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Paul Moore5778eab2007-02-28 15:14:22 -05001/*
2 * SELinux NetLabel Support
3 *
4 * This file provides the necessary glue to tie NetLabel into the SELinux
5 * subsystem.
6 *
7 * Author: Paul Moore <paul.moore@hp.com>
8 *
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007
13 *
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.
18 *
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.
23 *
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
27 *
28 */
29
30#include <linux/spinlock.h>
31#include <linux/rcupdate.h>
32#include <net/sock.h>
33#include <net/netlabel.h>
34
35#include "objsec.h"
36#include "security.h"
Adrian Bunkd4ee4232008-02-27 23:20:42 +020037#include "netlabel.h"
Paul Moore5778eab2007-02-28 15:14:22 -050038
39/**
Paul Moore5dbe1eb2008-01-29 08:44:18 -050040 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
41 * @skb: the packet
42 * @secattr: the NetLabel security attributes
43 * @sid: the SID
44 *
45 * Description:
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.
49 *
50 */
51static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
52 struct netlbl_lsm_secattr *secattr,
53 u32 *sid)
54{
55 int rc;
56
57 rc = security_netlbl_secattr_to_sid(secattr, sid);
58 if (rc == 0 &&
59 (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
60 (secattr->flags & NETLBL_SECATTR_CACHE))
61 netlbl_cache_add(skb, secattr);
62
63 return rc;
64}
65
66/**
Paul Mooreba6ff9f2007-06-07 18:37:15 -070067 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
68 * @sk: the socket to label
Paul Moore5778eab2007-02-28 15:14:22 -050069 * @sid: the SID to use
70 *
71 * Description:
72 * Attempt to label a socket using the NetLabel mechanism using the given
Paul Mooref74af6e2008-02-25 11:40:33 -050073 * SID. Returns zero values on success, negative values on failure.
Paul Moore5778eab2007-02-28 15:14:22 -050074 *
75 */
Paul Mooreba6ff9f2007-06-07 18:37:15 -070076static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
Paul Moore5778eab2007-02-28 15:14:22 -050077{
78 int rc;
Paul Mooreba6ff9f2007-06-07 18:37:15 -070079 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore5778eab2007-02-28 15:14:22 -050080 struct netlbl_lsm_secattr secattr;
81
Paul Moore45c950e2008-01-22 09:31:00 +110082 netlbl_secattr_init(&secattr);
83
Paul Moore5778eab2007-02-28 15:14:22 -050084 rc = security_netlbl_sid_to_secattr(sid, &secattr);
85 if (rc != 0)
Paul Moore45c950e2008-01-22 09:31:00 +110086 goto sock_setsid_return;
Paul Mooreba6ff9f2007-06-07 18:37:15 -070087 rc = netlbl_sock_setattr(sk, &secattr);
Paul Mooref74af6e2008-02-25 11:40:33 -050088 if (rc == 0)
Paul Moore5778eab2007-02-28 15:14:22 -050089 sksec->nlbl_state = NLBL_LABELED;
Paul Moore5778eab2007-02-28 15:14:22 -050090
Paul Moore45c950e2008-01-22 09:31:00 +110091sock_setsid_return:
92 netlbl_secattr_destroy(&secattr);
Paul Moore5778eab2007-02-28 15:14:22 -050093 return rc;
94}
95
96/**
97 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
98 *
99 * Description:
100 * Invalidate the NetLabel security attribute mapping cache.
101 *
102 */
103void selinux_netlbl_cache_invalidate(void)
104{
105 netlbl_cache_invalidate();
106}
107
108/**
109 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
110 * @ssec: the sk_security_struct
111 * @family: the socket family
112 *
113 * Description:
114 * Called when the NetLabel state of a sk_security_struct needs to be reset.
115 * The caller is responsibile for all the NetLabel sk_security_struct locking.
116 *
117 */
118void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
119 int family)
120{
Eric Parisa6aaafe2008-04-18 17:38:23 -0400121 if (family == PF_INET)
Paul Moore5778eab2007-02-28 15:14:22 -0500122 ssec->nlbl_state = NLBL_REQUIRE;
123 else
124 ssec->nlbl_state = NLBL_UNSET;
125}
126
127/**
Paul Moore5778eab2007-02-28 15:14:22 -0500128 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
129 * @skb: the packet
Paul Moore75e22912008-01-29 08:38:04 -0500130 * @family: protocol family
Paul Moore220deb92008-01-29 08:38:23 -0500131 * @type: NetLabel labeling protocol type
Paul Moore5778eab2007-02-28 15:14:22 -0500132 * @sid: the SID
133 *
134 * Description:
135 * Call the NetLabel mechanism to get the security attributes of the given
136 * packet and use those attributes to determine the correct context/SID to
137 * assign to the packet. Returns zero on success, negative values on failure.
138 *
139 */
Paul Moore75e22912008-01-29 08:38:04 -0500140int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
141 u16 family,
Paul Moore220deb92008-01-29 08:38:23 -0500142 u32 *type,
Paul Moore75e22912008-01-29 08:38:04 -0500143 u32 *sid)
Paul Moore5778eab2007-02-28 15:14:22 -0500144{
145 int rc;
146 struct netlbl_lsm_secattr secattr;
147
Paul Moore23bcdc12007-07-18 12:28:45 -0400148 if (!netlbl_enabled()) {
149 *sid = SECSID_NULL;
150 return 0;
151 }
152
Paul Moore5778eab2007-02-28 15:14:22 -0500153 netlbl_secattr_init(&secattr);
Paul Moore75e22912008-01-29 08:38:04 -0500154 rc = netlbl_skbuff_getattr(skb, family, &secattr);
Paul Moore5dbe1eb2008-01-29 08:44:18 -0500155 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
156 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
157 else
Paul Moore5778eab2007-02-28 15:14:22 -0500158 *sid = SECSID_NULL;
Paul Moore220deb92008-01-29 08:38:23 -0500159 *type = secattr.type;
Paul Moore5778eab2007-02-28 15:14:22 -0500160 netlbl_secattr_destroy(&secattr);
161
162 return rc;
163}
164
165/**
166 * selinux_netlbl_sock_graft - Netlabel the new socket
167 * @sk: the new connection
168 * @sock: the new socket
169 *
170 * Description:
171 * The connection represented by @sk is being grafted onto @sock so set the
172 * socket's NetLabel to match the SID of @sk.
173 *
174 */
175void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
176{
Paul Moore5778eab2007-02-28 15:14:22 -0500177 struct sk_security_struct *sksec = sk->sk_security;
178 struct netlbl_lsm_secattr secattr;
179 u32 nlbl_peer_sid;
180
Paul Mooref74af6e2008-02-25 11:40:33 -0500181 if (sksec->nlbl_state != NLBL_REQUIRE)
Paul Moore5778eab2007-02-28 15:14:22 -0500182 return;
Paul Moore5778eab2007-02-28 15:14:22 -0500183
184 netlbl_secattr_init(&secattr);
185 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
186 secattr.flags != NETLBL_SECATTR_NONE &&
Paul Moore5dbe1eb2008-01-29 08:44:18 -0500187 security_netlbl_secattr_to_sid(&secattr, &nlbl_peer_sid) == 0)
Paul Moore5778eab2007-02-28 15:14:22 -0500188 sksec->peer_sid = nlbl_peer_sid;
189 netlbl_secattr_destroy(&secattr);
190
191 /* Try to set the NetLabel on the socket to save time later, if we fail
192 * here we will pick up the pieces in later calls to
193 * selinux_netlbl_inode_permission(). */
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700194 selinux_netlbl_sock_setsid(sk, sksec->sid);
Paul Moore5778eab2007-02-28 15:14:22 -0500195}
196
197/**
198 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
199 * @sock: the socket to label
200 *
201 * Description:
202 * Attempt to label a socket using the NetLabel mechanism using the given
203 * SID. Returns zero values on success, negative values on failure.
204 *
205 */
206int selinux_netlbl_socket_post_create(struct socket *sock)
207{
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700208 struct sock *sk = sock->sk;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700209 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore5778eab2007-02-28 15:14:22 -0500210
Paul Mooref74af6e2008-02-25 11:40:33 -0500211 if (sksec->nlbl_state != NLBL_REQUIRE)
212 return 0;
Paul Moore5778eab2007-02-28 15:14:22 -0500213
Paul Mooref74af6e2008-02-25 11:40:33 -0500214 return selinux_netlbl_sock_setsid(sk, sksec->sid);
Paul Moore5778eab2007-02-28 15:14:22 -0500215}
216
217/**
218 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
219 * @inode: the file descriptor's inode
220 * @mask: the permission mask
221 *
222 * Description:
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
226 * values on failure.
227 *
228 */
229int selinux_netlbl_inode_permission(struct inode *inode, int mask)
230{
231 int rc;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700232 struct sock *sk;
Paul Moore5778eab2007-02-28 15:14:22 -0500233 struct socket *sock;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700234 struct sk_security_struct *sksec;
Paul Moore5778eab2007-02-28 15:14:22 -0500235
236 if (!S_ISSOCK(inode->i_mode) ||
237 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
238 return 0;
Paul Mooref74af6e2008-02-25 11:40:33 -0500239
Paul Moore5778eab2007-02-28 15:14:22 -0500240 sock = SOCKET_I(inode);
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700241 sk = sock->sk;
242 sksec = sk->sk_security;
Paul Mooref74af6e2008-02-25 11:40:33 -0500243 if (sksec->nlbl_state != NLBL_REQUIRE)
Paul Moore5778eab2007-02-28 15:14:22 -0500244 return 0;
Paul Mooref74af6e2008-02-25 11:40:33 -0500245
Paul Moore5778eab2007-02-28 15:14:22 -0500246 local_bh_disable();
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700247 bh_lock_sock_nested(sk);
Paul Mooref74af6e2008-02-25 11:40:33 -0500248 if (likely(sksec->nlbl_state == NLBL_REQUIRE))
249 rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
250 else
251 rc = 0;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700252 bh_unlock_sock(sk);
Paul Moore5778eab2007-02-28 15:14:22 -0500253 local_bh_enable();
Paul Moore5778eab2007-02-28 15:14:22 -0500254
255 return rc;
256}
257
258/**
259 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
260 * @sksec: the sock's sk_security_struct
261 * @skb: the packet
Paul Moore75e22912008-01-29 08:38:04 -0500262 * @family: protocol family
Paul Moore5778eab2007-02-28 15:14:22 -0500263 * @ad: the audit data
264 *
265 * Description:
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
268 * error.
269 *
270 */
271int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
272 struct sk_buff *skb,
Paul Moore75e22912008-01-29 08:38:04 -0500273 u16 family,
Paul Moore5778eab2007-02-28 15:14:22 -0500274 struct avc_audit_data *ad)
275{
276 int rc;
Paul Mooref36158c2007-07-18 12:28:46 -0400277 u32 nlbl_sid;
278 u32 perm;
279 struct netlbl_lsm_secattr secattr;
Paul Moore5778eab2007-02-28 15:14:22 -0500280
Paul Moore23bcdc12007-07-18 12:28:45 -0400281 if (!netlbl_enabled())
282 return 0;
283
Paul Mooref36158c2007-07-18 12:28:46 -0400284 netlbl_secattr_init(&secattr);
Paul Moore75e22912008-01-29 08:38:04 -0500285 rc = netlbl_skbuff_getattr(skb, family, &secattr);
Paul Moore5dbe1eb2008-01-29 08:44:18 -0500286 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
287 rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
288 else
Paul Mooref36158c2007-07-18 12:28:46 -0400289 nlbl_sid = SECINITSID_UNLABELED;
290 netlbl_secattr_destroy(&secattr);
Paul Moore5778eab2007-02-28 15:14:22 -0500291 if (rc != 0)
292 return rc;
Linus Torvalds8d9107e2007-07-13 16:53:18 -0700293
Paul Moore5778eab2007-02-28 15:14:22 -0500294 switch (sksec->sclass) {
295 case SECCLASS_UDP_SOCKET:
Paul Mooref36158c2007-07-18 12:28:46 -0400296 perm = UDP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500297 break;
298 case SECCLASS_TCP_SOCKET:
Paul Mooref36158c2007-07-18 12:28:46 -0400299 perm = TCP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500300 break;
301 default:
Paul Mooref36158c2007-07-18 12:28:46 -0400302 perm = RAWIP_SOCKET__RECVFROM;
Paul Moore5778eab2007-02-28 15:14:22 -0500303 }
304
Paul Mooref36158c2007-07-18 12:28:46 -0400305 rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
Paul Moore5778eab2007-02-28 15:14:22 -0500306 if (rc == 0)
307 return 0;
308
Paul Mooref36158c2007-07-18 12:28:46 -0400309 if (nlbl_sid != SECINITSID_UNLABELED)
310 netlbl_skbuff_err(skb, rc);
Paul Moore5778eab2007-02-28 15:14:22 -0500311 return rc;
312}
313
314/**
315 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
316 * @sock: the socket
317 * @level: the socket level or protocol
318 * @optname: the socket option name
319 *
320 * Description:
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.
325 *
326 */
327int selinux_netlbl_socket_setsockopt(struct socket *sock,
328 int level,
329 int optname)
330{
331 int rc = 0;
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700332 struct sock *sk = sock->sk;
333 struct sk_security_struct *sksec = sk->sk_security;
Paul Moore5778eab2007-02-28 15:14:22 -0500334 struct netlbl_lsm_secattr secattr;
335
Paul Moore5778eab2007-02-28 15:14:22 -0500336 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
337 sksec->nlbl_state == NLBL_LABELED) {
338 netlbl_secattr_init(&secattr);
Paul Mooreba6ff9f2007-06-07 18:37:15 -0700339 lock_sock(sk);
340 rc = netlbl_sock_getattr(sk, &secattr);
341 release_sock(sk);
Paul Moore5778eab2007-02-28 15:14:22 -0500342 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
343 rc = -EACCES;
344 netlbl_secattr_destroy(&secattr);
345 }
Paul Moore5778eab2007-02-28 15:14:22 -0500346
347 return rc;
348}