summaryrefslogtreecommitdiffstats
path: root/net/netlabel/netlabel_kapi.c
blob: e03a3282c5512017efad8b4c8a1213fb264b5ac3 (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
/*
 * NetLabel Kernel API
 *
 * This file defines the kernel API for the NetLabel system.  The NetLabel
 * system manages static and dynamic label mappings for network protocols such
 * as CIPSO and RIPSO.
 *
 * Author: Paul Moore <paul.moore@hp.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
 *
 * 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/init.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/bug.h>

#include "netlabel_domainhash.h"
#include "netlabel_unlabeled.h"
#include "netlabel_user.h"

/*
 * Security Attribute Functions
 */

/**
 * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
 * @catmap: the category bitmap
 * @offset: the offset to start searching at, in bits
 *
 * Description:
 * This function walks a LSM secattr category bitmap starting at @offset and
 * returns the spot of the first set bit or -ENOENT if no bits are set.
 *
 */
int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
			       u32 offset)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_idx;
	u32 node_bit;
	NETLBL_CATMAP_MAPTYPE bitmap;

	if (offset > iter->startbit) {
		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
			iter = iter->next;
			if (iter == NULL)
				return -ENOENT;
		}
		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
		node_bit = offset - iter->startbit -
			   (NETLBL_CATMAP_MAPSIZE * node_idx);
	} else {
		node_idx = 0;
		node_bit = 0;
	}
	bitmap = iter->bitmap[node_idx] >> node_bit;

	for (;;) {
		if (bitmap != 0) {
			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
				bitmap >>= 1;
				node_bit++;
			}
			return iter->startbit +
				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
		}
		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
			if (iter->next != NULL) {
				iter = iter->next;
				node_idx = 0;
			} else
				return -ENOENT;
		}
		bitmap = iter->bitmap[node_idx];
		node_bit = 0;
	}

	return -ENOENT;
}

/**
 * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
 * @catmap: the category bitmap
 * @offset: the offset to start searching at, in bits
 *
 * Description:
 * This function walks a LSM secattr category bitmap starting at @offset and
 * returns the spot of the first cleared bit or -ENOENT if the offset is past
 * the end of the bitmap.
 *
 */
int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
				   u32 offset)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_idx;
	u32 node_bit;
	NETLBL_CATMAP_MAPTYPE bitmask;
	NETLBL_CATMAP_MAPTYPE bitmap;

	if (offset > iter->startbit) {
		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
			iter = iter->next;
			if (iter == NULL)
				return -ENOENT;
		}
		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
		node_bit = offset - iter->startbit -
			   (NETLBL_CATMAP_MAPSIZE * node_idx);
	} else {
		node_idx = 0;
		node_bit = 0;
	}
	bitmask = NETLBL_CATMAP_BIT << node_bit;

	for (;;) {
		bitmap = iter->bitmap[node_idx];
		while (bitmask != 0 && (bitmap & bitmask) != 0) {
			bitmask <<= 1;
			node_bit++;
		}

		if (bitmask != 0)
			return iter->startbit +
				(NETLBL_CATMAP_MAPSIZE * node_idx) +
				node_bit - 1;
		else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
			if (iter->next == NULL)
				return iter->startbit +	NETLBL_CATMAP_SIZE - 1;
			iter = iter->next;
			node_idx = 0;
		}
		bitmask = NETLBL_CATMAP_BIT;
		node_bit = 0;
	}

	return -ENOENT;
}

/**
 * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
 * @catmap: the category bitmap
 * @bit: the bit to set
 * @flags: memory allocation flags
 *
 * Description:
 * Set the bit specified by @bit in @catmap.  Returns zero on success,
 * negative values on failure.
 *
 */
int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
				 u32 bit,
				 gfp_t flags)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_bit;
	u32 node_idx;

	while (iter->next != NULL &&
	       bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
		iter = iter->next;
	if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
		iter->next = netlbl_secattr_catmap_alloc(flags);
		if (iter->next == NULL)
			return -ENOMEM;
		iter = iter->next;
		iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
	}

	/* gcc always rounds to zero when doing integer division */
	node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
	node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
	iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;

	return 0;
}

/**
 * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
 * @catmap: the category bitmap
 * @start: the starting bit
 * @end: the last bit in the string
 * @flags: memory allocation flags
 *
 * Description:
 * Set a range of bits, starting at @start and ending with @end.  Returns zero
 * on success, negative values on failure.
 *
 */
int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
				 u32 start,
				 u32 end,
				 gfp_t flags)
{
	int ret_val = 0;
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 iter_max_spot;
	u32 spot;

	/* XXX - This could probably be made a bit faster by combining writes
	 * to the catmap instead of setting a single bit each time, but for
	 * right now skipping to the start of the range in the catmap should
	 * be a nice improvement over calling the individual setbit function
	 * repeatedly from a loop. */

	while (iter->next != NULL &&
	       start >= (iter->startbit + NETLBL_CATMAP_SIZE))
		iter = iter->next;
	iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;

	for (spot = start; spot <= end && ret_val == 0; spot++) {
		if (spot >= iter_max_spot && iter->next != NULL) {
			iter = iter->next;
			iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
		}
		ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC);
	}

	return ret_val;
}

/*
 * LSM Functions
 */

/**
 * netlbl_socket_setattr - Label a socket using the correct protocol
 * @sock: the socket to label
 * @secattr: the security attributes
 *
 * Description:
 * Attach the correct label to the given socket using the security attributes
 * specified in @secattr.  This function requires exclusive access to
 * @sock->sk, which means it either needs to be in the process of being
 * created or locked via lock_sock(sock->sk).  Returns zero on success,
 * negative values on failure.
 *
 */
int netlbl_socket_setattr(const struct socket *sock,
			  const struct netlbl_lsm_secattr *secattr)
{
	int ret_val = -ENOENT;
	struct netlbl_dom_map *dom_entry;

	if ((secattr->flags & NETLBL_SECATTR_DOMAIN) == 0)
		return -ENOENT;

	rcu_read_lock();
	dom_entry = netlbl_domhsh_getentry(secattr->domain);
	if (dom_entry == NULL)
		goto socket_setattr_return;
	switch (dom_entry->type) {
	case NETLBL_NLTYPE_CIPSOV4:
		ret_val = cipso_v4_socket_setattr(sock,
						  dom_entry->type_def.cipsov4,
						  secattr);
		break;
	case NETLBL_NLTYPE_UNLABELED:
		ret_val = 0;
		break;
	default:
		ret_val = -ENOENT;
	}

socket_setattr_return:
	rcu_read_unlock();
	return ret_val;
}

/**
 * netlbl_sock_getattr - Determine the security attributes of a sock
 * @sk: the sock
 * @secattr: the security attributes
 *
 * Description:
 * Examines the given sock to see any NetLabel style labeling has been
 * applied to the sock, if so it parses the socket label and returns the
 * security attributes in @secattr.  Returns zero on success, negative values
 * on failure.
 *
 */
int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
{
	int ret_val;

	ret_val = cipso_v4_sock_getattr(sk, secattr);
	if (ret_val == 0)
		return 0;

	return netlbl_unlabel_getattr(secattr);
}

/**
 * netlbl_socket_getattr - Determine the security attributes of a socket
 * @sock: the socket
 * @secattr: the security attributes
 *
 * Description:
 * Examines the given socket to see any NetLabel style labeling has been
 * applied to the socket, if so it parses the socket label and returns the
 * security attributes in @secattr.  Returns zero on success, negative values
 * on failure.
 *
 */
int netlbl_socket_getattr(const struct socket *sock,
			  struct netlbl_lsm_secattr *secattr)
{
	int ret_val;

	ret_val = cipso_v4_socket_getattr(sock, secattr);
	if (ret_val == 0)
		return 0;

	return netlbl_unlabel_getattr(secattr);
}

/**
 * netlbl_skbuff_getattr - Determine the security attributes of a packet
 * @skb: the packet
 * @secattr: the security attributes
 *
 * Description:
 * Examines the given packet to see if a recognized form of packet labeling
 * is present, if so it parses the packet label and returns the security
 * attributes in @secattr.  Returns zero on success, negative values on
 * failure.
 *
 */
int netlbl_skbuff_getattr(const struct sk_buff *skb,
			  struct netlbl_lsm_secattr *secattr)
{
	if (CIPSO_V4_OPTEXIST(skb) &&
	    cipso_v4_skbuff_getattr(skb, secattr) == 0)
		return 0;

	return netlbl_unlabel_getattr(secattr);
}

/**
 * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 * @skb: the packet
 * @error: the error code
 *
 * Description:
 * Deal with a LSM problem when handling the packet in @skb, typically this is
 * a permission denied problem (-EACCES).  The correct action is determined
 * according to the packet's labeling protocol.
 *
 */
void netlbl_skbuff_err(struct sk_buff *skb, int error)
{
	if (CIPSO_V4_OPTEXIST(skb))
		cipso_v4_error(skb, error, 0);
}

/**
 * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 *
 * Description:
 * For all of the NetLabel protocols that support some form of label mapping
 * cache, invalidate the cache.  Returns zero on success, negative values on
 * error.
 *
 */
void netlbl_cache_invalidate(void)
{
	cipso_v4_cache_invalidate();
}

/**
 * netlbl_cache_add - Add an entry to a NetLabel protocol cache
 * @skb: the packet
 * @secattr: the packet's security attributes
 *
 * Description:
 * Add the LSM security attributes for the given packet to the underlying
 * NetLabel protocol's label mapping cache.  Returns zero on success, negative
 * values on error.
 *
 */
int netlbl_cache_add(const struct sk_buff *skb,
		     const struct netlbl_lsm_secattr *secattr)
{
	if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
		return -ENOMSG;

	if (CIPSO_V4_OPTEXIST(skb))
		return cipso_v4_cache_add(skb, secattr);

	return -ENOMSG;
}

/*
 * Setup Functions
 */

/**
 * netlbl_init - Initialize NetLabel
 *
 * Description:
 * Perform the required NetLabel initialization before first use.
 *
 */
static int __init netlbl_init(void)
{
	int ret_val;

	printk(KERN_INFO "NetLabel: Initializing\n");
	printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
	       (1 << NETLBL_DOMHSH_BITSIZE));
	printk(KERN_INFO "NetLabel:  protocols ="
	       " UNLABELED"
	       " CIPSOv4"
	       "\n");

	ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
	if (ret_val != 0)
		goto init_failure;

	ret_val = netlbl_netlink_init();
	if (ret_val != 0)
		goto init_failure;

	ret_val = netlbl_unlabel_defconf();
	if (ret_val != 0)
		goto init_failure;
	printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");

	return 0;

init_failure:
	panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
}

subsys_initcall(netlbl_init);
OpenPOWER on IntegriCloud