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_sock_setsid - Label a socket using the NetLabel mechanism
40 * @sk: the socket to label
41 * @sid: the SID to use
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)
53 struct sk_security_struct *sksec = sk->sk_security;
54 struct netlbl_lsm_secattr secattr;
56 rc = security_netlbl_sid_to_secattr(sid, &secattr);
60 rc = netlbl_sock_setattr(sk, &secattr);
62 spin_lock_bh(&sksec->nlbl_lock);
63 sksec->nlbl_state = NLBL_LABELED;
64 spin_unlock_bh(&sksec->nlbl_lock);
71 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
74 * Invalidate the NetLabel security attribute mapping cache.
77 void selinux_netlbl_cache_invalidate(void)
79 netlbl_cache_invalidate();
83 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
84 * @ssec: the sk_security_struct
85 * @family: the socket family
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,
95 if (family == PF_INET)
96 ssec->nlbl_state = NLBL_REQUIRE;
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
107 * Called when a new sk_security_struct is allocated to initialize the NetLabel
111 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
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
125 * Clone the NetLabel specific sk_security_struct fields from @ssec to
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 */
136 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
137 newssec->sclass = ssec->sclass;
142 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
144 * @base_sid: the SELinux SID to use as a context for MLS only attributes
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)
156 struct netlbl_lsm_secattr secattr;
158 netlbl_secattr_init(&secattr);
159 rc = netlbl_skbuff_getattr(skb, &secattr);
160 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
161 rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
164 netlbl_secattr_destroy(&secattr);
170 * selinux_netlbl_sock_graft - Netlabel the new socket
171 * @sk: the new connection
172 * @sock: the new socket
175 * The connection represented by @sk is being grafted onto @sock so set the
176 * socket's NetLabel to match the SID of @sk.
179 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
181 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
182 struct sk_security_struct *sksec = sk->sk_security;
183 struct netlbl_lsm_secattr secattr;
186 sksec->sclass = isec->sclass;
190 if (sksec->nlbl_state != NLBL_REQUIRE) {
195 netlbl_secattr_init(&secattr);
196 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
197 secattr.flags != NETLBL_SECATTR_NONE &&
198 security_netlbl_secattr_to_sid(&secattr,
200 &nlbl_peer_sid) == 0)
201 sksec->peer_sid = nlbl_peer_sid;
202 netlbl_secattr_destroy(&secattr);
204 /* Try to set the NetLabel on the socket to save time later, if we fail
205 * here we will pick up the pieces in later calls to
206 * selinux_netlbl_inode_permission(). */
207 selinux_netlbl_sock_setsid(sk, sksec->sid);
213 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
214 * @sock: the socket to label
217 * Attempt to label a socket using the NetLabel mechanism using the given
218 * SID. Returns zero values on success, negative values on failure.
221 int selinux_netlbl_socket_post_create(struct socket *sock)
224 struct sock *sk = sock->sk;
225 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
226 struct sk_security_struct *sksec = sk->sk_security;
228 sksec->sclass = isec->sclass;
231 if (sksec->nlbl_state == NLBL_REQUIRE)
232 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
239 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
240 * @inode: the file descriptor's inode
241 * @mask: the permission mask
244 * Looks at a file's inode and if it is marked as a socket protected by
245 * NetLabel then verify that the socket has been labeled, if not try to label
246 * the socket now with the inode's SID. Returns zero on success, negative
250 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
255 struct sk_security_struct *sksec;
257 if (!S_ISSOCK(inode->i_mode) ||
258 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
260 sock = SOCKET_I(inode);
262 sksec = sk->sk_security;
265 if (sksec->nlbl_state != NLBL_REQUIRE) {
270 bh_lock_sock_nested(sk);
271 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
280 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
281 * @sksec: the sock's sk_security_struct
283 * @ad: the audit data
286 * Fetch the NetLabel security attributes from @skb and perform an access check
287 * against the receiving socket. Returns zero on success, negative values on
291 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
293 struct avc_audit_data *ad)
299 rc = selinux_netlbl_skbuff_getsid(skb, SECINITSID_NETMSG, &nlbl_sid);
302 if (nlbl_sid == SECSID_NULL)
303 nlbl_sid = SECINITSID_UNLABELED;
305 switch (sksec->sclass) {
306 case SECCLASS_UDP_SOCKET:
307 perm = UDP_SOCKET__RECVFROM;
309 case SECCLASS_TCP_SOCKET:
310 perm = TCP_SOCKET__RECVFROM;
313 perm = RAWIP_SOCKET__RECVFROM;
316 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
320 if (nlbl_sid != SECINITSID_UNLABELED)
321 netlbl_skbuff_err(skb, rc);
326 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
328 * @level: the socket level or protocol
329 * @optname: the socket option name
332 * Check the setsockopt() call and if the user is trying to replace the IP
333 * options on a socket and a NetLabel is in place for the socket deny the
334 * access; otherwise allow the access. Returns zero when the access is
335 * allowed, -EACCES when denied, and other negative values on error.
338 int selinux_netlbl_socket_setsockopt(struct socket *sock,
343 struct sock *sk = sock->sk;
344 struct sk_security_struct *sksec = sk->sk_security;
345 struct netlbl_lsm_secattr secattr;
348 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
349 sksec->nlbl_state == NLBL_LABELED) {
350 netlbl_secattr_init(&secattr);
352 rc = netlbl_sock_getattr(sk, &secattr);
354 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
356 netlbl_secattr_destroy(&secattr);