2 * SELinux NetLabel Support
4 * This file provides the necessary glue to tie NetLabel into the SELinux
7 * Author: Paul Moore <paul.moore@hp.com>
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007
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.
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.
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
30 #include <linux/spinlock.h>
31 #include <linux/rcupdate.h>
33 #include <net/netlabel.h>
39 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
41 * @secattr: the NetLabel security attributes
45 * Query the SELinux security server to lookup the correct SID for the given
46 * security attributes. If the query is successful, cache the result to speed
47 * up future lookups. Returns zero on success, negative values on failure.
50 static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
51 struct netlbl_lsm_secattr *secattr,
56 rc = security_netlbl_secattr_to_sid(secattr, sid);
58 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
59 (secattr->flags & NETLBL_SECATTR_CACHE))
60 netlbl_cache_add(skb, secattr);
66 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
67 * @sk: the socket to label
68 * @sid: the SID to use
71 * Attempt to label a socket using the NetLabel mechanism using the given
72 * SID. Returns zero values on success, negative values on failure. The
73 * caller is responsibile for calling rcu_read_lock() before calling this
74 * this function and rcu_read_unlock() after this function returns.
77 static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
80 struct sk_security_struct *sksec = sk->sk_security;
81 struct netlbl_lsm_secattr secattr;
83 netlbl_secattr_init(&secattr);
85 rc = security_netlbl_sid_to_secattr(sid, &secattr);
87 goto sock_setsid_return;
88 rc = netlbl_sock_setattr(sk, &secattr);
90 spin_lock_bh(&sksec->nlbl_lock);
91 sksec->nlbl_state = NLBL_LABELED;
92 spin_unlock_bh(&sksec->nlbl_lock);
96 netlbl_secattr_destroy(&secattr);
101 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
104 * Invalidate the NetLabel security attribute mapping cache.
107 void selinux_netlbl_cache_invalidate(void)
109 netlbl_cache_invalidate();
113 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
114 * @ssec: the sk_security_struct
115 * @family: the socket family
118 * Called when the NetLabel state of a sk_security_struct needs to be reset.
119 * The caller is responsibile for all the NetLabel sk_security_struct locking.
122 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
125 if (family == PF_INET)
126 ssec->nlbl_state = NLBL_REQUIRE;
128 ssec->nlbl_state = NLBL_UNSET;
132 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
133 * @ssec: the sk_security_struct
134 * @family: the socket family
137 * Called when a new sk_security_struct is allocated to initialize the NetLabel
141 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
144 /* No locking needed, we are the only one who has access to ssec */
145 selinux_netlbl_sk_security_reset(ssec, family);
146 spin_lock_init(&ssec->nlbl_lock);
150 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
151 * @ssec: the original sk_security_struct
152 * @newssec: the cloned sk_security_struct
155 * Clone the NetLabel specific sk_security_struct fields from @ssec to
159 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
160 struct sk_security_struct *newssec)
162 /* We don't need to take newssec->nlbl_lock because we are the only
163 * thread with access to newssec, but we do need to take the RCU read
164 * lock as other threads could have access to ssec */
166 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
171 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
173 * @family: protocol family
174 * @type: NetLabel labeling protocol type
178 * Call the NetLabel mechanism to get the security attributes of the given
179 * packet and use those attributes to determine the correct context/SID to
180 * assign to the packet. Returns zero on success, negative values on failure.
183 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
189 struct netlbl_lsm_secattr secattr;
191 if (!netlbl_enabled()) {
196 netlbl_secattr_init(&secattr);
197 rc = netlbl_skbuff_getattr(skb, family, &secattr);
198 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
199 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
202 *type = secattr.type;
203 netlbl_secattr_destroy(&secattr);
209 * selinux_netlbl_sock_graft - Netlabel the new socket
210 * @sk: the new connection
211 * @sock: the new socket
214 * The connection represented by @sk is being grafted onto @sock so set the
215 * socket's NetLabel to match the SID of @sk.
218 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
220 struct sk_security_struct *sksec = sk->sk_security;
221 struct netlbl_lsm_secattr secattr;
226 if (sksec->nlbl_state != NLBL_REQUIRE) {
231 netlbl_secattr_init(&secattr);
232 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
233 secattr.flags != NETLBL_SECATTR_NONE &&
234 security_netlbl_secattr_to_sid(&secattr, &nlbl_peer_sid) == 0)
235 sksec->peer_sid = nlbl_peer_sid;
236 netlbl_secattr_destroy(&secattr);
238 /* Try to set the NetLabel on the socket to save time later, if we fail
239 * here we will pick up the pieces in later calls to
240 * selinux_netlbl_inode_permission(). */
241 selinux_netlbl_sock_setsid(sk, sksec->sid);
247 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
248 * @sock: the socket to label
251 * Attempt to label a socket using the NetLabel mechanism using the given
252 * SID. Returns zero values on success, negative values on failure.
255 int selinux_netlbl_socket_post_create(struct socket *sock)
258 struct sock *sk = sock->sk;
259 struct sk_security_struct *sksec = sk->sk_security;
262 if (sksec->nlbl_state == NLBL_REQUIRE)
263 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
270 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
271 * @inode: the file descriptor's inode
272 * @mask: the permission mask
275 * Looks at a file's inode and if it is marked as a socket protected by
276 * NetLabel then verify that the socket has been labeled, if not try to label
277 * the socket now with the inode's SID. Returns zero on success, negative
281 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
286 struct sk_security_struct *sksec;
288 if (!S_ISSOCK(inode->i_mode) ||
289 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
291 sock = SOCKET_I(inode);
293 sksec = sk->sk_security;
296 if (sksec->nlbl_state != NLBL_REQUIRE) {
301 bh_lock_sock_nested(sk);
302 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
311 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
312 * @sksec: the sock's sk_security_struct
314 * @family: protocol family
315 * @ad: the audit data
318 * Fetch the NetLabel security attributes from @skb and perform an access check
319 * against the receiving socket. Returns zero on success, negative values on
323 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
326 struct avc_audit_data *ad)
331 struct netlbl_lsm_secattr secattr;
333 if (!netlbl_enabled())
336 netlbl_secattr_init(&secattr);
337 rc = netlbl_skbuff_getattr(skb, family, &secattr);
338 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
339 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
341 nlbl_sid = SECINITSID_UNLABELED;
342 netlbl_secattr_destroy(&secattr);
346 switch (sksec->sclass) {
347 case SECCLASS_UDP_SOCKET:
348 perm = UDP_SOCKET__RECVFROM;
350 case SECCLASS_TCP_SOCKET:
351 perm = TCP_SOCKET__RECVFROM;
354 perm = RAWIP_SOCKET__RECVFROM;
357 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
361 if (nlbl_sid != SECINITSID_UNLABELED)
362 netlbl_skbuff_err(skb, rc);
367 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
369 * @level: the socket level or protocol
370 * @optname: the socket option name
373 * Check the setsockopt() call and if the user is trying to replace the IP
374 * options on a socket and a NetLabel is in place for the socket deny the
375 * access; otherwise allow the access. Returns zero when the access is
376 * allowed, -EACCES when denied, and other negative values on error.
379 int selinux_netlbl_socket_setsockopt(struct socket *sock,
384 struct sock *sk = sock->sk;
385 struct sk_security_struct *sksec = sk->sk_security;
386 struct netlbl_lsm_secattr secattr;
389 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
390 sksec->nlbl_state == NLBL_LABELED) {
391 netlbl_secattr_init(&secattr);
393 rc = netlbl_sock_getattr(sk, &secattr);
395 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
397 netlbl_secattr_destroy(&secattr);