1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * SELinux NetLabel Support
5 * This file provides the necessary glue to tie NetLabel into the SELinux
8 * Author: Paul Moore <paul@paul-moore.com>
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
15 #include <linux/spinlock.h>
16 #include <linux/rcupdate.h>
17 #include <linux/gfp.h>
19 #include <linux/ipv6.h>
21 #include <net/netlabel.h>
30 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
32 * @family: the packet's address family
33 * @secattr: the NetLabel security attributes
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.
42 static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
44 struct netlbl_lsm_secattr *secattr,
49 rc = security_netlbl_secattr_to_sid(secattr, sid);
51 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
52 (secattr->flags & NETLBL_SECATTR_CACHE))
53 netlbl_cache_add(skb, family, secattr);
59 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
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.
68 static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
71 struct sk_security_struct *sksec = sk->sk_security;
72 struct netlbl_lsm_secattr *secattr;
74 if (sksec->nlbl_secattr != NULL)
75 return sksec->nlbl_secattr;
77 secattr = netlbl_secattr_alloc(GFP_ATOMIC);
80 rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
82 netlbl_secattr_free(secattr);
85 sksec->nlbl_secattr = secattr;
91 * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
95 * Query the socket's cached secattr and if the SID matches the cached value
96 * return the cache, otherwise return NULL.
99 static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
100 const struct sock *sk,
103 struct sk_security_struct *sksec = sk->sk_security;
104 struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
109 if ((secattr->flags & NETLBL_SECATTR_SECID) &&
110 (secattr->attr.secid == sid))
117 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
120 * Invalidate the NetLabel security attribute mapping cache.
123 void selinux_netlbl_cache_invalidate(void)
125 netlbl_cache_invalidate();
129 * selinux_netlbl_err - Handle a NetLabel packet error
131 * @family: the packet's address family
132 * @error: the error code
133 * @gateway: true if host is acting as a gateway, false otherwise
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.
142 void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway)
144 netlbl_skbuff_err(skb, family, error, gateway);
148 * selinux_netlbl_sk_security_free - Free the NetLabel fields
149 * @sksec: the sk_security_struct
152 * Free all of the memory in the NetLabel fields of a sk_security_struct.
155 void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
157 if (!sksec->nlbl_secattr)
160 netlbl_secattr_free(sksec->nlbl_secattr);
161 sksec->nlbl_secattr = NULL;
162 sksec->nlbl_state = NLBL_UNSET;
166 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
167 * @sksec: the sk_security_struct
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.
174 void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
176 sksec->nlbl_state = NLBL_UNSET;
180 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
182 * @family: protocol family
183 * @type: NetLabel labeling protocol type
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.
192 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
198 struct netlbl_lsm_secattr secattr;
200 if (!netlbl_enabled()) {
205 netlbl_secattr_init(&secattr);
206 rc = netlbl_skbuff_getattr(skb, family, &secattr);
207 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
208 rc = selinux_netlbl_sidlookup_cached(skb, family,
212 *type = secattr.type;
213 netlbl_secattr_destroy(&secattr);
219 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
221 * @family: protocol family
225 * Call the NetLabel mechanism to set the label of a packet using @sid.
226 * Returns zero on success, negative values on failure.
229 int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
234 struct netlbl_lsm_secattr secattr_storage;
235 struct netlbl_lsm_secattr *secattr = NULL;
238 /* if this is a locally generated packet check to see if it is already
239 * being labeled by it's parent socket, if it is just exit */
240 sk = skb_to_full_sk(skb);
242 struct sk_security_struct *sksec = sk->sk_security;
244 if (sksec->nlbl_state != NLBL_REQSKB)
246 secattr = selinux_netlbl_sock_getattr(sk, sid);
248 if (secattr == NULL) {
249 secattr = &secattr_storage;
250 netlbl_secattr_init(secattr);
251 rc = security_netlbl_sid_to_secattr(sid, secattr);
253 goto skbuff_setsid_return;
256 rc = netlbl_skbuff_setattr(skb, family, secattr);
258 skbuff_setsid_return:
259 if (secattr == &secattr_storage)
260 netlbl_secattr_destroy(secattr);
265 * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
266 * @asoc: incoming association.
270 * A new incoming connection is represented by @asoc, ......
271 * Returns zero on success, negative values on failure.
274 int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
278 struct netlbl_lsm_secattr secattr;
279 struct sk_security_struct *sksec = asoc->base.sk->sk_security;
280 struct sockaddr_in addr4;
281 struct sockaddr_in6 addr6;
283 if (asoc->base.sk->sk_family != PF_INET &&
284 asoc->base.sk->sk_family != PF_INET6)
287 netlbl_secattr_init(&secattr);
288 rc = security_netlbl_sid_to_secattr(asoc->secid, &secattr);
290 goto assoc_request_return;
292 /* Move skb hdr address info to a struct sockaddr and then call
293 * netlbl_conn_setattr().
295 if (ip_hdr(skb)->version == 4) {
296 addr4.sin_family = AF_INET;
297 addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
298 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr);
299 } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
300 addr6.sin6_family = AF_INET6;
301 addr6.sin6_addr = ipv6_hdr(skb)->saddr;
302 rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr);
308 sksec->nlbl_state = NLBL_LABELED;
310 assoc_request_return:
311 netlbl_secattr_destroy(&secattr);
316 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
317 * @req: incoming connection request socket
318 * @family: the request socket's address family
321 * A new incoming connection request is represented by @req, we need to label
322 * the new request_sock here and the stack will ensure the on-the-wire label
323 * will get preserved when a full sock is created once the connection handshake
324 * is complete. Returns zero on success, negative values on failure.
327 int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
330 struct netlbl_lsm_secattr secattr;
332 if (family != PF_INET && family != PF_INET6)
335 netlbl_secattr_init(&secattr);
336 rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
338 goto inet_conn_request_return;
339 rc = netlbl_req_setattr(req, &secattr);
340 inet_conn_request_return:
341 netlbl_secattr_destroy(&secattr);
346 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
348 * @family: the sock's address family
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.
356 void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
358 struct sk_security_struct *sksec = sk->sk_security;
360 if (family == PF_INET)
361 sksec->nlbl_state = NLBL_LABELED;
363 sksec->nlbl_state = NLBL_UNSET;
367 * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
369 * @newsk: the new sock
372 * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
374 void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
376 struct sk_security_struct *sksec = sk->sk_security;
377 struct sk_security_struct *newsksec = newsk->sk_security;
379 newsksec->nlbl_state = sksec->nlbl_state;
383 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
384 * @sk: the sock to label
385 * @family: protocol family
388 * Attempt to label a socket using the NetLabel mechanism using the given
389 * SID. Returns zero values on success, negative values on failure.
392 int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
395 struct sk_security_struct *sksec = sk->sk_security;
396 struct netlbl_lsm_secattr *secattr;
398 if (family != PF_INET && family != PF_INET6)
401 secattr = selinux_netlbl_sock_genattr(sk);
404 rc = netlbl_sock_setattr(sk, family, secattr);
407 sksec->nlbl_state = NLBL_LABELED;
410 sksec->nlbl_state = NLBL_REQSKB;
419 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
420 * @sksec: the sock's sk_security_struct
422 * @family: protocol family
423 * @ad: the audit data
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
431 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
434 struct common_audit_data *ad)
439 struct netlbl_lsm_secattr secattr;
441 if (!netlbl_enabled())
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);
450 nlbl_sid = SECINITSID_UNLABELED;
451 netlbl_secattr_destroy(&secattr);
455 switch (sksec->sclass) {
456 case SECCLASS_UDP_SOCKET:
457 perm = UDP_SOCKET__RECVFROM;
459 case SECCLASS_TCP_SOCKET:
460 perm = TCP_SOCKET__RECVFROM;
463 perm = RAWIP_SOCKET__RECVFROM;
466 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
470 if (nlbl_sid != SECINITSID_UNLABELED)
471 netlbl_skbuff_err(skb, family, rc, 0);
476 * selinux_netlbl_option - Is this a NetLabel option
477 * @level: the socket level or protocol
478 * @optname: the socket option name
481 * Returns true if @level and @optname refer to a NetLabel option.
482 * Helper for selinux_netlbl_socket_setsockopt().
484 static inline int selinux_netlbl_option(int level, int optname)
486 return (level == IPPROTO_IP && optname == IP_OPTIONS) ||
487 (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS);
491 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
493 * @level: the socket level or protocol
494 * @optname: the socket option name
497 * Check the setsockopt() call and if the user is trying to replace the IP
498 * options on a socket and a NetLabel is in place for the socket deny the
499 * access; otherwise allow the access. Returns zero when the access is
500 * allowed, -EACCES when denied, and other negative values on error.
503 int selinux_netlbl_socket_setsockopt(struct socket *sock,
508 struct sock *sk = sock->sk;
509 struct sk_security_struct *sksec = sk->sk_security;
510 struct netlbl_lsm_secattr secattr;
512 if (selinux_netlbl_option(level, optname) &&
513 (sksec->nlbl_state == NLBL_LABELED ||
514 sksec->nlbl_state == NLBL_CONNLABELED)) {
515 netlbl_secattr_init(&secattr);
517 /* call the netlabel function directly as we want to see the
518 * on-the-wire label that is assigned via the socket's options
519 * and not the cached netlabel/lsm attributes */
520 rc = netlbl_sock_getattr(sk, &secattr);
524 else if (rc == -ENOMSG)
526 netlbl_secattr_destroy(&secattr);
533 * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
535 * @sk: the socket to label
536 * @addr: the destination address
539 * Attempt to label a connected socket with NetLabel using the given address.
540 * Returns zero values on success, negative values on failure.
543 static int selinux_netlbl_socket_connect_helper(struct sock *sk,
544 struct sockaddr *addr)
547 struct sk_security_struct *sksec = sk->sk_security;
548 struct netlbl_lsm_secattr *secattr;
550 /* connected sockets are allowed to disconnect when the address family
551 * is set to AF_UNSPEC, if that is what is happening we want to reset
553 if (addr->sa_family == AF_UNSPEC) {
554 netlbl_sock_delattr(sk);
555 sksec->nlbl_state = NLBL_REQSKB;
559 secattr = selinux_netlbl_sock_genattr(sk);
560 if (secattr == NULL) {
564 rc = netlbl_conn_setattr(sk, addr, secattr);
566 sksec->nlbl_state = NLBL_CONNLABELED;
572 * selinux_netlbl_socket_connect_locked - Label a client-side socket on
574 * @sk: the socket to label
575 * @addr: the destination address
578 * Attempt to label a connected socket that already has the socket locked
579 * with NetLabel using the given address.
580 * Returns zero values on success, negative values on failure.
583 int selinux_netlbl_socket_connect_locked(struct sock *sk,
584 struct sockaddr *addr)
586 struct sk_security_struct *sksec = sk->sk_security;
588 if (sksec->nlbl_state != NLBL_REQSKB &&
589 sksec->nlbl_state != NLBL_CONNLABELED)
592 return selinux_netlbl_socket_connect_helper(sk, addr);
596 * selinux_netlbl_socket_connect - Label a client-side socket on connect
597 * @sk: the socket to label
598 * @addr: the destination address
601 * Attempt to label a connected socket with NetLabel using the given address.
602 * Returns zero values on success, negative values on failure.
605 int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
610 rc = selinux_netlbl_socket_connect_locked(sk, addr);