr6;
279
280 if (ep->base.sk->sk_family != PF_INET &&
281 ep->base.sk->sk_family != PF_INET6)
282 return 0;
283
284 netlbl_secattr_init(&secattr);
285 rc = security_netlbl_sid_to_secattr(&selinux_state,
286 ep->secid, &secattr);
287 if (rc != 0)
288 goto assoc_request_return;
289
290 /* Move skb hdr address info to a struct sockaddr and then call
291 * netlbl_conn_setattr().
292 */
293 if (ip_hdr(skb)->version == 4) {
294 addr4.sin_family = AF_INET;
295 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
296 rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr4, &secattr);
297 } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
298 addr6.sin6_family = AF_INET6;
299 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
300 rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr6, &secattr);
301 } else {
302 rc = -EAFNOSUPPORT;
303 }
304
305 if (rc == 0)
306 sksec->nlbl_state = NLBL_LABELED;
307
308assoc_request_return:
309 netlbl_secattr_destroy(&secattr);
310 return rc;
311}
312
313/**
314 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
315 * @req: incoming connection request socket
316 *
317 * Description:
318 * A new incoming connection request is represented by @req, we need to label
319 * the new request_sock here and the stack will ensure the on-the-wire label
320 * will get preserved when a full sock is created once the connection handshake
321 * is complete. Returns zero on success, negative values on failure.
322 *
323 */
324int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
325{
326 int rc;
327 struct netlbl_lsm_secattr secattr;
328
329 if (family != PF_INET && family != PF_INET6)
330 return 0;
331
332 netlbl_secattr_init(&secattr);
333 rc = security_netlbl_sid_to_secattr(&selinux_state, req->secid,
334 &secattr);
335 if (rc != 0)
336 goto inet_conn_request_return;
337 rc = netlbl_req_setattr(req, &secattr);
338inet_conn_request_return:
339 netlbl_secattr_destroy(&secattr);
340 return rc;
341}
342
343/**
344 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
345 * @sk: the new sock
346 *
347 * Description:
348 * A new connection has been established using @sk, we've already labeled the
349 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
350 * we need to set the NetLabel state here since we now have a sock structure.
351 *
352 */
353void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
354{
355 struct sk_security_struct *sksec = sk->sk_security;
356
357 if (family == PF_INET)
358 sksec->nlbl_state = NLBL_LABELED;
359 else
360 sksec->nlbl_state = NLBL_UNSET;
361}
362
363/**
364 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
365 * @sk: current sock
366 * @newsk: the new sock
367 *
368 * Description:
369 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
370 */
371void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
372{
373 struct sk_security_struct *sksec = sk->sk_security;
374 struct sk_security_struct *newsksec = newsk->sk_security;
375
376 newsksec->nlbl_state = sksec->nlbl_state;
377}
378
379/**
380 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
381 * @sock: the socket to label
382 * @family: protocol family
383 *
384 * Description:
385 * Attempt to label a socket using the NetLabel mechanism using the given
386 * SID. Returns zero values on success, negative values on failure.
387 *
388 */
389int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
390{
391 int rc;
392 struct sk_security_struct *sksec = sk->sk_security;
393 struct netlbl_lsm_secattr *secattr;
394
395 if (family != PF_INET && family != PF_INET6)
396 return 0;
397
398 secattr = selinux_netlbl_sock_genattr(sk);
399 if (secattr == NULL)
400 return -ENOMEM;
401 rc = netlbl_sock_setattr(sk, family, secattr);
402 switch (rc) {
403 case 0:
404 sksec->nlbl_state = NLBL_LABELED;
405 break;
406 case -EDESTADDRREQ:
407 sksec->nlbl_state = NLBL_REQSKB;
408 rc = 0;
409 break;
410 }
411
412 return rc;
413}
414
415/**
416 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
417 * @sksec: the sock's sk_security_struct
418 * @skb: the packet
419 * @family: protocol family
420 * @ad: the audit data
421 *
422 * Description:
423 * Fetch the NetLabel security attributes from @skb and perform an access check
424 * against the receiving socket. Returns zero on success, negative values on
425 * error.
426 *
427 */
428int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
429 struct sk_buff *skb,
430 u16 family,
431 struct common_audit_data *ad)
432{
433 int rc;
434 u32 nlbl_sid;
435 u32 perm;
436 struct netlbl_lsm_secattr secattr;
437
438 if (!netlbl_enabled())
439 return 0;
440
441 netlbl_secattr_init(&secattr);
442 rc = netlbl_skbuff_getattr(skb, family, &secattr);
443 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
444 rc = selinux_netlbl_sidlookup_cached(skb, family,
445 &secattr, &nlbl_sid);
446 else
447 nlbl_sid = SECINITSID_UNLABELED;
448 netlbl_secattr_destroy(&secattr);
449 if (rc != 0)
450 return rc;
451
452 switch (sksec->sclass) {
453 case SECCLASS_UDP_SOCKET:
454 perm = UDP_SOCKET__RECVFROM;
455 break;
456 case SECCLASS_TCP_SOCKET:
457 perm = TCP_SOCKET__RECVFROM;
458 break;
459 default:
460 perm = RAWIP_SOCKET__RECVFROM;
461 }
462
463 rc = avc_has_perm(&selinux_state,
464 sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
465 if (rc == 0)
466 return 0;
467
468 if (nlbl_sid != SECINITSID_UNLABELED)
469 netlbl_skbuff_err(skb, family, rc, 0);
470 return rc;
471}
472
473/**
474 * selinux_netlbl_option - Is this a NetLabel option
475 * @level: the socket level or protocol
476 * @optname: the socket option name
477 *
478 * Description:
479 * Returns true if @level and @optname refer to a NetLabel option.
480 * Helper for selinux_netlbl_socket_setsockopt().
481 */
482static inline int selinux_netlbl_option(int level, int optname)
483{
484 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
485 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
486}
487
488/**
489 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
490 * @sock: the socket
491 * @level: the socket level or protocol
492 * @optname: the socket option name
493 *
494 * Description:
495 * Check the setsockopt() call and if the user is trying to replace the IP
496 * options on a socket and a NetLabel is in place for the socket deny the
497 * access; otherwise allow the access. Returns zero when the access is
498 * allowed, -EACCES when denied, and other negative values on error.
499 *
500 */
501int selinux_netlbl_socket_setsockopt(struct socket *sock,
502 int level,
503 int optname)
504{
505 int rc = 0;
506 struct sock *sk = sock->sk;
507 struct sk_security_struct *sksec = sk->sk_security;
508 struct netlbl_lsm_secattr secattr;
509
510 if (selinux_netlbl_option(level, optname) &&
511 (sksec->nlbl_state == NLBL_LABELED ||
512 sksec->nlbl_state == NLBL_CONNLABELED)) {
513 netlbl_secattr_init(&secattr);
514 lock_sock(sk);
515 /* call the netlabel function directly as we want to see the
516 * on-the-wire label that is assigned via the socket's options
517 * and not the cached netlabel/lsm attributes */
518 rc = netlbl_sock_getattr(sk, &secattr);
519 release_sock(sk);
520 if (rc == 0)
521 rc = -EACCES;
522 else if (rc == -ENOMSG)
523 rc = 0;
524 netlbl_secattr_destroy(&secattr);
525 }
526
527 return rc;
528}
529
530/**
531 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
532 * connect
533 * @sk: the socket to label
534 * @addr: the destination address
535 *
536 * Description:
537 * Attempt to label a connected socket with NetLabel using the given address.
538 * Returns zero values on success, negative values on failure.
539 *
540 */
541static int selinux_netlbl_socket_connect_helper(struct sock *sk,
542 struct sockaddr *addr)
543{
544 int rc;
545 struct sk_security_struct *sksec = sk->sk_security;
546 struct netlbl_lsm_secattr *secattr;
547
548 /* connected sockets are allowed to disconnect when the address family
549 * is set to AF_UNSPEC, if that is what is happening we want to reset
550 * the socket */
551 if (addr->sa_family == AF_UNSPEC) {
552 netlbl_sock_delattr(sk);
553 sksec->nlbl_state = NLBL_REQSKB;
554 rc = 0;
555 return rc;
556 }
557 secattr = selinux_netlbl_sock_genattr(sk);
558 if (secattr == NULL) {
559 rc = -ENOMEM;
560 return rc;
561 }
562 rc = netlbl_conn_setattr(sk, addr, secattr);
563 if (rc == 0)
564 sksec->nlbl_state = NLBL_CONNLABELED;
565
566 return rc;
567}
568
569/**
570 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
571 * connect
572 * @sk: the socket to label
573 * @addr: the destination address
574 *
575 * Description:
576 * Attempt to label a connected socket that already has the socket locked
577 * with NetLabel using the given address.
578 * Returns zero values on success, negative values on failure.
579 *
580 */
581int selinux_netlbl_socket_connect_locked(struct sock *sk,
582 struct sockaddr *addr)
583{
584 struct sk_security_struct *sksec = sk->sk_security;
585
586 if (sksec->nlbl_state != NLBL_REQSKB &&
587 sksec->nlbl_state != NLBL_CONNLABELED)
588 return 0;
589
590 return selinux_netlbl_socket_connect_helper(sk, addr);
591}
592
593/**
594 * selinux_netlbl_socket_connect - Label a client-side socket on connect
595 * @sk: the socket to label
596 * @addr: the destination address
597 *
598 * Description:
599 * Attempt to label a connected socket with NetLabel using the given address.
600 * Returns zero values on success, negative values on failure.
601 *
602 */
603int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
604{
605 int rc;
606
607 lock_sock(sk);
608 rc = selinux_netlbl_socket_connect_locked(sk, addr);
609 release_sock(sk);
610
611 return rc;
612}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * SELinux NetLabel Support
4 *
5 * This file provides the necessary glue to tie NetLabel into the SELinux
6 * subsystem.
7 *
8 * Author: Paul Moore <paul@paul-moore.com>
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
13 */
14
15#include <linux/spinlock.h>
16#include <linux/rcupdate.h>
17#include <linux/gfp.h>
18#include <linux/ip.h>
19#include <linux/ipv6.h>
20#include <net/sock.h>
21#include <net/netlabel.h>
22#include <net/ip.h>
23#include <net/ipv6.h>
24
25#include "objsec.h"
26#include "security.h"
27#include "netlabel.h"
28
29/**
30 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
31 * @skb: the packet
32 * @secattr: the NetLabel security attributes
33 * @sid: the SID
34 *
35 * Description:
36 * Query the SELinux security server to lookup the correct SID for the given
37 * security attributes. If the query is successful, cache the result to speed
38 * up future lookups. Returns zero on success, negative values on failure.
39 *
40 */
41static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
42 u16 family,
43 struct netlbl_lsm_secattr *secattr,
44 u32 *sid)
45{
46 int rc;
47
48 rc = security_netlbl_secattr_to_sid(&selinux_state, secattr, sid);
49 if (rc == 0 &&
50 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
51 (secattr->flags & NETLBL_SECATTR_CACHE))
52 netlbl_cache_add(skb, family, secattr);
53
54 return rc;
55}
56
57/**
58 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
59 * @sk: the socket
60 *
61 * Description:
62 * Generate the NetLabel security attributes for a socket, making full use of
63 * the socket's attribute cache. Returns a pointer to the security attributes
64 * on success, NULL on failure.
65 *
66 */
67static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
68{
69 int rc;
70 struct sk_security_struct *sksec = sk->sk_security;
71 struct netlbl_lsm_secattr *secattr;
72
73 if (sksec->nlbl_secattr != NULL)
74 return sksec->nlbl_secattr;
75
76 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
77 if (secattr == NULL)
78 return NULL;
79 rc = security_netlbl_sid_to_secattr(&selinux_state, sksec->sid,
80 secattr);
81 if (rc != 0) {
82 netlbl_secattr_free(secattr);
83 return NULL;
84 }
85 sksec->nlbl_secattr = secattr;
86
87 return secattr;
88}
89
90/**
91 * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
92 * @sk: the socket
93 * @sid: the SID
94 *
95 * Query the socket's cached secattr and if the SID matches the cached value
96 * return the cache, otherwise return NULL.
97 *
98 */
99static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
100 const struct sock *sk,
101 u32 sid)
102{
103 struct sk_security_struct *sksec = sk->sk_security;
104 struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
105
106 if (secattr == NULL)
107 return NULL;
108
109 if ((secattr->flags & NETLBL_SECATTR_SECID) &&
110 (secattr->attr.secid == sid))
111 return secattr;
112
113 return NULL;
114}
115
116/**
117 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
118 *
119 * Description:
120 * Invalidate the NetLabel security attribute mapping cache.
121 *
122 */
123void selinux_netlbl_cache_invalidate(void)
124{
125 netlbl_cache_invalidate();
126}
127
128/**
129 * selinux_netlbl_err - Handle a NetLabel packet error
130 * @skb: the packet
131 * @error: the error code
132 * @gateway: true if host is acting as a gateway, false otherwise
133 *
134 * Description:
135 * When a packet is dropped due to a call to avc_has_perm() pass the error
136 * code to the NetLabel subsystem so any protocol specific processing can be
137 * done. This is safe to call even if you are unsure if NetLabel labeling is
138 * present on the packet, NetLabel is smart enough to only act when it should.
139 *
140 */
141void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
142{
143 netlbl_skbuff_err(skb, family, error, gateway);
144}
145
146/**
147 * selinux_netlbl_sk_security_free - Free the NetLabel fields
148 * @sksec: the sk_security_struct
149 *
150 * Description:
151 * Free all of the memory in the NetLabel fields of a sk_security_struct.
152 *
153 */
154void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
155{
156 if (sksec->nlbl_secattr != NULL)
157 netlbl_secattr_free(sksec->nlbl_secattr);
158}
159
160/**
161 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
162 * @sksec: the sk_security_struct
163 * @family: the socket family
164 *
165 * Description:
166 * Called when the NetLabel state of a sk_security_struct needs to be reset.
167 * The caller is responsible for all the NetLabel sk_security_struct locking.
168 *
169 */
170void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
171{
172 sksec->nlbl_state = NLBL_UNSET;
173}
174
175/**
176 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
177 * @skb: the packet
178 * @family: protocol family
179 * @type: NetLabel labeling protocol type
180 * @sid: the SID
181 *
182 * Description:
183 * Call the NetLabel mechanism to get the security attributes of the given
184 * packet and use those attributes to determine the correct context/SID to
185 * assign to the packet. Returns zero on success, negative values on failure.
186 *
187 */
188int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
189 u16 family,
190 u32 *type,
191 u32 *sid)
192{
193 int rc;
194 struct netlbl_lsm_secattr secattr;
195
196 if (!netlbl_enabled()) {
197 *sid = SECSID_NULL;
198 return 0;
199 }
200
201 netlbl_secattr_init(&secattr);
202 rc = netlbl_skbuff_getattr(skb, family, &secattr);
203 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
204 rc = selinux_netlbl_sidlookup_cached(skb, family,
205 &secattr, sid);
206 else
207 *sid = SECSID_NULL;
208 *type = secattr.type;
209 netlbl_secattr_destroy(&secattr);
210
211 return rc;
212}
213
214/**
215 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
216 * @skb: the packet
217 * @family: protocol family
218 * @sid: the SID
219 *
220 * Description
221 * Call the NetLabel mechanism to set the label of a packet using @sid.
222 * Returns zero on success, negative values on failure.
223 *
224 */
225int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
226 u16 family,
227 u32 sid)
228{
229 int rc;
230 struct netlbl_lsm_secattr secattr_storage;
231 struct netlbl_lsm_secattr *secattr = NULL;
232 struct sock *sk;
233
234 /* if this is a locally generated packet check to see if it is already
235 * being labeled by it's parent socket, if it is just exit */
236 sk = skb_to_full_sk(skb);
237 if (sk != NULL) {
238 struct sk_security_struct *sksec = sk->sk_security;
239
240 if (sksec->nlbl_state != NLBL_REQSKB)
241 return 0;
242 secattr = selinux_netlbl_sock_getattr(sk, sid);
243 }
244 if (secattr == NULL) {
245 secattr = &secattr_storage;
246 netlbl_secattr_init(secattr);
247 rc = security_netlbl_sid_to_secattr(&selinux_state, sid,
248 secattr);
249 if (rc != 0)
250 goto skbuff_setsid_return;
251 }
252
253 rc = netlbl_skbuff_setattr(skb, family, secattr);
254
255skbuff_setsid_return:
256 if (secattr == &secattr_storage)
257 netlbl_secattr_destroy(secattr);
258 return rc;
259}
260
261/**
262 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
263 * @ep: incoming association endpoint.
264 * @skb: the packet.
265 *
266 * Description:
267 * A new incoming connection is represented by @ep, ......
268 * Returns zero on success, negative values on failure.
269 *
270 */
271int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
272 struct sk_buff *skb)
273{
274 int rc;
275 struct netlbl_lsm_secattr secattr;
276 struct sk_security_struct *sksec = ep->base.sk->sk_security;
277 struct sockaddr_in addr4;
278 struct sockaddr_in6 addr6;
279
280 if (ep->base.sk->sk_family != PF_INET &&
281 ep->base.sk->sk_family != PF_INET6)
282 return 0;
283
284 netlbl_secattr_init(&secattr);
285 rc = security_netlbl_sid_to_secattr(&selinux_state,
286 ep->secid, &secattr);
287 if (rc != 0)
288 goto assoc_request_return;
289
290 /* Move skb hdr address info to a struct sockaddr and then call
291 * netlbl_conn_setattr().
292 */
293 if (ip_hdr(skb)->version == 4) {
294 addr4.sin_family = AF_INET;
295 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
296 rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr4, &secattr);
297 } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
298 addr6.sin6_family = AF_INET6;
299 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
300 rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr6, &secattr);
301 } else {
302 rc = -EAFNOSUPPORT;
303 }
304
305 if (rc == 0)
306 sksec->nlbl_state = NLBL_LABELED;
307
308assoc_request_return:
309 netlbl_secattr_destroy(&secattr);
310 return rc;
311}
312
313/**
314 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
315 * @req: incoming connection request socket
316 *
317 * Description:
318 * A new incoming connection request is represented by @req, we need to label
319 * the new request_sock here and the stack will ensure the on-the-wire label
320 * will get preserved when a full sock is created once the connection handshake
321 * is complete. Returns zero on success, negative values on failure.
322 *
323 */
324int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
325{
326 int rc;
327 struct netlbl_lsm_secattr secattr;
328
329 if (family != PF_INET && family != PF_INET6)
330 return 0;
331
332 netlbl_secattr_init(&secattr);
333 rc = security_netlbl_sid_to_secattr(&selinux_state, req->secid,
334 &secattr);
335 if (rc != 0)
336 goto inet_conn_request_return;
337 rc = netlbl_req_setattr(req, &secattr);
338inet_conn_request_return:
339 netlbl_secattr_destroy(&secattr);
340 return rc;
341}
342
343/**
344 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
345 * @sk: the new sock
346 *
347 * Description:
348 * A new connection has been established using @sk, we've already labeled the
349 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
350 * we need to set the NetLabel state here since we now have a sock structure.
351 *
352 */
353void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
354{
355 struct sk_security_struct *sksec = sk->sk_security;
356
357 if (family == PF_INET)
358 sksec->nlbl_state = NLBL_LABELED;
359 else
360 sksec->nlbl_state = NLBL_UNSET;
361}
362
363/**
364 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
365 * @sk: current sock
366 * @newsk: the new sock
367 *
368 * Description:
369 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
370 */
371void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
372{
373 struct sk_security_struct *sksec = sk->sk_security;
374 struct sk_security_struct *newsksec = newsk->sk_security;
375
376 newsksec->nlbl_state = sksec->nlbl_state;
377}
378
379/**
380 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
381 * @sock: the socket to label
382 * @family: protocol family
383 *
384 * Description:
385 * Attempt to label a socket using the NetLabel mechanism using the given
386 * SID. Returns zero values on success, negative values on failure.
387 *
388 */
389int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
390{
391 int rc;
392 struct sk_security_struct *sksec = sk->sk_security;
393 struct netlbl_lsm_secattr *secattr;
394
395 if (family != PF_INET && family != PF_INET6)
396 return 0;
397
398 secattr = selinux_netlbl_sock_genattr(sk);
399 if (secattr == NULL)
400 return -ENOMEM;
401 rc = netlbl_sock_setattr(sk, family, secattr);
402 switch (rc) {
403 case 0:
404 sksec->nlbl_state = NLBL_LABELED;
405 break;
406 case -EDESTADDRREQ:
407 sksec->nlbl_state = NLBL_REQSKB;
408 rc = 0;
409 break;
410 }
411
412 return rc;
413}
414
415/**
416 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
417 * @sksec: the sock's sk_security_struct
418 * @skb: the packet
419 * @family: protocol family
420 * @ad: the audit data
421 *
422 * Description:
423 * Fetch the NetLabel security attributes from @skb and perform an access check
424 * against the receiving socket. Returns zero on success, negative values on
425 * error.
426 *
427 */
428int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
429 struct sk_buff *skb,
430 u16 family,
431 struct common_audit_data *ad)
432{
433 int rc;
434 u32 nlbl_sid;
435 u32 perm;
436 struct netlbl_lsm_secattr secattr;
437
438 if (!netlbl_enabled())
439 return 0;
440
441 netlbl_secattr_init(&secattr);
442 rc = netlbl_skbuff_getattr(skb, family, &secattr);
443 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
444 rc = selinux_netlbl_sidlookup_cached(skb, family,
445 &secattr, &nlbl_sid);
446 else
447 nlbl_sid = SECINITSID_UNLABELED;
448 netlbl_secattr_destroy(&secattr);
449 if (rc != 0)
450 return rc;
451
452 switch (sksec->sclass) {
453 case SECCLASS_UDP_SOCKET:
454 perm = UDP_SOCKET__RECVFROM;
455 break;
456 case SECCLASS_TCP_SOCKET:
457 perm = TCP_SOCKET__RECVFROM;
458 break;
459 default:
460 perm = RAWIP_SOCKET__RECVFROM;
461 }
462
463 rc = avc_has_perm(&selinux_state,
464 sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
465 if (rc == 0)
466 return 0;
467
468 if (nlbl_sid != SECINITSID_UNLABELED)
469 netlbl_skbuff_err(skb, family, rc, 0);
470 return rc;
471}
472
473/**
474 * selinux_netlbl_option - Is this a NetLabel option
475 * @level: the socket level or protocol
476 * @optname: the socket option name
477 *
478 * Description:
479 * Returns true if @level and @optname refer to a NetLabel option.
480 * Helper for selinux_netlbl_socket_setsockopt().
481 */
482static inline int selinux_netlbl_option(int level, int optname)
483{
484 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
485 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
486}
487
488/**
489 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
490 * @sock: the socket
491 * @level: the socket level or protocol
492 * @optname: the socket option name
493 *
494 * Description:
495 * Check the setsockopt() call and if the user is trying to replace the IP
496 * options on a socket and a NetLabel is in place for the socket deny the
497 * access; otherwise allow the access. Returns zero when the access is
498 * allowed, -EACCES when denied, and other negative values on error.
499 *
500 */
501int selinux_netlbl_socket_setsockopt(struct socket *sock,
502 int level,
503 int optname)
504{
505 int rc = 0;
506 struct sock *sk = sock->sk;
507 struct sk_security_struct *sksec = sk->sk_security;
508 struct netlbl_lsm_secattr secattr;
509
510 if (selinux_netlbl_option(level, optname) &&
511 (sksec->nlbl_state == NLBL_LABELED ||
512 sksec->nlbl_state == NLBL_CONNLABELED)) {
513 netlbl_secattr_init(&secattr);
514 lock_sock(sk);
515 /* call the netlabel function directly as we want to see the
516 * on-the-wire label that is assigned via the socket's options
517 * and not the cached netlabel/lsm attributes */
518 rc = netlbl_sock_getattr(sk, &secattr);
519 release_sock(sk);
520 if (rc == 0)
521 rc = -EACCES;
522 else if (rc == -ENOMSG)
523 rc = 0;
524 netlbl_secattr_destroy(&secattr);
525 }
526
527 return rc;
528}
529
530/**
531 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
532 * connect
533 * @sk: the socket to label
534 * @addr: the destination address
535 *
536 * Description:
537 * Attempt to label a connected socket with NetLabel using the given address.
538 * Returns zero values on success, negative values on failure.
539 *
540 */
541static int selinux_netlbl_socket_connect_helper(struct sock *sk,
542 struct sockaddr *addr)
543{
544 int rc;
545 struct sk_security_struct *sksec = sk->sk_security;
546 struct netlbl_lsm_secattr *secattr;
547
548 /* connected sockets are allowed to disconnect when the address family
549 * is set to AF_UNSPEC, if that is what is happening we want to reset
550 * the socket */
551 if (addr->sa_family == AF_UNSPEC) {
552 netlbl_sock_delattr(sk);
553 sksec->nlbl_state = NLBL_REQSKB;
554 rc = 0;
555 return rc;
556 }
557 secattr = selinux_netlbl_sock_genattr(sk);
558 if (secattr == NULL) {
559 rc = -ENOMEM;
560 return rc;
561 }
562 rc = netlbl_conn_setattr(sk, addr, secattr);
563 if (rc == 0)
564 sksec->nlbl_state = NLBL_CONNLABELED;
565
566 return rc;
567}
568
569/**
570 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
571 * connect
572 * @sk: the socket to label
573 * @addr: the destination address
574 *
575 * Description:
576 * Attempt to label a connected socket that already has the socket locked
577 * with NetLabel using the given address.
578 * Returns zero values on success, negative values on failure.
579 *
580 */
581int selinux_netlbl_socket_connect_locked(struct sock *sk,
582 struct sockaddr *addr)
583{
584 struct sk_security_struct *sksec = sk->sk_security;
585
586 if (sksec->nlbl_state != NLBL_REQSKB &&
587 sksec->nlbl_state != NLBL_CONNLABELED)
588 return 0;
589
590 return selinux_netlbl_socket_connect_helper(sk, addr);
591}
592
593/**
594 * selinux_netlbl_socket_connect - Label a client-side socket on connect
595 * @sk: the socket to label
596 * @addr: the destination address
597 *
598 * Description:
599 * Attempt to label a connected socket with NetLabel using the given address.
600 * Returns zero values on success, negative values on failure.
601 *
602 */
603int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
604{
605 int rc;
606
607 lock_sock(sk);
608 rc = selinux_netlbl_socket_connect_locked(sk, addr);
609 release_sock(sk);
610
611 return rc;
612}