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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 * @family: the packet's address family
33 * @secattr: the NetLabel security attributes
34 * @sid: the SID
35 *
36 * Description:
37 * Query the SELinux security server to lookup the correct SID for the given
38 * security attributes. If the query is successful, cache the result to speed
39 * up future lookups. Returns zero on success, negative values on failure.
40 *
41 */
42static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
43 u16 family,
44 struct netlbl_lsm_secattr *secattr,
45 u32 *sid)
46{
47 int rc;
48
49 rc = security_netlbl_secattr_to_sid(&selinux_state, secattr, sid);
50 if (rc == 0 &&
51 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
52 (secattr->flags & NETLBL_SECATTR_CACHE))
53 netlbl_cache_add(skb, family, secattr);
54
55 return rc;
56}
57
58/**
59 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
60 * @sk: the socket
61 *
62 * Description:
63 * Generate the NetLabel security attributes for a socket, making full use of
64 * the socket's attribute cache. Returns a pointer to the security attributes
65 * on success, NULL on failure.
66 *
67 */
68static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
69{
70 int rc;
71 struct sk_security_struct *sksec = sk->sk_security;
72 struct netlbl_lsm_secattr *secattr;
73
74 if (sksec->nlbl_secattr != NULL)
75 return sksec->nlbl_secattr;
76
77 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
78 if (secattr == NULL)
79 return NULL;
80 rc = security_netlbl_sid_to_secattr(&selinux_state, sksec->sid,
81 secattr);
82 if (rc != 0) {
83 netlbl_secattr_free(secattr);
84 return NULL;
85 }
86 sksec->nlbl_secattr = secattr;
87
88 return secattr;
89}
90
91/**
92 * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
93 * @sk: the socket
94 * @sid: the SID
95 *
96 * Query the socket's cached secattr and if the SID matches the cached value
97 * return the cache, otherwise return NULL.
98 *
99 */
100static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
101 const struct sock *sk,
102 u32 sid)
103{
104 struct sk_security_struct *sksec = sk->sk_security;
105 struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
106
107 if (secattr == NULL)
108 return NULL;
109
110 if ((secattr->flags & NETLBL_SECATTR_SECID) &&
111 (secattr->attr.secid == sid))
112 return secattr;
113
114 return NULL;
115}
116
117/**
118 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
119 *
120 * Description:
121 * Invalidate the NetLabel security attribute mapping cache.
122 *
123 */
124void selinux_netlbl_cache_invalidate(void)
125{
126 netlbl_cache_invalidate();
127}
128
129/**
130 * selinux_netlbl_err - Handle a NetLabel packet error
131 * @skb: the packet
132 * @family: the packet's address family
133 * @error: the error code
134 * @gateway: true if host is acting as a gateway, false otherwise
135 *
136 * Description:
137 * When a packet is dropped due to a call to avc_has_perm() pass the error
138 * code to the NetLabel subsystem so any protocol specific processing can be
139 * done. This is safe to call even if you are unsure if NetLabel labeling is
140 * present on the packet, NetLabel is smart enough to only act when it should.
141 *
142 */
143void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
144{
145 netlbl_skbuff_err(skb, family, error, gateway);
146}
147
148/**
149 * selinux_netlbl_sk_security_free - Free the NetLabel fields
150 * @sksec: the sk_security_struct
151 *
152 * Description:
153 * Free all of the memory in the NetLabel fields of a sk_security_struct.
154 *
155 */
156void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
157{
158 if (sksec->nlbl_secattr != NULL)
159 netlbl_secattr_free(sksec->nlbl_secattr);
160}
161
162/**
163 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
164 * @sksec: the sk_security_struct
165 *
166 * Description:
167 * Called when the NetLabel state of a sk_security_struct needs to be reset.
168 * The caller is responsible for all the NetLabel sk_security_struct locking.
169 *
170 */
171void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
172{
173 sksec->nlbl_state = NLBL_UNSET;
174}
175
176/**
177 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
178 * @skb: the packet
179 * @family: protocol family
180 * @type: NetLabel labeling protocol type
181 * @sid: the SID
182 *
183 * Description:
184 * Call the NetLabel mechanism to get the security attributes of the given
185 * packet and use those attributes to determine the correct context/SID to
186 * assign to the packet. Returns zero on success, negative values on failure.
187 *
188 */
189int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
190 u16 family,
191 u32 *type,
192 u32 *sid)
193{
194 int rc;
195 struct netlbl_lsm_secattr secattr;
196
197 if (!netlbl_enabled()) {
198 *sid = SECSID_NULL;
199 return 0;
200 }
201
202 netlbl_secattr_init(&secattr);
203 rc = netlbl_skbuff_getattr(skb, family, &secattr);
204 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
205 rc = selinux_netlbl_sidlookup_cached(skb, family,
206 &secattr, sid);
207 else
208 *sid = SECSID_NULL;
209 *type = secattr.type;
210 netlbl_secattr_destroy(&secattr);
211
212 return rc;
213}
214
215/**
216 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
217 * @skb: the packet
218 * @family: protocol family
219 * @sid: the SID
220 *
221 * Description
222 * Call the NetLabel mechanism to set the label of a packet using @sid.
223 * Returns zero on success, negative values on failure.
224 *
225 */
226int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
227 u16 family,
228 u32 sid)
229{
230 int rc;
231 struct netlbl_lsm_secattr secattr_storage;
232 struct netlbl_lsm_secattr *secattr = NULL;
233 struct sock *sk;
234
235 /* if this is a locally generated packet check to see if it is already
236 * being labeled by it's parent socket, if it is just exit */
237 sk = skb_to_full_sk(skb);
238 if (sk != NULL) {
239 struct sk_security_struct *sksec = sk->sk_security;
240
241 if (sksec->nlbl_state != NLBL_REQSKB)
242 return 0;
243 secattr = selinux_netlbl_sock_getattr(sk, sid);
244 }
245 if (secattr == NULL) {
246 secattr = &secattr_storage;
247 netlbl_secattr_init(secattr);
248 rc = security_netlbl_sid_to_secattr(&selinux_state, sid,
249 secattr);
250 if (rc != 0)
251 goto skbuff_setsid_return;
252 }
253
254 rc = netlbl_skbuff_setattr(skb, family, secattr);
255
256skbuff_setsid_return:
257 if (secattr == &secattr_storage)
258 netlbl_secattr_destroy(secattr);
259 return rc;
260}
261
262/**
263 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
264 * @asoc: incoming association.
265 * @skb: the packet.
266 *
267 * Description:
268 * A new incoming connection is represented by @asoc, ......
269 * Returns zero on success, negative values on failure.
270 *
271 */
272int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
273 struct sk_buff *skb)
274{
275 int rc;
276 struct netlbl_lsm_secattr secattr;
277 struct sk_security_struct *sksec = asoc->base.sk->sk_security;
278 struct sockaddr_in addr4;
279 struct sockaddr_in6 addr6;
280
281 if (asoc->base.sk->sk_family != PF_INET &&
282 asoc->base.sk->sk_family != PF_INET6)
283 return 0;
284
285 netlbl_secattr_init(&secattr);
286 rc = security_netlbl_sid_to_secattr(&selinux_state,
287 asoc->secid, &secattr);
288 if (rc != 0)
289 goto assoc_request_return;
290
291 /* Move skb hdr address info to a struct sockaddr and then call
292 * netlbl_conn_setattr().
293 */
294 if (ip_hdr(skb)->version == 4) {
295 addr4.sin_family = AF_INET;
296 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
297 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr);
298 } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
299 addr6.sin6_family = AF_INET6;
300 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
301 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr);
302 } else {
303 rc = -EAFNOSUPPORT;
304 }
305
306 if (rc == 0)
307 sksec->nlbl_state = NLBL_LABELED;
308
309assoc_request_return:
310 netlbl_secattr_destroy(&secattr);
311 return rc;
312}
313
314/**
315 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
316 * @req: incoming connection request socket
317 * @family: the request socket's address family
318 *
319 * Description:
320 * A new incoming connection request is represented by @req, we need to label
321 * the new request_sock here and the stack will ensure the on-the-wire label
322 * will get preserved when a full sock is created once the connection handshake
323 * is complete. Returns zero on success, negative values on failure.
324 *
325 */
326int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
327{
328 int rc;
329 struct netlbl_lsm_secattr secattr;
330
331 if (family != PF_INET && family != PF_INET6)
332 return 0;
333
334 netlbl_secattr_init(&secattr);
335 rc = security_netlbl_sid_to_secattr(&selinux_state, req->secid,
336 &secattr);
337 if (rc != 0)
338 goto inet_conn_request_return;
339 rc = netlbl_req_setattr(req, &secattr);
340inet_conn_request_return:
341 netlbl_secattr_destroy(&secattr);
342 return rc;
343}
344
345/**
346 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
347 * @sk: the new sock
348 * @family: the sock's address family
349 *
350 * Description:
351 * A new connection has been established using @sk, we've already labeled the
352 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
353 * we need to set the NetLabel state here since we now have a sock structure.
354 *
355 */
356void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
357{
358 struct sk_security_struct *sksec = sk->sk_security;
359
360 if (family == PF_INET)
361 sksec->nlbl_state = NLBL_LABELED;
362 else
363 sksec->nlbl_state = NLBL_UNSET;
364}
365
366/**
367 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
368 * @sk: current sock
369 * @newsk: the new sock
370 *
371 * Description:
372 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
373 */
374void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
375{
376 struct sk_security_struct *sksec = sk->sk_security;
377 struct sk_security_struct *newsksec = newsk->sk_security;
378
379 newsksec->nlbl_state = sksec->nlbl_state;
380}
381
382/**
383 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
384 * @sk: the sock to label
385 * @family: protocol family
386 *
387 * Description:
388 * Attempt to label a socket using the NetLabel mechanism using the given
389 * SID. Returns zero values on success, negative values on failure.
390 *
391 */
392int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
393{
394 int rc;
395 struct sk_security_struct *sksec = sk->sk_security;
396 struct netlbl_lsm_secattr *secattr;
397
398 if (family != PF_INET && family != PF_INET6)
399 return 0;
400
401 secattr = selinux_netlbl_sock_genattr(sk);
402 if (secattr == NULL)
403 return -ENOMEM;
404 rc = netlbl_sock_setattr(sk, family, secattr);
405 switch (rc) {
406 case 0:
407 sksec->nlbl_state = NLBL_LABELED;
408 break;
409 case -EDESTADDRREQ:
410 sksec->nlbl_state = NLBL_REQSKB;
411 rc = 0;
412 break;
413 }
414
415 return rc;
416}
417
418/**
419 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
420 * @sksec: the sock's sk_security_struct
421 * @skb: the packet
422 * @family: protocol family
423 * @ad: the audit data
424 *
425 * Description:
426 * Fetch the NetLabel security attributes from @skb and perform an access check
427 * against the receiving socket. Returns zero on success, negative values on
428 * error.
429 *
430 */
431int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
432 struct sk_buff *skb,
433 u16 family,
434 struct common_audit_data *ad)
435{
436 int rc;
437 u32 nlbl_sid;
438 u32 perm;
439 struct netlbl_lsm_secattr secattr;
440
441 if (!netlbl_enabled())
442 return 0;
443
444 netlbl_secattr_init(&secattr);
445 rc = netlbl_skbuff_getattr(skb, family, &secattr);
446 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
447 rc = selinux_netlbl_sidlookup_cached(skb, family,
448 &secattr, &nlbl_sid);
449 else
450 nlbl_sid = SECINITSID_UNLABELED;
451 netlbl_secattr_destroy(&secattr);
452 if (rc != 0)
453 return rc;
454
455 switch (sksec->sclass) {
456 case SECCLASS_UDP_SOCKET:
457 perm = UDP_SOCKET__RECVFROM;
458 break;
459 case SECCLASS_TCP_SOCKET:
460 perm = TCP_SOCKET__RECVFROM;
461 break;
462 default:
463 perm = RAWIP_SOCKET__RECVFROM;
464 }
465
466 rc = avc_has_perm(&selinux_state,
467 sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
468 if (rc == 0)
469 return 0;
470
471 if (nlbl_sid != SECINITSID_UNLABELED)
472 netlbl_skbuff_err(skb, family, rc, 0);
473 return rc;
474}
475
476/**
477 * selinux_netlbl_option - Is this a NetLabel option
478 * @level: the socket level or protocol
479 * @optname: the socket option name
480 *
481 * Description:
482 * Returns true if @level and @optname refer to a NetLabel option.
483 * Helper for selinux_netlbl_socket_setsockopt().
484 */
485static inline int selinux_netlbl_option(int level, int optname)
486{
487 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
488 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
489}
490
491/**
492 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
493 * @sock: the socket
494 * @level: the socket level or protocol
495 * @optname: the socket option name
496 *
497 * Description:
498 * Check the setsockopt() call and if the user is trying to replace the IP
499 * options on a socket and a NetLabel is in place for the socket deny the
500 * access; otherwise allow the access. Returns zero when the access is
501 * allowed, -EACCES when denied, and other negative values on error.
502 *
503 */
504int selinux_netlbl_socket_setsockopt(struct socket *sock,
505 int level,
506 int optname)
507{
508 int rc = 0;
509 struct sock *sk = sock->sk;
510 struct sk_security_struct *sksec = sk->sk_security;
511 struct netlbl_lsm_secattr secattr;
512
513 if (selinux_netlbl_option(level, optname) &&
514 (sksec->nlbl_state == NLBL_LABELED ||
515 sksec->nlbl_state == NLBL_CONNLABELED)) {
516 netlbl_secattr_init(&secattr);
517 lock_sock(sk);
518 /* call the netlabel function directly as we want to see the
519 * on-the-wire label that is assigned via the socket's options
520 * and not the cached netlabel/lsm attributes */
521 rc = netlbl_sock_getattr(sk, &secattr);
522 release_sock(sk);
523 if (rc == 0)
524 rc = -EACCES;
525 else if (rc == -ENOMSG)
526 rc = 0;
527 netlbl_secattr_destroy(&secattr);
528 }
529
530 return rc;
531}
532
533/**
534 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
535 * connect
536 * @sk: the socket to label
537 * @addr: the destination address
538 *
539 * Description:
540 * Attempt to label a connected socket with NetLabel using the given address.
541 * Returns zero values on success, negative values on failure.
542 *
543 */
544static int selinux_netlbl_socket_connect_helper(struct sock *sk,
545 struct sockaddr *addr)
546{
547 int rc;
548 struct sk_security_struct *sksec = sk->sk_security;
549 struct netlbl_lsm_secattr *secattr;
550
551 /* connected sockets are allowed to disconnect when the address family
552 * is set to AF_UNSPEC, if that is what is happening we want to reset
553 * the socket */
554 if (addr->sa_family == AF_UNSPEC) {
555 netlbl_sock_delattr(sk);
556 sksec->nlbl_state = NLBL_REQSKB;
557 rc = 0;
558 return rc;
559 }
560 secattr = selinux_netlbl_sock_genattr(sk);
561 if (secattr == NULL) {
562 rc = -ENOMEM;
563 return rc;
564 }
565 rc = netlbl_conn_setattr(sk, addr, secattr);
566 if (rc == 0)
567 sksec->nlbl_state = NLBL_CONNLABELED;
568
569 return rc;
570}
571
572/**
573 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
574 * connect
575 * @sk: the socket to label
576 * @addr: the destination address
577 *
578 * Description:
579 * Attempt to label a connected socket that already has the socket locked
580 * with NetLabel using the given address.
581 * Returns zero values on success, negative values on failure.
582 *
583 */
584int selinux_netlbl_socket_connect_locked(struct sock *sk,
585 struct sockaddr *addr)
586{
587 struct sk_security_struct *sksec = sk->sk_security;
588
589 if (sksec->nlbl_state != NLBL_REQSKB &&
590 sksec->nlbl_state != NLBL_CONNLABELED)
591 return 0;
592
593 return selinux_netlbl_socket_connect_helper(sk, addr);
594}
595
596/**
597 * selinux_netlbl_socket_connect - Label a client-side socket on connect
598 * @sk: the socket to label
599 * @addr: the destination address
600 *
601 * Description:
602 * Attempt to label a connected socket with NetLabel using the given address.
603 * Returns zero values on success, negative values on failure.
604 *
605 */
606int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
607{
608 int rc;
609
610 lock_sock(sk);
611 rc = selinux_netlbl_socket_connect_locked(sk, addr);
612 release_sock(sk);
613
614 return rc;
615}
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 * @family: the packet's address family
33 * @secattr: the NetLabel security attributes
34 * @sid: the SID
35 *
36 * Description:
37 * Query the SELinux security server to lookup the correct SID for the given
38 * security attributes. If the query is successful, cache the result to speed
39 * up future lookups. Returns zero on success, negative values on failure.
40 *
41 */
42static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
43 u16 family,
44 struct netlbl_lsm_secattr *secattr,
45 u32 *sid)
46{
47 int rc;
48
49 rc = security_netlbl_secattr_to_sid(secattr, sid);
50 if (rc == 0 &&
51 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
52 (secattr->flags & NETLBL_SECATTR_CACHE))
53 netlbl_cache_add(skb, family, secattr);
54
55 return rc;
56}
57
58/**
59 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
60 * @sk: the socket
61 *
62 * Description:
63 * Generate the NetLabel security attributes for a socket, making full use of
64 * the socket's attribute cache. Returns a pointer to the security attributes
65 * on success, NULL on failure.
66 *
67 */
68static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
69{
70 int rc;
71 struct sk_security_struct *sksec = sk->sk_security;
72 struct netlbl_lsm_secattr *secattr;
73
74 if (sksec->nlbl_secattr != NULL)
75 return sksec->nlbl_secattr;
76
77 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
78 if (secattr == NULL)
79 return NULL;
80 rc = security_netlbl_sid_to_secattr(sksec->sid, 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 * @family: the packet's address family
132 * @error: the error code
133 * @gateway: true if host is acting as a gateway, false otherwise
134 *
135 * Description:
136 * When a packet is dropped due to a call to avc_has_perm() pass the error
137 * code to the NetLabel subsystem so any protocol specific processing can be
138 * done. This is safe to call even if you are unsure if NetLabel labeling is
139 * present on the packet, NetLabel is smart enough to only act when it should.
140 *
141 */
142void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
143{
144 netlbl_skbuff_err(skb, family, error, gateway);
145}
146
147/**
148 * selinux_netlbl_sk_security_free - Free the NetLabel fields
149 * @sksec: the sk_security_struct
150 *
151 * Description:
152 * Free all of the memory in the NetLabel fields of a sk_security_struct.
153 *
154 */
155void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
156{
157 if (!sksec->nlbl_secattr)
158 return;
159
160 netlbl_secattr_free(sksec->nlbl_secattr);
161 sksec->nlbl_secattr = NULL;
162 sksec->nlbl_state = NLBL_UNSET;
163}
164
165/**
166 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
167 * @sksec: the sk_security_struct
168 *
169 * Description:
170 * Called when the NetLabel state of a sk_security_struct needs to be reset.
171 * The caller is responsible for all the NetLabel sk_security_struct locking.
172 *
173 */
174void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
175{
176 sksec->nlbl_state = NLBL_UNSET;
177}
178
179/**
180 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
181 * @skb: the packet
182 * @family: protocol family
183 * @type: NetLabel labeling protocol type
184 * @sid: the SID
185 *
186 * Description:
187 * Call the NetLabel mechanism to get the security attributes of the given
188 * packet and use those attributes to determine the correct context/SID to
189 * assign to the packet. Returns zero on success, negative values on failure.
190 *
191 */
192int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
193 u16 family,
194 u32 *type,
195 u32 *sid)
196{
197 int rc;
198 struct netlbl_lsm_secattr secattr;
199
200 if (!netlbl_enabled()) {
201 *type = NETLBL_NLTYPE_NONE;
202 *sid = SECSID_NULL;
203 return 0;
204 }
205
206 netlbl_secattr_init(&secattr);
207 rc = netlbl_skbuff_getattr(skb, family, &secattr);
208 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
209 rc = selinux_netlbl_sidlookup_cached(skb, family,
210 &secattr, sid);
211 else
212 *sid = SECSID_NULL;
213 *type = secattr.type;
214 netlbl_secattr_destroy(&secattr);
215
216 return rc;
217}
218
219/**
220 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
221 * @skb: the packet
222 * @family: protocol family
223 * @sid: the SID
224 *
225 * Description
226 * Call the NetLabel mechanism to set the label of a packet using @sid.
227 * Returns zero on success, negative values on failure.
228 *
229 */
230int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
231 u16 family,
232 u32 sid)
233{
234 int rc;
235 struct netlbl_lsm_secattr secattr_storage;
236 struct netlbl_lsm_secattr *secattr = NULL;
237 struct sock *sk;
238
239 /* if this is a locally generated packet check to see if it is already
240 * being labeled by it's parent socket, if it is just exit */
241 sk = skb_to_full_sk(skb);
242 if (sk != NULL) {
243 struct sk_security_struct *sksec = sk->sk_security;
244
245 if (sksec->nlbl_state != NLBL_REQSKB)
246 return 0;
247 secattr = selinux_netlbl_sock_getattr(sk, sid);
248 }
249 if (secattr == NULL) {
250 secattr = &secattr_storage;
251 netlbl_secattr_init(secattr);
252 rc = security_netlbl_sid_to_secattr(sid, secattr);
253 if (rc != 0)
254 goto skbuff_setsid_return;
255 }
256
257 rc = netlbl_skbuff_setattr(skb, family, secattr);
258
259skbuff_setsid_return:
260 if (secattr == &secattr_storage)
261 netlbl_secattr_destroy(secattr);
262 return rc;
263}
264
265/**
266 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
267 * @asoc: incoming association.
268 * @skb: the packet.
269 *
270 * Description:
271 * A new incoming connection is represented by @asoc, ......
272 * Returns zero on success, negative values on failure.
273 *
274 */
275int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
276 struct sk_buff *skb)
277{
278 int rc;
279 struct netlbl_lsm_secattr secattr;
280 struct sk_security_struct *sksec = asoc->base.sk->sk_security;
281 struct sockaddr_in addr4;
282 struct sockaddr_in6 addr6;
283
284 if (asoc->base.sk->sk_family != PF_INET &&
285 asoc->base.sk->sk_family != PF_INET6)
286 return 0;
287
288 netlbl_secattr_init(&secattr);
289 rc = security_netlbl_sid_to_secattr(asoc->secid, &secattr);
290 if (rc != 0)
291 goto assoc_request_return;
292
293 /* Move skb hdr address info to a struct sockaddr and then call
294 * netlbl_conn_setattr().
295 */
296 if (ip_hdr(skb)->version == 4) {
297 addr4.sin_family = AF_INET;
298 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
299 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr);
300 } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
301 addr6.sin6_family = AF_INET6;
302 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
303 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr);
304 } else {
305 rc = -EAFNOSUPPORT;
306 }
307
308 if (rc == 0)
309 sksec->nlbl_state = NLBL_LABELED;
310
311assoc_request_return:
312 netlbl_secattr_destroy(&secattr);
313 return rc;
314}
315
316/**
317 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
318 * @req: incoming connection request socket
319 * @family: the request socket's address family
320 *
321 * Description:
322 * A new incoming connection request is represented by @req, we need to label
323 * the new request_sock here and the stack will ensure the on-the-wire label
324 * will get preserved when a full sock is created once the connection handshake
325 * is complete. Returns zero on success, negative values on failure.
326 *
327 */
328int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
329{
330 int rc;
331 struct netlbl_lsm_secattr secattr;
332
333 if (family != PF_INET && family != PF_INET6)
334 return 0;
335
336 netlbl_secattr_init(&secattr);
337 rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
338 if (rc != 0)
339 goto inet_conn_request_return;
340 rc = netlbl_req_setattr(req, &secattr);
341inet_conn_request_return:
342 netlbl_secattr_destroy(&secattr);
343 return rc;
344}
345
346/**
347 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
348 * @sk: the new sock
349 * @family: the sock's address family
350 *
351 * Description:
352 * A new connection has been established using @sk, we've already labeled the
353 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
354 * we need to set the NetLabel state here since we now have a sock structure.
355 *
356 */
357void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
358{
359 struct sk_security_struct *sksec = sk->sk_security;
360
361 if (family == PF_INET)
362 sksec->nlbl_state = NLBL_LABELED;
363 else
364 sksec->nlbl_state = NLBL_UNSET;
365}
366
367/**
368 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
369 * @sk: current sock
370 * @newsk: the new sock
371 *
372 * Description:
373 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
374 */
375void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
376{
377 struct sk_security_struct *sksec = sk->sk_security;
378 struct sk_security_struct *newsksec = newsk->sk_security;
379
380 newsksec->nlbl_state = sksec->nlbl_state;
381}
382
383/**
384 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
385 * @sk: the sock to label
386 * @family: protocol family
387 *
388 * Description:
389 * Attempt to label a socket using the NetLabel mechanism using the given
390 * SID. Returns zero values on success, negative values on failure.
391 *
392 */
393int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
394{
395 int rc;
396 struct sk_security_struct *sksec = sk->sk_security;
397 struct netlbl_lsm_secattr *secattr;
398
399 if (family != PF_INET && family != PF_INET6)
400 return 0;
401
402 secattr = selinux_netlbl_sock_genattr(sk);
403 if (secattr == NULL)
404 return -ENOMEM;
405 rc = netlbl_sock_setattr(sk, family, secattr);
406 switch (rc) {
407 case 0:
408 sksec->nlbl_state = NLBL_LABELED;
409 break;
410 case -EDESTADDRREQ:
411 sksec->nlbl_state = NLBL_REQSKB;
412 rc = 0;
413 break;
414 }
415
416 return rc;
417}
418
419/**
420 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
421 * @sksec: the sock's sk_security_struct
422 * @skb: the packet
423 * @family: protocol family
424 * @ad: the audit data
425 *
426 * Description:
427 * Fetch the NetLabel security attributes from @skb and perform an access check
428 * against the receiving socket. Returns zero on success, negative values on
429 * error.
430 *
431 */
432int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
433 struct sk_buff *skb,
434 u16 family,
435 struct common_audit_data *ad)
436{
437 int rc;
438 u32 nlbl_sid;
439 u32 perm;
440 struct netlbl_lsm_secattr secattr;
441
442 if (!netlbl_enabled())
443 return 0;
444
445 netlbl_secattr_init(&secattr);
446 rc = netlbl_skbuff_getattr(skb, family, &secattr);
447 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
448 rc = selinux_netlbl_sidlookup_cached(skb, family,
449 &secattr, &nlbl_sid);
450 else
451 nlbl_sid = SECINITSID_UNLABELED;
452 netlbl_secattr_destroy(&secattr);
453 if (rc != 0)
454 return rc;
455
456 switch (sksec->sclass) {
457 case SECCLASS_UDP_SOCKET:
458 perm = UDP_SOCKET__RECVFROM;
459 break;
460 case SECCLASS_TCP_SOCKET:
461 perm = TCP_SOCKET__RECVFROM;
462 break;
463 default:
464 perm = RAWIP_SOCKET__RECVFROM;
465 }
466
467 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
468 if (rc == 0)
469 return 0;
470
471 if (nlbl_sid != SECINITSID_UNLABELED)
472 netlbl_skbuff_err(skb, family, rc, 0);
473 return rc;
474}
475
476/**
477 * selinux_netlbl_option - Is this a NetLabel option
478 * @level: the socket level or protocol
479 * @optname: the socket option name
480 *
481 * Description:
482 * Returns true if @level and @optname refer to a NetLabel option.
483 * Helper for selinux_netlbl_socket_setsockopt().
484 */
485static inline int selinux_netlbl_option(int level, int optname)
486{
487 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
488 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
489}
490
491/**
492 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
493 * @sock: the socket
494 * @level: the socket level or protocol
495 * @optname: the socket option name
496 *
497 * Description:
498 * Check the setsockopt() call and if the user is trying to replace the IP
499 * options on a socket and a NetLabel is in place for the socket deny the
500 * access; otherwise allow the access. Returns zero when the access is
501 * allowed, -EACCES when denied, and other negative values on error.
502 *
503 */
504int selinux_netlbl_socket_setsockopt(struct socket *sock,
505 int level,
506 int optname)
507{
508 int rc = 0;
509 struct sock *sk = sock->sk;
510 struct sk_security_struct *sksec = sk->sk_security;
511 struct netlbl_lsm_secattr secattr;
512
513 if (selinux_netlbl_option(level, optname) &&
514 (sksec->nlbl_state == NLBL_LABELED ||
515 sksec->nlbl_state == NLBL_CONNLABELED)) {
516 netlbl_secattr_init(&secattr);
517 lock_sock(sk);
518 /* call the netlabel function directly as we want to see the
519 * on-the-wire label that is assigned via the socket's options
520 * and not the cached netlabel/lsm attributes */
521 rc = netlbl_sock_getattr(sk, &secattr);
522 release_sock(sk);
523 if (rc == 0)
524 rc = -EACCES;
525 else if (rc == -ENOMSG)
526 rc = 0;
527 netlbl_secattr_destroy(&secattr);
528 }
529
530 return rc;
531}
532
533/**
534 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
535 * connect
536 * @sk: the socket to label
537 * @addr: the destination address
538 *
539 * Description:
540 * Attempt to label a connected socket with NetLabel using the given address.
541 * Returns zero values on success, negative values on failure.
542 *
543 */
544static int selinux_netlbl_socket_connect_helper(struct sock *sk,
545 struct sockaddr *addr)
546{
547 int rc;
548 struct sk_security_struct *sksec = sk->sk_security;
549 struct netlbl_lsm_secattr *secattr;
550
551 /* connected sockets are allowed to disconnect when the address family
552 * is set to AF_UNSPEC, if that is what is happening we want to reset
553 * the socket */
554 if (addr->sa_family == AF_UNSPEC) {
555 netlbl_sock_delattr(sk);
556 sksec->nlbl_state = NLBL_REQSKB;
557 rc = 0;
558 return rc;
559 }
560 secattr = selinux_netlbl_sock_genattr(sk);
561 if (secattr == NULL) {
562 rc = -ENOMEM;
563 return rc;
564 }
565 rc = netlbl_conn_setattr(sk, addr, secattr);
566 if (rc == 0)
567 sksec->nlbl_state = NLBL_CONNLABELED;
568
569 return rc;
570}
571
572/**
573 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
574 * connect
575 * @sk: the socket to label
576 * @addr: the destination address
577 *
578 * Description:
579 * Attempt to label a connected socket that already has the socket locked
580 * with NetLabel using the given address.
581 * Returns zero values on success, negative values on failure.
582 *
583 */
584int selinux_netlbl_socket_connect_locked(struct sock *sk,
585 struct sockaddr *addr)
586{
587 struct sk_security_struct *sksec = sk->sk_security;
588
589 if (sksec->nlbl_state != NLBL_REQSKB &&
590 sksec->nlbl_state != NLBL_CONNLABELED)
591 return 0;
592
593 return selinux_netlbl_socket_connect_helper(sk, addr);
594}
595
596/**
597 * selinux_netlbl_socket_connect - Label a client-side socket on connect
598 * @sk: the socket to label
599 * @addr: the destination address
600 *
601 * Description:
602 * Attempt to label a connected socket with NetLabel using the given address.
603 * Returns zero values on success, negative values on failure.
604 *
605 */
606int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
607{
608 int rc;
609
610 lock_sock(sk);
611 rc = selinux_netlbl_socket_connect_locked(sk, addr);
612 release_sock(sk);
613
614 return rc;
615}