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>
40 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
42 * @secattr: the NetLabel security attributes
46 * Query the SELinux security server to lookup the correct SID for the given
47 * security attributes. If the query is successful, cache the result to speed
48 * up future lookups. Returns zero on success, negative values on failure.
51 static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
52 struct netlbl_lsm_secattr *secattr,
57 rc = security_netlbl_secattr_to_sid(secattr, sid);
59 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
60 (secattr->flags & NETLBL_SECATTR_CACHE))
61 netlbl_cache_add(skb, secattr);
67 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
68 * @sk: the socket to label
71 * Attempt to label a socket using the NetLabel mechanism. Returns zero values
72 * on success, negative values on failure.
75 static int selinux_netlbl_sock_setsid(struct sock *sk)
78 struct sk_security_struct *sksec = sk->sk_security;
79 struct netlbl_lsm_secattr secattr;
81 if (sksec->nlbl_state != NLBL_REQUIRE)
84 netlbl_secattr_init(&secattr);
86 rc = security_netlbl_sid_to_secattr(sksec->sid, &secattr);
88 goto sock_setsid_return;
89 rc = netlbl_sock_setattr(sk, &secattr);
91 sksec->nlbl_state = NLBL_LABELED;
94 netlbl_secattr_destroy(&secattr);
99 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
102 * Invalidate the NetLabel security attribute mapping cache.
105 void selinux_netlbl_cache_invalidate(void)
107 netlbl_cache_invalidate();
111 * selinux_netlbl_err - Handle a NetLabel packet error
113 * @error: the error code
114 * @gateway: true if host is acting as a gateway, false otherwise
117 * When a packet is dropped due to a call to avc_has_perm() pass the error
118 * code to the NetLabel subsystem so any protocol specific processing can be
119 * done. This is safe to call even if you are unsure if NetLabel labeling is
120 * present on the packet, NetLabel is smart enough to only act when it should.
123 void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
125 netlbl_skbuff_err(skb, error, gateway);
129 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
130 * @ssec: the sk_security_struct
131 * @family: the socket family
134 * Called when the NetLabel state of a sk_security_struct needs to be reset.
135 * The caller is responsibile for all the NetLabel sk_security_struct locking.
138 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
141 if (family == PF_INET)
142 ssec->nlbl_state = NLBL_REQUIRE;
144 ssec->nlbl_state = NLBL_UNSET;
148 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
150 * @family: protocol family
151 * @type: NetLabel labeling protocol type
155 * Call the NetLabel mechanism to get the security attributes of the given
156 * packet and use those attributes to determine the correct context/SID to
157 * assign to the packet. Returns zero on success, negative values on failure.
160 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
166 struct netlbl_lsm_secattr secattr;
168 if (!netlbl_enabled()) {
173 netlbl_secattr_init(&secattr);
174 rc = netlbl_skbuff_getattr(skb, family, &secattr);
175 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
176 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
179 *type = secattr.type;
180 netlbl_secattr_destroy(&secattr);
186 * selinux_netlbl_sock_graft - Netlabel the new socket
187 * @sk: the new connection
188 * @sock: the new socket
191 * The connection represented by @sk is being grafted onto @sock so set the
192 * socket's NetLabel to match the SID of @sk.
195 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
197 /* Try to set the NetLabel on the socket to save time later, if we fail
198 * here we will pick up the pieces in later calls to
199 * selinux_netlbl_inode_permission(). */
200 selinux_netlbl_sock_setsid(sk);
204 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
205 * @sock: the socket to label
208 * Attempt to label a socket using the NetLabel mechanism using the given
209 * SID. Returns zero values on success, negative values on failure.
212 int selinux_netlbl_socket_post_create(struct socket *sock)
214 return selinux_netlbl_sock_setsid(sock->sk);
218 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
219 * @inode: the file descriptor's inode
220 * @mask: the permission mask
223 * Looks at a file's inode and if it is marked as a socket protected by
224 * NetLabel then verify that the socket has been labeled, if not try to label
225 * the socket now with the inode's SID. Returns zero on success, negative
229 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
234 struct sk_security_struct *sksec;
236 if (!S_ISSOCK(inode->i_mode) ||
237 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
240 sock = SOCKET_I(inode);
242 sksec = sk->sk_security;
243 if (sksec->nlbl_state != NLBL_REQUIRE)
247 bh_lock_sock_nested(sk);
248 if (likely(sksec->nlbl_state == NLBL_REQUIRE))
249 rc = selinux_netlbl_sock_setsid(sk);
259 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
260 * @sksec: the sock's sk_security_struct
262 * @family: protocol family
263 * @ad: the audit data
266 * Fetch the NetLabel security attributes from @skb and perform an access check
267 * against the receiving socket. Returns zero on success, negative values on
271 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
274 struct avc_audit_data *ad)
279 struct netlbl_lsm_secattr secattr;
281 if (!netlbl_enabled())
284 netlbl_secattr_init(&secattr);
285 rc = netlbl_skbuff_getattr(skb, family, &secattr);
286 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
287 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
289 nlbl_sid = SECINITSID_UNLABELED;
290 netlbl_secattr_destroy(&secattr);
294 switch (sksec->sclass) {
295 case SECCLASS_UDP_SOCKET:
296 perm = UDP_SOCKET__RECVFROM;
298 case SECCLASS_TCP_SOCKET:
299 perm = TCP_SOCKET__RECVFROM;
302 perm = RAWIP_SOCKET__RECVFROM;
305 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
309 if (nlbl_sid != SECINITSID_UNLABELED)
310 netlbl_skbuff_err(skb, rc, 0);
315 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
317 * @level: the socket level or protocol
318 * @optname: the socket option name
321 * Check the setsockopt() call and if the user is trying to replace the IP
322 * options on a socket and a NetLabel is in place for the socket deny the
323 * access; otherwise allow the access. Returns zero when the access is
324 * allowed, -EACCES when denied, and other negative values on error.
327 int selinux_netlbl_socket_setsockopt(struct socket *sock,
332 struct sock *sk = sock->sk;
333 struct sk_security_struct *sksec = sk->sk_security;
334 struct netlbl_lsm_secattr secattr;
336 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
337 sksec->nlbl_state == NLBL_LABELED) {
338 netlbl_secattr_init(&secattr);
340 rc = netlbl_sock_getattr(sk, &secattr);
342 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
344 netlbl_secattr_destroy(&secattr);