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446fda4f PM |
1 | /* |
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 | /* | |
948bf85c | 16 | * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 |
446fda4f PM |
17 | * |
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> | |
ffb733c6 | 46 | #include <asm/atomic.h> |
446fda4f | 47 | #include <asm/bug.h> |
50e5d35c | 48 | #include <asm/unaligned.h> |
446fda4f | 49 | |
446fda4f | 50 | /* List of available DOI definitions */ |
446fda4f PM |
51 | /* 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. */ | |
8ce11e6a | 55 | static DEFINE_SPINLOCK(cipso_v4_doi_list_lock); |
1596c97a | 56 | static LIST_HEAD(cipso_v4_doi_list); |
446fda4f PM |
57 | |
58 | /* Label mapping cache */ | |
59 | int cipso_v4_cache_enabled = 1; | |
60 | int 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 | |
64 | struct cipso_v4_map_cache_bkt { | |
65 | spinlock_t lock; | |
66 | u32 size; | |
67 | struct list_head list; | |
68 | }; | |
69 | struct cipso_v4_map_cache_entry { | |
70 | u32 hash; | |
71 | unsigned char *key; | |
72 | size_t key_len; | |
73 | ||
ffb733c6 | 74 | struct netlbl_lsm_cache *lsm_data; |
446fda4f PM |
75 | |
76 | u32 activity; | |
77 | struct list_head list; | |
78 | }; | |
79 | static struct cipso_v4_map_cache_bkt *cipso_v4_cache = NULL; | |
80 | ||
81 | /* Restricted bitmap (tag #1) flags */ | |
82 | int cipso_v4_rbm_optfmt = 0; | |
83 | int cipso_v4_rbm_strictvalid = 1; | |
84 | ||
f998e8cb PM |
85 | /* |
86 | * 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 | ||
446fda4f PM |
112 | /* |
113 | * Helper Functions | |
114 | */ | |
115 | ||
116 | /** | |
117 | * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit | |
118 | * @bitmap: the bitmap | |
119 | * @bitmap_len: length in bits | |
120 | * @offset: starting offset | |
121 | * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit | |
122 | * | |
123 | * Description: | |
124 | * Starting at @offset, walk the bitmap from left to right until either the | |
125 | * desired bit is found or we reach the end. Return the bit offset, -1 if | |
126 | * not found, or -2 if error. | |
127 | */ | |
128 | static int cipso_v4_bitmap_walk(const unsigned char *bitmap, | |
129 | u32 bitmap_len, | |
130 | u32 offset, | |
131 | u8 state) | |
132 | { | |
133 | u32 bit_spot; | |
134 | u32 byte_offset; | |
135 | unsigned char bitmask; | |
136 | unsigned char byte; | |
137 | ||
138 | /* gcc always rounds to zero when doing integer division */ | |
139 | byte_offset = offset / 8; | |
140 | byte = bitmap[byte_offset]; | |
141 | bit_spot = offset; | |
142 | bitmask = 0x80 >> (offset % 8); | |
143 | ||
144 | while (bit_spot < bitmap_len) { | |
145 | if ((state && (byte & bitmask) == bitmask) || | |
146 | (state == 0 && (byte & bitmask) == 0)) | |
147 | return bit_spot; | |
148 | ||
149 | bit_spot++; | |
150 | bitmask >>= 1; | |
151 | if (bitmask == 0) { | |
152 | byte = bitmap[++byte_offset]; | |
153 | bitmask = 0x80; | |
154 | } | |
155 | } | |
156 | ||
157 | return -1; | |
158 | } | |
159 | ||
160 | /** | |
161 | * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap | |
162 | * @bitmap: the bitmap | |
163 | * @bit: the bit | |
164 | * @state: if non-zero, set the bit (1) else clear the bit (0) | |
165 | * | |
166 | * Description: | |
167 | * Set a single bit in the bitmask. Returns zero on success, negative values | |
168 | * on error. | |
169 | */ | |
170 | static void cipso_v4_bitmap_setbit(unsigned char *bitmap, | |
171 | u32 bit, | |
172 | u8 state) | |
173 | { | |
174 | u32 byte_spot; | |
175 | u8 bitmask; | |
176 | ||
177 | /* gcc always rounds to zero when doing integer division */ | |
178 | byte_spot = bit / 8; | |
179 | bitmask = 0x80 >> (bit % 8); | |
180 | if (state) | |
181 | bitmap[byte_spot] |= bitmask; | |
182 | else | |
183 | bitmap[byte_spot] &= ~bitmask; | |
184 | } | |
185 | ||
446fda4f PM |
186 | /** |
187 | * cipso_v4_cache_entry_free - Frees a cache entry | |
188 | * @entry: the entry to free | |
189 | * | |
190 | * Description: | |
ffb733c6 | 191 | * This function frees the memory associated with a cache entry including the |
192 | * LSM cache data if there are no longer any users, i.e. reference count == 0. | |
446fda4f PM |
193 | * |
194 | */ | |
195 | static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) | |
196 | { | |
ffb733c6 | 197 | if (entry->lsm_data) |
198 | netlbl_secattr_cache_free(entry->lsm_data); | |
446fda4f PM |
199 | kfree(entry->key); |
200 | kfree(entry); | |
201 | } | |
202 | ||
203 | /** | |
204 | * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache | |
205 | * @key: the hash key | |
206 | * @key_len: the length of the key in bytes | |
207 | * | |
208 | * Description: | |
209 | * The CIPSO tag hashing function. Returns a 32-bit hash value. | |
210 | * | |
211 | */ | |
212 | static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len) | |
213 | { | |
214 | return jhash(key, key_len, 0); | |
215 | } | |
216 | ||
217 | /* | |
218 | * Label Mapping Cache Functions | |
219 | */ | |
220 | ||
221 | /** | |
222 | * cipso_v4_cache_init - Initialize the CIPSO cache | |
223 | * | |
224 | * Description: | |
225 | * Initializes the CIPSO label mapping cache, this function should be called | |
226 | * before any of the other functions defined in this file. Returns zero on | |
227 | * success, negative values on error. | |
228 | * | |
229 | */ | |
230 | static int cipso_v4_cache_init(void) | |
231 | { | |
232 | u32 iter; | |
233 | ||
234 | cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS, | |
235 | sizeof(struct cipso_v4_map_cache_bkt), | |
236 | GFP_KERNEL); | |
237 | if (cipso_v4_cache == NULL) | |
238 | return -ENOMEM; | |
239 | ||
240 | for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { | |
241 | spin_lock_init(&cipso_v4_cache[iter].lock); | |
242 | cipso_v4_cache[iter].size = 0; | |
243 | INIT_LIST_HEAD(&cipso_v4_cache[iter].list); | |
244 | } | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | /** | |
250 | * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache | |
251 | * | |
252 | * Description: | |
253 | * Invalidates and frees any entries in the CIPSO cache. Returns zero on | |
254 | * success and negative values on failure. | |
255 | * | |
256 | */ | |
257 | void cipso_v4_cache_invalidate(void) | |
258 | { | |
259 | struct cipso_v4_map_cache_entry *entry, *tmp_entry; | |
260 | u32 iter; | |
261 | ||
262 | for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { | |
609c92fe | 263 | spin_lock_bh(&cipso_v4_cache[iter].lock); |
446fda4f PM |
264 | list_for_each_entry_safe(entry, |
265 | tmp_entry, | |
266 | &cipso_v4_cache[iter].list, list) { | |
267 | list_del(&entry->list); | |
268 | cipso_v4_cache_entry_free(entry); | |
269 | } | |
270 | cipso_v4_cache[iter].size = 0; | |
609c92fe | 271 | spin_unlock_bh(&cipso_v4_cache[iter].lock); |
446fda4f PM |
272 | } |
273 | ||
274 | return; | |
275 | } | |
276 | ||
277 | /** | |
278 | * cipso_v4_cache_check - Check the CIPSO cache for a label mapping | |
279 | * @key: the buffer to check | |
280 | * @key_len: buffer length in bytes | |
281 | * @secattr: the security attribute struct to use | |
282 | * | |
283 | * Description: | |
284 | * This function checks the cache to see if a label mapping already exists for | |
285 | * the given key. If there is a match then the cache is adjusted and the | |
286 | * @secattr struct is populated with the correct LSM security attributes. The | |
287 | * cache is adjusted in the following manner if the entry is not already the | |
288 | * first in the cache bucket: | |
289 | * | |
290 | * 1. The cache entry's activity counter is incremented | |
291 | * 2. The previous (higher ranking) entry's activity counter is decremented | |
292 | * 3. If the difference between the two activity counters is geater than | |
293 | * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped | |
294 | * | |
295 | * Returns zero on success, -ENOENT for a cache miss, and other negative values | |
296 | * on error. | |
297 | * | |
298 | */ | |
299 | static int cipso_v4_cache_check(const unsigned char *key, | |
300 | u32 key_len, | |
301 | struct netlbl_lsm_secattr *secattr) | |
302 | { | |
303 | u32 bkt; | |
304 | struct cipso_v4_map_cache_entry *entry; | |
305 | struct cipso_v4_map_cache_entry *prev_entry = NULL; | |
306 | u32 hash; | |
307 | ||
308 | if (!cipso_v4_cache_enabled) | |
309 | return -ENOENT; | |
310 | ||
311 | hash = cipso_v4_map_cache_hash(key, key_len); | |
5e0f8923 | 312 | bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
609c92fe | 313 | spin_lock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
314 | list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) { |
315 | if (entry->hash == hash && | |
316 | entry->key_len == key_len && | |
317 | memcmp(entry->key, key, key_len) == 0) { | |
318 | entry->activity += 1; | |
ffb733c6 | 319 | atomic_inc(&entry->lsm_data->refcount); |
320 | secattr->cache = entry->lsm_data; | |
701a90ba | 321 | secattr->flags |= NETLBL_SECATTR_CACHE; |
16efd454 | 322 | secattr->type = NETLBL_NLTYPE_CIPSOV4; |
446fda4f | 323 | if (prev_entry == NULL) { |
609c92fe | 324 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
325 | return 0; |
326 | } | |
327 | ||
328 | if (prev_entry->activity > 0) | |
329 | prev_entry->activity -= 1; | |
330 | if (entry->activity > prev_entry->activity && | |
331 | entry->activity - prev_entry->activity > | |
332 | CIPSO_V4_CACHE_REORDERLIMIT) { | |
333 | __list_del(entry->list.prev, entry->list.next); | |
334 | __list_add(&entry->list, | |
335 | prev_entry->list.prev, | |
336 | &prev_entry->list); | |
337 | } | |
338 | ||
609c92fe | 339 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
340 | return 0; |
341 | } | |
342 | prev_entry = entry; | |
343 | } | |
609c92fe | 344 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
345 | |
346 | return -ENOENT; | |
347 | } | |
348 | ||
349 | /** | |
350 | * cipso_v4_cache_add - Add an entry to the CIPSO cache | |
351 | * @skb: the packet | |
352 | * @secattr: the packet's security attributes | |
353 | * | |
354 | * Description: | |
355 | * Add a new entry into the CIPSO label mapping cache. Add the new entry to | |
356 | * head of the cache bucket's list, if the cache bucket is out of room remove | |
357 | * the last entry in the list first. It is important to note that there is | |
358 | * currently no checking for duplicate keys. Returns zero on success, | |
359 | * negative values on failure. | |
360 | * | |
361 | */ | |
362 | int cipso_v4_cache_add(const struct sk_buff *skb, | |
363 | const struct netlbl_lsm_secattr *secattr) | |
364 | { | |
365 | int ret_val = -EPERM; | |
366 | u32 bkt; | |
367 | struct cipso_v4_map_cache_entry *entry = NULL; | |
368 | struct cipso_v4_map_cache_entry *old_entry = NULL; | |
369 | unsigned char *cipso_ptr; | |
370 | u32 cipso_ptr_len; | |
371 | ||
372 | if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) | |
373 | return 0; | |
374 | ||
375 | cipso_ptr = CIPSO_V4_OPTPTR(skb); | |
376 | cipso_ptr_len = cipso_ptr[1]; | |
377 | ||
378 | entry = kzalloc(sizeof(*entry), GFP_ATOMIC); | |
379 | if (entry == NULL) | |
380 | return -ENOMEM; | |
fac5d731 | 381 | entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC); |
446fda4f PM |
382 | if (entry->key == NULL) { |
383 | ret_val = -ENOMEM; | |
384 | goto cache_add_failure; | |
385 | } | |
446fda4f PM |
386 | entry->key_len = cipso_ptr_len; |
387 | entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); | |
ffb733c6 | 388 | atomic_inc(&secattr->cache->refcount); |
389 | entry->lsm_data = secattr->cache; | |
446fda4f | 390 | |
5e0f8923 | 391 | bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
609c92fe | 392 | spin_lock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
393 | if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) { |
394 | list_add(&entry->list, &cipso_v4_cache[bkt].list); | |
395 | cipso_v4_cache[bkt].size += 1; | |
396 | } else { | |
397 | old_entry = list_entry(cipso_v4_cache[bkt].list.prev, | |
398 | struct cipso_v4_map_cache_entry, list); | |
399 | list_del(&old_entry->list); | |
400 | list_add(&entry->list, &cipso_v4_cache[bkt].list); | |
401 | cipso_v4_cache_entry_free(old_entry); | |
402 | } | |
609c92fe | 403 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
446fda4f PM |
404 | |
405 | return 0; | |
406 | ||
407 | cache_add_failure: | |
408 | if (entry) | |
409 | cipso_v4_cache_entry_free(entry); | |
410 | return ret_val; | |
411 | } | |
412 | ||
413 | /* | |
414 | * DOI List Functions | |
415 | */ | |
416 | ||
417 | /** | |
418 | * cipso_v4_doi_search - Searches for a DOI definition | |
419 | * @doi: the DOI to search for | |
420 | * | |
421 | * Description: | |
422 | * Search the DOI definition list for a DOI definition with a DOI value that | |
423 | * matches @doi. The caller is responsibile for calling rcu_read_[un]lock(). | |
424 | * Returns a pointer to the DOI definition on success and NULL on failure. | |
425 | */ | |
426 | static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) | |
427 | { | |
428 | struct cipso_v4_doi *iter; | |
429 | ||
430 | list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) | |
b1edeb10 | 431 | if (iter->doi == doi && atomic_read(&iter->refcount)) |
446fda4f PM |
432 | return iter; |
433 | return NULL; | |
434 | } | |
435 | ||
436 | /** | |
437 | * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine | |
438 | * @doi_def: the DOI structure | |
439 | * | |
440 | * Description: | |
441 | * The caller defines a new DOI for use by the CIPSO engine and calls this | |
442 | * function to add it to the list of acceptable domains. The caller must | |
443 | * ensure that the mapping table specified in @doi_def->map meets all of the | |
444 | * requirements of the mapping type (see cipso_ipv4.h for details). Returns | |
445 | * zero on success and non-zero on failure. | |
446 | * | |
447 | */ | |
448 | int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) | |
449 | { | |
6ce61a7c PM |
450 | u32 iter; |
451 | ||
446fda4f PM |
452 | if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN) |
453 | return -EINVAL; | |
6ce61a7c PM |
454 | for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) { |
455 | switch (doi_def->tags[iter]) { | |
456 | case CIPSO_V4_TAG_RBITMAP: | |
457 | break; | |
484b3669 PM |
458 | case CIPSO_V4_TAG_RANGE: |
459 | if (doi_def->type != CIPSO_V4_MAP_PASS) | |
460 | return -EINVAL; | |
461 | break; | |
6ce61a7c PM |
462 | case CIPSO_V4_TAG_INVALID: |
463 | if (iter == 0) | |
464 | return -EINVAL; | |
465 | break; | |
654bbc2a PM |
466 | case CIPSO_V4_TAG_ENUM: |
467 | if (doi_def->type != CIPSO_V4_MAP_PASS) | |
468 | return -EINVAL; | |
469 | break; | |
6ce61a7c PM |
470 | default: |
471 | return -EINVAL; | |
472 | } | |
473 | } | |
446fda4f | 474 | |
b1edeb10 | 475 | atomic_set(&doi_def->refcount, 1); |
446fda4f | 476 | INIT_RCU_HEAD(&doi_def->rcu); |
446fda4f | 477 | |
446fda4f PM |
478 | spin_lock(&cipso_v4_doi_list_lock); |
479 | if (cipso_v4_doi_search(doi_def->doi) != NULL) | |
4be2700f | 480 | goto doi_add_failure; |
446fda4f PM |
481 | list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); |
482 | spin_unlock(&cipso_v4_doi_list_lock); | |
446fda4f PM |
483 | |
484 | return 0; | |
485 | ||
4be2700f | 486 | doi_add_failure: |
446fda4f | 487 | spin_unlock(&cipso_v4_doi_list_lock); |
446fda4f PM |
488 | return -EEXIST; |
489 | } | |
490 | ||
b1edeb10 PM |
491 | /** |
492 | * cipso_v4_doi_free - Frees a DOI definition | |
493 | * @entry: the entry's RCU field | |
494 | * | |
495 | * Description: | |
496 | * This function frees all of the memory associated with a DOI definition. | |
497 | * | |
498 | */ | |
499 | void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) | |
500 | { | |
501 | if (doi_def == NULL) | |
502 | return; | |
503 | ||
504 | switch (doi_def->type) { | |
505 | case CIPSO_V4_MAP_STD: | |
506 | kfree(doi_def->map.std->lvl.cipso); | |
507 | kfree(doi_def->map.std->lvl.local); | |
508 | kfree(doi_def->map.std->cat.cipso); | |
509 | kfree(doi_def->map.std->cat.local); | |
510 | break; | |
511 | } | |
512 | kfree(doi_def); | |
513 | } | |
514 | ||
515 | /** | |
516 | * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer | |
517 | * @entry: the entry's RCU field | |
518 | * | |
519 | * Description: | |
520 | * This function is designed to be used as a callback to the call_rcu() | |
521 | * function so that the memory allocated to the DOI definition can be released | |
522 | * safely. | |
523 | * | |
524 | */ | |
525 | static void cipso_v4_doi_free_rcu(struct rcu_head *entry) | |
526 | { | |
527 | struct cipso_v4_doi *doi_def; | |
528 | ||
529 | doi_def = container_of(entry, struct cipso_v4_doi, rcu); | |
530 | cipso_v4_doi_free(doi_def); | |
531 | } | |
532 | ||
446fda4f PM |
533 | /** |
534 | * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine | |
535 | * @doi: the DOI value | |
32f50cde | 536 | * @audit_secid: the LSM secid to use in the audit message |
446fda4f PM |
537 | * |
538 | * Description: | |
b1edeb10 PM |
539 | * Removes a DOI definition from the CIPSO engine. The NetLabel routines will |
540 | * be called to release their own LSM domain mappings as well as our own | |
541 | * domain list. Returns zero on success and negative values on failure. | |
446fda4f PM |
542 | * |
543 | */ | |
b1edeb10 | 544 | int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) |
446fda4f PM |
545 | { |
546 | struct cipso_v4_doi *doi_def; | |
446fda4f | 547 | |
4be2700f PM |
548 | spin_lock(&cipso_v4_doi_list_lock); |
549 | doi_def = cipso_v4_doi_search(doi); | |
b1edeb10 | 550 | if (doi_def == NULL) { |
446fda4f | 551 | spin_unlock(&cipso_v4_doi_list_lock); |
b1edeb10 | 552 | return -ENOENT; |
446fda4f | 553 | } |
b1edeb10 PM |
554 | if (!atomic_dec_and_test(&doi_def->refcount)) { |
555 | spin_unlock(&cipso_v4_doi_list_lock); | |
556 | return -EBUSY; | |
557 | } | |
558 | list_del_rcu(&doi_def->list); | |
4be2700f | 559 | spin_unlock(&cipso_v4_doi_list_lock); |
446fda4f | 560 | |
b1edeb10 PM |
561 | cipso_v4_cache_invalidate(); |
562 | call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); | |
563 | ||
564 | return 0; | |
446fda4f PM |
565 | } |
566 | ||
567 | /** | |
b1edeb10 | 568 | * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition |
446fda4f PM |
569 | * @doi: the DOI value |
570 | * | |
571 | * Description: | |
572 | * Searches for a valid DOI definition and if one is found it is returned to | |
573 | * the caller. Otherwise NULL is returned. The caller must ensure that | |
b1edeb10 PM |
574 | * rcu_read_lock() is held while accessing the returned definition and the DOI |
575 | * definition reference count is decremented when the caller is done. | |
446fda4f PM |
576 | * |
577 | */ | |
578 | struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) | |
579 | { | |
b1edeb10 PM |
580 | struct cipso_v4_doi *doi_def; |
581 | ||
582 | rcu_read_lock(); | |
583 | doi_def = cipso_v4_doi_search(doi); | |
584 | if (doi_def == NULL) | |
585 | goto doi_getdef_return; | |
586 | if (!atomic_inc_not_zero(&doi_def->refcount)) | |
587 | doi_def = NULL; | |
588 | ||
589 | doi_getdef_return: | |
590 | rcu_read_unlock(); | |
591 | return doi_def; | |
592 | } | |
593 | ||
594 | /** | |
595 | * cipso_v4_doi_putdef - Releases a reference for the given DOI definition | |
596 | * @doi_def: the DOI definition | |
597 | * | |
598 | * Description: | |
599 | * Releases a DOI definition reference obtained from cipso_v4_doi_getdef(). | |
600 | * | |
601 | */ | |
602 | void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) | |
603 | { | |
604 | if (doi_def == NULL) | |
605 | return; | |
606 | ||
607 | if (!atomic_dec_and_test(&doi_def->refcount)) | |
608 | return; | |
609 | spin_lock(&cipso_v4_doi_list_lock); | |
610 | list_del_rcu(&doi_def->list); | |
611 | spin_unlock(&cipso_v4_doi_list_lock); | |
612 | ||
613 | cipso_v4_cache_invalidate(); | |
614 | call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); | |
446fda4f PM |
615 | } |
616 | ||
617 | /** | |
fcd48280 PM |
618 | * cipso_v4_doi_walk - Iterate through the DOI definitions |
619 | * @skip_cnt: skip past this number of DOI definitions, updated | |
620 | * @callback: callback for each DOI definition | |
621 | * @cb_arg: argument for the callback function | |
446fda4f PM |
622 | * |
623 | * Description: | |
fcd48280 PM |
624 | * Iterate over the DOI definition list, skipping the first @skip_cnt entries. |
625 | * For each entry call @callback, if @callback returns a negative value stop | |
626 | * 'walking' through the list and return. Updates the value in @skip_cnt upon | |
627 | * return. Returns zero on success, negative values on failure. | |
446fda4f PM |
628 | * |
629 | */ | |
fcd48280 PM |
630 | int cipso_v4_doi_walk(u32 *skip_cnt, |
631 | int (*callback) (struct cipso_v4_doi *doi_def, void *arg), | |
632 | void *cb_arg) | |
446fda4f | 633 | { |
fcd48280 | 634 | int ret_val = -ENOENT; |
446fda4f | 635 | u32 doi_cnt = 0; |
fcd48280 | 636 | struct cipso_v4_doi *iter_doi; |
446fda4f | 637 | |
446fda4f | 638 | rcu_read_lock(); |
fcd48280 | 639 | list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list) |
b1edeb10 | 640 | if (atomic_read(&iter_doi->refcount) > 0) { |
fcd48280 PM |
641 | if (doi_cnt++ < *skip_cnt) |
642 | continue; | |
643 | ret_val = callback(iter_doi, cb_arg); | |
644 | if (ret_val < 0) { | |
645 | doi_cnt--; | |
646 | goto doi_walk_return; | |
446fda4f | 647 | } |
446fda4f | 648 | } |
446fda4f | 649 | |
fcd48280 | 650 | doi_walk_return: |
446fda4f | 651 | rcu_read_unlock(); |
fcd48280 PM |
652 | *skip_cnt = doi_cnt; |
653 | return ret_val; | |
446fda4f PM |
654 | } |
655 | ||
446fda4f PM |
656 | /* |
657 | * Label Mapping Functions | |
658 | */ | |
659 | ||
660 | /** | |
661 | * cipso_v4_map_lvl_valid - Checks to see if the given level is understood | |
662 | * @doi_def: the DOI definition | |
663 | * @level: the level to check | |
664 | * | |
665 | * Description: | |
666 | * Checks the given level against the given DOI definition and returns a | |
667 | * negative value if the level does not have a valid mapping and a zero value | |
668 | * if the level is defined by the DOI. | |
669 | * | |
670 | */ | |
671 | static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level) | |
672 | { | |
673 | switch (doi_def->type) { | |
674 | case CIPSO_V4_MAP_PASS: | |
675 | return 0; | |
676 | case CIPSO_V4_MAP_STD: | |
677 | if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL) | |
678 | return 0; | |
679 | break; | |
680 | } | |
681 | ||
682 | return -EFAULT; | |
683 | } | |
684 | ||
685 | /** | |
686 | * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network | |
687 | * @doi_def: the DOI definition | |
688 | * @host_lvl: the host MLS level | |
689 | * @net_lvl: the network/CIPSO MLS level | |
690 | * | |
691 | * Description: | |
692 | * Perform a label mapping to translate a local MLS level to the correct | |
693 | * CIPSO level using the given DOI definition. Returns zero on success, | |
694 | * negative values otherwise. | |
695 | * | |
696 | */ | |
697 | static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def, | |
698 | u32 host_lvl, | |
699 | u32 *net_lvl) | |
700 | { | |
701 | switch (doi_def->type) { | |
702 | case CIPSO_V4_MAP_PASS: | |
703 | *net_lvl = host_lvl; | |
704 | return 0; | |
705 | case CIPSO_V4_MAP_STD: | |
c6387a86 PM |
706 | if (host_lvl < doi_def->map.std->lvl.local_size && |
707 | doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) { | |
446fda4f PM |
708 | *net_lvl = doi_def->map.std->lvl.local[host_lvl]; |
709 | return 0; | |
710 | } | |
c6387a86 | 711 | return -EPERM; |
446fda4f PM |
712 | } |
713 | ||
714 | return -EINVAL; | |
715 | } | |
716 | ||
717 | /** | |
718 | * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host | |
719 | * @doi_def: the DOI definition | |
720 | * @net_lvl: the network/CIPSO MLS level | |
721 | * @host_lvl: the host MLS level | |
722 | * | |
723 | * Description: | |
724 | * Perform a label mapping to translate a CIPSO level to the correct local MLS | |
725 | * level using the given DOI definition. Returns zero on success, negative | |
726 | * values otherwise. | |
727 | * | |
728 | */ | |
729 | static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def, | |
730 | u32 net_lvl, | |
731 | u32 *host_lvl) | |
732 | { | |
733 | struct cipso_v4_std_map_tbl *map_tbl; | |
734 | ||
735 | switch (doi_def->type) { | |
736 | case CIPSO_V4_MAP_PASS: | |
737 | *host_lvl = net_lvl; | |
738 | return 0; | |
739 | case CIPSO_V4_MAP_STD: | |
740 | map_tbl = doi_def->map.std; | |
741 | if (net_lvl < map_tbl->lvl.cipso_size && | |
742 | map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) { | |
743 | *host_lvl = doi_def->map.std->lvl.cipso[net_lvl]; | |
744 | return 0; | |
745 | } | |
c6387a86 | 746 | return -EPERM; |
446fda4f PM |
747 | } |
748 | ||
749 | return -EINVAL; | |
750 | } | |
751 | ||
752 | /** | |
753 | * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid | |
754 | * @doi_def: the DOI definition | |
755 | * @bitmap: category bitmap | |
756 | * @bitmap_len: bitmap length in bytes | |
757 | * | |
758 | * Description: | |
759 | * Checks the given category bitmap against the given DOI definition and | |
760 | * returns a negative value if any of the categories in the bitmap do not have | |
761 | * a valid mapping and a zero value if all of the categories are valid. | |
762 | * | |
763 | */ | |
764 | static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def, | |
765 | const unsigned char *bitmap, | |
766 | u32 bitmap_len) | |
767 | { | |
768 | int cat = -1; | |
769 | u32 bitmap_len_bits = bitmap_len * 8; | |
044a68ed PM |
770 | u32 cipso_cat_size; |
771 | u32 *cipso_array; | |
446fda4f PM |
772 | |
773 | switch (doi_def->type) { | |
774 | case CIPSO_V4_MAP_PASS: | |
775 | return 0; | |
776 | case CIPSO_V4_MAP_STD: | |
044a68ed PM |
777 | cipso_cat_size = doi_def->map.std->cat.cipso_size; |
778 | cipso_array = doi_def->map.std->cat.cipso; | |
446fda4f PM |
779 | for (;;) { |
780 | cat = cipso_v4_bitmap_walk(bitmap, | |
781 | bitmap_len_bits, | |
782 | cat + 1, | |
783 | 1); | |
784 | if (cat < 0) | |
785 | break; | |
786 | if (cat >= cipso_cat_size || | |
787 | cipso_array[cat] >= CIPSO_V4_INV_CAT) | |
788 | return -EFAULT; | |
789 | } | |
790 | ||
791 | if (cat == -1) | |
792 | return 0; | |
793 | break; | |
794 | } | |
795 | ||
796 | return -EFAULT; | |
797 | } | |
798 | ||
799 | /** | |
800 | * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network | |
801 | * @doi_def: the DOI definition | |
02752760 | 802 | * @secattr: the security attributes |
446fda4f PM |
803 | * @net_cat: the zero'd out category bitmap in network/CIPSO format |
804 | * @net_cat_len: the length of the CIPSO bitmap in bytes | |
805 | * | |
806 | * Description: | |
807 | * Perform a label mapping to translate a local MLS category bitmap to the | |
808 | * correct CIPSO bitmap using the given DOI definition. Returns the minimum | |
809 | * size in bytes of the network bitmap on success, negative values otherwise. | |
810 | * | |
811 | */ | |
812 | static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, | |
02752760 | 813 | const struct netlbl_lsm_secattr *secattr, |
446fda4f PM |
814 | unsigned char *net_cat, |
815 | u32 net_cat_len) | |
816 | { | |
817 | int host_spot = -1; | |
02752760 | 818 | u32 net_spot = CIPSO_V4_INV_CAT; |
446fda4f | 819 | u32 net_spot_max = 0; |
446fda4f | 820 | u32 net_clen_bits = net_cat_len * 8; |
02752760 PM |
821 | u32 host_cat_size = 0; |
822 | u32 *host_cat_array = NULL; | |
446fda4f | 823 | |
02752760 | 824 | if (doi_def->type == CIPSO_V4_MAP_STD) { |
044a68ed PM |
825 | host_cat_size = doi_def->map.std->cat.local_size; |
826 | host_cat_array = doi_def->map.std->cat.local; | |
02752760 PM |
827 | } |
828 | ||
829 | for (;;) { | |
16efd454 | 830 | host_spot = netlbl_secattr_catmap_walk(secattr->attr.mls.cat, |
02752760 PM |
831 | host_spot + 1); |
832 | if (host_spot < 0) | |
833 | break; | |
834 | ||
835 | switch (doi_def->type) { | |
836 | case CIPSO_V4_MAP_PASS: | |
837 | net_spot = host_spot; | |
838 | break; | |
839 | case CIPSO_V4_MAP_STD: | |
446fda4f PM |
840 | if (host_spot >= host_cat_size) |
841 | return -EPERM; | |
446fda4f | 842 | net_spot = host_cat_array[host_spot]; |
9fade4bf PM |
843 | if (net_spot >= CIPSO_V4_INV_CAT) |
844 | return -EPERM; | |
02752760 | 845 | break; |
446fda4f | 846 | } |
02752760 PM |
847 | if (net_spot >= net_clen_bits) |
848 | return -ENOSPC; | |
849 | cipso_v4_bitmap_setbit(net_cat, net_spot, 1); | |
446fda4f | 850 | |
02752760 PM |
851 | if (net_spot > net_spot_max) |
852 | net_spot_max = net_spot; | |
446fda4f PM |
853 | } |
854 | ||
02752760 PM |
855 | if (++net_spot_max % 8) |
856 | return net_spot_max / 8 + 1; | |
857 | return net_spot_max / 8; | |
446fda4f PM |
858 | } |
859 | ||
860 | /** | |
861 | * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host | |
862 | * @doi_def: the DOI definition | |
863 | * @net_cat: the category bitmap in network/CIPSO format | |
864 | * @net_cat_len: the length of the CIPSO bitmap in bytes | |
02752760 | 865 | * @secattr: the security attributes |
446fda4f PM |
866 | * |
867 | * Description: | |
868 | * Perform a label mapping to translate a CIPSO bitmap to the correct local | |
02752760 PM |
869 | * MLS category bitmap using the given DOI definition. Returns zero on |
870 | * success, negative values on failure. | |
446fda4f PM |
871 | * |
872 | */ | |
873 | static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, | |
874 | const unsigned char *net_cat, | |
875 | u32 net_cat_len, | |
02752760 | 876 | struct netlbl_lsm_secattr *secattr) |
446fda4f | 877 | { |
02752760 | 878 | int ret_val; |
446fda4f | 879 | int net_spot = -1; |
02752760 | 880 | u32 host_spot = CIPSO_V4_INV_CAT; |
446fda4f | 881 | u32 net_clen_bits = net_cat_len * 8; |
02752760 PM |
882 | u32 net_cat_size = 0; |
883 | u32 *net_cat_array = NULL; | |
446fda4f | 884 | |
02752760 | 885 | if (doi_def->type == CIPSO_V4_MAP_STD) { |
044a68ed PM |
886 | net_cat_size = doi_def->map.std->cat.cipso_size; |
887 | net_cat_array = doi_def->map.std->cat.cipso; | |
02752760 | 888 | } |
446fda4f | 889 | |
02752760 PM |
890 | for (;;) { |
891 | net_spot = cipso_v4_bitmap_walk(net_cat, | |
892 | net_clen_bits, | |
893 | net_spot + 1, | |
894 | 1); | |
895 | if (net_spot < 0) { | |
896 | if (net_spot == -2) | |
897 | return -EFAULT; | |
898 | return 0; | |
899 | } | |
900 | ||
901 | switch (doi_def->type) { | |
902 | case CIPSO_V4_MAP_PASS: | |
903 | host_spot = net_spot; | |
904 | break; | |
905 | case CIPSO_V4_MAP_STD: | |
906 | if (net_spot >= net_cat_size) | |
907 | return -EPERM; | |
446fda4f | 908 | host_spot = net_cat_array[net_spot]; |
9fade4bf PM |
909 | if (host_spot >= CIPSO_V4_INV_CAT) |
910 | return -EPERM; | |
02752760 | 911 | break; |
446fda4f | 912 | } |
16efd454 | 913 | ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat, |
02752760 PM |
914 | host_spot, |
915 | GFP_ATOMIC); | |
916 | if (ret_val != 0) | |
917 | return ret_val; | |
446fda4f PM |
918 | } |
919 | ||
920 | return -EINVAL; | |
921 | } | |
922 | ||
654bbc2a PM |
923 | /** |
924 | * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid | |
925 | * @doi_def: the DOI definition | |
926 | * @enumcat: category list | |
927 | * @enumcat_len: length of the category list in bytes | |
928 | * | |
929 | * Description: | |
930 | * Checks the given categories against the given DOI definition and returns a | |
931 | * negative value if any of the categories do not have a valid mapping and a | |
932 | * zero value if all of the categories are valid. | |
933 | * | |
934 | */ | |
935 | static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def, | |
936 | const unsigned char *enumcat, | |
937 | u32 enumcat_len) | |
938 | { | |
939 | u16 cat; | |
940 | int cat_prev = -1; | |
941 | u32 iter; | |
942 | ||
943 | if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01) | |
944 | return -EFAULT; | |
945 | ||
946 | for (iter = 0; iter < enumcat_len; iter += 2) { | |
d3e2ce3b | 947 | cat = get_unaligned_be16(&enumcat[iter]); |
654bbc2a PM |
948 | if (cat <= cat_prev) |
949 | return -EFAULT; | |
950 | cat_prev = cat; | |
951 | } | |
952 | ||
953 | return 0; | |
954 | } | |
955 | ||
956 | /** | |
957 | * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network | |
958 | * @doi_def: the DOI definition | |
959 | * @secattr: the security attributes | |
960 | * @net_cat: the zero'd out category list in network/CIPSO format | |
961 | * @net_cat_len: the length of the CIPSO category list in bytes | |
962 | * | |
963 | * Description: | |
964 | * Perform a label mapping to translate a local MLS category bitmap to the | |
965 | * correct CIPSO category list using the given DOI definition. Returns the | |
966 | * size in bytes of the network category bitmap on success, negative values | |
967 | * otherwise. | |
968 | * | |
969 | */ | |
970 | static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def, | |
971 | const struct netlbl_lsm_secattr *secattr, | |
972 | unsigned char *net_cat, | |
973 | u32 net_cat_len) | |
974 | { | |
975 | int cat = -1; | |
976 | u32 cat_iter = 0; | |
977 | ||
978 | for (;;) { | |
16efd454 PM |
979 | cat = netlbl_secattr_catmap_walk(secattr->attr.mls.cat, |
980 | cat + 1); | |
654bbc2a PM |
981 | if (cat < 0) |
982 | break; | |
983 | if ((cat_iter + 2) > net_cat_len) | |
984 | return -ENOSPC; | |
985 | ||
986 | *((__be16 *)&net_cat[cat_iter]) = htons(cat); | |
987 | cat_iter += 2; | |
988 | } | |
989 | ||
990 | return cat_iter; | |
991 | } | |
992 | ||
993 | /** | |
994 | * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host | |
995 | * @doi_def: the DOI definition | |
996 | * @net_cat: the category list in network/CIPSO format | |
997 | * @net_cat_len: the length of the CIPSO bitmap in bytes | |
998 | * @secattr: the security attributes | |
999 | * | |
1000 | * Description: | |
1001 | * Perform a label mapping to translate a CIPSO category list to the correct | |
1002 | * local MLS category bitmap using the given DOI definition. Returns zero on | |
1003 | * success, negative values on failure. | |
1004 | * | |
1005 | */ | |
1006 | static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def, | |
1007 | const unsigned char *net_cat, | |
1008 | u32 net_cat_len, | |
1009 | struct netlbl_lsm_secattr *secattr) | |
1010 | { | |
1011 | int ret_val; | |
1012 | u32 iter; | |
1013 | ||
1014 | for (iter = 0; iter < net_cat_len; iter += 2) { | |
16efd454 | 1015 | ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat, |
d3e2ce3b | 1016 | get_unaligned_be16(&net_cat[iter]), |
50e5d35c | 1017 | GFP_ATOMIC); |
654bbc2a PM |
1018 | if (ret_val != 0) |
1019 | return ret_val; | |
1020 | } | |
1021 | ||
1022 | return 0; | |
1023 | } | |
1024 | ||
484b3669 PM |
1025 | /** |
1026 | * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid | |
1027 | * @doi_def: the DOI definition | |
1028 | * @rngcat: category list | |
1029 | * @rngcat_len: length of the category list in bytes | |
1030 | * | |
1031 | * Description: | |
1032 | * Checks the given categories against the given DOI definition and returns a | |
1033 | * negative value if any of the categories do not have a valid mapping and a | |
1034 | * zero value if all of the categories are valid. | |
1035 | * | |
1036 | */ | |
1037 | static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def, | |
1038 | const unsigned char *rngcat, | |
1039 | u32 rngcat_len) | |
1040 | { | |
1041 | u16 cat_high; | |
1042 | u16 cat_low; | |
1043 | u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1; | |
1044 | u32 iter; | |
1045 | ||
1046 | if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01) | |
1047 | return -EFAULT; | |
1048 | ||
1049 | for (iter = 0; iter < rngcat_len; iter += 4) { | |
d3e2ce3b | 1050 | cat_high = get_unaligned_be16(&rngcat[iter]); |
484b3669 | 1051 | if ((iter + 4) <= rngcat_len) |
d3e2ce3b | 1052 | cat_low = get_unaligned_be16(&rngcat[iter + 2]); |
484b3669 PM |
1053 | else |
1054 | cat_low = 0; | |
1055 | ||
1056 | if (cat_high > cat_prev) | |
1057 | return -EFAULT; | |
1058 | ||
1059 | cat_prev = cat_low; | |
1060 | } | |
1061 | ||
1062 | return 0; | |
1063 | } | |
1064 | ||
1065 | /** | |
1066 | * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network | |
1067 | * @doi_def: the DOI definition | |
1068 | * @secattr: the security attributes | |
1069 | * @net_cat: the zero'd out category list in network/CIPSO format | |
1070 | * @net_cat_len: the length of the CIPSO category list in bytes | |
1071 | * | |
1072 | * Description: | |
1073 | * Perform a label mapping to translate a local MLS category bitmap to the | |
1074 | * correct CIPSO category list using the given DOI definition. Returns the | |
1075 | * size in bytes of the network category bitmap on success, negative values | |
1076 | * otherwise. | |
1077 | * | |
1078 | */ | |
1079 | static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def, | |
1080 | const struct netlbl_lsm_secattr *secattr, | |
1081 | unsigned char *net_cat, | |
1082 | u32 net_cat_len) | |
1083 | { | |
484b3669 | 1084 | int iter = -1; |
f998e8cb | 1085 | u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2]; |
484b3669 PM |
1086 | u32 array_cnt = 0; |
1087 | u32 cat_size = 0; | |
1088 | ||
f998e8cb | 1089 | /* make sure we don't overflow the 'array[]' variable */ |
128c6b6c PM |
1090 | if (net_cat_len > |
1091 | (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN)) | |
1092 | return -ENOSPC; | |
484b3669 PM |
1093 | |
1094 | for (;;) { | |
16efd454 PM |
1095 | iter = netlbl_secattr_catmap_walk(secattr->attr.mls.cat, |
1096 | iter + 1); | |
484b3669 PM |
1097 | if (iter < 0) |
1098 | break; | |
1099 | cat_size += (iter == 0 ? 0 : sizeof(u16)); | |
1100 | if (cat_size > net_cat_len) | |
1101 | return -ENOSPC; | |
1102 | array[array_cnt++] = iter; | |
1103 | ||
16efd454 PM |
1104 | iter = netlbl_secattr_catmap_walk_rng(secattr->attr.mls.cat, |
1105 | iter); | |
484b3669 PM |
1106 | if (iter < 0) |
1107 | return -EFAULT; | |
1108 | cat_size += sizeof(u16); | |
1109 | if (cat_size > net_cat_len) | |
1110 | return -ENOSPC; | |
1111 | array[array_cnt++] = iter; | |
1112 | } | |
1113 | ||
1114 | for (iter = 0; array_cnt > 0;) { | |
1115 | *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]); | |
1116 | iter += 2; | |
1117 | array_cnt--; | |
1118 | if (array[array_cnt] != 0) { | |
1119 | *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]); | |
1120 | iter += 2; | |
1121 | } | |
1122 | } | |
1123 | ||
1124 | return cat_size; | |
1125 | } | |
1126 | ||
1127 | /** | |
1128 | * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host | |
1129 | * @doi_def: the DOI definition | |
1130 | * @net_cat: the category list in network/CIPSO format | |
1131 | * @net_cat_len: the length of the CIPSO bitmap in bytes | |
1132 | * @secattr: the security attributes | |
1133 | * | |
1134 | * Description: | |
1135 | * Perform a label mapping to translate a CIPSO category list to the correct | |
1136 | * local MLS category bitmap using the given DOI definition. Returns zero on | |
1137 | * success, negative values on failure. | |
1138 | * | |
1139 | */ | |
1140 | static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def, | |
1141 | const unsigned char *net_cat, | |
1142 | u32 net_cat_len, | |
1143 | struct netlbl_lsm_secattr *secattr) | |
1144 | { | |
1145 | int ret_val; | |
1146 | u32 net_iter; | |
1147 | u16 cat_low; | |
1148 | u16 cat_high; | |
1149 | ||
132adf54 | 1150 | for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) { |
d3e2ce3b | 1151 | cat_high = get_unaligned_be16(&net_cat[net_iter]); |
484b3669 | 1152 | if ((net_iter + 4) <= net_cat_len) |
d3e2ce3b | 1153 | cat_low = get_unaligned_be16(&net_cat[net_iter + 2]); |
484b3669 PM |
1154 | else |
1155 | cat_low = 0; | |
1156 | ||
16efd454 | 1157 | ret_val = netlbl_secattr_catmap_setrng(secattr->attr.mls.cat, |
484b3669 PM |
1158 | cat_low, |
1159 | cat_high, | |
1160 | GFP_ATOMIC); | |
1161 | if (ret_val != 0) | |
1162 | return ret_val; | |
1163 | } | |
1164 | ||
1165 | return 0; | |
1166 | } | |
1167 | ||
446fda4f PM |
1168 | /* |
1169 | * Protocol Handling Functions | |
1170 | */ | |
1171 | ||
446fda4f PM |
1172 | /** |
1173 | * cipso_v4_gentag_hdr - Generate a CIPSO option header | |
1174 | * @doi_def: the DOI definition | |
91b1ed0a | 1175 | * @len: the total tag length in bytes, not including this header |
446fda4f PM |
1176 | * @buf: the CIPSO option buffer |
1177 | * | |
1178 | * Description: | |
91b1ed0a | 1179 | * Write a CIPSO header into the beginning of @buffer. |
446fda4f PM |
1180 | * |
1181 | */ | |
91b1ed0a PM |
1182 | static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def, |
1183 | unsigned char *buf, | |
1184 | u32 len) | |
446fda4f | 1185 | { |
446fda4f PM |
1186 | buf[0] = IPOPT_CIPSO; |
1187 | buf[1] = CIPSO_V4_HDR_LEN + len; | |
714e85be | 1188 | *(__be32 *)&buf[2] = htonl(doi_def->doi); |
446fda4f PM |
1189 | } |
1190 | ||
446fda4f PM |
1191 | /** |
1192 | * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1) | |
1193 | * @doi_def: the DOI definition | |
1194 | * @secattr: the security attributes | |
1195 | * @buffer: the option buffer | |
1196 | * @buffer_len: length of buffer in bytes | |
1197 | * | |
1198 | * Description: | |
1199 | * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The | |
1200 | * actual buffer length may be larger than the indicated size due to | |
91b1ed0a PM |
1201 | * translation between host and network category bitmaps. Returns the size of |
1202 | * the tag on success, negative values on failure. | |
446fda4f PM |
1203 | * |
1204 | */ | |
1205 | static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, | |
1206 | const struct netlbl_lsm_secattr *secattr, | |
91b1ed0a PM |
1207 | unsigned char *buffer, |
1208 | u32 buffer_len) | |
446fda4f | 1209 | { |
701a90ba | 1210 | int ret_val; |
91b1ed0a | 1211 | u32 tag_len; |
446fda4f PM |
1212 | u32 level; |
1213 | ||
701a90ba PM |
1214 | if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0) |
1215 | return -EPERM; | |
1216 | ||
16efd454 PM |
1217 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1218 | secattr->attr.mls.lvl, | |
1219 | &level); | |
91b1ed0a PM |
1220 | if (ret_val != 0) |
1221 | return ret_val; | |
446fda4f | 1222 | |
91b1ed0a | 1223 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
446fda4f | 1224 | ret_val = cipso_v4_map_cat_rbm_hton(doi_def, |
02752760 | 1225 | secattr, |
91b1ed0a PM |
1226 | &buffer[4], |
1227 | buffer_len - 4); | |
446fda4f | 1228 | if (ret_val < 0) |
91b1ed0a | 1229 | return ret_val; |
446fda4f PM |
1230 | |
1231 | /* This will send packets using the "optimized" format when | |
1232 | * possibile as specified in section 3.4.2.6 of the | |
1233 | * CIPSO draft. */ | |
701a90ba | 1234 | if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10) |
91b1ed0a | 1235 | tag_len = 14; |
701a90ba | 1236 | else |
91b1ed0a PM |
1237 | tag_len = 4 + ret_val; |
1238 | } else | |
1239 | tag_len = 4; | |
446fda4f | 1240 | |
91b1ed0a PM |
1241 | buffer[0] = 0x01; |
1242 | buffer[1] = tag_len; | |
1243 | buffer[3] = level; | |
446fda4f | 1244 | |
91b1ed0a | 1245 | return tag_len; |
446fda4f PM |
1246 | } |
1247 | ||
1248 | /** | |
1249 | * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag | |
1250 | * @doi_def: the DOI definition | |
1251 | * @tag: the CIPSO tag | |
1252 | * @secattr: the security attributes | |
1253 | * | |
1254 | * Description: | |
1255 | * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security | |
1256 | * attributes in @secattr. Return zero on success, negatives values on | |
1257 | * failure. | |
1258 | * | |
1259 | */ | |
1260 | static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, | |
1261 | const unsigned char *tag, | |
1262 | struct netlbl_lsm_secattr *secattr) | |
1263 | { | |
1264 | int ret_val; | |
1265 | u8 tag_len = tag[1]; | |
1266 | u32 level; | |
1267 | ||
1268 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); | |
1269 | if (ret_val != 0) | |
1270 | return ret_val; | |
16efd454 | 1271 | secattr->attr.mls.lvl = level; |
701a90ba | 1272 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
446fda4f PM |
1273 | |
1274 | if (tag_len > 4) { | |
16efd454 PM |
1275 | secattr->attr.mls.cat = |
1276 | netlbl_secattr_catmap_alloc(GFP_ATOMIC); | |
1277 | if (secattr->attr.mls.cat == NULL) | |
446fda4f PM |
1278 | return -ENOMEM; |
1279 | ||
1280 | ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def, | |
1281 | &tag[4], | |
1282 | tag_len - 4, | |
02752760 PM |
1283 | secattr); |
1284 | if (ret_val != 0) { | |
16efd454 | 1285 | netlbl_secattr_catmap_free(secattr->attr.mls.cat); |
446fda4f PM |
1286 | return ret_val; |
1287 | } | |
02752760 PM |
1288 | |
1289 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; | |
446fda4f PM |
1290 | } |
1291 | ||
1292 | return 0; | |
1293 | } | |
1294 | ||
654bbc2a PM |
1295 | /** |
1296 | * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2) | |
1297 | * @doi_def: the DOI definition | |
1298 | * @secattr: the security attributes | |
1299 | * @buffer: the option buffer | |
1300 | * @buffer_len: length of buffer in bytes | |
1301 | * | |
1302 | * Description: | |
1303 | * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the | |
1304 | * size of the tag on success, negative values on failure. | |
1305 | * | |
1306 | */ | |
1307 | static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, | |
1308 | const struct netlbl_lsm_secattr *secattr, | |
1309 | unsigned char *buffer, | |
1310 | u32 buffer_len) | |
1311 | { | |
1312 | int ret_val; | |
1313 | u32 tag_len; | |
1314 | u32 level; | |
1315 | ||
1316 | if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) | |
1317 | return -EPERM; | |
1318 | ||
16efd454 PM |
1319 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1320 | secattr->attr.mls.lvl, | |
1321 | &level); | |
654bbc2a PM |
1322 | if (ret_val != 0) |
1323 | return ret_val; | |
1324 | ||
1325 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { | |
1326 | ret_val = cipso_v4_map_cat_enum_hton(doi_def, | |
1327 | secattr, | |
1328 | &buffer[4], | |
1329 | buffer_len - 4); | |
1330 | if (ret_val < 0) | |
1331 | return ret_val; | |
1332 | ||
1333 | tag_len = 4 + ret_val; | |
1334 | } else | |
1335 | tag_len = 4; | |
1336 | ||
1337 | buffer[0] = 0x02; | |
1338 | buffer[1] = tag_len; | |
1339 | buffer[3] = level; | |
1340 | ||
1341 | return tag_len; | |
1342 | } | |
1343 | ||
1344 | /** | |
1345 | * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag | |
1346 | * @doi_def: the DOI definition | |
1347 | * @tag: the CIPSO tag | |
1348 | * @secattr: the security attributes | |
1349 | * | |
1350 | * Description: | |
1351 | * Parse a CIPSO enumerated tag (tag type #2) and return the security | |
1352 | * attributes in @secattr. Return zero on success, negatives values on | |
1353 | * failure. | |
1354 | * | |
1355 | */ | |
1356 | static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, | |
1357 | const unsigned char *tag, | |
1358 | struct netlbl_lsm_secattr *secattr) | |
1359 | { | |
1360 | int ret_val; | |
1361 | u8 tag_len = tag[1]; | |
1362 | u32 level; | |
1363 | ||
1364 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); | |
1365 | if (ret_val != 0) | |
1366 | return ret_val; | |
16efd454 | 1367 | secattr->attr.mls.lvl = level; |
654bbc2a PM |
1368 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
1369 | ||
1370 | if (tag_len > 4) { | |
16efd454 PM |
1371 | secattr->attr.mls.cat = |
1372 | netlbl_secattr_catmap_alloc(GFP_ATOMIC); | |
1373 | if (secattr->attr.mls.cat == NULL) | |
654bbc2a PM |
1374 | return -ENOMEM; |
1375 | ||
1376 | ret_val = cipso_v4_map_cat_enum_ntoh(doi_def, | |
1377 | &tag[4], | |
1378 | tag_len - 4, | |
1379 | secattr); | |
1380 | if (ret_val != 0) { | |
16efd454 | 1381 | netlbl_secattr_catmap_free(secattr->attr.mls.cat); |
654bbc2a PM |
1382 | return ret_val; |
1383 | } | |
1384 | ||
1385 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; | |
1386 | } | |
1387 | ||
1388 | return 0; | |
1389 | } | |
1390 | ||
484b3669 PM |
1391 | /** |
1392 | * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5) | |
1393 | * @doi_def: the DOI definition | |
1394 | * @secattr: the security attributes | |
1395 | * @buffer: the option buffer | |
1396 | * @buffer_len: length of buffer in bytes | |
1397 | * | |
1398 | * Description: | |
1399 | * Generate a CIPSO option using the ranged tag, tag type #5. Returns the | |
1400 | * size of the tag on success, negative values on failure. | |
1401 | * | |
1402 | */ | |
1403 | static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def, | |
1404 | const struct netlbl_lsm_secattr *secattr, | |
1405 | unsigned char *buffer, | |
1406 | u32 buffer_len) | |
1407 | { | |
1408 | int ret_val; | |
1409 | u32 tag_len; | |
1410 | u32 level; | |
1411 | ||
1412 | if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) | |
1413 | return -EPERM; | |
1414 | ||
16efd454 PM |
1415 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1416 | secattr->attr.mls.lvl, | |
1417 | &level); | |
484b3669 PM |
1418 | if (ret_val != 0) |
1419 | return ret_val; | |
1420 | ||
1421 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { | |
1422 | ret_val = cipso_v4_map_cat_rng_hton(doi_def, | |
1423 | secattr, | |
1424 | &buffer[4], | |
1425 | buffer_len - 4); | |
1426 | if (ret_val < 0) | |
1427 | return ret_val; | |
1428 | ||
1429 | tag_len = 4 + ret_val; | |
1430 | } else | |
1431 | tag_len = 4; | |
1432 | ||
1433 | buffer[0] = 0x05; | |
1434 | buffer[1] = tag_len; | |
1435 | buffer[3] = level; | |
1436 | ||
1437 | return tag_len; | |
1438 | } | |
1439 | ||
1440 | /** | |
1441 | * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag | |
1442 | * @doi_def: the DOI definition | |
1443 | * @tag: the CIPSO tag | |
1444 | * @secattr: the security attributes | |
1445 | * | |
1446 | * Description: | |
1447 | * Parse a CIPSO ranged tag (tag type #5) and return the security attributes | |
1448 | * in @secattr. Return zero on success, negatives values on failure. | |
1449 | * | |
1450 | */ | |
1451 | static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, | |
1452 | const unsigned char *tag, | |
1453 | struct netlbl_lsm_secattr *secattr) | |
1454 | { | |
1455 | int ret_val; | |
1456 | u8 tag_len = tag[1]; | |
1457 | u32 level; | |
1458 | ||
1459 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); | |
1460 | if (ret_val != 0) | |
1461 | return ret_val; | |
16efd454 | 1462 | secattr->attr.mls.lvl = level; |
484b3669 PM |
1463 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
1464 | ||
1465 | if (tag_len > 4) { | |
16efd454 PM |
1466 | secattr->attr.mls.cat = |
1467 | netlbl_secattr_catmap_alloc(GFP_ATOMIC); | |
1468 | if (secattr->attr.mls.cat == NULL) | |
484b3669 PM |
1469 | return -ENOMEM; |
1470 | ||
1471 | ret_val = cipso_v4_map_cat_rng_ntoh(doi_def, | |
1472 | &tag[4], | |
1473 | tag_len - 4, | |
1474 | secattr); | |
1475 | if (ret_val != 0) { | |
16efd454 | 1476 | netlbl_secattr_catmap_free(secattr->attr.mls.cat); |
484b3669 PM |
1477 | return ret_val; |
1478 | } | |
1479 | ||
1480 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; | |
1481 | } | |
1482 | ||
1483 | return 0; | |
1484 | } | |
1485 | ||
446fda4f PM |
1486 | /** |
1487 | * cipso_v4_validate - Validate a CIPSO option | |
1488 | * @option: the start of the option, on error it is set to point to the error | |
1489 | * | |
1490 | * Description: | |
1491 | * This routine is called to validate a CIPSO option, it checks all of the | |
1492 | * fields to ensure that they are at least valid, see the draft snippet below | |
1493 | * for details. If the option is valid then a zero value is returned and | |
1494 | * the value of @option is unchanged. If the option is invalid then a | |
1495 | * non-zero value is returned and @option is adjusted to point to the | |
1496 | * offending portion of the option. From the IETF draft ... | |
1497 | * | |
1498 | * "If any field within the CIPSO options, such as the DOI identifier, is not | |
1499 | * recognized the IP datagram is discarded and an ICMP 'parameter problem' | |
1500 | * (type 12) is generated and returned. The ICMP code field is set to 'bad | |
1501 | * parameter' (code 0) and the pointer is set to the start of the CIPSO field | |
1502 | * that is unrecognized." | |
1503 | * | |
1504 | */ | |
1505 | int cipso_v4_validate(unsigned char **option) | |
1506 | { | |
1507 | unsigned char *opt = *option; | |
1508 | unsigned char *tag; | |
1509 | unsigned char opt_iter; | |
1510 | unsigned char err_offset = 0; | |
1511 | u8 opt_len; | |
1512 | u8 tag_len; | |
1513 | struct cipso_v4_doi *doi_def = NULL; | |
1514 | u32 tag_iter; | |
1515 | ||
1516 | /* caller already checks for length values that are too large */ | |
1517 | opt_len = opt[1]; | |
1518 | if (opt_len < 8) { | |
1519 | err_offset = 1; | |
1520 | goto validate_return; | |
1521 | } | |
1522 | ||
1523 | rcu_read_lock(); | |
d3e2ce3b | 1524 | doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2])); |
446fda4f PM |
1525 | if (doi_def == NULL) { |
1526 | err_offset = 2; | |
1527 | goto validate_return_locked; | |
1528 | } | |
1529 | ||
1530 | opt_iter = 6; | |
1531 | tag = opt + opt_iter; | |
1532 | while (opt_iter < opt_len) { | |
1533 | for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];) | |
1534 | if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID || | |
1535 | ++tag_iter == CIPSO_V4_TAG_MAXCNT) { | |
1536 | err_offset = opt_iter; | |
1537 | goto validate_return_locked; | |
1538 | } | |
1539 | ||
1540 | tag_len = tag[1]; | |
1541 | if (tag_len > (opt_len - opt_iter)) { | |
1542 | err_offset = opt_iter + 1; | |
1543 | goto validate_return_locked; | |
1544 | } | |
1545 | ||
1546 | switch (tag[0]) { | |
1547 | case CIPSO_V4_TAG_RBITMAP: | |
1548 | if (tag_len < 4) { | |
1549 | err_offset = opt_iter + 1; | |
1550 | goto validate_return_locked; | |
1551 | } | |
1552 | ||
1553 | /* We are already going to do all the verification | |
1554 | * necessary at the socket layer so from our point of | |
1555 | * view it is safe to turn these checks off (and less | |
1556 | * work), however, the CIPSO draft says we should do | |
1557 | * all the CIPSO validations here but it doesn't | |
1558 | * really specify _exactly_ what we need to validate | |
1559 | * ... so, just make it a sysctl tunable. */ | |
1560 | if (cipso_v4_rbm_strictvalid) { | |
1561 | if (cipso_v4_map_lvl_valid(doi_def, | |
1562 | tag[3]) < 0) { | |
1563 | err_offset = opt_iter + 3; | |
1564 | goto validate_return_locked; | |
1565 | } | |
1566 | if (tag_len > 4 && | |
1567 | cipso_v4_map_cat_rbm_valid(doi_def, | |
1568 | &tag[4], | |
1569 | tag_len - 4) < 0) { | |
1570 | err_offset = opt_iter + 4; | |
1571 | goto validate_return_locked; | |
1572 | } | |
1573 | } | |
1574 | break; | |
654bbc2a PM |
1575 | case CIPSO_V4_TAG_ENUM: |
1576 | if (tag_len < 4) { | |
1577 | err_offset = opt_iter + 1; | |
1578 | goto validate_return_locked; | |
1579 | } | |
1580 | ||
1581 | if (cipso_v4_map_lvl_valid(doi_def, | |
1582 | tag[3]) < 0) { | |
1583 | err_offset = opt_iter + 3; | |
1584 | goto validate_return_locked; | |
1585 | } | |
1586 | if (tag_len > 4 && | |
1587 | cipso_v4_map_cat_enum_valid(doi_def, | |
1588 | &tag[4], | |
1589 | tag_len - 4) < 0) { | |
1590 | err_offset = opt_iter + 4; | |
1591 | goto validate_return_locked; | |
1592 | } | |
1593 | break; | |
484b3669 PM |
1594 | case CIPSO_V4_TAG_RANGE: |
1595 | if (tag_len < 4) { | |
1596 | err_offset = opt_iter + 1; | |
1597 | goto validate_return_locked; | |
1598 | } | |
1599 | ||
1600 | if (cipso_v4_map_lvl_valid(doi_def, | |
1601 | tag[3]) < 0) { | |
1602 | err_offset = opt_iter + 3; | |
1603 | goto validate_return_locked; | |
1604 | } | |
1605 | if (tag_len > 4 && | |
1606 | cipso_v4_map_cat_rng_valid(doi_def, | |
1607 | &tag[4], | |
1608 | tag_len - 4) < 0) { | |
1609 | err_offset = opt_iter + 4; | |
1610 | goto validate_return_locked; | |
1611 | } | |
1612 | break; | |
446fda4f PM |
1613 | default: |
1614 | err_offset = opt_iter; | |
1615 | goto validate_return_locked; | |
1616 | } | |
1617 | ||
1618 | tag += tag_len; | |
1619 | opt_iter += tag_len; | |
1620 | } | |
1621 | ||
1622 | validate_return_locked: | |
1623 | rcu_read_unlock(); | |
1624 | validate_return: | |
1625 | *option = opt + err_offset; | |
1626 | return err_offset; | |
1627 | } | |
1628 | ||
1629 | /** | |
1630 | * cipso_v4_error - Send the correct reponse for a bad packet | |
1631 | * @skb: the packet | |
1632 | * @error: the error code | |
1633 | * @gateway: CIPSO gateway flag | |
1634 | * | |
1635 | * Description: | |
1636 | * Based on the error code given in @error, send an ICMP error message back to | |
1637 | * the originating host. From the IETF draft ... | |
1638 | * | |
1639 | * "If the contents of the CIPSO [option] are valid but the security label is | |
1640 | * outside of the configured host or port label range, the datagram is | |
1641 | * discarded and an ICMP 'destination unreachable' (type 3) is generated and | |
1642 | * returned. The code field of the ICMP is set to 'communication with | |
1643 | * destination network administratively prohibited' (code 9) or to | |
1644 | * 'communication with destination host administratively prohibited' | |
1645 | * (code 10). The value of the code is dependent on whether the originator | |
1646 | * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The | |
1647 | * recipient of the ICMP message MUST be able to handle either value. The | |
1648 | * same procedure is performed if a CIPSO [option] can not be added to an | |
1649 | * IP packet because it is too large to fit in the IP options area." | |
1650 | * | |
1651 | * "If the error is triggered by receipt of an ICMP message, the message is | |
1652 | * discarded and no response is permitted (consistent with general ICMP | |
1653 | * processing rules)." | |
1654 | * | |
1655 | */ | |
1656 | void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) | |
1657 | { | |
eddc9ec5 | 1658 | if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES) |
446fda4f PM |
1659 | return; |
1660 | ||
1661 | if (gateway) | |
1662 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0); | |
1663 | else | |
1664 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0); | |
1665 | } | |
1666 | ||
1667 | /** | |
948bf85c PM |
1668 | * cipso_v4_genopt - Generate a CIPSO option |
1669 | * @buf: the option buffer | |
1670 | * @buf_len: the size of opt_buf | |
446fda4f | 1671 | * @doi_def: the CIPSO DOI to use |
948bf85c | 1672 | * @secattr: the security attributes |
446fda4f PM |
1673 | * |
1674 | * Description: | |
948bf85c PM |
1675 | * Generate a CIPSO option using the DOI definition and security attributes |
1676 | * passed to the function. Returns the length of the option on success and | |
1677 | * negative values on failure. | |
446fda4f PM |
1678 | * |
1679 | */ | |
948bf85c PM |
1680 | static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, |
1681 | const struct cipso_v4_doi *doi_def, | |
1682 | const struct netlbl_lsm_secattr *secattr) | |
446fda4f | 1683 | { |
948bf85c | 1684 | int ret_val; |
446fda4f | 1685 | u32 iter; |
446fda4f | 1686 | |
948bf85c PM |
1687 | if (buf_len <= CIPSO_V4_HDR_LEN) |
1688 | return -ENOSPC; | |
91b1ed0a | 1689 | |
446fda4f PM |
1690 | /* XXX - This code assumes only one tag per CIPSO option which isn't |
1691 | * really a good assumption to make but since we only support the MAC | |
1692 | * tags right now it is a safe assumption. */ | |
1693 | iter = 0; | |
1694 | do { | |
91b1ed0a | 1695 | memset(buf, 0, buf_len); |
446fda4f PM |
1696 | switch (doi_def->tags[iter]) { |
1697 | case CIPSO_V4_TAG_RBITMAP: | |
1698 | ret_val = cipso_v4_gentag_rbm(doi_def, | |
91b1ed0a PM |
1699 | secattr, |
1700 | &buf[CIPSO_V4_HDR_LEN], | |
1701 | buf_len - CIPSO_V4_HDR_LEN); | |
446fda4f | 1702 | break; |
654bbc2a PM |
1703 | case CIPSO_V4_TAG_ENUM: |
1704 | ret_val = cipso_v4_gentag_enum(doi_def, | |
1705 | secattr, | |
1706 | &buf[CIPSO_V4_HDR_LEN], | |
1707 | buf_len - CIPSO_V4_HDR_LEN); | |
1708 | break; | |
484b3669 PM |
1709 | case CIPSO_V4_TAG_RANGE: |
1710 | ret_val = cipso_v4_gentag_rng(doi_def, | |
1711 | secattr, | |
1712 | &buf[CIPSO_V4_HDR_LEN], | |
1713 | buf_len - CIPSO_V4_HDR_LEN); | |
1714 | break; | |
446fda4f | 1715 | default: |
948bf85c | 1716 | return -EPERM; |
446fda4f PM |
1717 | } |
1718 | ||
1719 | iter++; | |
91b1ed0a | 1720 | } while (ret_val < 0 && |
446fda4f PM |
1721 | iter < CIPSO_V4_TAG_MAXCNT && |
1722 | doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); | |
91b1ed0a | 1723 | if (ret_val < 0) |
948bf85c | 1724 | return ret_val; |
91b1ed0a | 1725 | cipso_v4_gentag_hdr(doi_def, buf, ret_val); |
948bf85c PM |
1726 | return CIPSO_V4_HDR_LEN + ret_val; |
1727 | } | |
1728 | ||
1729 | /** | |
1730 | * cipso_v4_sock_setattr - Add a CIPSO option to a socket | |
1731 | * @sk: the socket | |
1732 | * @doi_def: the CIPSO DOI to use | |
1733 | * @secattr: the specific security attributes of the socket | |
1734 | * | |
1735 | * Description: | |
1736 | * Set the CIPSO option on the given socket using the DOI definition and | |
1737 | * security attributes passed to the function. This function requires | |
1738 | * exclusive access to @sk, which means it either needs to be in the | |
1739 | * process of being created or locked. Returns zero on success and negative | |
1740 | * values on failure. | |
1741 | * | |
1742 | */ | |
1743 | int cipso_v4_sock_setattr(struct sock *sk, | |
1744 | const struct cipso_v4_doi *doi_def, | |
1745 | const struct netlbl_lsm_secattr *secattr) | |
1746 | { | |
1747 | int ret_val = -EPERM; | |
1748 | unsigned char *buf = NULL; | |
1749 | u32 buf_len; | |
1750 | u32 opt_len; | |
1751 | struct ip_options *opt = NULL; | |
1752 | struct inet_sock *sk_inet; | |
1753 | struct inet_connection_sock *sk_conn; | |
1754 | ||
1755 | /* In the case of sock_create_lite(), the sock->sk field is not | |
1756 | * defined yet but it is not a problem as the only users of these | |
1757 | * "lite" PF_INET sockets are functions which do an accept() call | |
1758 | * afterwards so we will label the socket as part of the accept(). */ | |
1759 | if (sk == NULL) | |
1760 | return 0; | |
1761 | ||
1762 | /* We allocate the maximum CIPSO option size here so we are probably | |
1763 | * being a little wasteful, but it makes our life _much_ easier later | |
1764 | * on and after all we are only talking about 40 bytes. */ | |
1765 | buf_len = CIPSO_V4_OPT_LEN_MAX; | |
1766 | buf = kmalloc(buf_len, GFP_ATOMIC); | |
1767 | if (buf == NULL) { | |
1768 | ret_val = -ENOMEM; | |
1769 | goto socket_setattr_failure; | |
1770 | } | |
1771 | ||
1772 | ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); | |
1773 | if (ret_val < 0) | |
1774 | goto socket_setattr_failure; | |
1775 | buf_len = ret_val; | |
446fda4f PM |
1776 | |
1777 | /* We can't use ip_options_get() directly because it makes a call to | |
1778 | * ip_options_get_alloc() which allocates memory with GFP_KERNEL and | |
f8687afe PM |
1779 | * we won't always have CAP_NET_RAW even though we _always_ want to |
1780 | * set the IPOPT_CIPSO option. */ | |
446fda4f PM |
1781 | opt_len = (buf_len + 3) & ~3; |
1782 | opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); | |
1783 | if (opt == NULL) { | |
1784 | ret_val = -ENOMEM; | |
1785 | goto socket_setattr_failure; | |
1786 | } | |
1787 | memcpy(opt->__data, buf, buf_len); | |
1788 | opt->optlen = opt_len; | |
f8687afe | 1789 | opt->cipso = sizeof(struct iphdr); |
446fda4f PM |
1790 | kfree(buf); |
1791 | buf = NULL; | |
446fda4f PM |
1792 | |
1793 | sk_inet = inet_sk(sk); | |
1794 | if (sk_inet->is_icsk) { | |
1795 | sk_conn = inet_csk(sk); | |
1796 | if (sk_inet->opt) | |
1797 | sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen; | |
1798 | sk_conn->icsk_ext_hdr_len += opt->optlen; | |
1799 | sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); | |
1800 | } | |
1801 | opt = xchg(&sk_inet->opt, opt); | |
1802 | kfree(opt); | |
1803 | ||
1804 | return 0; | |
1805 | ||
1806 | socket_setattr_failure: | |
1807 | kfree(buf); | |
1808 | kfree(opt); | |
1809 | return ret_val; | |
1810 | } | |
1811 | ||
1812 | /** | |
63d804ea PM |
1813 | * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions |
1814 | * @cipso: the CIPSO v4 option | |
446fda4f PM |
1815 | * @secattr: the security attributes |
1816 | * | |
1817 | * Description: | |
63d804ea PM |
1818 | * Inspect @cipso and return the security attributes in @secattr. Returns zero |
1819 | * on success and negative values on failure. | |
446fda4f PM |
1820 | * |
1821 | */ | |
63d804ea PM |
1822 | static int cipso_v4_getattr(const unsigned char *cipso, |
1823 | struct netlbl_lsm_secattr *secattr) | |
446fda4f PM |
1824 | { |
1825 | int ret_val = -ENOMSG; | |
446fda4f PM |
1826 | u32 doi; |
1827 | struct cipso_v4_doi *doi_def; | |
1828 | ||
63d804ea PM |
1829 | if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0) |
1830 | return 0; | |
446fda4f | 1831 | |
d3e2ce3b | 1832 | doi = get_unaligned_be32(&cipso[2]); |
446fda4f | 1833 | rcu_read_lock(); |
9bb5fd2b | 1834 | doi_def = cipso_v4_doi_search(doi); |
63d804ea PM |
1835 | if (doi_def == NULL) |
1836 | goto getattr_return; | |
91b1ed0a PM |
1837 | /* XXX - This code assumes only one tag per CIPSO option which isn't |
1838 | * really a good assumption to make but since we only support the MAC | |
1839 | * tags right now it is a safe assumption. */ | |
63d804ea | 1840 | switch (cipso[6]) { |
446fda4f | 1841 | case CIPSO_V4_TAG_RBITMAP: |
63d804ea | 1842 | ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr); |
446fda4f | 1843 | break; |
654bbc2a | 1844 | case CIPSO_V4_TAG_ENUM: |
63d804ea | 1845 | ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr); |
654bbc2a | 1846 | break; |
484b3669 | 1847 | case CIPSO_V4_TAG_RANGE: |
63d804ea | 1848 | ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr); |
484b3669 | 1849 | break; |
446fda4f | 1850 | } |
16efd454 PM |
1851 | if (ret_val == 0) |
1852 | secattr->type = NETLBL_NLTYPE_CIPSOV4; | |
446fda4f | 1853 | |
63d804ea PM |
1854 | getattr_return: |
1855 | rcu_read_unlock(); | |
14a72f53 PM |
1856 | return ret_val; |
1857 | } | |
1858 | ||
63d804ea PM |
1859 | /** |
1860 | * cipso_v4_sock_getattr - Get the security attributes from a sock | |
1861 | * @sk: the sock | |
1862 | * @secattr: the security attributes | |
1863 | * | |
1864 | * Description: | |
1865 | * Query @sk to see if there is a CIPSO option attached to the sock and if | |
1866 | * there is return the CIPSO security attributes in @secattr. This function | |
1867 | * requires that @sk be locked, or privately held, but it does not do any | |
1868 | * locking itself. Returns zero on success and negative values on failure. | |
1869 | * | |
1870 | */ | |
1871 | int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) | |
1872 | { | |
1873 | struct ip_options *opt; | |
1874 | ||
1875 | opt = inet_sk(sk)->opt; | |
1876 | if (opt == NULL || opt->cipso == 0) | |
1877 | return -ENOMSG; | |
1878 | ||
1879 | return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr), | |
1880 | secattr); | |
1881 | } | |
1882 | ||
948bf85c PM |
1883 | /** |
1884 | * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet | |
1885 | * @skb: the packet | |
1886 | * @secattr: the security attributes | |
1887 | * | |
1888 | * Description: | |
1889 | * Set the CIPSO option on the given packet based on the security attributes. | |
1890 | * Returns a pointer to the IP header on success and NULL on failure. | |
1891 | * | |
1892 | */ | |
1893 | int cipso_v4_skbuff_setattr(struct sk_buff *skb, | |
1894 | const struct cipso_v4_doi *doi_def, | |
1895 | const struct netlbl_lsm_secattr *secattr) | |
1896 | { | |
1897 | int ret_val; | |
1898 | struct iphdr *iph; | |
1899 | struct ip_options *opt = &IPCB(skb)->opt; | |
1900 | unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; | |
1901 | u32 buf_len = CIPSO_V4_OPT_LEN_MAX; | |
1902 | u32 opt_len; | |
1903 | int len_delta; | |
1904 | ||
1905 | buf_len = cipso_v4_genopt(buf, buf_len, doi_def, secattr); | |
1906 | if (buf_len < 0) | |
1907 | return buf_len; | |
1908 | opt_len = (buf_len + 3) & ~3; | |
1909 | ||
1910 | /* we overwrite any existing options to ensure that we have enough | |
1911 | * room for the CIPSO option, the reason is that we _need_ to guarantee | |
1912 | * that the security label is applied to the packet - we do the same | |
1913 | * thing when using the socket options and it hasn't caused a problem, | |
1914 | * if we need to we can always revisit this choice later */ | |
1915 | ||
1916 | len_delta = opt_len - opt->optlen; | |
1917 | /* if we don't ensure enough headroom we could panic on the skb_push() | |
1918 | * call below so make sure we have enough, we are also "mangling" the | |
1919 | * packet so we should probably do a copy-on-write call anyway */ | |
1920 | ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); | |
1921 | if (ret_val < 0) | |
1922 | return ret_val; | |
1923 | ||
1924 | if (len_delta > 0) { | |
1925 | /* we assume that the header + opt->optlen have already been | |
1926 | * "pushed" in ip_options_build() or similar */ | |
1927 | iph = ip_hdr(skb); | |
1928 | skb_push(skb, len_delta); | |
1929 | memmove((char *)iph - len_delta, iph, iph->ihl << 2); | |
1930 | skb_reset_network_header(skb); | |
1931 | iph = ip_hdr(skb); | |
1932 | } else if (len_delta < 0) { | |
1933 | iph = ip_hdr(skb); | |
1934 | memset(iph + 1, IPOPT_NOP, opt->optlen); | |
1935 | } else | |
1936 | iph = ip_hdr(skb); | |
1937 | ||
1938 | if (opt->optlen > 0) | |
1939 | memset(opt, 0, sizeof(*opt)); | |
1940 | opt->optlen = opt_len; | |
1941 | opt->cipso = sizeof(struct iphdr); | |
1942 | opt->is_changed = 1; | |
1943 | ||
1944 | /* we have to do the following because we are being called from a | |
1945 | * netfilter hook which means the packet already has had the header | |
1946 | * fields populated and the checksum calculated - yes this means we | |
1947 | * are doing more work than needed but we do it to keep the core | |
1948 | * stack clean and tidy */ | |
1949 | memcpy(iph + 1, buf, buf_len); | |
1950 | if (opt_len > buf_len) | |
1951 | memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); | |
1952 | if (len_delta != 0) { | |
1953 | iph->ihl = 5 + (opt_len >> 2); | |
1954 | iph->tot_len = htons(skb->len); | |
1955 | } | |
1956 | ip_send_check(iph); | |
1957 | ||
1958 | return 0; | |
1959 | } | |
1960 | ||
1961 | /** | |
1962 | * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet | |
1963 | * @skb: the packet | |
1964 | * | |
1965 | * Description: | |
1966 | * Removes any and all CIPSO options from the given packet. Returns zero on | |
1967 | * success, negative values on failure. | |
1968 | * | |
1969 | */ | |
1970 | int cipso_v4_skbuff_delattr(struct sk_buff *skb) | |
1971 | { | |
1972 | int ret_val; | |
1973 | struct iphdr *iph; | |
1974 | struct ip_options *opt = &IPCB(skb)->opt; | |
1975 | unsigned char *cipso_ptr; | |
1976 | ||
1977 | if (opt->cipso == 0) | |
1978 | return 0; | |
1979 | ||
1980 | /* since we are changing the packet we should make a copy */ | |
1981 | ret_val = skb_cow(skb, skb_headroom(skb)); | |
1982 | if (ret_val < 0) | |
1983 | return ret_val; | |
1984 | ||
1985 | /* the easiest thing to do is just replace the cipso option with noop | |
1986 | * options since we don't change the size of the packet, although we | |
1987 | * still need to recalculate the checksum */ | |
1988 | ||
1989 | iph = ip_hdr(skb); | |
1990 | cipso_ptr = (unsigned char *)iph + opt->cipso; | |
1991 | memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); | |
1992 | opt->cipso = 0; | |
1993 | opt->is_changed = 1; | |
1994 | ||
1995 | ip_send_check(iph); | |
1996 | ||
1997 | return 0; | |
1998 | } | |
1999 | ||
446fda4f PM |
2000 | /** |
2001 | * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option | |
2002 | * @skb: the packet | |
2003 | * @secattr: the security attributes | |
2004 | * | |
2005 | * Description: | |
2006 | * Parse the given packet's CIPSO option and return the security attributes. | |
2007 | * Returns zero on success and negative values on failure. | |
2008 | * | |
2009 | */ | |
2010 | int cipso_v4_skbuff_getattr(const struct sk_buff *skb, | |
2011 | struct netlbl_lsm_secattr *secattr) | |
2012 | { | |
63d804ea | 2013 | return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr); |
446fda4f PM |
2014 | } |
2015 | ||
2016 | /* | |
2017 | * Setup Functions | |
2018 | */ | |
2019 | ||
2020 | /** | |
2021 | * cipso_v4_init - Initialize the CIPSO module | |
2022 | * | |
2023 | * Description: | |
2024 | * Initialize the CIPSO module and prepare it for use. Returns zero on success | |
2025 | * and negative values on failure. | |
2026 | * | |
2027 | */ | |
2028 | static int __init cipso_v4_init(void) | |
2029 | { | |
2030 | int ret_val; | |
2031 | ||
2032 | ret_val = cipso_v4_cache_init(); | |
2033 | if (ret_val != 0) | |
2034 | panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n", | |
2035 | ret_val); | |
2036 | ||
2037 | return 0; | |
2038 | } | |
2039 | ||
2040 | subsys_initcall(cipso_v4_init); |