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, 2008
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>
34 #include <net/inet_sock.h>
35 #include <net/inet_connection_sock.h>
42 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
44 * @secattr: the NetLabel security attributes
48 * Query the SELinux security server to lookup the correct SID for the given
49 * security attributes. If the query is successful, cache the result to speed
50 * up future lookups. Returns zero on success, negative values on failure.
53 static int selinux_netlbl_sidlookup_cached(struct sk_buff
*skb
,
54 struct netlbl_lsm_secattr
*secattr
,
59 rc
= security_netlbl_secattr_to_sid(secattr
, sid
);
61 (secattr
->flags
& NETLBL_SECATTR_CACHEABLE
) &&
62 (secattr
->flags
& NETLBL_SECATTR_CACHE
))
63 netlbl_cache_add(skb
, secattr
);
69 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
70 * @sk: the socket to label
73 * Attempt to label a socket using the NetLabel mechanism. Returns zero values
74 * on success, negative values on failure.
77 static int selinux_netlbl_sock_setsid(struct sock
*sk
)
80 struct sk_security_struct
*sksec
= sk
->sk_security
;
81 struct netlbl_lsm_secattr secattr
;
82 struct inet_sock
*sk_inet
;
83 struct inet_connection_sock
*sk_conn
;
85 if (sksec
->nlbl_state
!= NLBL_REQUIRE
)
88 netlbl_secattr_init(&secattr
);
90 rc
= security_netlbl_sid_to_secattr(sksec
->sid
, &secattr
);
92 goto sock_setsid_return
;
93 rc
= netlbl_sock_setattr(sk
, &secattr
);
96 sksec
->nlbl_state
= NLBL_LABELED
;
99 /* we are going to possibly end up labeling the individual
100 * packets later which is problematic for stream sockets
101 * because of the additional IP header size, our solution is to
102 * allow for the maximum IP header length (40 bytes for IPv4,
103 * we don't have to worry about IPv6 yet) just in case */
104 sk_inet
= inet_sk(sk
);
105 if (sk_inet
->is_icsk
) {
106 sk_conn
= inet_csk(sk
);
108 sk_conn
->icsk_ext_hdr_len
-=
109 sk_inet
->opt
->optlen
;
110 sk_conn
->icsk_ext_hdr_len
+= 40;
111 sk_conn
->icsk_sync_mss(sk
, sk_conn
->icsk_pmtu_cookie
);
113 sksec
->nlbl_state
= NLBL_REQSKB
;
119 netlbl_secattr_destroy(&secattr
);
124 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
127 * Invalidate the NetLabel security attribute mapping cache.
130 void selinux_netlbl_cache_invalidate(void)
132 netlbl_cache_invalidate();
136 * selinux_netlbl_err - Handle a NetLabel packet error
138 * @error: the error code
139 * @gateway: true if host is acting as a gateway, false otherwise
142 * When a packet is dropped due to a call to avc_has_perm() pass the error
143 * code to the NetLabel subsystem so any protocol specific processing can be
144 * done. This is safe to call even if you are unsure if NetLabel labeling is
145 * present on the packet, NetLabel is smart enough to only act when it should.
148 void selinux_netlbl_err(struct sk_buff
*skb
, int error
, int gateway
)
150 netlbl_skbuff_err(skb
, error
, gateway
);
154 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
155 * @ssec: the sk_security_struct
156 * @family: the socket family
159 * Called when the NetLabel state of a sk_security_struct needs to be reset.
160 * The caller is responsibile for all the NetLabel sk_security_struct locking.
163 void selinux_netlbl_sk_security_reset(struct sk_security_struct
*ssec
,
166 if (family
== PF_INET
)
167 ssec
->nlbl_state
= NLBL_REQUIRE
;
169 ssec
->nlbl_state
= NLBL_UNSET
;
173 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
175 * @family: protocol family
176 * @type: NetLabel labeling protocol type
180 * Call the NetLabel mechanism to get the security attributes of the given
181 * packet and use those attributes to determine the correct context/SID to
182 * assign to the packet. Returns zero on success, negative values on failure.
185 int selinux_netlbl_skbuff_getsid(struct sk_buff
*skb
,
191 struct netlbl_lsm_secattr secattr
;
193 if (!netlbl_enabled()) {
198 netlbl_secattr_init(&secattr
);
199 rc
= netlbl_skbuff_getattr(skb
, family
, &secattr
);
200 if (rc
== 0 && secattr
.flags
!= NETLBL_SECATTR_NONE
)
201 rc
= selinux_netlbl_sidlookup_cached(skb
, &secattr
, sid
);
204 *type
= secattr
.type
;
205 netlbl_secattr_destroy(&secattr
);
211 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
213 * @family: protocol family
217 * Call the NetLabel mechanism to set the label of a packet using @sid.
218 * Returns zero on auccess, negative values on failure.
221 int selinux_netlbl_skbuff_setsid(struct sk_buff
*skb
,
226 struct netlbl_lsm_secattr secattr
;
229 /* if this is a locally generated packet check to see if it is already
230 * being labeled by it's parent socket, if it is just exit */
233 struct sk_security_struct
*sksec
= sk
->sk_security
;
234 if (sksec
->nlbl_state
!= NLBL_REQSKB
)
238 netlbl_secattr_init(&secattr
);
239 rc
= security_netlbl_sid_to_secattr(sid
, &secattr
);
241 goto skbuff_setsid_return
;
242 rc
= netlbl_skbuff_setattr(skb
, family
, &secattr
);
244 skbuff_setsid_return
:
245 netlbl_secattr_destroy(&secattr
);
250 * selinux_netlbl_sock_graft - Netlabel the new socket
251 * @sk: the new connection
252 * @sock: the new socket
255 * The connection represented by @sk is being grafted onto @sock so set the
256 * socket's NetLabel to match the SID of @sk.
259 void selinux_netlbl_sock_graft(struct sock
*sk
, struct socket
*sock
)
261 /* Try to set the NetLabel on the socket to save time later, if we fail
262 * here we will pick up the pieces in later calls to
263 * selinux_netlbl_inode_permission(). */
264 selinux_netlbl_sock_setsid(sk
);
268 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
269 * @sock: the socket to label
272 * Attempt to label a socket using the NetLabel mechanism using the given
273 * SID. Returns zero values on success, negative values on failure.
276 int selinux_netlbl_socket_post_create(struct socket
*sock
)
278 return selinux_netlbl_sock_setsid(sock
->sk
);
282 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
283 * @inode: the file descriptor's inode
284 * @mask: the permission mask
287 * Looks at a file's inode and if it is marked as a socket protected by
288 * NetLabel then verify that the socket has been labeled, if not try to label
289 * the socket now with the inode's SID. Returns zero on success, negative
293 int selinux_netlbl_inode_permission(struct inode
*inode
, int mask
)
298 struct sk_security_struct
*sksec
;
300 if (!S_ISSOCK(inode
->i_mode
) ||
301 ((mask
& (MAY_WRITE
| MAY_APPEND
)) == 0))
304 sock
= SOCKET_I(inode
);
306 sksec
= sk
->sk_security
;
307 if (sksec
->nlbl_state
!= NLBL_REQUIRE
)
311 bh_lock_sock_nested(sk
);
312 if (likely(sksec
->nlbl_state
== NLBL_REQUIRE
))
313 rc
= selinux_netlbl_sock_setsid(sk
);
323 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
324 * @sksec: the sock's sk_security_struct
326 * @family: protocol family
327 * @ad: the audit data
330 * Fetch the NetLabel security attributes from @skb and perform an access check
331 * against the receiving socket. Returns zero on success, negative values on
335 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct
*sksec
,
338 struct avc_audit_data
*ad
)
343 struct netlbl_lsm_secattr secattr
;
345 if (!netlbl_enabled())
348 netlbl_secattr_init(&secattr
);
349 rc
= netlbl_skbuff_getattr(skb
, family
, &secattr
);
350 if (rc
== 0 && secattr
.flags
!= NETLBL_SECATTR_NONE
)
351 rc
= selinux_netlbl_sidlookup_cached(skb
, &secattr
, &nlbl_sid
);
353 nlbl_sid
= SECINITSID_UNLABELED
;
354 netlbl_secattr_destroy(&secattr
);
358 switch (sksec
->sclass
) {
359 case SECCLASS_UDP_SOCKET
:
360 perm
= UDP_SOCKET__RECVFROM
;
362 case SECCLASS_TCP_SOCKET
:
363 perm
= TCP_SOCKET__RECVFROM
;
366 perm
= RAWIP_SOCKET__RECVFROM
;
369 rc
= avc_has_perm(sksec
->sid
, nlbl_sid
, sksec
->sclass
, perm
, ad
);
373 if (nlbl_sid
!= SECINITSID_UNLABELED
)
374 netlbl_skbuff_err(skb
, rc
, 0);
379 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
381 * @level: the socket level or protocol
382 * @optname: the socket option name
385 * Check the setsockopt() call and if the user is trying to replace the IP
386 * options on a socket and a NetLabel is in place for the socket deny the
387 * access; otherwise allow the access. Returns zero when the access is
388 * allowed, -EACCES when denied, and other negative values on error.
391 int selinux_netlbl_socket_setsockopt(struct socket
*sock
,
396 struct sock
*sk
= sock
->sk
;
397 struct sk_security_struct
*sksec
= sk
->sk_security
;
398 struct netlbl_lsm_secattr secattr
;
400 if (level
== IPPROTO_IP
&& optname
== IP_OPTIONS
&&
401 sksec
->nlbl_state
== NLBL_LABELED
) {
402 netlbl_secattr_init(&secattr
);
404 rc
= netlbl_sock_getattr(sk
, &secattr
);
406 if (rc
== 0 && secattr
.flags
!= NETLBL_SECATTR_NONE
)
408 netlbl_secattr_destroy(&secattr
);