fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / security / selinux / netlabel.c
blobd243ddc723a55c06c507dbc2cdcca14c425d54f9
1 /*
2 * SELinux NetLabel Support
4 * This file provides the necessary glue to tie NetLabel into the SELinux
5 * subsystem.
7 * Author: Paul Moore <paul.moore@hp.com>
9 */
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>
32 #include <net/sock.h>
33 #include <net/netlabel.h>
35 #include "objsec.h"
36 #include "security.h"
38 /**
39 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
40 * @sk: the socket to label
41 * @sid: the SID to use
43 * Description:
44 * Attempt to label a socket using the NetLabel mechanism using the given
45 * SID. Returns zero values on success, negative values on failure. The
46 * caller is responsibile for calling rcu_read_lock() before calling this
47 * this function and rcu_read_unlock() after this function returns.
50 static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
52 int rc;
53 struct sk_security_struct *sksec = sk->sk_security;
54 struct netlbl_lsm_secattr secattr;
56 rc = security_netlbl_sid_to_secattr(sid, &secattr);
57 if (rc != 0)
58 return rc;
60 rc = netlbl_sock_setattr(sk, &secattr);
61 if (rc == 0) {
62 spin_lock_bh(&sksec->nlbl_lock);
63 sksec->nlbl_state = NLBL_LABELED;
64 spin_unlock_bh(&sksec->nlbl_lock);
67 return rc;
70 /**
71 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
73 * Description:
74 * Invalidate the NetLabel security attribute mapping cache.
77 void selinux_netlbl_cache_invalidate(void)
79 netlbl_cache_invalidate();
82 /**
83 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
84 * @ssec: the sk_security_struct
85 * @family: the socket family
87 * Description:
88 * Called when the NetLabel state of a sk_security_struct needs to be reset.
89 * The caller is responsibile for all the NetLabel sk_security_struct locking.
92 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
93 int family)
95 if (family == PF_INET)
96 ssec->nlbl_state = NLBL_REQUIRE;
97 else
98 ssec->nlbl_state = NLBL_UNSET;
102 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
103 * @ssec: the sk_security_struct
104 * @family: the socket family
106 * Description:
107 * Called when a new sk_security_struct is allocated to initialize the NetLabel
108 * fields.
111 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
112 int family)
114 /* No locking needed, we are the only one who has access to ssec */
115 selinux_netlbl_sk_security_reset(ssec, family);
116 spin_lock_init(&ssec->nlbl_lock);
120 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
121 * @ssec: the original sk_security_struct
122 * @newssec: the cloned sk_security_struct
124 * Description:
125 * Clone the NetLabel specific sk_security_struct fields from @ssec to
126 * @newssec.
129 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
130 struct sk_security_struct *newssec)
132 /* We don't need to take newssec->nlbl_lock because we are the only
133 * thread with access to newssec, but we do need to take the RCU read
134 * lock as other threads could have access to ssec */
135 rcu_read_lock();
136 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
137 newssec->sclass = ssec->sclass;
138 rcu_read_unlock();
142 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
143 * @skb: the packet
144 * @base_sid: the SELinux SID to use as a context for MLS only attributes
145 * @sid: the SID
147 * Description:
148 * Call the NetLabel mechanism to get the security attributes of the given
149 * packet and use those attributes to determine the correct context/SID to
150 * assign to the packet. Returns zero on success, negative values on failure.
153 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
155 int rc;
156 struct netlbl_lsm_secattr secattr;
158 if (!netlbl_enabled()) {
159 *sid = SECSID_NULL;
160 return 0;
163 netlbl_secattr_init(&secattr);
164 rc = netlbl_skbuff_getattr(skb, &secattr);
165 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
166 rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
167 if (rc == 0 &&
168 (secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
169 (secattr.flags & NETLBL_SECATTR_CACHE))
170 netlbl_cache_add(skb, &secattr);
171 } else
172 *sid = SECSID_NULL;
173 netlbl_secattr_destroy(&secattr);
175 return rc;
179 * selinux_netlbl_sock_graft - Netlabel the new socket
180 * @sk: the new connection
181 * @sock: the new socket
183 * Description:
184 * The connection represented by @sk is being grafted onto @sock so set the
185 * socket's NetLabel to match the SID of @sk.
188 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
190 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
191 struct sk_security_struct *sksec = sk->sk_security;
192 struct netlbl_lsm_secattr secattr;
193 u32 nlbl_peer_sid;
195 sksec->sclass = isec->sclass;
197 rcu_read_lock();
199 if (sksec->nlbl_state != NLBL_REQUIRE) {
200 rcu_read_unlock();
201 return;
204 netlbl_secattr_init(&secattr);
205 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
206 secattr.flags != NETLBL_SECATTR_NONE &&
207 security_netlbl_secattr_to_sid(&secattr,
208 SECINITSID_NETMSG,
209 &nlbl_peer_sid) == 0)
210 sksec->peer_sid = nlbl_peer_sid;
211 netlbl_secattr_destroy(&secattr);
213 /* Try to set the NetLabel on the socket to save time later, if we fail
214 * here we will pick up the pieces in later calls to
215 * selinux_netlbl_inode_permission(). */
216 selinux_netlbl_sock_setsid(sk, sksec->sid);
218 rcu_read_unlock();
222 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
223 * @sock: the socket to label
225 * Description:
226 * Attempt to label a socket using the NetLabel mechanism using the given
227 * SID. Returns zero values on success, negative values on failure.
230 int selinux_netlbl_socket_post_create(struct socket *sock)
232 int rc = 0;
233 struct sock *sk = sock->sk;
234 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
235 struct sk_security_struct *sksec = sk->sk_security;
237 sksec->sclass = isec->sclass;
239 rcu_read_lock();
240 if (sksec->nlbl_state == NLBL_REQUIRE)
241 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
242 rcu_read_unlock();
244 return rc;
248 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
249 * @inode: the file descriptor's inode
250 * @mask: the permission mask
252 * Description:
253 * Looks at a file's inode and if it is marked as a socket protected by
254 * NetLabel then verify that the socket has been labeled, if not try to label
255 * the socket now with the inode's SID. Returns zero on success, negative
256 * values on failure.
259 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
261 int rc;
262 struct sock *sk;
263 struct socket *sock;
264 struct sk_security_struct *sksec;
266 if (!S_ISSOCK(inode->i_mode) ||
267 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
268 return 0;
269 sock = SOCKET_I(inode);
270 sk = sock->sk;
271 sksec = sk->sk_security;
273 rcu_read_lock();
274 if (sksec->nlbl_state != NLBL_REQUIRE) {
275 rcu_read_unlock();
276 return 0;
278 local_bh_disable();
279 bh_lock_sock_nested(sk);
280 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
281 bh_unlock_sock(sk);
282 local_bh_enable();
283 rcu_read_unlock();
285 return rc;
289 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
290 * @sksec: the sock's sk_security_struct
291 * @skb: the packet
292 * @ad: the audit data
294 * Description:
295 * Fetch the NetLabel security attributes from @skb and perform an access check
296 * against the receiving socket. Returns zero on success, negative values on
297 * error.
300 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
301 struct sk_buff *skb,
302 struct avc_audit_data *ad)
304 int rc;
305 u32 nlbl_sid;
306 u32 perm;
307 struct netlbl_lsm_secattr secattr;
309 if (!netlbl_enabled())
310 return 0;
312 netlbl_secattr_init(&secattr);
313 rc = netlbl_skbuff_getattr(skb, &secattr);
314 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
315 rc = security_netlbl_secattr_to_sid(&secattr,
316 SECINITSID_NETMSG,
317 &nlbl_sid);
318 if (rc == 0 &&
319 (secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
320 (secattr.flags & NETLBL_SECATTR_CACHE))
321 netlbl_cache_add(skb, &secattr);
322 } else
323 nlbl_sid = SECINITSID_UNLABELED;
324 netlbl_secattr_destroy(&secattr);
325 if (rc != 0)
326 return rc;
328 switch (sksec->sclass) {
329 case SECCLASS_UDP_SOCKET:
330 perm = UDP_SOCKET__RECVFROM;
331 break;
332 case SECCLASS_TCP_SOCKET:
333 perm = TCP_SOCKET__RECVFROM;
334 break;
335 default:
336 perm = RAWIP_SOCKET__RECVFROM;
339 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
340 if (rc == 0)
341 return 0;
343 if (nlbl_sid != SECINITSID_UNLABELED)
344 netlbl_skbuff_err(skb, rc);
345 return rc;
349 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
350 * @sock: the socket
351 * @level: the socket level or protocol
352 * @optname: the socket option name
354 * Description:
355 * Check the setsockopt() call and if the user is trying to replace the IP
356 * options on a socket and a NetLabel is in place for the socket deny the
357 * access; otherwise allow the access. Returns zero when the access is
358 * allowed, -EACCES when denied, and other negative values on error.
361 int selinux_netlbl_socket_setsockopt(struct socket *sock,
362 int level,
363 int optname)
365 int rc = 0;
366 struct sock *sk = sock->sk;
367 struct sk_security_struct *sksec = sk->sk_security;
368 struct netlbl_lsm_secattr secattr;
370 rcu_read_lock();
371 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
372 sksec->nlbl_state == NLBL_LABELED) {
373 netlbl_secattr_init(&secattr);
374 lock_sock(sk);
375 rc = netlbl_sock_getattr(sk, &secattr);
376 release_sock(sk);
377 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
378 rc = -EACCES;
379 netlbl_secattr_destroy(&secattr);
381 rcu_read_unlock();
383 return rc;