blob: 2e78f6bd97756db7920367e5fe07ce23e6cd6eb7 [file] [log] [blame]
Paul Moore446fda42006-08-03 16:48:06 -07001/*
2 * CIPSO - Commercial IP Security Option
3 *
4 * This is an implementation of the CIPSO 2.2 protocol as specified in
5 * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
6 * FIPS-188, copies of both documents can be found in the Documentation
7 * directory. While CIPSO never became a full IETF RFC standard many vendors
8 * have chosen to adopt the protocol and over the years it has become a
9 * de-facto standard for labeled networking.
10 *
11 * Author: Paul Moore <paul.moore@hp.com>
12 *
13 */
14
15/*
Paul Moore948bf852008-10-10 10:16:32 -040016 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
Paul Moore446fda42006-08-03 16:48:06 -070017 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
26 * the GNU General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program; if not, write to the Free Software
30 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
31 *
32 */
33
34#include <linux/init.h>
35#include <linux/types.h>
36#include <linux/rcupdate.h>
37#include <linux/list.h>
38#include <linux/spinlock.h>
39#include <linux/string.h>
40#include <linux/jhash.h>
41#include <net/ip.h>
42#include <net/icmp.h>
43#include <net/tcp.h>
44#include <net/netlabel.h>
45#include <net/cipso_ipv4.h>
paul.moore@hp.comffb733c2006-10-04 11:46:31 -040046#include <asm/atomic.h>
Paul Moore446fda42006-08-03 16:48:06 -070047#include <asm/bug.h>
Paul Moore50e5d352007-06-07 18:38:14 -070048#include <asm/unaligned.h>
Paul Moore446fda42006-08-03 16:48:06 -070049
Paul Moore446fda42006-08-03 16:48:06 -070050/* List of available DOI definitions */
Paul Moore446fda42006-08-03 16:48:06 -070051/* XXX - This currently assumes a minimal number of different DOIs in use,
52 * if in practice there are a lot of different DOIs this list should
53 * probably be turned into a hash table or something similar so we
54 * can do quick lookups. */
Adrian Bunk8ce11e62006-08-07 21:50:48 -070055static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
Denis Cheng1596c972007-12-07 00:49:47 -080056static LIST_HEAD(cipso_v4_doi_list);
Paul Moore446fda42006-08-03 16:48:06 -070057
58/* Label mapping cache */
59int cipso_v4_cache_enabled = 1;
60int cipso_v4_cache_bucketsize = 10;
61#define CIPSO_V4_CACHE_BUCKETBITS 7
62#define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS)
63#define CIPSO_V4_CACHE_REORDERLIMIT 10
64struct cipso_v4_map_cache_bkt {
65 spinlock_t lock;
66 u32 size;
67 struct list_head list;
68};
69struct cipso_v4_map_cache_entry {
70 u32 hash;
71 unsigned char *key;
72 size_t key_len;
73
paul.moore@hp.comffb733c2006-10-04 11:46:31 -040074 struct netlbl_lsm_cache *lsm_data;
Paul Moore446fda42006-08-03 16:48:06 -070075
76 u32 activity;
77 struct list_head list;
78};
79static struct cipso_v4_map_cache_bkt *cipso_v4_cache = NULL;
80
81/* Restricted bitmap (tag #1) flags */
82int cipso_v4_rbm_optfmt = 0;
83int cipso_v4_rbm_strictvalid = 1;
84
85/*
Paul Mooref998e8c2007-02-28 15:14:20 -050086 * Protocol Constants
87 */
88
89/* Maximum size of the CIPSO IP option, derived from the fact that the maximum
90 * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
91#define CIPSO_V4_OPT_LEN_MAX 40
92
93/* Length of the base CIPSO option, this includes the option type (1 byte), the
94 * option length (1 byte), and the DOI (4 bytes). */
95#define CIPSO_V4_HDR_LEN 6
96
97/* Base length of the restrictive category bitmap tag (tag #1). */
98#define CIPSO_V4_TAG_RBM_BLEN 4
99
100/* Base length of the enumerated category tag (tag #2). */
101#define CIPSO_V4_TAG_ENUM_BLEN 4
102
103/* Base length of the ranged categories bitmap tag (tag #5). */
104#define CIPSO_V4_TAG_RNG_BLEN 4
105/* The maximum number of category ranges permitted in the ranged category tag
106 * (tag #5). You may note that the IETF draft states that the maximum number
107 * of category ranges is 7, but if the low end of the last category range is
108 * zero then it is possibile to fit 8 category ranges because the zero should
109 * be omitted. */
110#define CIPSO_V4_TAG_RNG_CAT_MAX 8
111
Paul Moore15c45f72008-10-10 10:16:34 -0400112/* Base length of the local tag (non-standard tag).
113 * Tag definition (may change between kernel versions)
114 *
115 * 0 8 16 24 32
116 * +----------+----------+----------+----------+
117 * | 10000000 | 00000110 | 32-bit secid value |
118 * +----------+----------+----------+----------+
119 * | in (host byte order)|
120 * +----------+----------+
121 *
122 */
123#define CIPSO_V4_TAG_LOC_BLEN 6
124
Paul Mooref998e8c2007-02-28 15:14:20 -0500125/*
Paul Moore446fda42006-08-03 16:48:06 -0700126 * Helper Functions
127 */
128
129/**
130 * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
131 * @bitmap: the bitmap
132 * @bitmap_len: length in bits
133 * @offset: starting offset
134 * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
135 *
136 * Description:
137 * Starting at @offset, walk the bitmap from left to right until either the
138 * desired bit is found or we reach the end. Return the bit offset, -1 if
139 * not found, or -2 if error.
140 */
141static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
142 u32 bitmap_len,
143 u32 offset,
144 u8 state)
145{
146 u32 bit_spot;
147 u32 byte_offset;
148 unsigned char bitmask;
149 unsigned char byte;
150
151 /* gcc always rounds to zero when doing integer division */
152 byte_offset = offset / 8;
153 byte = bitmap[byte_offset];
154 bit_spot = offset;
155 bitmask = 0x80 >> (offset % 8);
156
157 while (bit_spot < bitmap_len) {
158 if ((state && (byte & bitmask) == bitmask) ||
159 (state == 0 && (byte & bitmask) == 0))
160 return bit_spot;
161
162 bit_spot++;
163 bitmask >>= 1;
164 if (bitmask == 0) {
165 byte = bitmap[++byte_offset];
166 bitmask = 0x80;
167 }
168 }
169
170 return -1;
171}
172
173/**
174 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
175 * @bitmap: the bitmap
176 * @bit: the bit
177 * @state: if non-zero, set the bit (1) else clear the bit (0)
178 *
179 * Description:
180 * Set a single bit in the bitmask. Returns zero on success, negative values
181 * on error.
182 */
183static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
184 u32 bit,
185 u8 state)
186{
187 u32 byte_spot;
188 u8 bitmask;
189
190 /* gcc always rounds to zero when doing integer division */
191 byte_spot = bit / 8;
192 bitmask = 0x80 >> (bit % 8);
193 if (state)
194 bitmap[byte_spot] |= bitmask;
195 else
196 bitmap[byte_spot] &= ~bitmask;
197}
198
199/**
Paul Moore446fda42006-08-03 16:48:06 -0700200 * cipso_v4_cache_entry_free - Frees a cache entry
201 * @entry: the entry to free
202 *
203 * Description:
paul.moore@hp.comffb733c2006-10-04 11:46:31 -0400204 * This function frees the memory associated with a cache entry including the
205 * LSM cache data if there are no longer any users, i.e. reference count == 0.
Paul Moore446fda42006-08-03 16:48:06 -0700206 *
207 */
208static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
209{
paul.moore@hp.comffb733c2006-10-04 11:46:31 -0400210 if (entry->lsm_data)
211 netlbl_secattr_cache_free(entry->lsm_data);
Paul Moore446fda42006-08-03 16:48:06 -0700212 kfree(entry->key);
213 kfree(entry);
214}
215
216/**
217 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
218 * @key: the hash key
219 * @key_len: the length of the key in bytes
220 *
221 * Description:
222 * The CIPSO tag hashing function. Returns a 32-bit hash value.
223 *
224 */
225static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
226{
227 return jhash(key, key_len, 0);
228}
229
230/*
231 * Label Mapping Cache Functions
232 */
233
234/**
235 * cipso_v4_cache_init - Initialize the CIPSO cache
236 *
237 * Description:
238 * Initializes the CIPSO label mapping cache, this function should be called
239 * before any of the other functions defined in this file. Returns zero on
240 * success, negative values on error.
241 *
242 */
243static int cipso_v4_cache_init(void)
244{
245 u32 iter;
246
247 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
248 sizeof(struct cipso_v4_map_cache_bkt),
249 GFP_KERNEL);
250 if (cipso_v4_cache == NULL)
251 return -ENOMEM;
252
253 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
254 spin_lock_init(&cipso_v4_cache[iter].lock);
255 cipso_v4_cache[iter].size = 0;
256 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
257 }
258
259 return 0;
260}
261
262/**
263 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
264 *
265 * Description:
266 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
267 * success and negative values on failure.
268 *
269 */
270void cipso_v4_cache_invalidate(void)
271{
272 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
273 u32 iter;
274
275 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
Paul Moore609c92f2006-09-25 15:52:37 -0700276 spin_lock_bh(&cipso_v4_cache[iter].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700277 list_for_each_entry_safe(entry,
278 tmp_entry,
279 &cipso_v4_cache[iter].list, list) {
280 list_del(&entry->list);
281 cipso_v4_cache_entry_free(entry);
282 }
283 cipso_v4_cache[iter].size = 0;
Paul Moore609c92f2006-09-25 15:52:37 -0700284 spin_unlock_bh(&cipso_v4_cache[iter].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700285 }
286
287 return;
288}
289
290/**
291 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
292 * @key: the buffer to check
293 * @key_len: buffer length in bytes
294 * @secattr: the security attribute struct to use
295 *
296 * Description:
297 * This function checks the cache to see if a label mapping already exists for
298 * the given key. If there is a match then the cache is adjusted and the
299 * @secattr struct is populated with the correct LSM security attributes. The
300 * cache is adjusted in the following manner if the entry is not already the
301 * first in the cache bucket:
302 *
303 * 1. The cache entry's activity counter is incremented
304 * 2. The previous (higher ranking) entry's activity counter is decremented
305 * 3. If the difference between the two activity counters is geater than
306 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
307 *
308 * Returns zero on success, -ENOENT for a cache miss, and other negative values
309 * on error.
310 *
311 */
312static int cipso_v4_cache_check(const unsigned char *key,
313 u32 key_len,
314 struct netlbl_lsm_secattr *secattr)
315{
316 u32 bkt;
317 struct cipso_v4_map_cache_entry *entry;
318 struct cipso_v4_map_cache_entry *prev_entry = NULL;
319 u32 hash;
320
321 if (!cipso_v4_cache_enabled)
322 return -ENOENT;
323
324 hash = cipso_v4_map_cache_hash(key, key_len);
Pavel Emelyanov5e0f8922008-05-13 23:23:55 -0700325 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
Paul Moore609c92f2006-09-25 15:52:37 -0700326 spin_lock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700327 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
328 if (entry->hash == hash &&
329 entry->key_len == key_len &&
330 memcmp(entry->key, key, key_len) == 0) {
331 entry->activity += 1;
paul.moore@hp.comffb733c2006-10-04 11:46:31 -0400332 atomic_inc(&entry->lsm_data->refcount);
333 secattr->cache = entry->lsm_data;
Paul Moore701a90b2006-11-17 17:38:46 -0500334 secattr->flags |= NETLBL_SECATTR_CACHE;
Paul Moore16efd452008-01-29 08:37:59 -0500335 secattr->type = NETLBL_NLTYPE_CIPSOV4;
Paul Moore446fda42006-08-03 16:48:06 -0700336 if (prev_entry == NULL) {
Paul Moore609c92f2006-09-25 15:52:37 -0700337 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700338 return 0;
339 }
340
341 if (prev_entry->activity > 0)
342 prev_entry->activity -= 1;
343 if (entry->activity > prev_entry->activity &&
344 entry->activity - prev_entry->activity >
345 CIPSO_V4_CACHE_REORDERLIMIT) {
346 __list_del(entry->list.prev, entry->list.next);
347 __list_add(&entry->list,
348 prev_entry->list.prev,
349 &prev_entry->list);
350 }
351
Paul Moore609c92f2006-09-25 15:52:37 -0700352 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700353 return 0;
354 }
355 prev_entry = entry;
356 }
Paul Moore609c92f2006-09-25 15:52:37 -0700357 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700358
359 return -ENOENT;
360}
361
362/**
363 * cipso_v4_cache_add - Add an entry to the CIPSO cache
364 * @skb: the packet
365 * @secattr: the packet's security attributes
366 *
367 * Description:
368 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
369 * head of the cache bucket's list, if the cache bucket is out of room remove
370 * the last entry in the list first. It is important to note that there is
371 * currently no checking for duplicate keys. Returns zero on success,
372 * negative values on failure.
373 *
374 */
375int cipso_v4_cache_add(const struct sk_buff *skb,
376 const struct netlbl_lsm_secattr *secattr)
377{
378 int ret_val = -EPERM;
379 u32 bkt;
380 struct cipso_v4_map_cache_entry *entry = NULL;
381 struct cipso_v4_map_cache_entry *old_entry = NULL;
382 unsigned char *cipso_ptr;
383 u32 cipso_ptr_len;
384
385 if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
386 return 0;
387
388 cipso_ptr = CIPSO_V4_OPTPTR(skb);
389 cipso_ptr_len = cipso_ptr[1];
390
391 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
392 if (entry == NULL)
393 return -ENOMEM;
Arnaldo Carvalho de Melofac5d732006-11-17 11:14:16 -0200394 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
Paul Moore446fda42006-08-03 16:48:06 -0700395 if (entry->key == NULL) {
396 ret_val = -ENOMEM;
397 goto cache_add_failure;
398 }
Paul Moore446fda42006-08-03 16:48:06 -0700399 entry->key_len = cipso_ptr_len;
400 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
paul.moore@hp.comffb733c2006-10-04 11:46:31 -0400401 atomic_inc(&secattr->cache->refcount);
402 entry->lsm_data = secattr->cache;
Paul Moore446fda42006-08-03 16:48:06 -0700403
Pavel Emelyanov5e0f8922008-05-13 23:23:55 -0700404 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
Paul Moore609c92f2006-09-25 15:52:37 -0700405 spin_lock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700406 if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
407 list_add(&entry->list, &cipso_v4_cache[bkt].list);
408 cipso_v4_cache[bkt].size += 1;
409 } else {
410 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
411 struct cipso_v4_map_cache_entry, list);
412 list_del(&old_entry->list);
413 list_add(&entry->list, &cipso_v4_cache[bkt].list);
414 cipso_v4_cache_entry_free(old_entry);
415 }
Paul Moore609c92f2006-09-25 15:52:37 -0700416 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
Paul Moore446fda42006-08-03 16:48:06 -0700417
418 return 0;
419
420cache_add_failure:
421 if (entry)
422 cipso_v4_cache_entry_free(entry);
423 return ret_val;
424}
425
426/*
427 * DOI List Functions
428 */
429
430/**
431 * cipso_v4_doi_search - Searches for a DOI definition
432 * @doi: the DOI to search for
433 *
434 * Description:
435 * Search the DOI definition list for a DOI definition with a DOI value that
436 * matches @doi. The caller is responsibile for calling rcu_read_[un]lock().
437 * Returns a pointer to the DOI definition on success and NULL on failure.
438 */
439static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
440{
441 struct cipso_v4_doi *iter;
442
443 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
Paul Mooreb1edeb12008-10-10 10:16:31 -0400444 if (iter->doi == doi && atomic_read(&iter->refcount))
Paul Moore446fda42006-08-03 16:48:06 -0700445 return iter;
446 return NULL;
447}
448
449/**
450 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
451 * @doi_def: the DOI structure
452 *
453 * Description:
454 * The caller defines a new DOI for use by the CIPSO engine and calls this
455 * function to add it to the list of acceptable domains. The caller must
456 * ensure that the mapping table specified in @doi_def->map meets all of the
457 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
458 * zero on success and non-zero on failure.
459 *
460 */
461int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
462{
Paul Moore6ce61a72006-11-17 17:38:48 -0500463 u32 iter;
464
Paul Moore446fda42006-08-03 16:48:06 -0700465 if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
466 return -EINVAL;
Paul Moore6ce61a72006-11-17 17:38:48 -0500467 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
468 switch (doi_def->tags[iter]) {
469 case CIPSO_V4_TAG_RBITMAP:
470 break;
Paul Moore484b3662006-11-29 13:18:20 -0500471 case CIPSO_V4_TAG_RANGE:
472 if (doi_def->type != CIPSO_V4_MAP_PASS)
473 return -EINVAL;
474 break;
Paul Moore6ce61a72006-11-17 17:38:48 -0500475 case CIPSO_V4_TAG_INVALID:
476 if (iter == 0)
477 return -EINVAL;
478 break;
Paul Moore654bbc22006-11-29 13:18:19 -0500479 case CIPSO_V4_TAG_ENUM:
480 if (doi_def->type != CIPSO_V4_MAP_PASS)
481 return -EINVAL;
482 break;
Paul Moore15c45f72008-10-10 10:16:34 -0400483 case CIPSO_V4_TAG_LOCAL:
484 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
485 return -EINVAL;
486 break;
Paul Moore6ce61a72006-11-17 17:38:48 -0500487 default:
488 return -EINVAL;
489 }
490 }
Paul Moore446fda42006-08-03 16:48:06 -0700491
Paul Mooreb1edeb12008-10-10 10:16:31 -0400492 atomic_set(&doi_def->refcount, 1);
Paul Moore446fda42006-08-03 16:48:06 -0700493 INIT_RCU_HEAD(&doi_def->rcu);
Paul Moore446fda42006-08-03 16:48:06 -0700494
Paul Moore446fda42006-08-03 16:48:06 -0700495 spin_lock(&cipso_v4_doi_list_lock);
496 if (cipso_v4_doi_search(doi_def->doi) != NULL)
Paul Moore4be27002007-10-26 04:29:08 -0700497 goto doi_add_failure;
Paul Moore446fda42006-08-03 16:48:06 -0700498 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
499 spin_unlock(&cipso_v4_doi_list_lock);
Paul Moore446fda42006-08-03 16:48:06 -0700500
501 return 0;
502
Paul Moore4be27002007-10-26 04:29:08 -0700503doi_add_failure:
Paul Moore446fda42006-08-03 16:48:06 -0700504 spin_unlock(&cipso_v4_doi_list_lock);
Paul Moore446fda42006-08-03 16:48:06 -0700505 return -EEXIST;
506}
507
508/**
Paul Mooreb1edeb12008-10-10 10:16:31 -0400509 * cipso_v4_doi_free - Frees a DOI definition
510 * @entry: the entry's RCU field
Paul Moore446fda42006-08-03 16:48:06 -0700511 *
512 * Description:
Paul Mooreb1edeb12008-10-10 10:16:31 -0400513 * This function frees all of the memory associated with a DOI definition.
Paul Moore446fda42006-08-03 16:48:06 -0700514 *
515 */
Paul Mooreb1edeb12008-10-10 10:16:31 -0400516void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
Paul Moore446fda42006-08-03 16:48:06 -0700517{
Paul Mooreb1edeb12008-10-10 10:16:31 -0400518 if (doi_def == NULL)
519 return;
Paul Moore446fda42006-08-03 16:48:06 -0700520
Paul Mooreb1edeb12008-10-10 10:16:31 -0400521 switch (doi_def->type) {
Paul Moore15c45f72008-10-10 10:16:34 -0400522 case CIPSO_V4_MAP_TRANS:
Paul Mooreb1edeb12008-10-10 10:16:31 -0400523 kfree(doi_def->map.std->lvl.cipso);
524 kfree(doi_def->map.std->lvl.local);
525 kfree(doi_def->map.std->cat.cipso);
526 kfree(doi_def->map.std->cat.local);
527 break;
Paul Moore446fda42006-08-03 16:48:06 -0700528 }
Paul Mooreb1edeb12008-10-10 10:16:31 -0400529 kfree(doi_def);
Paul Moore446fda42006-08-03 16:48:06 -0700530}
531
532/**
Paul Mooreb1edeb12008-10-10 10:16:31 -0400533 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
534 * @entry: the entry's RCU field
535 *
536 * Description:
537 * This function is designed to be used as a callback to the call_rcu()
538 * function so that the memory allocated to the DOI definition can be released
539 * safely.
540 *
541 */
542static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
543{
544 struct cipso_v4_doi *doi_def;
545
546 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
547 cipso_v4_doi_free(doi_def);
548}
549
550/**
551 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
552 * @doi: the DOI value
553 * @audit_secid: the LSM secid to use in the audit message
554 *
555 * Description:
556 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
557 * be called to release their own LSM domain mappings as well as our own
558 * domain list. Returns zero on success and negative values on failure.
559 *
560 */
561int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
562{
563 struct cipso_v4_doi *doi_def;
564
565 spin_lock(&cipso_v4_doi_list_lock);
566 doi_def = cipso_v4_doi_search(doi);
567 if (doi_def == NULL) {
568 spin_unlock(&cipso_v4_doi_list_lock);
569 return -ENOENT;
570 }
571 if (!atomic_dec_and_test(&doi_def->refcount)) {
572 spin_unlock(&cipso_v4_doi_list_lock);
573 return -EBUSY;
574 }
575 list_del_rcu(&doi_def->list);
576 spin_unlock(&cipso_v4_doi_list_lock);
577
578 cipso_v4_cache_invalidate();
579 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
580
581 return 0;
582}
583
584/**
585 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
Paul Moore446fda42006-08-03 16:48:06 -0700586 * @doi: the DOI value
587 *
588 * Description:
589 * Searches for a valid DOI definition and if one is found it is returned to
590 * the caller. Otherwise NULL is returned. The caller must ensure that
Paul Mooreb1edeb12008-10-10 10:16:31 -0400591 * rcu_read_lock() is held while accessing the returned definition and the DOI
592 * definition reference count is decremented when the caller is done.
Paul Moore446fda42006-08-03 16:48:06 -0700593 *
594 */
595struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
596{
Paul Mooreb1edeb12008-10-10 10:16:31 -0400597 struct cipso_v4_doi *doi_def;
598
599 rcu_read_lock();
600 doi_def = cipso_v4_doi_search(doi);
601 if (doi_def == NULL)
602 goto doi_getdef_return;
603 if (!atomic_inc_not_zero(&doi_def->refcount))
604 doi_def = NULL;
605
606doi_getdef_return:
607 rcu_read_unlock();
608 return doi_def;
609}
610
611/**
612 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
613 * @doi_def: the DOI definition
614 *
615 * Description:
616 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
617 *
618 */
619void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
620{
621 if (doi_def == NULL)
622 return;
623
624 if (!atomic_dec_and_test(&doi_def->refcount))
625 return;
626 spin_lock(&cipso_v4_doi_list_lock);
627 list_del_rcu(&doi_def->list);
628 spin_unlock(&cipso_v4_doi_list_lock);
629
630 cipso_v4_cache_invalidate();
631 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
Paul Moore446fda42006-08-03 16:48:06 -0700632}
633
634/**
Paul Moorefcd48282006-09-25 15:56:09 -0700635 * cipso_v4_doi_walk - Iterate through the DOI definitions
636 * @skip_cnt: skip past this number of DOI definitions, updated
637 * @callback: callback for each DOI definition
638 * @cb_arg: argument for the callback function
Paul Moore446fda42006-08-03 16:48:06 -0700639 *
640 * Description:
Paul Moorefcd48282006-09-25 15:56:09 -0700641 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
642 * For each entry call @callback, if @callback returns a negative value stop
643 * 'walking' through the list and return. Updates the value in @skip_cnt upon
644 * return. Returns zero on success, negative values on failure.
Paul Moore446fda42006-08-03 16:48:06 -0700645 *
646 */
Paul Moorefcd48282006-09-25 15:56:09 -0700647int cipso_v4_doi_walk(u32 *skip_cnt,
648 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
649 void *cb_arg)
Paul Moore446fda42006-08-03 16:48:06 -0700650{
Paul Moorefcd48282006-09-25 15:56:09 -0700651 int ret_val = -ENOENT;
Paul Moore446fda42006-08-03 16:48:06 -0700652 u32 doi_cnt = 0;
Paul Moorefcd48282006-09-25 15:56:09 -0700653 struct cipso_v4_doi *iter_doi;
Paul Moore446fda42006-08-03 16:48:06 -0700654
655 rcu_read_lock();
Paul Moorefcd48282006-09-25 15:56:09 -0700656 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
Paul Mooreb1edeb12008-10-10 10:16:31 -0400657 if (atomic_read(&iter_doi->refcount) > 0) {
Paul Moorefcd48282006-09-25 15:56:09 -0700658 if (doi_cnt++ < *skip_cnt)
659 continue;
660 ret_val = callback(iter_doi, cb_arg);
661 if (ret_val < 0) {
662 doi_cnt--;
663 goto doi_walk_return;
Paul Moore446fda42006-08-03 16:48:06 -0700664 }
Paul Moorefcd48282006-09-25 15:56:09 -0700665 }
Paul Moore446fda42006-08-03 16:48:06 -0700666
Paul Moorefcd48282006-09-25 15:56:09 -0700667doi_walk_return:
Paul Moore446fda42006-08-03 16:48:06 -0700668 rcu_read_unlock();
Paul Moorefcd48282006-09-25 15:56:09 -0700669 *skip_cnt = doi_cnt;
670 return ret_val;
Paul Moore446fda42006-08-03 16:48:06 -0700671}
672
Paul Moore446fda42006-08-03 16:48:06 -0700673/*
674 * Label Mapping Functions
675 */
676
677/**
678 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
679 * @doi_def: the DOI definition
680 * @level: the level to check
681 *
682 * Description:
683 * Checks the given level against the given DOI definition and returns a
684 * negative value if the level does not have a valid mapping and a zero value
685 * if the level is defined by the DOI.
686 *
687 */
688static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
689{
690 switch (doi_def->type) {
691 case CIPSO_V4_MAP_PASS:
692 return 0;
Paul Moore15c45f72008-10-10 10:16:34 -0400693 case CIPSO_V4_MAP_TRANS:
Paul Moore446fda42006-08-03 16:48:06 -0700694 if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
695 return 0;
696 break;
697 }
698
699 return -EFAULT;
700}
701
702/**
703 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
704 * @doi_def: the DOI definition
705 * @host_lvl: the host MLS level
706 * @net_lvl: the network/CIPSO MLS level
707 *
708 * Description:
709 * Perform a label mapping to translate a local MLS level to the correct
710 * CIPSO level using the given DOI definition. Returns zero on success,
711 * negative values otherwise.
712 *
713 */
714static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
715 u32 host_lvl,
716 u32 *net_lvl)
717{
718 switch (doi_def->type) {
719 case CIPSO_V4_MAP_PASS:
720 *net_lvl = host_lvl;
721 return 0;
Paul Moore15c45f72008-10-10 10:16:34 -0400722 case CIPSO_V4_MAP_TRANS:
Paul Moorec6387a82007-03-02 13:19:02 -0800723 if (host_lvl < doi_def->map.std->lvl.local_size &&
724 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
Paul Moore446fda42006-08-03 16:48:06 -0700725 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
726 return 0;
727 }
Paul Moorec6387a82007-03-02 13:19:02 -0800728 return -EPERM;
Paul Moore446fda42006-08-03 16:48:06 -0700729 }
730
731 return -EINVAL;
732}
733
734/**
735 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
736 * @doi_def: the DOI definition
737 * @net_lvl: the network/CIPSO MLS level
738 * @host_lvl: the host MLS level
739 *
740 * Description:
741 * Perform a label mapping to translate a CIPSO level to the correct local MLS
742 * level using the given DOI definition. Returns zero on success, negative
743 * values otherwise.
744 *
745 */
746static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
747 u32 net_lvl,
748 u32 *host_lvl)
749{
750 struct cipso_v4_std_map_tbl *map_tbl;
751
752 switch (doi_def->type) {
753 case CIPSO_V4_MAP_PASS:
754 *host_lvl = net_lvl;
755 return 0;
Paul Moore15c45f72008-10-10 10:16:34 -0400756 case CIPSO_V4_MAP_TRANS:
Paul Moore446fda42006-08-03 16:48:06 -0700757 map_tbl = doi_def->map.std;
758 if (net_lvl < map_tbl->lvl.cipso_size &&
759 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
760 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
761 return 0;
762 }
Paul Moorec6387a82007-03-02 13:19:02 -0800763 return -EPERM;
Paul Moore446fda42006-08-03 16:48:06 -0700764 }
765
766 return -EINVAL;
767}
768
769/**
770 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
771 * @doi_def: the DOI definition
772 * @bitmap: category bitmap
773 * @bitmap_len: bitmap length in bytes
774 *
775 * Description:
776 * Checks the given category bitmap against the given DOI definition and
777 * returns a negative value if any of the categories in the bitmap do not have
778 * a valid mapping and a zero value if all of the categories are valid.
779 *
780 */
781static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
782 const unsigned char *bitmap,
783 u32 bitmap_len)
784{
785 int cat = -1;
786 u32 bitmap_len_bits = bitmap_len * 8;
Paul Moore044a68e2006-10-11 19:10:47 -0400787 u32 cipso_cat_size;
788 u32 *cipso_array;
Paul Moore446fda42006-08-03 16:48:06 -0700789
790 switch (doi_def->type) {
791 case CIPSO_V4_MAP_PASS:
792 return 0;
Paul Moore15c45f72008-10-10 10:16:34 -0400793 case CIPSO_V4_MAP_TRANS:
Paul Moore044a68e2006-10-11 19:10:47 -0400794 cipso_cat_size = doi_def->map.std->cat.cipso_size;
795 cipso_array = doi_def->map.std->cat.cipso;
Paul Moore446fda42006-08-03 16:48:06 -0700796 for (;;) {
797 cat = cipso_v4_bitmap_walk(bitmap,
798 bitmap_len_bits,
799 cat + 1,
800 1);
801 if (cat < 0)
802 break;
803 if (cat >= cipso_cat_size ||
804 cipso_array[cat] >= CIPSO_V4_INV_CAT)
805 return -EFAULT;
806 }
807
808 if (cat == -1)
809 return 0;
810 break;
811 }
812
813 return -EFAULT;
814}
815
816/**
817 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
818 * @doi_def: the DOI definition
Paul Moore02752762006-11-29 13:18:18 -0500819 * @secattr: the security attributes
Paul Moore446fda42006-08-03 16:48:06 -0700820 * @net_cat: the zero'd out category bitmap in network/CIPSO format
821 * @net_cat_len: the length of the CIPSO bitmap in bytes
822 *
823 * Description:
824 * Perform a label mapping to translate a local MLS category bitmap to the
825 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
826 * size in bytes of the network bitmap on success, negative values otherwise.
827 *
828 */
829static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
Paul Moore02752762006-11-29 13:18:18 -0500830 const struct netlbl_lsm_secattr *secattr,
Paul Moore446fda42006-08-03 16:48:06 -0700831 unsigned char *net_cat,
832 u32 net_cat_len)
833{
834 int host_spot = -1;
Paul Moore02752762006-11-29 13:18:18 -0500835 u32 net_spot = CIPSO_V4_INV_CAT;
Paul Moore446fda42006-08-03 16:48:06 -0700836 u32 net_spot_max = 0;
Paul Moore446fda42006-08-03 16:48:06 -0700837 u32 net_clen_bits = net_cat_len * 8;
Paul Moore02752762006-11-29 13:18:18 -0500838 u32 host_cat_size = 0;
839 u32 *host_cat_array = NULL;
Paul Moore446fda42006-08-03 16:48:06 -0700840
Paul Moore15c45f72008-10-10 10:16:34 -0400841 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
Paul Moore044a68e2006-10-11 19:10:47 -0400842 host_cat_size = doi_def->map.std->cat.local_size;
843 host_cat_array = doi_def->map.std->cat.local;
Paul Moore02752762006-11-29 13:18:18 -0500844 }
845
846 for (;;) {
Paul Moore16efd452008-01-29 08:37:59 -0500847 host_spot = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
Paul Moore02752762006-11-29 13:18:18 -0500848 host_spot + 1);
849 if (host_spot < 0)
850 break;
851
852 switch (doi_def->type) {
853 case CIPSO_V4_MAP_PASS:
854 net_spot = host_spot;
855 break;
Paul Moore15c45f72008-10-10 10:16:34 -0400856 case CIPSO_V4_MAP_TRANS:
Paul Moore446fda42006-08-03 16:48:06 -0700857 if (host_spot >= host_cat_size)
858 return -EPERM;
Paul Moore446fda42006-08-03 16:48:06 -0700859 net_spot = host_cat_array[host_spot];
Paul Moore9fade4b2006-11-17 17:38:50 -0500860 if (net_spot >= CIPSO_V4_INV_CAT)
861 return -EPERM;
Paul Moore02752762006-11-29 13:18:18 -0500862 break;
Paul Moore446fda42006-08-03 16:48:06 -0700863 }
Paul Moore02752762006-11-29 13:18:18 -0500864 if (net_spot >= net_clen_bits)
865 return -ENOSPC;
866 cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
Paul Moore446fda42006-08-03 16:48:06 -0700867
Paul Moore02752762006-11-29 13:18:18 -0500868 if (net_spot > net_spot_max)
869 net_spot_max = net_spot;
Paul Moore446fda42006-08-03 16:48:06 -0700870 }
871
Paul Moore02752762006-11-29 13:18:18 -0500872 if (++net_spot_max % 8)
873 return net_spot_max / 8 + 1;
874 return net_spot_max / 8;
Paul Moore446fda42006-08-03 16:48:06 -0700875}
876
877/**
878 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
879 * @doi_def: the DOI definition
880 * @net_cat: the category bitmap in network/CIPSO format
881 * @net_cat_len: the length of the CIPSO bitmap in bytes
Paul Moore02752762006-11-29 13:18:18 -0500882 * @secattr: the security attributes
Paul Moore446fda42006-08-03 16:48:06 -0700883 *
884 * Description:
885 * Perform a label mapping to translate a CIPSO bitmap to the correct local
Paul Moore02752762006-11-29 13:18:18 -0500886 * MLS category bitmap using the given DOI definition. Returns zero on
887 * success, negative values on failure.
Paul Moore446fda42006-08-03 16:48:06 -0700888 *
889 */
890static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
891 const unsigned char *net_cat,
892 u32 net_cat_len,
Paul Moore02752762006-11-29 13:18:18 -0500893 struct netlbl_lsm_secattr *secattr)
Paul Moore446fda42006-08-03 16:48:06 -0700894{
Paul Moore02752762006-11-29 13:18:18 -0500895 int ret_val;
Paul Moore446fda42006-08-03 16:48:06 -0700896 int net_spot = -1;
Paul Moore02752762006-11-29 13:18:18 -0500897 u32 host_spot = CIPSO_V4_INV_CAT;
Paul Moore446fda42006-08-03 16:48:06 -0700898 u32 net_clen_bits = net_cat_len * 8;
Paul Moore02752762006-11-29 13:18:18 -0500899 u32 net_cat_size = 0;
900 u32 *net_cat_array = NULL;
Paul Moore446fda42006-08-03 16:48:06 -0700901
Paul Moore15c45f72008-10-10 10:16:34 -0400902 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
Paul Moore044a68e2006-10-11 19:10:47 -0400903 net_cat_size = doi_def->map.std->cat.cipso_size;
904 net_cat_array = doi_def->map.std->cat.cipso;
Paul Moore02752762006-11-29 13:18:18 -0500905 }
Paul Moore446fda42006-08-03 16:48:06 -0700906
Paul Moore02752762006-11-29 13:18:18 -0500907 for (;;) {
908 net_spot = cipso_v4_bitmap_walk(net_cat,
909 net_clen_bits,
910 net_spot + 1,
911 1);
912 if (net_spot < 0) {
913 if (net_spot == -2)
914 return -EFAULT;
915 return 0;
916 }
917
918 switch (doi_def->type) {
919 case CIPSO_V4_MAP_PASS:
920 host_spot = net_spot;
921 break;
Paul Moore15c45f72008-10-10 10:16:34 -0400922 case CIPSO_V4_MAP_TRANS:
Paul Moore02752762006-11-29 13:18:18 -0500923 if (net_spot >= net_cat_size)
924 return -EPERM;
Paul Moore446fda42006-08-03 16:48:06 -0700925 host_spot = net_cat_array[net_spot];
Paul Moore9fade4b2006-11-17 17:38:50 -0500926 if (host_spot >= CIPSO_V4_INV_CAT)
927 return -EPERM;
Paul Moore02752762006-11-29 13:18:18 -0500928 break;
Paul Moore446fda42006-08-03 16:48:06 -0700929 }
Paul Moore16efd452008-01-29 08:37:59 -0500930 ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
Paul Moore02752762006-11-29 13:18:18 -0500931 host_spot,
932 GFP_ATOMIC);
933 if (ret_val != 0)
934 return ret_val;
Paul Moore446fda42006-08-03 16:48:06 -0700935 }
936
937 return -EINVAL;
938}
939
Paul Moore654bbc22006-11-29 13:18:19 -0500940/**
941 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
942 * @doi_def: the DOI definition
943 * @enumcat: category list
944 * @enumcat_len: length of the category list in bytes
945 *
946 * Description:
947 * Checks the given categories against the given DOI definition and returns a
948 * negative value if any of the categories do not have a valid mapping and a
949 * zero value if all of the categories are valid.
950 *
951 */
952static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
953 const unsigned char *enumcat,
954 u32 enumcat_len)
955{
956 u16 cat;
957 int cat_prev = -1;
958 u32 iter;
959
960 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
961 return -EFAULT;
962
963 for (iter = 0; iter < enumcat_len; iter += 2) {
Harvey Harrisond3e2ce32008-05-02 16:26:16 -0700964 cat = get_unaligned_be16(&enumcat[iter]);
Paul Moore654bbc22006-11-29 13:18:19 -0500965 if (cat <= cat_prev)
966 return -EFAULT;
967 cat_prev = cat;
968 }
969
970 return 0;
971}
972
973/**
974 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
975 * @doi_def: the DOI definition
976 * @secattr: the security attributes
977 * @net_cat: the zero'd out category list in network/CIPSO format
978 * @net_cat_len: the length of the CIPSO category list in bytes
979 *
980 * Description:
981 * Perform a label mapping to translate a local MLS category bitmap to the
982 * correct CIPSO category list using the given DOI definition. Returns the
983 * size in bytes of the network category bitmap on success, negative values
984 * otherwise.
985 *
986 */
987static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
988 const struct netlbl_lsm_secattr *secattr,
989 unsigned char *net_cat,
990 u32 net_cat_len)
991{
992 int cat = -1;
993 u32 cat_iter = 0;
994
995 for (;;) {
Paul Moore16efd452008-01-29 08:37:59 -0500996 cat = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
997 cat + 1);
Paul Moore654bbc22006-11-29 13:18:19 -0500998 if (cat < 0)
999 break;
1000 if ((cat_iter + 2) > net_cat_len)
1001 return -ENOSPC;
1002
1003 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
1004 cat_iter += 2;
1005 }
1006
1007 return cat_iter;
1008}
1009
1010/**
1011 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
1012 * @doi_def: the DOI definition
1013 * @net_cat: the category list in network/CIPSO format
1014 * @net_cat_len: the length of the CIPSO bitmap in bytes
1015 * @secattr: the security attributes
1016 *
1017 * Description:
1018 * Perform a label mapping to translate a CIPSO category list to the correct
1019 * local MLS category bitmap using the given DOI definition. Returns zero on
1020 * success, negative values on failure.
1021 *
1022 */
1023static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
1024 const unsigned char *net_cat,
1025 u32 net_cat_len,
1026 struct netlbl_lsm_secattr *secattr)
1027{
1028 int ret_val;
1029 u32 iter;
1030
1031 for (iter = 0; iter < net_cat_len; iter += 2) {
Paul Moore16efd452008-01-29 08:37:59 -05001032 ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001033 get_unaligned_be16(&net_cat[iter]),
Paul Moore50e5d352007-06-07 18:38:14 -07001034 GFP_ATOMIC);
Paul Moore654bbc22006-11-29 13:18:19 -05001035 if (ret_val != 0)
1036 return ret_val;
1037 }
1038
1039 return 0;
1040}
1041
Paul Moore484b3662006-11-29 13:18:20 -05001042/**
1043 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
1044 * @doi_def: the DOI definition
1045 * @rngcat: category list
1046 * @rngcat_len: length of the category list in bytes
1047 *
1048 * Description:
1049 * Checks the given categories against the given DOI definition and returns a
1050 * negative value if any of the categories do not have a valid mapping and a
1051 * zero value if all of the categories are valid.
1052 *
1053 */
1054static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1055 const unsigned char *rngcat,
1056 u32 rngcat_len)
1057{
1058 u16 cat_high;
1059 u16 cat_low;
1060 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1061 u32 iter;
1062
1063 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1064 return -EFAULT;
1065
1066 for (iter = 0; iter < rngcat_len; iter += 4) {
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001067 cat_high = get_unaligned_be16(&rngcat[iter]);
Paul Moore484b3662006-11-29 13:18:20 -05001068 if ((iter + 4) <= rngcat_len)
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001069 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
Paul Moore484b3662006-11-29 13:18:20 -05001070 else
1071 cat_low = 0;
1072
1073 if (cat_high > cat_prev)
1074 return -EFAULT;
1075
1076 cat_prev = cat_low;
1077 }
1078
1079 return 0;
1080}
1081
1082/**
1083 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1084 * @doi_def: the DOI definition
1085 * @secattr: the security attributes
1086 * @net_cat: the zero'd out category list in network/CIPSO format
1087 * @net_cat_len: the length of the CIPSO category list in bytes
1088 *
1089 * Description:
1090 * Perform a label mapping to translate a local MLS category bitmap to the
1091 * correct CIPSO category list using the given DOI definition. Returns the
1092 * size in bytes of the network category bitmap on success, negative values
1093 * otherwise.
1094 *
1095 */
1096static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1097 const struct netlbl_lsm_secattr *secattr,
1098 unsigned char *net_cat,
1099 u32 net_cat_len)
1100{
Paul Moore484b3662006-11-29 13:18:20 -05001101 int iter = -1;
Paul Mooref998e8c2007-02-28 15:14:20 -05001102 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
Paul Moore484b3662006-11-29 13:18:20 -05001103 u32 array_cnt = 0;
1104 u32 cat_size = 0;
1105
Paul Mooref998e8c2007-02-28 15:14:20 -05001106 /* make sure we don't overflow the 'array[]' variable */
Paul Moore128c6b62007-02-28 15:14:21 -05001107 if (net_cat_len >
1108 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1109 return -ENOSPC;
Paul Moore484b3662006-11-29 13:18:20 -05001110
1111 for (;;) {
Paul Moore16efd452008-01-29 08:37:59 -05001112 iter = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
1113 iter + 1);
Paul Moore484b3662006-11-29 13:18:20 -05001114 if (iter < 0)
1115 break;
1116 cat_size += (iter == 0 ? 0 : sizeof(u16));
1117 if (cat_size > net_cat_len)
1118 return -ENOSPC;
1119 array[array_cnt++] = iter;
1120
Paul Moore16efd452008-01-29 08:37:59 -05001121 iter = netlbl_secattr_catmap_walk_rng(secattr->attr.mls.cat,
1122 iter);
Paul Moore484b3662006-11-29 13:18:20 -05001123 if (iter < 0)
1124 return -EFAULT;
1125 cat_size += sizeof(u16);
1126 if (cat_size > net_cat_len)
1127 return -ENOSPC;
1128 array[array_cnt++] = iter;
1129 }
1130
1131 for (iter = 0; array_cnt > 0;) {
1132 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1133 iter += 2;
1134 array_cnt--;
1135 if (array[array_cnt] != 0) {
1136 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1137 iter += 2;
1138 }
1139 }
1140
1141 return cat_size;
1142}
1143
1144/**
1145 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1146 * @doi_def: the DOI definition
1147 * @net_cat: the category list in network/CIPSO format
1148 * @net_cat_len: the length of the CIPSO bitmap in bytes
1149 * @secattr: the security attributes
1150 *
1151 * Description:
1152 * Perform a label mapping to translate a CIPSO category list to the correct
1153 * local MLS category bitmap using the given DOI definition. Returns zero on
1154 * success, negative values on failure.
1155 *
1156 */
1157static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1158 const unsigned char *net_cat,
1159 u32 net_cat_len,
1160 struct netlbl_lsm_secattr *secattr)
1161{
1162 int ret_val;
1163 u32 net_iter;
1164 u16 cat_low;
1165 u16 cat_high;
1166
Stephen Hemminger132adf52007-03-08 20:44:43 -08001167 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001168 cat_high = get_unaligned_be16(&net_cat[net_iter]);
Paul Moore484b3662006-11-29 13:18:20 -05001169 if ((net_iter + 4) <= net_cat_len)
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001170 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
Paul Moore484b3662006-11-29 13:18:20 -05001171 else
1172 cat_low = 0;
1173
Paul Moore16efd452008-01-29 08:37:59 -05001174 ret_val = netlbl_secattr_catmap_setrng(secattr->attr.mls.cat,
Paul Moore484b3662006-11-29 13:18:20 -05001175 cat_low,
1176 cat_high,
1177 GFP_ATOMIC);
1178 if (ret_val != 0)
1179 return ret_val;
1180 }
1181
1182 return 0;
1183}
1184
Paul Moore446fda42006-08-03 16:48:06 -07001185/*
1186 * Protocol Handling Functions
1187 */
1188
Paul Moore446fda42006-08-03 16:48:06 -07001189/**
1190 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1191 * @doi_def: the DOI definition
Paul Moore91b1ed02006-11-17 17:38:49 -05001192 * @len: the total tag length in bytes, not including this header
Paul Moore446fda42006-08-03 16:48:06 -07001193 * @buf: the CIPSO option buffer
1194 *
1195 * Description:
Paul Moore91b1ed02006-11-17 17:38:49 -05001196 * Write a CIPSO header into the beginning of @buffer.
Paul Moore446fda42006-08-03 16:48:06 -07001197 *
1198 */
Paul Moore91b1ed02006-11-17 17:38:49 -05001199static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1200 unsigned char *buf,
1201 u32 len)
Paul Moore446fda42006-08-03 16:48:06 -07001202{
Paul Moore446fda42006-08-03 16:48:06 -07001203 buf[0] = IPOPT_CIPSO;
1204 buf[1] = CIPSO_V4_HDR_LEN + len;
Al Viro714e85b2006-11-14 20:51:49 -08001205 *(__be32 *)&buf[2] = htonl(doi_def->doi);
Paul Moore446fda42006-08-03 16:48:06 -07001206}
1207
Paul Moore446fda42006-08-03 16:48:06 -07001208/**
1209 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1210 * @doi_def: the DOI definition
1211 * @secattr: the security attributes
1212 * @buffer: the option buffer
1213 * @buffer_len: length of buffer in bytes
1214 *
1215 * Description:
1216 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1217 * actual buffer length may be larger than the indicated size due to
Paul Moore91b1ed02006-11-17 17:38:49 -05001218 * translation between host and network category bitmaps. Returns the size of
1219 * the tag on success, negative values on failure.
Paul Moore446fda42006-08-03 16:48:06 -07001220 *
1221 */
1222static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1223 const struct netlbl_lsm_secattr *secattr,
Paul Moore91b1ed02006-11-17 17:38:49 -05001224 unsigned char *buffer,
1225 u32 buffer_len)
Paul Moore446fda42006-08-03 16:48:06 -07001226{
Paul Moore701a90b2006-11-17 17:38:46 -05001227 int ret_val;
Paul Moore91b1ed02006-11-17 17:38:49 -05001228 u32 tag_len;
Paul Moore446fda42006-08-03 16:48:06 -07001229 u32 level;
1230
Paul Moore701a90b2006-11-17 17:38:46 -05001231 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1232 return -EPERM;
1233
Paul Moore16efd452008-01-29 08:37:59 -05001234 ret_val = cipso_v4_map_lvl_hton(doi_def,
1235 secattr->attr.mls.lvl,
1236 &level);
Paul Moore91b1ed02006-11-17 17:38:49 -05001237 if (ret_val != 0)
1238 return ret_val;
Paul Moore446fda42006-08-03 16:48:06 -07001239
Paul Moore91b1ed02006-11-17 17:38:49 -05001240 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
Paul Moore446fda42006-08-03 16:48:06 -07001241 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
Paul Moore02752762006-11-29 13:18:18 -05001242 secattr,
Paul Moore91b1ed02006-11-17 17:38:49 -05001243 &buffer[4],
1244 buffer_len - 4);
Paul Moore446fda42006-08-03 16:48:06 -07001245 if (ret_val < 0)
Paul Moore91b1ed02006-11-17 17:38:49 -05001246 return ret_val;
Paul Moore446fda42006-08-03 16:48:06 -07001247
1248 /* This will send packets using the "optimized" format when
1249 * possibile as specified in section 3.4.2.6 of the
1250 * CIPSO draft. */
Paul Moore701a90b2006-11-17 17:38:46 -05001251 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
Paul Moore91b1ed02006-11-17 17:38:49 -05001252 tag_len = 14;
Paul Moore701a90b2006-11-17 17:38:46 -05001253 else
Paul Moore91b1ed02006-11-17 17:38:49 -05001254 tag_len = 4 + ret_val;
1255 } else
1256 tag_len = 4;
Paul Moore446fda42006-08-03 16:48:06 -07001257
Paul Moore15c45f72008-10-10 10:16:34 -04001258 buffer[0] = CIPSO_V4_TAG_RBITMAP;
Paul Moore91b1ed02006-11-17 17:38:49 -05001259 buffer[1] = tag_len;
1260 buffer[3] = level;
Paul Moore446fda42006-08-03 16:48:06 -07001261
Paul Moore91b1ed02006-11-17 17:38:49 -05001262 return tag_len;
Paul Moore446fda42006-08-03 16:48:06 -07001263}
1264
1265/**
1266 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1267 * @doi_def: the DOI definition
1268 * @tag: the CIPSO tag
1269 * @secattr: the security attributes
1270 *
1271 * Description:
1272 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1273 * attributes in @secattr. Return zero on success, negatives values on
1274 * failure.
1275 *
1276 */
1277static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1278 const unsigned char *tag,
1279 struct netlbl_lsm_secattr *secattr)
1280{
1281 int ret_val;
1282 u8 tag_len = tag[1];
1283 u32 level;
1284
1285 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1286 if (ret_val != 0)
1287 return ret_val;
Paul Moore16efd452008-01-29 08:37:59 -05001288 secattr->attr.mls.lvl = level;
Paul Moore701a90b2006-11-17 17:38:46 -05001289 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
Paul Moore446fda42006-08-03 16:48:06 -07001290
1291 if (tag_len > 4) {
Paul Moore16efd452008-01-29 08:37:59 -05001292 secattr->attr.mls.cat =
1293 netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1294 if (secattr->attr.mls.cat == NULL)
Paul Moore446fda42006-08-03 16:48:06 -07001295 return -ENOMEM;
1296
1297 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1298 &tag[4],
1299 tag_len - 4,
Paul Moore02752762006-11-29 13:18:18 -05001300 secattr);
1301 if (ret_val != 0) {
Paul Moore16efd452008-01-29 08:37:59 -05001302 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
Paul Moore446fda42006-08-03 16:48:06 -07001303 return ret_val;
1304 }
Paul Moore02752762006-11-29 13:18:18 -05001305
1306 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
Paul Moore446fda42006-08-03 16:48:06 -07001307 }
1308
1309 return 0;
1310}
1311
1312/**
Paul Moore654bbc22006-11-29 13:18:19 -05001313 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1314 * @doi_def: the DOI definition
1315 * @secattr: the security attributes
1316 * @buffer: the option buffer
1317 * @buffer_len: length of buffer in bytes
1318 *
1319 * Description:
1320 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1321 * size of the tag on success, negative values on failure.
1322 *
1323 */
1324static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1325 const struct netlbl_lsm_secattr *secattr,
1326 unsigned char *buffer,
1327 u32 buffer_len)
1328{
1329 int ret_val;
1330 u32 tag_len;
1331 u32 level;
1332
1333 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1334 return -EPERM;
1335
Paul Moore16efd452008-01-29 08:37:59 -05001336 ret_val = cipso_v4_map_lvl_hton(doi_def,
1337 secattr->attr.mls.lvl,
1338 &level);
Paul Moore654bbc22006-11-29 13:18:19 -05001339 if (ret_val != 0)
1340 return ret_val;
1341
1342 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1343 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1344 secattr,
1345 &buffer[4],
1346 buffer_len - 4);
1347 if (ret_val < 0)
1348 return ret_val;
1349
1350 tag_len = 4 + ret_val;
1351 } else
1352 tag_len = 4;
1353
Paul Moore15c45f72008-10-10 10:16:34 -04001354 buffer[0] = CIPSO_V4_TAG_ENUM;
Paul Moore654bbc22006-11-29 13:18:19 -05001355 buffer[1] = tag_len;
1356 buffer[3] = level;
1357
1358 return tag_len;
1359}
1360
1361/**
1362 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1363 * @doi_def: the DOI definition
1364 * @tag: the CIPSO tag
1365 * @secattr: the security attributes
1366 *
1367 * Description:
1368 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1369 * attributes in @secattr. Return zero on success, negatives values on
1370 * failure.
1371 *
1372 */
1373static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1374 const unsigned char *tag,
1375 struct netlbl_lsm_secattr *secattr)
1376{
1377 int ret_val;
1378 u8 tag_len = tag[1];
1379 u32 level;
1380
1381 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1382 if (ret_val != 0)
1383 return ret_val;
Paul Moore16efd452008-01-29 08:37:59 -05001384 secattr->attr.mls.lvl = level;
Paul Moore654bbc22006-11-29 13:18:19 -05001385 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1386
1387 if (tag_len > 4) {
Paul Moore16efd452008-01-29 08:37:59 -05001388 secattr->attr.mls.cat =
1389 netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1390 if (secattr->attr.mls.cat == NULL)
Paul Moore654bbc22006-11-29 13:18:19 -05001391 return -ENOMEM;
1392
1393 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1394 &tag[4],
1395 tag_len - 4,
1396 secattr);
1397 if (ret_val != 0) {
Paul Moore16efd452008-01-29 08:37:59 -05001398 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
Paul Moore654bbc22006-11-29 13:18:19 -05001399 return ret_val;
1400 }
1401
1402 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1403 }
1404
1405 return 0;
1406}
1407
1408/**
Paul Moore484b3662006-11-29 13:18:20 -05001409 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1410 * @doi_def: the DOI definition
1411 * @secattr: the security attributes
1412 * @buffer: the option buffer
1413 * @buffer_len: length of buffer in bytes
1414 *
1415 * Description:
1416 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1417 * size of the tag on success, negative values on failure.
1418 *
1419 */
1420static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1421 const struct netlbl_lsm_secattr *secattr,
1422 unsigned char *buffer,
1423 u32 buffer_len)
1424{
1425 int ret_val;
1426 u32 tag_len;
1427 u32 level;
1428
1429 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1430 return -EPERM;
1431
Paul Moore16efd452008-01-29 08:37:59 -05001432 ret_val = cipso_v4_map_lvl_hton(doi_def,
1433 secattr->attr.mls.lvl,
1434 &level);
Paul Moore484b3662006-11-29 13:18:20 -05001435 if (ret_val != 0)
1436 return ret_val;
1437
1438 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1439 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1440 secattr,
1441 &buffer[4],
1442 buffer_len - 4);
1443 if (ret_val < 0)
1444 return ret_val;
1445
1446 tag_len = 4 + ret_val;
1447 } else
1448 tag_len = 4;
1449
Paul Moore15c45f72008-10-10 10:16:34 -04001450 buffer[0] = CIPSO_V4_TAG_RANGE;
Paul Moore484b3662006-11-29 13:18:20 -05001451 buffer[1] = tag_len;
1452 buffer[3] = level;
1453
1454 return tag_len;
1455}
1456
1457/**
1458 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1459 * @doi_def: the DOI definition
1460 * @tag: the CIPSO tag
1461 * @secattr: the security attributes
1462 *
1463 * Description:
1464 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1465 * in @secattr. Return zero on success, negatives values on failure.
1466 *
1467 */
1468static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1469 const unsigned char *tag,
1470 struct netlbl_lsm_secattr *secattr)
1471{
1472 int ret_val;
1473 u8 tag_len = tag[1];
1474 u32 level;
1475
1476 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1477 if (ret_val != 0)
1478 return ret_val;
Paul Moore16efd452008-01-29 08:37:59 -05001479 secattr->attr.mls.lvl = level;
Paul Moore484b3662006-11-29 13:18:20 -05001480 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1481
1482 if (tag_len > 4) {
Paul Moore16efd452008-01-29 08:37:59 -05001483 secattr->attr.mls.cat =
1484 netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1485 if (secattr->attr.mls.cat == NULL)
Paul Moore484b3662006-11-29 13:18:20 -05001486 return -ENOMEM;
1487
1488 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1489 &tag[4],
1490 tag_len - 4,
1491 secattr);
1492 if (ret_val != 0) {
Paul Moore16efd452008-01-29 08:37:59 -05001493 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
Paul Moore484b3662006-11-29 13:18:20 -05001494 return ret_val;
1495 }
1496
1497 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1498 }
1499
1500 return 0;
1501}
1502
1503/**
Paul Moore15c45f72008-10-10 10:16:34 -04001504 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1505 * @doi_def: the DOI definition
1506 * @secattr: the security attributes
1507 * @buffer: the option buffer
1508 * @buffer_len: length of buffer in bytes
1509 *
1510 * Description:
1511 * Generate a CIPSO option using the local tag. Returns the size of the tag
1512 * on success, negative values on failure.
1513 *
1514 */
1515static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1516 const struct netlbl_lsm_secattr *secattr,
1517 unsigned char *buffer,
1518 u32 buffer_len)
1519{
1520 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1521 return -EPERM;
1522
1523 buffer[0] = CIPSO_V4_TAG_LOCAL;
1524 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1525 *(u32 *)&buffer[2] = secattr->attr.secid;
1526
1527 return CIPSO_V4_TAG_LOC_BLEN;
1528}
1529
1530/**
1531 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1532 * @doi_def: the DOI definition
1533 * @tag: the CIPSO tag
1534 * @secattr: the security attributes
1535 *
1536 * Description:
1537 * Parse a CIPSO local tag and return the security attributes in @secattr.
1538 * Return zero on success, negatives values on failure.
1539 *
1540 */
1541static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1542 const unsigned char *tag,
1543 struct netlbl_lsm_secattr *secattr)
1544{
1545 secattr->attr.secid = *(u32 *)&tag[2];
1546 secattr->flags |= NETLBL_SECATTR_SECID;
1547
1548 return 0;
1549}
1550
1551/**
Paul Moore446fda42006-08-03 16:48:06 -07001552 * cipso_v4_validate - Validate a CIPSO option
1553 * @option: the start of the option, on error it is set to point to the error
1554 *
1555 * Description:
1556 * This routine is called to validate a CIPSO option, it checks all of the
1557 * fields to ensure that they are at least valid, see the draft snippet below
1558 * for details. If the option is valid then a zero value is returned and
1559 * the value of @option is unchanged. If the option is invalid then a
1560 * non-zero value is returned and @option is adjusted to point to the
1561 * offending portion of the option. From the IETF draft ...
1562 *
1563 * "If any field within the CIPSO options, such as the DOI identifier, is not
1564 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1565 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1566 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1567 * that is unrecognized."
1568 *
1569 */
Paul Moore15c45f72008-10-10 10:16:34 -04001570int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
Paul Moore446fda42006-08-03 16:48:06 -07001571{
1572 unsigned char *opt = *option;
1573 unsigned char *tag;
1574 unsigned char opt_iter;
1575 unsigned char err_offset = 0;
1576 u8 opt_len;
1577 u8 tag_len;
1578 struct cipso_v4_doi *doi_def = NULL;
1579 u32 tag_iter;
1580
1581 /* caller already checks for length values that are too large */
1582 opt_len = opt[1];
1583 if (opt_len < 8) {
1584 err_offset = 1;
1585 goto validate_return;
1586 }
1587
1588 rcu_read_lock();
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001589 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
Paul Moore446fda42006-08-03 16:48:06 -07001590 if (doi_def == NULL) {
1591 err_offset = 2;
1592 goto validate_return_locked;
1593 }
1594
Paul Moore15c45f72008-10-10 10:16:34 -04001595 opt_iter = CIPSO_V4_HDR_LEN;
Paul Moore446fda42006-08-03 16:48:06 -07001596 tag = opt + opt_iter;
1597 while (opt_iter < opt_len) {
1598 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1599 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1600 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1601 err_offset = opt_iter;
1602 goto validate_return_locked;
1603 }
1604
1605 tag_len = tag[1];
1606 if (tag_len > (opt_len - opt_iter)) {
1607 err_offset = opt_iter + 1;
1608 goto validate_return_locked;
1609 }
1610
1611 switch (tag[0]) {
1612 case CIPSO_V4_TAG_RBITMAP:
Paul Moore15c45f72008-10-10 10:16:34 -04001613 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
Paul Moore446fda42006-08-03 16:48:06 -07001614 err_offset = opt_iter + 1;
1615 goto validate_return_locked;
1616 }
1617
1618 /* We are already going to do all the verification
1619 * necessary at the socket layer so from our point of
1620 * view it is safe to turn these checks off (and less
1621 * work), however, the CIPSO draft says we should do
1622 * all the CIPSO validations here but it doesn't
1623 * really specify _exactly_ what we need to validate
1624 * ... so, just make it a sysctl tunable. */
1625 if (cipso_v4_rbm_strictvalid) {
1626 if (cipso_v4_map_lvl_valid(doi_def,
1627 tag[3]) < 0) {
1628 err_offset = opt_iter + 3;
1629 goto validate_return_locked;
1630 }
Paul Moore15c45f72008-10-10 10:16:34 -04001631 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
Paul Moore446fda42006-08-03 16:48:06 -07001632 cipso_v4_map_cat_rbm_valid(doi_def,
1633 &tag[4],
1634 tag_len - 4) < 0) {
1635 err_offset = opt_iter + 4;
1636 goto validate_return_locked;
1637 }
1638 }
1639 break;
Paul Moore654bbc22006-11-29 13:18:19 -05001640 case CIPSO_V4_TAG_ENUM:
Paul Moore15c45f72008-10-10 10:16:34 -04001641 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
Paul Moore654bbc22006-11-29 13:18:19 -05001642 err_offset = opt_iter + 1;
1643 goto validate_return_locked;
1644 }
1645
1646 if (cipso_v4_map_lvl_valid(doi_def,
1647 tag[3]) < 0) {
1648 err_offset = opt_iter + 3;
1649 goto validate_return_locked;
1650 }
Paul Moore15c45f72008-10-10 10:16:34 -04001651 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
Paul Moore654bbc22006-11-29 13:18:19 -05001652 cipso_v4_map_cat_enum_valid(doi_def,
1653 &tag[4],
1654 tag_len - 4) < 0) {
1655 err_offset = opt_iter + 4;
1656 goto validate_return_locked;
1657 }
1658 break;
Paul Moore484b3662006-11-29 13:18:20 -05001659 case CIPSO_V4_TAG_RANGE:
Paul Moore15c45f72008-10-10 10:16:34 -04001660 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
Paul Moore484b3662006-11-29 13:18:20 -05001661 err_offset = opt_iter + 1;
1662 goto validate_return_locked;
1663 }
1664
1665 if (cipso_v4_map_lvl_valid(doi_def,
1666 tag[3]) < 0) {
1667 err_offset = opt_iter + 3;
1668 goto validate_return_locked;
1669 }
Paul Moore15c45f72008-10-10 10:16:34 -04001670 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
Paul Moore484b3662006-11-29 13:18:20 -05001671 cipso_v4_map_cat_rng_valid(doi_def,
1672 &tag[4],
1673 tag_len - 4) < 0) {
1674 err_offset = opt_iter + 4;
1675 goto validate_return_locked;
1676 }
1677 break;
Paul Moore15c45f72008-10-10 10:16:34 -04001678 case CIPSO_V4_TAG_LOCAL:
1679 /* This is a non-standard tag that we only allow for
1680 * local connections, so if the incoming interface is
1681 * not the loopback device drop the packet. */
1682 if (!(skb->dev->flags & IFF_LOOPBACK)) {
1683 err_offset = opt_iter;
1684 goto validate_return_locked;
1685 }
1686 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1687 err_offset = opt_iter + 1;
1688 goto validate_return_locked;
1689 }
1690 break;
Paul Moore446fda42006-08-03 16:48:06 -07001691 default:
1692 err_offset = opt_iter;
1693 goto validate_return_locked;
1694 }
1695
1696 tag += tag_len;
1697 opt_iter += tag_len;
1698 }
1699
1700validate_return_locked:
1701 rcu_read_unlock();
1702validate_return:
1703 *option = opt + err_offset;
1704 return err_offset;
1705}
1706
1707/**
1708 * cipso_v4_error - Send the correct reponse for a bad packet
1709 * @skb: the packet
1710 * @error: the error code
1711 * @gateway: CIPSO gateway flag
1712 *
1713 * Description:
1714 * Based on the error code given in @error, send an ICMP error message back to
1715 * the originating host. From the IETF draft ...
1716 *
1717 * "If the contents of the CIPSO [option] are valid but the security label is
1718 * outside of the configured host or port label range, the datagram is
1719 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1720 * returned. The code field of the ICMP is set to 'communication with
1721 * destination network administratively prohibited' (code 9) or to
1722 * 'communication with destination host administratively prohibited'
1723 * (code 10). The value of the code is dependent on whether the originator
1724 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1725 * recipient of the ICMP message MUST be able to handle either value. The
1726 * same procedure is performed if a CIPSO [option] can not be added to an
1727 * IP packet because it is too large to fit in the IP options area."
1728 *
1729 * "If the error is triggered by receipt of an ICMP message, the message is
1730 * discarded and no response is permitted (consistent with general ICMP
1731 * processing rules)."
1732 *
1733 */
1734void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1735{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001736 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
Paul Moore446fda42006-08-03 16:48:06 -07001737 return;
1738
1739 if (gateway)
1740 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
1741 else
1742 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
1743}
1744
1745/**
Paul Moore948bf852008-10-10 10:16:32 -04001746 * cipso_v4_genopt - Generate a CIPSO option
1747 * @buf: the option buffer
1748 * @buf_len: the size of opt_buf
Paul Moore446fda42006-08-03 16:48:06 -07001749 * @doi_def: the CIPSO DOI to use
Paul Moore948bf852008-10-10 10:16:32 -04001750 * @secattr: the security attributes
Paul Moore446fda42006-08-03 16:48:06 -07001751 *
1752 * Description:
Paul Moore948bf852008-10-10 10:16:32 -04001753 * Generate a CIPSO option using the DOI definition and security attributes
1754 * passed to the function. Returns the length of the option on success and
1755 * negative values on failure.
Paul Moore446fda42006-08-03 16:48:06 -07001756 *
1757 */
Paul Moore948bf852008-10-10 10:16:32 -04001758static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1759 const struct cipso_v4_doi *doi_def,
1760 const struct netlbl_lsm_secattr *secattr)
Paul Moore446fda42006-08-03 16:48:06 -07001761{
Paul Moore948bf852008-10-10 10:16:32 -04001762 int ret_val;
Paul Moore446fda42006-08-03 16:48:06 -07001763 u32 iter;
Paul Moore446fda42006-08-03 16:48:06 -07001764
Paul Moore948bf852008-10-10 10:16:32 -04001765 if (buf_len <= CIPSO_V4_HDR_LEN)
1766 return -ENOSPC;
Paul Moore91b1ed02006-11-17 17:38:49 -05001767
Paul Moore446fda42006-08-03 16:48:06 -07001768 /* XXX - This code assumes only one tag per CIPSO option which isn't
1769 * really a good assumption to make but since we only support the MAC
1770 * tags right now it is a safe assumption. */
1771 iter = 0;
1772 do {
Paul Moore91b1ed02006-11-17 17:38:49 -05001773 memset(buf, 0, buf_len);
Paul Moore446fda42006-08-03 16:48:06 -07001774 switch (doi_def->tags[iter]) {
1775 case CIPSO_V4_TAG_RBITMAP:
1776 ret_val = cipso_v4_gentag_rbm(doi_def,
Paul Moore91b1ed02006-11-17 17:38:49 -05001777 secattr,
1778 &buf[CIPSO_V4_HDR_LEN],
1779 buf_len - CIPSO_V4_HDR_LEN);
Paul Moore446fda42006-08-03 16:48:06 -07001780 break;
Paul Moore654bbc22006-11-29 13:18:19 -05001781 case CIPSO_V4_TAG_ENUM:
1782 ret_val = cipso_v4_gentag_enum(doi_def,
1783 secattr,
1784 &buf[CIPSO_V4_HDR_LEN],
1785 buf_len - CIPSO_V4_HDR_LEN);
1786 break;
Paul Moore484b3662006-11-29 13:18:20 -05001787 case CIPSO_V4_TAG_RANGE:
1788 ret_val = cipso_v4_gentag_rng(doi_def,
1789 secattr,
1790 &buf[CIPSO_V4_HDR_LEN],
1791 buf_len - CIPSO_V4_HDR_LEN);
1792 break;
Paul Moore15c45f72008-10-10 10:16:34 -04001793 case CIPSO_V4_TAG_LOCAL:
1794 ret_val = cipso_v4_gentag_loc(doi_def,
1795 secattr,
1796 &buf[CIPSO_V4_HDR_LEN],
1797 buf_len - CIPSO_V4_HDR_LEN);
1798 break;
Paul Moore446fda42006-08-03 16:48:06 -07001799 default:
Paul Moore948bf852008-10-10 10:16:32 -04001800 return -EPERM;
Paul Moore446fda42006-08-03 16:48:06 -07001801 }
1802
1803 iter++;
Paul Moore91b1ed02006-11-17 17:38:49 -05001804 } while (ret_val < 0 &&
Paul Moore446fda42006-08-03 16:48:06 -07001805 iter < CIPSO_V4_TAG_MAXCNT &&
1806 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
Paul Moore91b1ed02006-11-17 17:38:49 -05001807 if (ret_val < 0)
Paul Moore948bf852008-10-10 10:16:32 -04001808 return ret_val;
Paul Moore91b1ed02006-11-17 17:38:49 -05001809 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
Paul Moore948bf852008-10-10 10:16:32 -04001810 return CIPSO_V4_HDR_LEN + ret_val;
1811}
1812
1813/**
1814 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1815 * @sk: the socket
1816 * @doi_def: the CIPSO DOI to use
1817 * @secattr: the specific security attributes of the socket
1818 *
1819 * Description:
1820 * Set the CIPSO option on the given socket using the DOI definition and
1821 * security attributes passed to the function. This function requires
1822 * exclusive access to @sk, which means it either needs to be in the
1823 * process of being created or locked. Returns zero on success and negative
1824 * values on failure.
1825 *
1826 */
1827int cipso_v4_sock_setattr(struct sock *sk,
1828 const struct cipso_v4_doi *doi_def,
1829 const struct netlbl_lsm_secattr *secattr)
1830{
1831 int ret_val = -EPERM;
1832 unsigned char *buf = NULL;
1833 u32 buf_len;
1834 u32 opt_len;
1835 struct ip_options *opt = NULL;
1836 struct inet_sock *sk_inet;
1837 struct inet_connection_sock *sk_conn;
1838
1839 /* In the case of sock_create_lite(), the sock->sk field is not
1840 * defined yet but it is not a problem as the only users of these
1841 * "lite" PF_INET sockets are functions which do an accept() call
1842 * afterwards so we will label the socket as part of the accept(). */
1843 if (sk == NULL)
1844 return 0;
1845
1846 /* We allocate the maximum CIPSO option size here so we are probably
1847 * being a little wasteful, but it makes our life _much_ easier later
1848 * on and after all we are only talking about 40 bytes. */
1849 buf_len = CIPSO_V4_OPT_LEN_MAX;
1850 buf = kmalloc(buf_len, GFP_ATOMIC);
1851 if (buf == NULL) {
1852 ret_val = -ENOMEM;
1853 goto socket_setattr_failure;
1854 }
1855
1856 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1857 if (ret_val < 0)
1858 goto socket_setattr_failure;
1859 buf_len = ret_val;
Paul Moore446fda42006-08-03 16:48:06 -07001860
1861 /* We can't use ip_options_get() directly because it makes a call to
1862 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
Paul Mooref8687af2006-10-30 15:22:15 -08001863 * we won't always have CAP_NET_RAW even though we _always_ want to
1864 * set the IPOPT_CIPSO option. */
Paul Moore446fda42006-08-03 16:48:06 -07001865 opt_len = (buf_len + 3) & ~3;
1866 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1867 if (opt == NULL) {
1868 ret_val = -ENOMEM;
1869 goto socket_setattr_failure;
1870 }
1871 memcpy(opt->__data, buf, buf_len);
1872 opt->optlen = opt_len;
Paul Mooref8687af2006-10-30 15:22:15 -08001873 opt->cipso = sizeof(struct iphdr);
Paul Moore446fda42006-08-03 16:48:06 -07001874 kfree(buf);
1875 buf = NULL;
Paul Moore446fda42006-08-03 16:48:06 -07001876
1877 sk_inet = inet_sk(sk);
1878 if (sk_inet->is_icsk) {
1879 sk_conn = inet_csk(sk);
1880 if (sk_inet->opt)
1881 sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen;
1882 sk_conn->icsk_ext_hdr_len += opt->optlen;
1883 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1884 }
1885 opt = xchg(&sk_inet->opt, opt);
1886 kfree(opt);
1887
1888 return 0;
1889
1890socket_setattr_failure:
1891 kfree(buf);
1892 kfree(opt);
1893 return ret_val;
1894}
1895
1896/**
Paul Moore014ab192008-10-10 10:16:33 -04001897 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
1898 * @sk: the socket
1899 *
1900 * Description:
1901 * Removes the CIPSO option from a socket, if present.
1902 *
1903 */
1904void cipso_v4_sock_delattr(struct sock *sk)
1905{
1906 u8 hdr_delta;
1907 struct ip_options *opt;
1908 struct inet_sock *sk_inet;
1909
1910 sk_inet = inet_sk(sk);
1911 opt = sk_inet->opt;
1912 if (opt == NULL || opt->cipso == 0)
1913 return;
1914
1915 if (opt->srr || opt->rr || opt->ts || opt->router_alert) {
1916 u8 cipso_len;
1917 u8 cipso_off;
1918 unsigned char *cipso_ptr;
1919 int iter;
1920 int optlen_new;
1921
1922 cipso_off = opt->cipso - sizeof(struct iphdr);
1923 cipso_ptr = &opt->__data[cipso_off];
1924 cipso_len = cipso_ptr[1];
1925
1926 if (opt->srr > opt->cipso)
1927 opt->srr -= cipso_len;
1928 if (opt->rr > opt->cipso)
1929 opt->rr -= cipso_len;
1930 if (opt->ts > opt->cipso)
1931 opt->ts -= cipso_len;
1932 if (opt->router_alert > opt->cipso)
1933 opt->router_alert -= cipso_len;
1934 opt->cipso = 0;
1935
1936 memmove(cipso_ptr, cipso_ptr + cipso_len,
1937 opt->optlen - cipso_off - cipso_len);
1938
1939 /* determining the new total option length is tricky because of
1940 * the padding necessary, the only thing i can think to do at
1941 * this point is walk the options one-by-one, skipping the
1942 * padding at the end to determine the actual option size and
1943 * from there we can determine the new total option length */
1944 iter = 0;
1945 optlen_new = 0;
1946 while (iter < opt->optlen)
1947 if (opt->__data[iter] != IPOPT_NOP) {
1948 iter += opt->__data[iter + 1];
1949 optlen_new = iter;
1950 } else
1951 iter++;
1952 hdr_delta = opt->optlen;
1953 opt->optlen = (optlen_new + 3) & ~3;
1954 hdr_delta -= opt->optlen;
1955 } else {
1956 /* only the cipso option was present on the socket so we can
1957 * remove the entire option struct */
1958 sk_inet->opt = NULL;
1959 hdr_delta = opt->optlen;
1960 kfree(opt);
1961 }
1962
1963 if (sk_inet->is_icsk && hdr_delta > 0) {
1964 struct inet_connection_sock *sk_conn = inet_csk(sk);
1965 sk_conn->icsk_ext_hdr_len -= hdr_delta;
1966 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1967 }
1968}
1969
1970/**
Paul Moore63d804ea2007-09-15 21:45:13 -07001971 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
1972 * @cipso: the CIPSO v4 option
1973 * @secattr: the security attributes
1974 *
1975 * Description:
1976 * Inspect @cipso and return the security attributes in @secattr. Returns zero
1977 * on success and negative values on failure.
1978 *
1979 */
1980static int cipso_v4_getattr(const unsigned char *cipso,
1981 struct netlbl_lsm_secattr *secattr)
1982{
1983 int ret_val = -ENOMSG;
1984 u32 doi;
1985 struct cipso_v4_doi *doi_def;
1986
1987 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
1988 return 0;
1989
Harvey Harrisond3e2ce32008-05-02 16:26:16 -07001990 doi = get_unaligned_be32(&cipso[2]);
Paul Moore63d804ea2007-09-15 21:45:13 -07001991 rcu_read_lock();
1992 doi_def = cipso_v4_doi_search(doi);
1993 if (doi_def == NULL)
1994 goto getattr_return;
1995 /* XXX - This code assumes only one tag per CIPSO option which isn't
1996 * really a good assumption to make but since we only support the MAC
1997 * tags right now it is a safe assumption. */
1998 switch (cipso[6]) {
1999 case CIPSO_V4_TAG_RBITMAP:
2000 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2001 break;
2002 case CIPSO_V4_TAG_ENUM:
2003 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2004 break;
2005 case CIPSO_V4_TAG_RANGE:
2006 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2007 break;
Paul Moore15c45f72008-10-10 10:16:34 -04002008 case CIPSO_V4_TAG_LOCAL:
2009 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2010 break;
Paul Moore63d804ea2007-09-15 21:45:13 -07002011 }
Paul Moore16efd452008-01-29 08:37:59 -05002012 if (ret_val == 0)
2013 secattr->type = NETLBL_NLTYPE_CIPSOV4;
Paul Moore63d804ea2007-09-15 21:45:13 -07002014
2015getattr_return:
2016 rcu_read_unlock();
2017 return ret_val;
2018}
2019
2020/**
Paul Moore14a72f52006-09-25 15:52:01 -07002021 * cipso_v4_sock_getattr - Get the security attributes from a sock
2022 * @sk: the sock
2023 * @secattr: the security attributes
2024 *
2025 * Description:
2026 * Query @sk to see if there is a CIPSO option attached to the sock and if
2027 * there is return the CIPSO security attributes in @secattr. This function
2028 * requires that @sk be locked, or privately held, but it does not do any
2029 * locking itself. Returns zero on success and negative values on failure.
2030 *
2031 */
2032int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2033{
Paul Moore63d804ea2007-09-15 21:45:13 -07002034 struct ip_options *opt;
Paul Moore14a72f52006-09-25 15:52:01 -07002035
Paul Moore63d804ea2007-09-15 21:45:13 -07002036 opt = inet_sk(sk)->opt;
2037 if (opt == NULL || opt->cipso == 0)
Paul Moore14a72f52006-09-25 15:52:01 -07002038 return -ENOMSG;
Paul Moore14a72f52006-09-25 15:52:01 -07002039
Paul Moore63d804ea2007-09-15 21:45:13 -07002040 return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr),
2041 secattr);
Paul Moore14a72f52006-09-25 15:52:01 -07002042}
2043
2044/**
Paul Moore948bf852008-10-10 10:16:32 -04002045 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2046 * @skb: the packet
2047 * @secattr: the security attributes
2048 *
2049 * Description:
2050 * Set the CIPSO option on the given packet based on the security attributes.
2051 * Returns a pointer to the IP header on success and NULL on failure.
2052 *
2053 */
2054int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2055 const struct cipso_v4_doi *doi_def,
2056 const struct netlbl_lsm_secattr *secattr)
2057{
2058 int ret_val;
2059 struct iphdr *iph;
2060 struct ip_options *opt = &IPCB(skb)->opt;
2061 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2062 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2063 u32 opt_len;
2064 int len_delta;
2065
roel kluin00af5c62008-10-29 15:55:53 -04002066 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2067 if (ret_val < 0)
2068 return ret_val;
2069 buf_len = ret_val;
Paul Moore948bf852008-10-10 10:16:32 -04002070 opt_len = (buf_len + 3) & ~3;
2071
2072 /* we overwrite any existing options to ensure that we have enough
2073 * room for the CIPSO option, the reason is that we _need_ to guarantee
2074 * that the security label is applied to the packet - we do the same
2075 * thing when using the socket options and it hasn't caused a problem,
2076 * if we need to we can always revisit this choice later */
2077
2078 len_delta = opt_len - opt->optlen;
2079 /* if we don't ensure enough headroom we could panic on the skb_push()
2080 * call below so make sure we have enough, we are also "mangling" the
2081 * packet so we should probably do a copy-on-write call anyway */
2082 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2083 if (ret_val < 0)
2084 return ret_val;
2085
2086 if (len_delta > 0) {
2087 /* we assume that the header + opt->optlen have already been
2088 * "pushed" in ip_options_build() or similar */
2089 iph = ip_hdr(skb);
2090 skb_push(skb, len_delta);
2091 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2092 skb_reset_network_header(skb);
2093 iph = ip_hdr(skb);
2094 } else if (len_delta < 0) {
2095 iph = ip_hdr(skb);
2096 memset(iph + 1, IPOPT_NOP, opt->optlen);
2097 } else
2098 iph = ip_hdr(skb);
2099
2100 if (opt->optlen > 0)
2101 memset(opt, 0, sizeof(*opt));
2102 opt->optlen = opt_len;
2103 opt->cipso = sizeof(struct iphdr);
2104 opt->is_changed = 1;
2105
2106 /* we have to do the following because we are being called from a
2107 * netfilter hook which means the packet already has had the header
2108 * fields populated and the checksum calculated - yes this means we
2109 * are doing more work than needed but we do it to keep the core
2110 * stack clean and tidy */
2111 memcpy(iph + 1, buf, buf_len);
2112 if (opt_len > buf_len)
2113 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2114 if (len_delta != 0) {
2115 iph->ihl = 5 + (opt_len >> 2);
2116 iph->tot_len = htons(skb->len);
2117 }
2118 ip_send_check(iph);
2119
2120 return 0;
2121}
2122
2123/**
2124 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2125 * @skb: the packet
2126 *
2127 * Description:
2128 * Removes any and all CIPSO options from the given packet. Returns zero on
2129 * success, negative values on failure.
2130 *
2131 */
2132int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2133{
2134 int ret_val;
2135 struct iphdr *iph;
2136 struct ip_options *opt = &IPCB(skb)->opt;
2137 unsigned char *cipso_ptr;
2138
2139 if (opt->cipso == 0)
2140 return 0;
2141
2142 /* since we are changing the packet we should make a copy */
2143 ret_val = skb_cow(skb, skb_headroom(skb));
2144 if (ret_val < 0)
2145 return ret_val;
2146
2147 /* the easiest thing to do is just replace the cipso option with noop
2148 * options since we don't change the size of the packet, although we
2149 * still need to recalculate the checksum */
2150
2151 iph = ip_hdr(skb);
2152 cipso_ptr = (unsigned char *)iph + opt->cipso;
2153 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2154 opt->cipso = 0;
2155 opt->is_changed = 1;
2156
2157 ip_send_check(iph);
2158
2159 return 0;
2160}
2161
2162/**
Paul Moore446fda42006-08-03 16:48:06 -07002163 * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
2164 * @skb: the packet
2165 * @secattr: the security attributes
2166 *
2167 * Description:
2168 * Parse the given packet's CIPSO option and return the security attributes.
2169 * Returns zero on success and negative values on failure.
2170 *
2171 */
2172int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
2173 struct netlbl_lsm_secattr *secattr)
2174{
Paul Moore63d804ea2007-09-15 21:45:13 -07002175 return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr);
Paul Moore446fda42006-08-03 16:48:06 -07002176}
2177
2178/*
2179 * Setup Functions
2180 */
2181
2182/**
2183 * cipso_v4_init - Initialize the CIPSO module
2184 *
2185 * Description:
2186 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2187 * and negative values on failure.
2188 *
2189 */
2190static int __init cipso_v4_init(void)
2191{
2192 int ret_val;
2193
2194 ret_val = cipso_v4_cache_init();
2195 if (ret_val != 0)
2196 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2197 ret_val);
2198
2199 return 0;
2200}
2201
2202subsys_initcall(cipso_v4_init);