Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: e68823741ad5836a54f38f34e98a86193dbc70eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
/*
 * SELinux NetLabel Support
 *
 * This file provides the necessary glue to tie NetLabel into the SELinux
 * subsystem.
 *
 * Author: Paul Moore <paul.moore@hp.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/sock.h>
#include <net/netlabel.h>
#include <net/ip.h>
#include <net/ipv6.h>

#include "objsec.h"
#include "security.h"
#include "netlabel.h"

/**
 * selinux_netlbl_sidlookup_cached - Cache a SID lookup
 * @skb: the packet
 * @secattr: the NetLabel security attributes
 * @sid: the SID
 *
 * Description:
 * Query the SELinux security server to lookup the correct SID for the given
 * security attributes.  If the query is successful, cache the result to speed
 * up future lookups.  Returns zero on success, negative values on failure.
 *
 */
static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
					   struct netlbl_lsm_secattr *secattr,
					   u32 *sid)
{
	int rc;

	rc = security_netlbl_secattr_to_sid(secattr, sid);
	if (rc == 0 &&
	    (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
	    (secattr->flags & NETLBL_SECATTR_CACHE))
		netlbl_cache_add(skb, secattr);

	return rc;
}

/**
 * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
 * @sk: the socket
 *
 * Description:
 * Generate the NetLabel security attributes for a socket, making full use of
 * the socket's attribute cache.  Returns a pointer to the security attributes
 * on success, NULL on failure.
 *
 */
static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
{
	int rc;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr *secattr;

	if (sksec->nlbl_secattr != NULL)
		return sksec->nlbl_secattr;

	secattr = netlbl_secattr_alloc(GFP_ATOMIC);
	if (secattr == NULL)
		return NULL;
	rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
	if (rc != 0) {
		netlbl_secattr_free(secattr);
		return NULL;
	}
	sksec->nlbl_secattr = secattr;

	return secattr;
}

/**
 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
 *
 * Description:
 * Invalidate the NetLabel security attribute mapping cache.
 *
 */
void selinux_netlbl_cache_invalidate(void)
{
	netlbl_cache_invalidate();
}

/**
 * selinux_netlbl_err - Handle a NetLabel packet error
 * @skb: the packet
 * @error: the error code
 * @gateway: true if host is acting as a gateway, false otherwise
 *
 * Description:
 * When a packet is dropped due to a call to avc_has_perm() pass the error
 * code to the NetLabel subsystem so any protocol specific processing can be
 * done.  This is safe to call even if you are unsure if NetLabel labeling is
 * present on the packet, NetLabel is smart enough to only act when it should.
 *
 */
void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
{
	netlbl_skbuff_err(skb, error, gateway);
}

/**
 * selinux_netlbl_sk_security_free - Free the NetLabel fields
 * @sssec: the sk_security_struct
 *
 * Description:
 * Free all of the memory in the NetLabel fields of a sk_security_struct.
 *
 */
void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec)
{
	if (ssec->nlbl_secattr != NULL)
		netlbl_secattr_free(ssec->nlbl_secattr);
}

/**
 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
 * @ssec: the sk_security_struct
 * @family: the socket family
 *
 * Description:
 * Called when the NetLabel state of a sk_security_struct needs to be reset.
 * The caller is responsibile for all the NetLabel sk_security_struct locking.
 *
 */
void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec)
{
	ssec->nlbl_state = NLBL_UNSET;
}

/**
 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
 * @skb: the packet
 * @family: protocol family
 * @type: NetLabel labeling protocol type
 * @sid: the SID
 *
 * Description:
 * Call the NetLabel mechanism to get the security attributes of the given
 * packet and use those attributes to determine the correct context/SID to
 * assign to the packet.  Returns zero on success, negative values on failure.
 *
 */
int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
				 u16 family,
				 u32 *type,
				 u32 *sid)
{
	int rc;
	struct netlbl_lsm_secattr secattr;

	if (!netlbl_enabled()) {
		*sid = SECSID_NULL;
		return 0;
	}

	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, family, &secattr);
	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
		rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
	else
		*sid = SECSID_NULL;
	*type = secattr.type;
	netlbl_secattr_destroy(&secattr);

	return rc;
}

/**
 * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
 * @skb: the packet
 * @family: protocol family
 * @sid: the SID
 *
 * Description
 * Call the NetLabel mechanism to set the label of a packet using @sid.
 * Returns zero on auccess, negative values on failure.
 *
 */
int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
				 u16 family,
				 u32 sid)
{
	int rc;
	struct netlbl_lsm_secattr secattr_storage;
	struct netlbl_lsm_secattr *secattr = NULL;
	struct sock *sk;

	/* if this is a locally generated packet check to see if it is already
	 * being labeled by it's parent socket, if it is just exit */
	sk = skb->sk;
	if (sk != NULL) {
		struct sk_security_struct *sksec = sk->sk_security;
		if (sksec->nlbl_state != NLBL_REQSKB)
			return 0;
		secattr = sksec->nlbl_secattr;
	}
	if (secattr == NULL) {
		secattr = &secattr_storage;
		netlbl_secattr_init(secattr);
		rc = security_netlbl_sid_to_secattr(sid, secattr);
		if (rc != 0)
			goto skbuff_setsid_return;
	}

	rc = netlbl_skbuff_setattr(skb, family, secattr);

skbuff_setsid_return:
	if (secattr == &secattr_storage)
		netlbl_secattr_destroy(secattr);
	return rc;
}

/**
 * selinux_netlbl_inet_conn_request - Label an incoming stream connection
 * @req: incoming connection request socket
 *
 * Description:
 * A new incoming connection request is represented by @req, we need to label
 * the new request_sock here and the stack will ensure the on-the-wire label
 * will get preserved when a full sock is created once the connection handshake
 * is complete.  Returns zero on success, negative values on failure.
 *
 */
int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
{
	int rc;
	struct netlbl_lsm_secattr secattr;

	if (family != PF_INET)
		return 0;

	netlbl_secattr_init(&secattr);
	rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
	if (rc != 0)
		goto inet_conn_request_return;
	rc = netlbl_req_setattr(req, &secattr);
inet_conn_request_return:
	netlbl_secattr_destroy(&secattr);
	return rc;
}

/**
 * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
 * @sk: the new sock
 *
 * Description:
 * A new connection has been established using @sk, we've already labeled the
 * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
 * we need to set the NetLabel state here since we now have a sock structure.
 *
 */
void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
{
	struct sk_security_struct *sksec = sk->sk_security;

	if (family == PF_INET)
		sksec->nlbl_state = NLBL_LABELED;
	else
		sksec->nlbl_state = NLBL_UNSET;
}

/**
 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
 * @sock: the socket to label
 * @family: protocol family
 *
 * Description:
 * Attempt to label a socket using the NetLabel mechanism using the given
 * SID.  Returns zero values on success, negative values on failure.
 *
 */
int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
{
	int rc;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr *secattr;

	if (family != PF_INET)
		return 0;

	secattr = selinux_netlbl_sock_genattr(sk);
	if (secattr == NULL)
		return -ENOMEM;
	rc = netlbl_sock_setattr(sk, family, secattr);
	switch (rc) {
	case 0:
		sksec->nlbl_state = NLBL_LABELED;
		break;
	case -EDESTADDRREQ:
		sksec->nlbl_state = NLBL_REQSKB;
		rc = 0;
		break;
	}

	return rc;
}

/**
 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
 * @sksec: the sock's sk_security_struct
 * @skb: the packet
 * @family: protocol family
 * @ad: the audit data
 *
 * Description:
 * Fetch the NetLabel security attributes from @skb and perform an access check
 * against the receiving socket.  Returns zero on success, negative values on
 * error.
 *
 */
int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
				struct sk_buff *skb,
				u16 family,
				struct common_audit_data *ad)
{
	int rc;
	u32 nlbl_sid;
	u32 perm;
	struct netlbl_lsm_secattr secattr;

	if (!netlbl_enabled())
		return 0;

	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, family, &secattr);
	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
		rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
	else
		nlbl_sid = SECINITSID_UNLABELED;
	netlbl_secattr_destroy(&secattr);
	if (rc != 0)
		return rc;

	switch (sksec->sclass) {
	case SECCLASS_UDP_SOCKET:
		perm = UDP_SOCKET__RECVFROM;
		break;
	case SECCLASS_TCP_SOCKET:
		perm = TCP_SOCKET__RECVFROM;
		break;
	default:
		perm = RAWIP_SOCKET__RECVFROM;
	}

	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
	if (rc == 0)
		return 0;

	if (nlbl_sid != SECINITSID_UNLABELED)
		netlbl_skbuff_err(skb, rc, 0);
	return rc;
}

/**
 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
 * @sock: the socket
 * @level: the socket level or protocol
 * @optname: the socket option name
 *
 * Description:
 * Check the setsockopt() call and if the user is trying to replace the IP
 * options on a socket and a NetLabel is in place for the socket deny the
 * access; otherwise allow the access.  Returns zero when the access is
 * allowed, -EACCES when denied, and other negative values on error.
 *
 */
int selinux_netlbl_socket_setsockopt(struct socket *sock,
				     int level,
				     int optname)
{
	int rc = 0;
	struct sock *sk = sock->sk;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr secattr;

	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	    (sksec->nlbl_state == NLBL_LABELED ||
	     sksec->nlbl_state == NLBL_CONNLABELED)) {
		netlbl_secattr_init(&secattr);
		lock_sock(sk);
		rc = netlbl_sock_getattr(sk, &secattr);
		release_sock(sk);
		if (rc == 0)
			rc = -EACCES;
		else if (rc == -ENOMSG)
			rc = 0;
		netlbl_secattr_destroy(&secattr);
	}

	return rc;
}

/**
 * selinux_netlbl_socket_connect - Label a client-side socket on connect
 * @sk: the socket to label
 * @addr: the destination address
 *
 * Description:
 * Attempt to label a connected socket with NetLabel using the given address.
 * Returns zero values on success, negative values on failure.
 *
 */
int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
{
	int rc;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr *secattr;

	if (sksec->nlbl_state != NLBL_REQSKB &&
	    sksec->nlbl_state != NLBL_CONNLABELED)
		return 0;

	local_bh_disable();
	bh_lock_sock_nested(sk);

	/* connected sockets are allowed to disconnect when the address family
	 * is set to AF_UNSPEC, if that is what is happening we want to reset
	 * the socket */
	if (addr->sa_family == AF_UNSPEC) {
		netlbl_sock_delattr(sk);
		sksec->nlbl_state = NLBL_REQSKB;
		rc = 0;
		goto socket_connect_return;
	}
	secattr = selinux_netlbl_sock_genattr(sk);
	if (secattr == NULL) {
		rc = -ENOMEM;
		goto socket_connect_return;
	}
	rc = netlbl_conn_setattr(sk, addr, secattr);
	if (rc == 0)
		sksec->nlbl_state = NLBL_CONNLABELED;

socket_connect_return:
	bh_unlock_sock(sk);
	local_bh_enable();
	return rc;
}