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. While CIPSO never became a full IETF RFC standard many vendors |
7 | * have chosen to adopt the protocol and over the years it has become a |
8 | * de-facto standard for labeled networking. |
9 | * |
10 | * The CIPSO draft specification can be found in the kernel's Documentation |
11 | * directory as well as the following URL: |
12 | * http://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt |
13 | * The FIPS-188 specification can be found at the following URL: |
14 | * http://www.itl.nist.gov/fipspubs/fip188.htm |
15 | * |
16 | * Author: Paul Moore <paul.moore@hp.com> |
17 | * |
18 | */ |
19 | |
20 | /* |
21 | * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 |
22 | * |
23 | * This program is free software; you can redistribute it and/or modify |
24 | * it under the terms of the GNU General Public License as published by |
25 | * the Free Software Foundation; either version 2 of the License, or |
26 | * (at your option) any later version. |
27 | * |
28 | * This program is distributed in the hope that it will be useful, |
29 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
30 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
31 | * the GNU General Public License for more details. |
32 | * |
33 | * You should have received a copy of the GNU General Public License |
34 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
35 | * |
36 | */ |
37 | |
38 | #include <linux/init.h> |
39 | #include <linux/types.h> |
40 | #include <linux/rcupdate.h> |
41 | #include <linux/list.h> |
42 | #include <linux/spinlock.h> |
43 | #include <linux/string.h> |
44 | #include <linux/jhash.h> |
45 | #include <linux/audit.h> |
46 | #include <linux/slab.h> |
47 | #include <net/ip.h> |
48 | #include <net/icmp.h> |
49 | #include <net/tcp.h> |
50 | #include <net/netlabel.h> |
51 | #include <net/cipso_ipv4.h> |
52 | #include <linux/atomic.h> |
53 | #include <linux/bug.h> |
54 | #include <asm/unaligned.h> |
55 | |
56 | /* List of available DOI definitions */ |
57 | /* XXX - This currently assumes a minimal number of different DOIs in use, |
58 | * if in practice there are a lot of different DOIs this list should |
59 | * probably be turned into a hash table or something similar so we |
60 | * can do quick lookups. */ |
61 | static DEFINE_SPINLOCK(cipso_v4_doi_list_lock); |
62 | static LIST_HEAD(cipso_v4_doi_list); |
63 | |
64 | /* Label mapping cache */ |
65 | int cipso_v4_cache_enabled = 1; |
66 | int cipso_v4_cache_bucketsize = 10; |
67 | #define CIPSO_V4_CACHE_BUCKETBITS 7 |
68 | #define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS) |
69 | #define CIPSO_V4_CACHE_REORDERLIMIT 10 |
70 | struct cipso_v4_map_cache_bkt { |
71 | spinlock_t lock; |
72 | u32 size; |
73 | struct list_head list; |
74 | }; |
75 | |
76 | struct cipso_v4_map_cache_entry { |
77 | u32 hash; |
78 | unsigned char *key; |
79 | size_t key_len; |
80 | |
81 | struct netlbl_lsm_cache *lsm_data; |
82 | |
83 | u32 activity; |
84 | struct list_head list; |
85 | }; |
86 | |
87 | static struct cipso_v4_map_cache_bkt *cipso_v4_cache; |
88 | |
89 | /* Restricted bitmap (tag #1) flags */ |
90 | int cipso_v4_rbm_optfmt = 0; |
91 | int cipso_v4_rbm_strictvalid = 1; |
92 | |
93 | /* |
94 | * Protocol Constants |
95 | */ |
96 | |
97 | /* Maximum size of the CIPSO IP option, derived from the fact that the maximum |
98 | * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */ |
99 | #define CIPSO_V4_OPT_LEN_MAX 40 |
100 | |
101 | /* Length of the base CIPSO option, this includes the option type (1 byte), the |
102 | * option length (1 byte), and the DOI (4 bytes). */ |
103 | #define CIPSO_V4_HDR_LEN 6 |
104 | |
105 | /* Base length of the restrictive category bitmap tag (tag #1). */ |
106 | #define CIPSO_V4_TAG_RBM_BLEN 4 |
107 | |
108 | /* Base length of the enumerated category tag (tag #2). */ |
109 | #define CIPSO_V4_TAG_ENUM_BLEN 4 |
110 | |
111 | /* Base length of the ranged categories bitmap tag (tag #5). */ |
112 | #define CIPSO_V4_TAG_RNG_BLEN 4 |
113 | /* The maximum number of category ranges permitted in the ranged category tag |
114 | * (tag #5). You may note that the IETF draft states that the maximum number |
115 | * of category ranges is 7, but if the low end of the last category range is |
116 | * zero then it is possible to fit 8 category ranges because the zero should |
117 | * be omitted. */ |
118 | #define CIPSO_V4_TAG_RNG_CAT_MAX 8 |
119 | |
120 | /* Base length of the local tag (non-standard tag). |
121 | * Tag definition (may change between kernel versions) |
122 | * |
123 | * 0 8 16 24 32 |
124 | * +----------+----------+----------+----------+ |
125 | * | 10000000 | 00000110 | 32-bit secid value | |
126 | * +----------+----------+----------+----------+ |
127 | * | in (host byte order)| |
128 | * +----------+----------+ |
129 | * |
130 | */ |
131 | #define CIPSO_V4_TAG_LOC_BLEN 6 |
132 | |
133 | /* |
134 | * Helper Functions |
135 | */ |
136 | |
137 | /** |
138 | * cipso_v4_cache_entry_free - Frees a cache entry |
139 | * @entry: the entry to free |
140 | * |
141 | * Description: |
142 | * This function frees the memory associated with a cache entry including the |
143 | * LSM cache data if there are no longer any users, i.e. reference count == 0. |
144 | * |
145 | */ |
146 | static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) |
147 | { |
148 | if (entry->lsm_data) |
149 | netlbl_secattr_cache_free(entry->lsm_data); |
150 | kfree(entry->key); |
151 | kfree(entry); |
152 | } |
153 | |
154 | /** |
155 | * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache |
156 | * @key: the hash key |
157 | * @key_len: the length of the key in bytes |
158 | * |
159 | * Description: |
160 | * The CIPSO tag hashing function. Returns a 32-bit hash value. |
161 | * |
162 | */ |
163 | static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len) |
164 | { |
165 | return jhash(key, key_len, 0); |
166 | } |
167 | |
168 | /* |
169 | * Label Mapping Cache Functions |
170 | */ |
171 | |
172 | /** |
173 | * cipso_v4_cache_init - Initialize the CIPSO cache |
174 | * |
175 | * Description: |
176 | * Initializes the CIPSO label mapping cache, this function should be called |
177 | * before any of the other functions defined in this file. Returns zero on |
178 | * success, negative values on error. |
179 | * |
180 | */ |
181 | static int __init cipso_v4_cache_init(void) |
182 | { |
183 | u32 iter; |
184 | |
185 | cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS, |
186 | sizeof(struct cipso_v4_map_cache_bkt), |
187 | GFP_KERNEL); |
188 | if (!cipso_v4_cache) |
189 | return -ENOMEM; |
190 | |
191 | for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
192 | spin_lock_init(&cipso_v4_cache[iter].lock); |
193 | cipso_v4_cache[iter].size = 0; |
194 | INIT_LIST_HEAD(&cipso_v4_cache[iter].list); |
195 | } |
196 | |
197 | return 0; |
198 | } |
199 | |
200 | /** |
201 | * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache |
202 | * |
203 | * Description: |
204 | * Invalidates and frees any entries in the CIPSO cache. Returns zero on |
205 | * success and negative values on failure. |
206 | * |
207 | */ |
208 | void cipso_v4_cache_invalidate(void) |
209 | { |
210 | struct cipso_v4_map_cache_entry *entry, *tmp_entry; |
211 | u32 iter; |
212 | |
213 | for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
214 | spin_lock_bh(&cipso_v4_cache[iter].lock); |
215 | list_for_each_entry_safe(entry, |
216 | tmp_entry, |
217 | &cipso_v4_cache[iter].list, list) { |
218 | list_del(&entry->list); |
219 | cipso_v4_cache_entry_free(entry); |
220 | } |
221 | cipso_v4_cache[iter].size = 0; |
222 | spin_unlock_bh(&cipso_v4_cache[iter].lock); |
223 | } |
224 | } |
225 | |
226 | /** |
227 | * cipso_v4_cache_check - Check the CIPSO cache for a label mapping |
228 | * @key: the buffer to check |
229 | * @key_len: buffer length in bytes |
230 | * @secattr: the security attribute struct to use |
231 | * |
232 | * Description: |
233 | * This function checks the cache to see if a label mapping already exists for |
234 | * the given key. If there is a match then the cache is adjusted and the |
235 | * @secattr struct is populated with the correct LSM security attributes. The |
236 | * cache is adjusted in the following manner if the entry is not already the |
237 | * first in the cache bucket: |
238 | * |
239 | * 1. The cache entry's activity counter is incremented |
240 | * 2. The previous (higher ranking) entry's activity counter is decremented |
241 | * 3. If the difference between the two activity counters is geater than |
242 | * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped |
243 | * |
244 | * Returns zero on success, -ENOENT for a cache miss, and other negative values |
245 | * on error. |
246 | * |
247 | */ |
248 | static int cipso_v4_cache_check(const unsigned char *key, |
249 | u32 key_len, |
250 | struct netlbl_lsm_secattr *secattr) |
251 | { |
252 | u32 bkt; |
253 | struct cipso_v4_map_cache_entry *entry; |
254 | struct cipso_v4_map_cache_entry *prev_entry = NULL; |
255 | u32 hash; |
256 | |
257 | if (!cipso_v4_cache_enabled) |
258 | return -ENOENT; |
259 | |
260 | hash = cipso_v4_map_cache_hash(key, key_len); |
261 | bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
262 | spin_lock_bh(&cipso_v4_cache[bkt].lock); |
263 | list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) { |
264 | if (entry->hash == hash && |
265 | entry->key_len == key_len && |
266 | memcmp(entry->key, key, key_len) == 0) { |
267 | entry->activity += 1; |
268 | refcount_inc(&entry->lsm_data->refcount); |
269 | secattr->cache = entry->lsm_data; |
270 | secattr->flags |= NETLBL_SECATTR_CACHE; |
271 | secattr->type = NETLBL_NLTYPE_CIPSOV4; |
272 | if (!prev_entry) { |
273 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
274 | return 0; |
275 | } |
276 | |
277 | if (prev_entry->activity > 0) |
278 | prev_entry->activity -= 1; |
279 | if (entry->activity > prev_entry->activity && |
280 | entry->activity - prev_entry->activity > |
281 | CIPSO_V4_CACHE_REORDERLIMIT) { |
282 | __list_del(entry->list.prev, entry->list.next); |
283 | __list_add(&entry->list, |
284 | prev_entry->list.prev, |
285 | &prev_entry->list); |
286 | } |
287 | |
288 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
289 | return 0; |
290 | } |
291 | prev_entry = entry; |
292 | } |
293 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
294 | |
295 | return -ENOENT; |
296 | } |
297 | |
298 | /** |
299 | * cipso_v4_cache_add - Add an entry to the CIPSO cache |
300 | * @skb: the packet |
301 | * @secattr: the packet's security attributes |
302 | * |
303 | * Description: |
304 | * Add a new entry into the CIPSO label mapping cache. Add the new entry to |
305 | * head of the cache bucket's list, if the cache bucket is out of room remove |
306 | * the last entry in the list first. It is important to note that there is |
307 | * currently no checking for duplicate keys. Returns zero on success, |
308 | * negative values on failure. |
309 | * |
310 | */ |
311 | int cipso_v4_cache_add(const unsigned char *cipso_ptr, |
312 | const struct netlbl_lsm_secattr *secattr) |
313 | { |
314 | int ret_val = -EPERM; |
315 | u32 bkt; |
316 | struct cipso_v4_map_cache_entry *entry = NULL; |
317 | struct cipso_v4_map_cache_entry *old_entry = NULL; |
318 | u32 cipso_ptr_len; |
319 | |
320 | if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) |
321 | return 0; |
322 | |
323 | cipso_ptr_len = cipso_ptr[1]; |
324 | |
325 | entry = kzalloc(sizeof(*entry), GFP_ATOMIC); |
326 | if (!entry) |
327 | return -ENOMEM; |
328 | entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC); |
329 | if (!entry->key) { |
330 | ret_val = -ENOMEM; |
331 | goto cache_add_failure; |
332 | } |
333 | entry->key_len = cipso_ptr_len; |
334 | entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); |
335 | refcount_inc(&secattr->cache->refcount); |
336 | entry->lsm_data = secattr->cache; |
337 | |
338 | bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
339 | spin_lock_bh(&cipso_v4_cache[bkt].lock); |
340 | if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) { |
341 | list_add(&entry->list, &cipso_v4_cache[bkt].list); |
342 | cipso_v4_cache[bkt].size += 1; |
343 | } else { |
344 | old_entry = list_entry(cipso_v4_cache[bkt].list.prev, |
345 | struct cipso_v4_map_cache_entry, list); |
346 | list_del(&old_entry->list); |
347 | list_add(&entry->list, &cipso_v4_cache[bkt].list); |
348 | cipso_v4_cache_entry_free(old_entry); |
349 | } |
350 | spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
351 | |
352 | return 0; |
353 | |
354 | cache_add_failure: |
355 | if (entry) |
356 | cipso_v4_cache_entry_free(entry); |
357 | return ret_val; |
358 | } |
359 | |
360 | /* |
361 | * DOI List Functions |
362 | */ |
363 | |
364 | /** |
365 | * cipso_v4_doi_search - Searches for a DOI definition |
366 | * @doi: the DOI to search for |
367 | * |
368 | * Description: |
369 | * Search the DOI definition list for a DOI definition with a DOI value that |
370 | * matches @doi. The caller is responsible for calling rcu_read_[un]lock(). |
371 | * Returns a pointer to the DOI definition on success and NULL on failure. |
372 | */ |
373 | static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) |
374 | { |
375 | struct cipso_v4_doi *iter; |
376 | |
377 | list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) |
378 | if (iter->doi == doi && refcount_read(&iter->refcount)) |
379 | return iter; |
380 | return NULL; |
381 | } |
382 | |
383 | /** |
384 | * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine |
385 | * @doi_def: the DOI structure |
386 | * @audit_info: NetLabel audit information |
387 | * |
388 | * Description: |
389 | * The caller defines a new DOI for use by the CIPSO engine and calls this |
390 | * function to add it to the list of acceptable domains. The caller must |
391 | * ensure that the mapping table specified in @doi_def->map meets all of the |
392 | * requirements of the mapping type (see cipso_ipv4.h for details). Returns |
393 | * zero on success and non-zero on failure. |
394 | * |
395 | */ |
396 | int cipso_v4_doi_add(struct cipso_v4_doi *doi_def, |
397 | struct netlbl_audit *audit_info) |
398 | { |
399 | int ret_val = -EINVAL; |
400 | u32 iter; |
401 | u32 doi; |
402 | u32 doi_type; |
403 | struct audit_buffer *audit_buf; |
404 | |
405 | doi = doi_def->doi; |
406 | doi_type = doi_def->type; |
407 | |
408 | if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN) |
409 | goto doi_add_return; |
410 | for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) { |
411 | switch (doi_def->tags[iter]) { |
412 | case CIPSO_V4_TAG_RBITMAP: |
413 | break; |
414 | case CIPSO_V4_TAG_RANGE: |
415 | case CIPSO_V4_TAG_ENUM: |
416 | if (doi_def->type != CIPSO_V4_MAP_PASS) |
417 | goto doi_add_return; |
418 | break; |
419 | case CIPSO_V4_TAG_LOCAL: |
420 | if (doi_def->type != CIPSO_V4_MAP_LOCAL) |
421 | goto doi_add_return; |
422 | break; |
423 | case CIPSO_V4_TAG_INVALID: |
424 | if (iter == 0) |
425 | goto doi_add_return; |
426 | break; |
427 | default: |
428 | goto doi_add_return; |
429 | } |
430 | } |
431 | |
432 | refcount_set(&doi_def->refcount, 1); |
433 | |
434 | spin_lock(&cipso_v4_doi_list_lock); |
435 | if (cipso_v4_doi_search(doi_def->doi)) { |
436 | spin_unlock(&cipso_v4_doi_list_lock); |
437 | ret_val = -EEXIST; |
438 | goto doi_add_return; |
439 | } |
440 | list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); |
441 | spin_unlock(&cipso_v4_doi_list_lock); |
442 | ret_val = 0; |
443 | |
444 | doi_add_return: |
445 | audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info); |
446 | if (audit_buf) { |
447 | const char *type_str; |
448 | switch (doi_type) { |
449 | case CIPSO_V4_MAP_TRANS: |
450 | type_str = "trans" ; |
451 | break; |
452 | case CIPSO_V4_MAP_PASS: |
453 | type_str = "pass" ; |
454 | break; |
455 | case CIPSO_V4_MAP_LOCAL: |
456 | type_str = "local" ; |
457 | break; |
458 | default: |
459 | type_str = "(unknown)" ; |
460 | } |
461 | audit_log_format(audit_buf, |
462 | " cipso_doi=%u cipso_type=%s res=%u" , |
463 | doi, type_str, ret_val == 0 ? 1 : 0); |
464 | audit_log_end(audit_buf); |
465 | } |
466 | |
467 | return ret_val; |
468 | } |
469 | |
470 | /** |
471 | * cipso_v4_doi_free - Frees a DOI definition |
472 | * @doi_def: the DOI definition |
473 | * |
474 | * Description: |
475 | * This function frees all of the memory associated with a DOI definition. |
476 | * |
477 | */ |
478 | void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) |
479 | { |
480 | if (!doi_def) |
481 | return; |
482 | |
483 | switch (doi_def->type) { |
484 | case CIPSO_V4_MAP_TRANS: |
485 | kfree(doi_def->map.std->lvl.cipso); |
486 | kfree(doi_def->map.std->lvl.local); |
487 | kfree(doi_def->map.std->cat.cipso); |
488 | kfree(doi_def->map.std->cat.local); |
489 | break; |
490 | } |
491 | kfree(doi_def); |
492 | } |
493 | |
494 | /** |
495 | * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer |
496 | * @entry: the entry's RCU field |
497 | * |
498 | * Description: |
499 | * This function is designed to be used as a callback to the call_rcu() |
500 | * function so that the memory allocated to the DOI definition can be released |
501 | * safely. |
502 | * |
503 | */ |
504 | static void cipso_v4_doi_free_rcu(struct rcu_head *entry) |
505 | { |
506 | struct cipso_v4_doi *doi_def; |
507 | |
508 | doi_def = container_of(entry, struct cipso_v4_doi, rcu); |
509 | cipso_v4_doi_free(doi_def); |
510 | } |
511 | |
512 | /** |
513 | * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine |
514 | * @doi: the DOI value |
515 | * @audit_secid: the LSM secid to use in the audit message |
516 | * |
517 | * Description: |
518 | * Removes a DOI definition from the CIPSO engine. The NetLabel routines will |
519 | * be called to release their own LSM domain mappings as well as our own |
520 | * domain list. Returns zero on success and negative values on failure. |
521 | * |
522 | */ |
523 | int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) |
524 | { |
525 | int ret_val; |
526 | struct cipso_v4_doi *doi_def; |
527 | struct audit_buffer *audit_buf; |
528 | |
529 | spin_lock(&cipso_v4_doi_list_lock); |
530 | doi_def = cipso_v4_doi_search(doi); |
531 | if (!doi_def) { |
532 | spin_unlock(&cipso_v4_doi_list_lock); |
533 | ret_val = -ENOENT; |
534 | goto doi_remove_return; |
535 | } |
536 | if (!refcount_dec_and_test(&doi_def->refcount)) { |
537 | spin_unlock(&cipso_v4_doi_list_lock); |
538 | ret_val = -EBUSY; |
539 | goto doi_remove_return; |
540 | } |
541 | list_del_rcu(&doi_def->list); |
542 | spin_unlock(&cipso_v4_doi_list_lock); |
543 | |
544 | cipso_v4_cache_invalidate(); |
545 | call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); |
546 | ret_val = 0; |
547 | |
548 | doi_remove_return: |
549 | audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info); |
550 | if (audit_buf) { |
551 | audit_log_format(audit_buf, |
552 | " cipso_doi=%u res=%u" , |
553 | doi, ret_val == 0 ? 1 : 0); |
554 | audit_log_end(audit_buf); |
555 | } |
556 | |
557 | return ret_val; |
558 | } |
559 | |
560 | /** |
561 | * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition |
562 | * @doi: the DOI value |
563 | * |
564 | * Description: |
565 | * Searches for a valid DOI definition and if one is found it is returned to |
566 | * the caller. Otherwise NULL is returned. The caller must ensure that |
567 | * rcu_read_lock() is held while accessing the returned definition and the DOI |
568 | * definition reference count is decremented when the caller is done. |
569 | * |
570 | */ |
571 | struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) |
572 | { |
573 | struct cipso_v4_doi *doi_def; |
574 | |
575 | rcu_read_lock(); |
576 | doi_def = cipso_v4_doi_search(doi); |
577 | if (!doi_def) |
578 | goto doi_getdef_return; |
579 | if (!refcount_inc_not_zero(&doi_def->refcount)) |
580 | doi_def = NULL; |
581 | |
582 | doi_getdef_return: |
583 | rcu_read_unlock(); |
584 | return doi_def; |
585 | } |
586 | |
587 | /** |
588 | * cipso_v4_doi_putdef - Releases a reference for the given DOI definition |
589 | * @doi_def: the DOI definition |
590 | * |
591 | * Description: |
592 | * Releases a DOI definition reference obtained from cipso_v4_doi_getdef(). |
593 | * |
594 | */ |
595 | void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) |
596 | { |
597 | if (!doi_def) |
598 | return; |
599 | |
600 | if (!refcount_dec_and_test(&doi_def->refcount)) |
601 | return; |
602 | spin_lock(&cipso_v4_doi_list_lock); |
603 | list_del_rcu(&doi_def->list); |
604 | spin_unlock(&cipso_v4_doi_list_lock); |
605 | |
606 | cipso_v4_cache_invalidate(); |
607 | call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); |
608 | } |
609 | |
610 | /** |
611 | * cipso_v4_doi_walk - Iterate through the DOI definitions |
612 | * @skip_cnt: skip past this number of DOI definitions, updated |
613 | * @callback: callback for each DOI definition |
614 | * @cb_arg: argument for the callback function |
615 | * |
616 | * Description: |
617 | * Iterate over the DOI definition list, skipping the first @skip_cnt entries. |
618 | * For each entry call @callback, if @callback returns a negative value stop |
619 | * 'walking' through the list and return. Updates the value in @skip_cnt upon |
620 | * return. Returns zero on success, negative values on failure. |
621 | * |
622 | */ |
623 | int cipso_v4_doi_walk(u32 *skip_cnt, |
624 | int (*callback) (struct cipso_v4_doi *doi_def, void *arg), |
625 | void *cb_arg) |
626 | { |
627 | int ret_val = -ENOENT; |
628 | u32 doi_cnt = 0; |
629 | struct cipso_v4_doi *iter_doi; |
630 | |
631 | rcu_read_lock(); |
632 | list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list) |
633 | if (refcount_read(&iter_doi->refcount) > 0) { |
634 | if (doi_cnt++ < *skip_cnt) |
635 | continue; |
636 | ret_val = callback(iter_doi, cb_arg); |
637 | if (ret_val < 0) { |
638 | doi_cnt--; |
639 | goto doi_walk_return; |
640 | } |
641 | } |
642 | |
643 | doi_walk_return: |
644 | rcu_read_unlock(); |
645 | *skip_cnt = doi_cnt; |
646 | return ret_val; |
647 | } |
648 | |
649 | /* |
650 | * Label Mapping Functions |
651 | */ |
652 | |
653 | /** |
654 | * cipso_v4_map_lvl_valid - Checks to see if the given level is understood |
655 | * @doi_def: the DOI definition |
656 | * @level: the level to check |
657 | * |
658 | * Description: |
659 | * Checks the given level against the given DOI definition and returns a |
660 | * negative value if the level does not have a valid mapping and a zero value |
661 | * if the level is defined by the DOI. |
662 | * |
663 | */ |
664 | static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level) |
665 | { |
666 | switch (doi_def->type) { |
667 | case CIPSO_V4_MAP_PASS: |
668 | return 0; |
669 | case CIPSO_V4_MAP_TRANS: |
670 | if ((level < doi_def->map.std->lvl.cipso_size) && |
671 | (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)) |
672 | return 0; |
673 | break; |
674 | } |
675 | |
676 | return -EFAULT; |
677 | } |
678 | |
679 | /** |
680 | * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network |
681 | * @doi_def: the DOI definition |
682 | * @host_lvl: the host MLS level |
683 | * @net_lvl: the network/CIPSO MLS level |
684 | * |
685 | * Description: |
686 | * Perform a label mapping to translate a local MLS level to the correct |
687 | * CIPSO level using the given DOI definition. Returns zero on success, |
688 | * negative values otherwise. |
689 | * |
690 | */ |
691 | static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def, |
692 | u32 host_lvl, |
693 | u32 *net_lvl) |
694 | { |
695 | switch (doi_def->type) { |
696 | case CIPSO_V4_MAP_PASS: |
697 | *net_lvl = host_lvl; |
698 | return 0; |
699 | case CIPSO_V4_MAP_TRANS: |
700 | if (host_lvl < doi_def->map.std->lvl.local_size && |
701 | doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) { |
702 | *net_lvl = doi_def->map.std->lvl.local[host_lvl]; |
703 | return 0; |
704 | } |
705 | return -EPERM; |
706 | } |
707 | |
708 | return -EINVAL; |
709 | } |
710 | |
711 | /** |
712 | * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host |
713 | * @doi_def: the DOI definition |
714 | * @net_lvl: the network/CIPSO MLS level |
715 | * @host_lvl: the host MLS level |
716 | * |
717 | * Description: |
718 | * Perform a label mapping to translate a CIPSO level to the correct local MLS |
719 | * level using the given DOI definition. Returns zero on success, negative |
720 | * values otherwise. |
721 | * |
722 | */ |
723 | static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def, |
724 | u32 net_lvl, |
725 | u32 *host_lvl) |
726 | { |
727 | struct cipso_v4_std_map_tbl *map_tbl; |
728 | |
729 | switch (doi_def->type) { |
730 | case CIPSO_V4_MAP_PASS: |
731 | *host_lvl = net_lvl; |
732 | return 0; |
733 | case CIPSO_V4_MAP_TRANS: |
734 | map_tbl = doi_def->map.std; |
735 | if (net_lvl < map_tbl->lvl.cipso_size && |
736 | map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) { |
737 | *host_lvl = doi_def->map.std->lvl.cipso[net_lvl]; |
738 | return 0; |
739 | } |
740 | return -EPERM; |
741 | } |
742 | |
743 | return -EINVAL; |
744 | } |
745 | |
746 | /** |
747 | * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid |
748 | * @doi_def: the DOI definition |
749 | * @bitmap: category bitmap |
750 | * @bitmap_len: bitmap length in bytes |
751 | * |
752 | * Description: |
753 | * Checks the given category bitmap against the given DOI definition and |
754 | * returns a negative value if any of the categories in the bitmap do not have |
755 | * a valid mapping and a zero value if all of the categories are valid. |
756 | * |
757 | */ |
758 | static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def, |
759 | const unsigned char *bitmap, |
760 | u32 bitmap_len) |
761 | { |
762 | int cat = -1; |
763 | u32 bitmap_len_bits = bitmap_len * 8; |
764 | u32 cipso_cat_size; |
765 | u32 *cipso_array; |
766 | |
767 | switch (doi_def->type) { |
768 | case CIPSO_V4_MAP_PASS: |
769 | return 0; |
770 | case CIPSO_V4_MAP_TRANS: |
771 | cipso_cat_size = doi_def->map.std->cat.cipso_size; |
772 | cipso_array = doi_def->map.std->cat.cipso; |
773 | for (;;) { |
774 | cat = netlbl_bitmap_walk(bitmap, |
775 | bitmap_len_bits, |
776 | cat + 1, |
777 | 1); |
778 | if (cat < 0) |
779 | break; |
780 | if (cat >= cipso_cat_size || |
781 | cipso_array[cat] >= CIPSO_V4_INV_CAT) |
782 | return -EFAULT; |
783 | } |
784 | |
785 | if (cat == -1) |
786 | return 0; |
787 | break; |
788 | } |
789 | |
790 | return -EFAULT; |
791 | } |
792 | |
793 | /** |
794 | * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network |
795 | * @doi_def: the DOI definition |
796 | * @secattr: the security attributes |
797 | * @net_cat: the zero'd out category bitmap in network/CIPSO format |
798 | * @net_cat_len: the length of the CIPSO bitmap in bytes |
799 | * |
800 | * Description: |
801 | * Perform a label mapping to translate a local MLS category bitmap to the |
802 | * correct CIPSO bitmap using the given DOI definition. Returns the minimum |
803 | * size in bytes of the network bitmap on success, negative values otherwise. |
804 | * |
805 | */ |
806 | static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, |
807 | const struct netlbl_lsm_secattr *secattr, |
808 | unsigned char *net_cat, |
809 | u32 net_cat_len) |
810 | { |
811 | int host_spot = -1; |
812 | u32 net_spot = CIPSO_V4_INV_CAT; |
813 | u32 net_spot_max = 0; |
814 | u32 net_clen_bits = net_cat_len * 8; |
815 | u32 host_cat_size = 0; |
816 | u32 *host_cat_array = NULL; |
817 | |
818 | if (doi_def->type == CIPSO_V4_MAP_TRANS) { |
819 | host_cat_size = doi_def->map.std->cat.local_size; |
820 | host_cat_array = doi_def->map.std->cat.local; |
821 | } |
822 | |
823 | for (;;) { |
824 | host_spot = netlbl_catmap_walk(secattr->attr.mls.cat, |
825 | host_spot + 1); |
826 | if (host_spot < 0) |
827 | break; |
828 | |
829 | switch (doi_def->type) { |
830 | case CIPSO_V4_MAP_PASS: |
831 | net_spot = host_spot; |
832 | break; |
833 | case CIPSO_V4_MAP_TRANS: |
834 | if (host_spot >= host_cat_size) |
835 | return -EPERM; |
836 | net_spot = host_cat_array[host_spot]; |
837 | if (net_spot >= CIPSO_V4_INV_CAT) |
838 | return -EPERM; |
839 | break; |
840 | } |
841 | if (net_spot >= net_clen_bits) |
842 | return -ENOSPC; |
843 | netlbl_bitmap_setbit(net_cat, net_spot, 1); |
844 | |
845 | if (net_spot > net_spot_max) |
846 | net_spot_max = net_spot; |
847 | } |
848 | |
849 | if (++net_spot_max % 8) |
850 | return net_spot_max / 8 + 1; |
851 | return net_spot_max / 8; |
852 | } |
853 | |
854 | /** |
855 | * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host |
856 | * @doi_def: the DOI definition |
857 | * @net_cat: the category bitmap in network/CIPSO format |
858 | * @net_cat_len: the length of the CIPSO bitmap in bytes |
859 | * @secattr: the security attributes |
860 | * |
861 | * Description: |
862 | * Perform a label mapping to translate a CIPSO bitmap to the correct local |
863 | * MLS category bitmap using the given DOI definition. Returns zero on |
864 | * success, negative values on failure. |
865 | * |
866 | */ |
867 | static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, |
868 | const unsigned char *net_cat, |
869 | u32 net_cat_len, |
870 | struct netlbl_lsm_secattr *secattr) |
871 | { |
872 | int ret_val; |
873 | int net_spot = -1; |
874 | u32 host_spot = CIPSO_V4_INV_CAT; |
875 | u32 net_clen_bits = net_cat_len * 8; |
876 | u32 net_cat_size = 0; |
877 | u32 *net_cat_array = NULL; |
878 | |
879 | if (doi_def->type == CIPSO_V4_MAP_TRANS) { |
880 | net_cat_size = doi_def->map.std->cat.cipso_size; |
881 | net_cat_array = doi_def->map.std->cat.cipso; |
882 | } |
883 | |
884 | for (;;) { |
885 | net_spot = netlbl_bitmap_walk(net_cat, |
886 | net_clen_bits, |
887 | net_spot + 1, |
888 | 1); |
889 | if (net_spot < 0) { |
890 | if (net_spot == -2) |
891 | return -EFAULT; |
892 | return 0; |
893 | } |
894 | |
895 | switch (doi_def->type) { |
896 | case CIPSO_V4_MAP_PASS: |
897 | host_spot = net_spot; |
898 | break; |
899 | case CIPSO_V4_MAP_TRANS: |
900 | if (net_spot >= net_cat_size) |
901 | return -EPERM; |
902 | host_spot = net_cat_array[net_spot]; |
903 | if (host_spot >= CIPSO_V4_INV_CAT) |
904 | return -EPERM; |
905 | break; |
906 | } |
907 | ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, |
908 | host_spot, |
909 | GFP_ATOMIC); |
910 | if (ret_val != 0) |
911 | return ret_val; |
912 | } |
913 | |
914 | return -EINVAL; |
915 | } |
916 | |
917 | /** |
918 | * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid |
919 | * @doi_def: the DOI definition |
920 | * @enumcat: category list |
921 | * @enumcat_len: length of the category list in bytes |
922 | * |
923 | * Description: |
924 | * Checks the given categories against the given DOI definition and returns a |
925 | * negative value if any of the categories do not have a valid mapping and a |
926 | * zero value if all of the categories are valid. |
927 | * |
928 | */ |
929 | static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def, |
930 | const unsigned char *enumcat, |
931 | u32 enumcat_len) |
932 | { |
933 | u16 cat; |
934 | int cat_prev = -1; |
935 | u32 iter; |
936 | |
937 | if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01) |
938 | return -EFAULT; |
939 | |
940 | for (iter = 0; iter < enumcat_len; iter += 2) { |
941 | cat = get_unaligned_be16(&enumcat[iter]); |
942 | if (cat <= cat_prev) |
943 | return -EFAULT; |
944 | cat_prev = cat; |
945 | } |
946 | |
947 | return 0; |
948 | } |
949 | |
950 | /** |
951 | * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network |
952 | * @doi_def: the DOI definition |
953 | * @secattr: the security attributes |
954 | * @net_cat: the zero'd out category list in network/CIPSO format |
955 | * @net_cat_len: the length of the CIPSO category list in bytes |
956 | * |
957 | * Description: |
958 | * Perform a label mapping to translate a local MLS category bitmap to the |
959 | * correct CIPSO category list using the given DOI definition. Returns the |
960 | * size in bytes of the network category bitmap on success, negative values |
961 | * otherwise. |
962 | * |
963 | */ |
964 | static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def, |
965 | const struct netlbl_lsm_secattr *secattr, |
966 | unsigned char *net_cat, |
967 | u32 net_cat_len) |
968 | { |
969 | int cat = -1; |
970 | u32 cat_iter = 0; |
971 | |
972 | for (;;) { |
973 | cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1); |
974 | if (cat < 0) |
975 | break; |
976 | if ((cat_iter + 2) > net_cat_len) |
977 | return -ENOSPC; |
978 | |
979 | *((__be16 *)&net_cat[cat_iter]) = htons(cat); |
980 | cat_iter += 2; |
981 | } |
982 | |
983 | return cat_iter; |
984 | } |
985 | |
986 | /** |
987 | * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host |
988 | * @doi_def: the DOI definition |
989 | * @net_cat: the category list in network/CIPSO format |
990 | * @net_cat_len: the length of the CIPSO bitmap in bytes |
991 | * @secattr: the security attributes |
992 | * |
993 | * Description: |
994 | * Perform a label mapping to translate a CIPSO category list to the correct |
995 | * local MLS category bitmap using the given DOI definition. Returns zero on |
996 | * success, negative values on failure. |
997 | * |
998 | */ |
999 | static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def, |
1000 | const unsigned char *net_cat, |
1001 | u32 net_cat_len, |
1002 | struct netlbl_lsm_secattr *secattr) |
1003 | { |
1004 | int ret_val; |
1005 | u32 iter; |
1006 | |
1007 | for (iter = 0; iter < net_cat_len; iter += 2) { |
1008 | ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, |
1009 | get_unaligned_be16(&net_cat[iter]), |
1010 | GFP_ATOMIC); |
1011 | if (ret_val != 0) |
1012 | return ret_val; |
1013 | } |
1014 | |
1015 | return 0; |
1016 | } |
1017 | |
1018 | /** |
1019 | * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid |
1020 | * @doi_def: the DOI definition |
1021 | * @rngcat: category list |
1022 | * @rngcat_len: length of the category list in bytes |
1023 | * |
1024 | * Description: |
1025 | * Checks the given categories against the given DOI definition and returns a |
1026 | * negative value if any of the categories do not have a valid mapping and a |
1027 | * zero value if all of the categories are valid. |
1028 | * |
1029 | */ |
1030 | static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def, |
1031 | const unsigned char *rngcat, |
1032 | u32 rngcat_len) |
1033 | { |
1034 | u16 cat_high; |
1035 | u16 cat_low; |
1036 | u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1; |
1037 | u32 iter; |
1038 | |
1039 | if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01) |
1040 | return -EFAULT; |
1041 | |
1042 | for (iter = 0; iter < rngcat_len; iter += 4) { |
1043 | cat_high = get_unaligned_be16(&rngcat[iter]); |
1044 | if ((iter + 4) <= rngcat_len) |
1045 | cat_low = get_unaligned_be16(&rngcat[iter + 2]); |
1046 | else |
1047 | cat_low = 0; |
1048 | |
1049 | if (cat_high > cat_prev) |
1050 | return -EFAULT; |
1051 | |
1052 | cat_prev = cat_low; |
1053 | } |
1054 | |
1055 | return 0; |
1056 | } |
1057 | |
1058 | /** |
1059 | * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network |
1060 | * @doi_def: the DOI definition |
1061 | * @secattr: the security attributes |
1062 | * @net_cat: the zero'd out category list in network/CIPSO format |
1063 | * @net_cat_len: the length of the CIPSO category list in bytes |
1064 | * |
1065 | * Description: |
1066 | * Perform a label mapping to translate a local MLS category bitmap to the |
1067 | * correct CIPSO category list using the given DOI definition. Returns the |
1068 | * size in bytes of the network category bitmap on success, negative values |
1069 | * otherwise. |
1070 | * |
1071 | */ |
1072 | static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def, |
1073 | const struct netlbl_lsm_secattr *secattr, |
1074 | unsigned char *net_cat, |
1075 | u32 net_cat_len) |
1076 | { |
1077 | int iter = -1; |
1078 | u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2]; |
1079 | u32 array_cnt = 0; |
1080 | u32 cat_size = 0; |
1081 | |
1082 | /* make sure we don't overflow the 'array[]' variable */ |
1083 | if (net_cat_len > |
1084 | (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN)) |
1085 | return -ENOSPC; |
1086 | |
1087 | for (;;) { |
1088 | iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1); |
1089 | if (iter < 0) |
1090 | break; |
1091 | cat_size += (iter == 0 ? 0 : sizeof(u16)); |
1092 | if (cat_size > net_cat_len) |
1093 | return -ENOSPC; |
1094 | array[array_cnt++] = iter; |
1095 | |
1096 | iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter); |
1097 | if (iter < 0) |
1098 | return -EFAULT; |
1099 | cat_size += sizeof(u16); |
1100 | if (cat_size > net_cat_len) |
1101 | return -ENOSPC; |
1102 | array[array_cnt++] = iter; |
1103 | } |
1104 | |
1105 | for (iter = 0; array_cnt > 0;) { |
1106 | *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]); |
1107 | iter += 2; |
1108 | array_cnt--; |
1109 | if (array[array_cnt] != 0) { |
1110 | *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]); |
1111 | iter += 2; |
1112 | } |
1113 | } |
1114 | |
1115 | return cat_size; |
1116 | } |
1117 | |
1118 | /** |
1119 | * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host |
1120 | * @doi_def: the DOI definition |
1121 | * @net_cat: the category list in network/CIPSO format |
1122 | * @net_cat_len: the length of the CIPSO bitmap in bytes |
1123 | * @secattr: the security attributes |
1124 | * |
1125 | * Description: |
1126 | * Perform a label mapping to translate a CIPSO category list to the correct |
1127 | * local MLS category bitmap using the given DOI definition. Returns zero on |
1128 | * success, negative values on failure. |
1129 | * |
1130 | */ |
1131 | static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def, |
1132 | const unsigned char *net_cat, |
1133 | u32 net_cat_len, |
1134 | struct netlbl_lsm_secattr *secattr) |
1135 | { |
1136 | int ret_val; |
1137 | u32 net_iter; |
1138 | u16 cat_low; |
1139 | u16 cat_high; |
1140 | |
1141 | for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) { |
1142 | cat_high = get_unaligned_be16(&net_cat[net_iter]); |
1143 | if ((net_iter + 4) <= net_cat_len) |
1144 | cat_low = get_unaligned_be16(&net_cat[net_iter + 2]); |
1145 | else |
1146 | cat_low = 0; |
1147 | |
1148 | ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat, |
1149 | cat_low, |
1150 | cat_high, |
1151 | GFP_ATOMIC); |
1152 | if (ret_val != 0) |
1153 | return ret_val; |
1154 | } |
1155 | |
1156 | return 0; |
1157 | } |
1158 | |
1159 | /* |
1160 | * Protocol Handling Functions |
1161 | */ |
1162 | |
1163 | /** |
1164 | * cipso_v4_gentag_hdr - Generate a CIPSO option header |
1165 | * @doi_def: the DOI definition |
1166 | * @len: the total tag length in bytes, not including this header |
1167 | * @buf: the CIPSO option buffer |
1168 | * |
1169 | * Description: |
1170 | * Write a CIPSO header into the beginning of @buffer. |
1171 | * |
1172 | */ |
1173 | static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def, |
1174 | unsigned char *buf, |
1175 | u32 len) |
1176 | { |
1177 | buf[0] = IPOPT_CIPSO; |
1178 | buf[1] = CIPSO_V4_HDR_LEN + len; |
1179 | *(__be32 *)&buf[2] = htonl(doi_def->doi); |
1180 | } |
1181 | |
1182 | /** |
1183 | * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1) |
1184 | * @doi_def: the DOI definition |
1185 | * @secattr: the security attributes |
1186 | * @buffer: the option buffer |
1187 | * @buffer_len: length of buffer in bytes |
1188 | * |
1189 | * Description: |
1190 | * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The |
1191 | * actual buffer length may be larger than the indicated size due to |
1192 | * translation between host and network category bitmaps. Returns the size of |
1193 | * the tag on success, negative values on failure. |
1194 | * |
1195 | */ |
1196 | static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, |
1197 | const struct netlbl_lsm_secattr *secattr, |
1198 | unsigned char *buffer, |
1199 | u32 buffer_len) |
1200 | { |
1201 | int ret_val; |
1202 | u32 tag_len; |
1203 | u32 level; |
1204 | |
1205 | if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0) |
1206 | return -EPERM; |
1207 | |
1208 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1209 | secattr->attr.mls.lvl, |
1210 | &level); |
1211 | if (ret_val != 0) |
1212 | return ret_val; |
1213 | |
1214 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
1215 | ret_val = cipso_v4_map_cat_rbm_hton(doi_def, |
1216 | secattr, |
1217 | &buffer[4], |
1218 | buffer_len - 4); |
1219 | if (ret_val < 0) |
1220 | return ret_val; |
1221 | |
1222 | /* This will send packets using the "optimized" format when |
1223 | * possible as specified in section 3.4.2.6 of the |
1224 | * CIPSO draft. */ |
1225 | if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10) |
1226 | tag_len = 14; |
1227 | else |
1228 | tag_len = 4 + ret_val; |
1229 | } else |
1230 | tag_len = 4; |
1231 | |
1232 | buffer[0] = CIPSO_V4_TAG_RBITMAP; |
1233 | buffer[1] = tag_len; |
1234 | buffer[3] = level; |
1235 | |
1236 | return tag_len; |
1237 | } |
1238 | |
1239 | /** |
1240 | * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag |
1241 | * @doi_def: the DOI definition |
1242 | * @tag: the CIPSO tag |
1243 | * @secattr: the security attributes |
1244 | * |
1245 | * Description: |
1246 | * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security |
1247 | * attributes in @secattr. Return zero on success, negatives values on |
1248 | * failure. |
1249 | * |
1250 | */ |
1251 | static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, |
1252 | const unsigned char *tag, |
1253 | struct netlbl_lsm_secattr *secattr) |
1254 | { |
1255 | int ret_val; |
1256 | u8 tag_len = tag[1]; |
1257 | u32 level; |
1258 | |
1259 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
1260 | if (ret_val != 0) |
1261 | return ret_val; |
1262 | secattr->attr.mls.lvl = level; |
1263 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
1264 | |
1265 | if (tag_len > 4) { |
1266 | ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def, |
1267 | &tag[4], |
1268 | tag_len - 4, |
1269 | secattr); |
1270 | if (ret_val != 0) { |
1271 | netlbl_catmap_free(secattr->attr.mls.cat); |
1272 | return ret_val; |
1273 | } |
1274 | |
1275 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
1276 | } |
1277 | |
1278 | return 0; |
1279 | } |
1280 | |
1281 | /** |
1282 | * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2) |
1283 | * @doi_def: the DOI definition |
1284 | * @secattr: the security attributes |
1285 | * @buffer: the option buffer |
1286 | * @buffer_len: length of buffer in bytes |
1287 | * |
1288 | * Description: |
1289 | * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the |
1290 | * size of the tag on success, negative values on failure. |
1291 | * |
1292 | */ |
1293 | static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, |
1294 | const struct netlbl_lsm_secattr *secattr, |
1295 | unsigned char *buffer, |
1296 | u32 buffer_len) |
1297 | { |
1298 | int ret_val; |
1299 | u32 tag_len; |
1300 | u32 level; |
1301 | |
1302 | if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) |
1303 | return -EPERM; |
1304 | |
1305 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1306 | secattr->attr.mls.lvl, |
1307 | &level); |
1308 | if (ret_val != 0) |
1309 | return ret_val; |
1310 | |
1311 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
1312 | ret_val = cipso_v4_map_cat_enum_hton(doi_def, |
1313 | secattr, |
1314 | &buffer[4], |
1315 | buffer_len - 4); |
1316 | if (ret_val < 0) |
1317 | return ret_val; |
1318 | |
1319 | tag_len = 4 + ret_val; |
1320 | } else |
1321 | tag_len = 4; |
1322 | |
1323 | buffer[0] = CIPSO_V4_TAG_ENUM; |
1324 | buffer[1] = tag_len; |
1325 | buffer[3] = level; |
1326 | |
1327 | return tag_len; |
1328 | } |
1329 | |
1330 | /** |
1331 | * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag |
1332 | * @doi_def: the DOI definition |
1333 | * @tag: the CIPSO tag |
1334 | * @secattr: the security attributes |
1335 | * |
1336 | * Description: |
1337 | * Parse a CIPSO enumerated tag (tag type #2) and return the security |
1338 | * attributes in @secattr. Return zero on success, negatives values on |
1339 | * failure. |
1340 | * |
1341 | */ |
1342 | static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, |
1343 | const unsigned char *tag, |
1344 | struct netlbl_lsm_secattr *secattr) |
1345 | { |
1346 | int ret_val; |
1347 | u8 tag_len = tag[1]; |
1348 | u32 level; |
1349 | |
1350 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
1351 | if (ret_val != 0) |
1352 | return ret_val; |
1353 | secattr->attr.mls.lvl = level; |
1354 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
1355 | |
1356 | if (tag_len > 4) { |
1357 | ret_val = cipso_v4_map_cat_enum_ntoh(doi_def, |
1358 | &tag[4], |
1359 | tag_len - 4, |
1360 | secattr); |
1361 | if (ret_val != 0) { |
1362 | netlbl_catmap_free(secattr->attr.mls.cat); |
1363 | return ret_val; |
1364 | } |
1365 | |
1366 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
1367 | } |
1368 | |
1369 | return 0; |
1370 | } |
1371 | |
1372 | /** |
1373 | * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5) |
1374 | * @doi_def: the DOI definition |
1375 | * @secattr: the security attributes |
1376 | * @buffer: the option buffer |
1377 | * @buffer_len: length of buffer in bytes |
1378 | * |
1379 | * Description: |
1380 | * Generate a CIPSO option using the ranged tag, tag type #5. Returns the |
1381 | * size of the tag on success, negative values on failure. |
1382 | * |
1383 | */ |
1384 | static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def, |
1385 | const struct netlbl_lsm_secattr *secattr, |
1386 | unsigned char *buffer, |
1387 | u32 buffer_len) |
1388 | { |
1389 | int ret_val; |
1390 | u32 tag_len; |
1391 | u32 level; |
1392 | |
1393 | if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) |
1394 | return -EPERM; |
1395 | |
1396 | ret_val = cipso_v4_map_lvl_hton(doi_def, |
1397 | secattr->attr.mls.lvl, |
1398 | &level); |
1399 | if (ret_val != 0) |
1400 | return ret_val; |
1401 | |
1402 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
1403 | ret_val = cipso_v4_map_cat_rng_hton(doi_def, |
1404 | secattr, |
1405 | &buffer[4], |
1406 | buffer_len - 4); |
1407 | if (ret_val < 0) |
1408 | return ret_val; |
1409 | |
1410 | tag_len = 4 + ret_val; |
1411 | } else |
1412 | tag_len = 4; |
1413 | |
1414 | buffer[0] = CIPSO_V4_TAG_RANGE; |
1415 | buffer[1] = tag_len; |
1416 | buffer[3] = level; |
1417 | |
1418 | return tag_len; |
1419 | } |
1420 | |
1421 | /** |
1422 | * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag |
1423 | * @doi_def: the DOI definition |
1424 | * @tag: the CIPSO tag |
1425 | * @secattr: the security attributes |
1426 | * |
1427 | * Description: |
1428 | * Parse a CIPSO ranged tag (tag type #5) and return the security attributes |
1429 | * in @secattr. Return zero on success, negatives values on failure. |
1430 | * |
1431 | */ |
1432 | static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, |
1433 | const unsigned char *tag, |
1434 | struct netlbl_lsm_secattr *secattr) |
1435 | { |
1436 | int ret_val; |
1437 | u8 tag_len = tag[1]; |
1438 | u32 level; |
1439 | |
1440 | ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
1441 | if (ret_val != 0) |
1442 | return ret_val; |
1443 | secattr->attr.mls.lvl = level; |
1444 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
1445 | |
1446 | if (tag_len > 4) { |
1447 | ret_val = cipso_v4_map_cat_rng_ntoh(doi_def, |
1448 | &tag[4], |
1449 | tag_len - 4, |
1450 | secattr); |
1451 | if (ret_val != 0) { |
1452 | netlbl_catmap_free(secattr->attr.mls.cat); |
1453 | return ret_val; |
1454 | } |
1455 | |
1456 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
1457 | } |
1458 | |
1459 | return 0; |
1460 | } |
1461 | |
1462 | /** |
1463 | * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard) |
1464 | * @doi_def: the DOI definition |
1465 | * @secattr: the security attributes |
1466 | * @buffer: the option buffer |
1467 | * @buffer_len: length of buffer in bytes |
1468 | * |
1469 | * Description: |
1470 | * Generate a CIPSO option using the local tag. Returns the size of the tag |
1471 | * on success, negative values on failure. |
1472 | * |
1473 | */ |
1474 | static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def, |
1475 | const struct netlbl_lsm_secattr *secattr, |
1476 | unsigned char *buffer, |
1477 | u32 buffer_len) |
1478 | { |
1479 | if (!(secattr->flags & NETLBL_SECATTR_SECID)) |
1480 | return -EPERM; |
1481 | |
1482 | buffer[0] = CIPSO_V4_TAG_LOCAL; |
1483 | buffer[1] = CIPSO_V4_TAG_LOC_BLEN; |
1484 | *(u32 *)&buffer[2] = secattr->attr.secid; |
1485 | |
1486 | return CIPSO_V4_TAG_LOC_BLEN; |
1487 | } |
1488 | |
1489 | /** |
1490 | * cipso_v4_parsetag_loc - Parse a CIPSO local tag |
1491 | * @doi_def: the DOI definition |
1492 | * @tag: the CIPSO tag |
1493 | * @secattr: the security attributes |
1494 | * |
1495 | * Description: |
1496 | * Parse a CIPSO local tag and return the security attributes in @secattr. |
1497 | * Return zero on success, negatives values on failure. |
1498 | * |
1499 | */ |
1500 | static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def, |
1501 | const unsigned char *tag, |
1502 | struct netlbl_lsm_secattr *secattr) |
1503 | { |
1504 | secattr->attr.secid = *(u32 *)&tag[2]; |
1505 | secattr->flags |= NETLBL_SECATTR_SECID; |
1506 | |
1507 | return 0; |
1508 | } |
1509 | |
1510 | /** |
1511 | * cipso_v4_optptr - Find the CIPSO option in the packet |
1512 | * @skb: the packet |
1513 | * |
1514 | * Description: |
1515 | * Parse the packet's IP header looking for a CIPSO option. Returns a pointer |
1516 | * to the start of the CIPSO option on success, NULL if one is not found. |
1517 | * |
1518 | */ |
1519 | unsigned char *cipso_v4_optptr(const struct sk_buff *skb) |
1520 | { |
1521 | const struct iphdr *iph = ip_hdr(skb); |
1522 | unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]); |
1523 | int optlen; |
1524 | int taglen; |
1525 | |
1526 | for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) { |
1527 | switch (optptr[0]) { |
1528 | case IPOPT_END: |
1529 | return NULL; |
1530 | case IPOPT_NOOP: |
1531 | taglen = 1; |
1532 | break; |
1533 | default: |
1534 | taglen = optptr[1]; |
1535 | } |
1536 | if (!taglen || taglen > optlen) |
1537 | return NULL; |
1538 | if (optptr[0] == IPOPT_CIPSO) |
1539 | return optptr; |
1540 | |
1541 | optlen -= taglen; |
1542 | optptr += taglen; |
1543 | } |
1544 | |
1545 | return NULL; |
1546 | } |
1547 | |
1548 | /** |
1549 | * cipso_v4_validate - Validate a CIPSO option |
1550 | * @option: the start of the option, on error it is set to point to the error |
1551 | * |
1552 | * Description: |
1553 | * This routine is called to validate a CIPSO option, it checks all of the |
1554 | * fields to ensure that they are at least valid, see the draft snippet below |
1555 | * for details. If the option is valid then a zero value is returned and |
1556 | * the value of @option is unchanged. If the option is invalid then a |
1557 | * non-zero value is returned and @option is adjusted to point to the |
1558 | * offending portion of the option. From the IETF draft ... |
1559 | * |
1560 | * "If any field within the CIPSO options, such as the DOI identifier, is not |
1561 | * recognized the IP datagram is discarded and an ICMP 'parameter problem' |
1562 | * (type 12) is generated and returned. The ICMP code field is set to 'bad |
1563 | * parameter' (code 0) and the pointer is set to the start of the CIPSO field |
1564 | * that is unrecognized." |
1565 | * |
1566 | */ |
1567 | int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) |
1568 | { |
1569 | unsigned char *opt = *option; |
1570 | unsigned char *tag; |
1571 | unsigned char opt_iter; |
1572 | unsigned char err_offset = 0; |
1573 | u8 opt_len; |
1574 | u8 tag_len; |
1575 | struct cipso_v4_doi *doi_def = NULL; |
1576 | u32 tag_iter; |
1577 | |
1578 | /* caller already checks for length values that are too large */ |
1579 | opt_len = opt[1]; |
1580 | if (opt_len < 8) { |
1581 | err_offset = 1; |
1582 | goto validate_return; |
1583 | } |
1584 | |
1585 | rcu_read_lock(); |
1586 | doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2])); |
1587 | if (!doi_def) { |
1588 | err_offset = 2; |
1589 | goto validate_return_locked; |
1590 | } |
1591 | |
1592 | opt_iter = CIPSO_V4_HDR_LEN; |
1593 | tag = opt + opt_iter; |
1594 | while (opt_iter < opt_len) { |
1595 | for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];) |
1596 | if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID || |
1597 | ++tag_iter == CIPSO_V4_TAG_MAXCNT) { |
1598 | err_offset = opt_iter; |
1599 | goto validate_return_locked; |
1600 | } |
1601 | |
1602 | if (opt_iter + 1 == opt_len) { |
1603 | err_offset = opt_iter; |
1604 | goto validate_return_locked; |
1605 | } |
1606 | tag_len = tag[1]; |
1607 | if (tag_len > (opt_len - opt_iter)) { |
1608 | err_offset = opt_iter + 1; |
1609 | goto validate_return_locked; |
1610 | } |
1611 | |
1612 | switch (tag[0]) { |
1613 | case CIPSO_V4_TAG_RBITMAP: |
1614 | if (tag_len < CIPSO_V4_TAG_RBM_BLEN) { |
1615 | err_offset = opt_iter + 1; |
1616 | goto validate_return_locked; |
1617 | } |
1618 | |
1619 | /* We are already going to do all the verification |
1620 | * necessary at the socket layer so from our point of |
1621 | * view it is safe to turn these checks off (and less |
1622 | * work), however, the CIPSO draft says we should do |
1623 | * all the CIPSO validations here but it doesn't |
1624 | * really specify _exactly_ what we need to validate |
1625 | * ... so, just make it a sysctl tunable. */ |
1626 | if (cipso_v4_rbm_strictvalid) { |
1627 | if (cipso_v4_map_lvl_valid(doi_def, |
1628 | tag[3]) < 0) { |
1629 | err_offset = opt_iter + 3; |
1630 | goto validate_return_locked; |
1631 | } |
1632 | if (tag_len > CIPSO_V4_TAG_RBM_BLEN && |
1633 | cipso_v4_map_cat_rbm_valid(doi_def, |
1634 | &tag[4], |
1635 | tag_len - 4) < 0) { |
1636 | err_offset = opt_iter + 4; |
1637 | goto validate_return_locked; |
1638 | } |
1639 | } |
1640 | break; |
1641 | case CIPSO_V4_TAG_ENUM: |
1642 | if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) { |
1643 | err_offset = opt_iter + 1; |
1644 | goto validate_return_locked; |
1645 | } |
1646 | |
1647 | if (cipso_v4_map_lvl_valid(doi_def, |
1648 | tag[3]) < 0) { |
1649 | err_offset = opt_iter + 3; |
1650 | goto validate_return_locked; |
1651 | } |
1652 | if (tag_len > CIPSO_V4_TAG_ENUM_BLEN && |
1653 | cipso_v4_map_cat_enum_valid(doi_def, |
1654 | &tag[4], |
1655 | tag_len - 4) < 0) { |
1656 | err_offset = opt_iter + 4; |
1657 | goto validate_return_locked; |
1658 | } |
1659 | break; |
1660 | case CIPSO_V4_TAG_RANGE: |
1661 | if (tag_len < CIPSO_V4_TAG_RNG_BLEN) { |
1662 | err_offset = opt_iter + 1; |
1663 | goto validate_return_locked; |
1664 | } |
1665 | |
1666 | if (cipso_v4_map_lvl_valid(doi_def, |
1667 | tag[3]) < 0) { |
1668 | err_offset = opt_iter + 3; |
1669 | goto validate_return_locked; |
1670 | } |
1671 | if (tag_len > CIPSO_V4_TAG_RNG_BLEN && |
1672 | cipso_v4_map_cat_rng_valid(doi_def, |
1673 | &tag[4], |
1674 | tag_len - 4) < 0) { |
1675 | err_offset = opt_iter + 4; |
1676 | goto validate_return_locked; |
1677 | } |
1678 | break; |
1679 | case CIPSO_V4_TAG_LOCAL: |
1680 | /* This is a non-standard tag that we only allow for |
1681 | * local connections, so if the incoming interface is |
1682 | * not the loopback device drop the packet. Further, |
1683 | * there is no legitimate reason for setting this from |
1684 | * userspace so reject it if skb is NULL. */ |
1685 | if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) { |
1686 | err_offset = opt_iter; |
1687 | goto validate_return_locked; |
1688 | } |
1689 | if (tag_len != CIPSO_V4_TAG_LOC_BLEN) { |
1690 | err_offset = opt_iter + 1; |
1691 | goto validate_return_locked; |
1692 | } |
1693 | break; |
1694 | default: |
1695 | err_offset = opt_iter; |
1696 | goto validate_return_locked; |
1697 | } |
1698 | |
1699 | tag += tag_len; |
1700 | opt_iter += tag_len; |
1701 | } |
1702 | |
1703 | validate_return_locked: |
1704 | rcu_read_unlock(); |
1705 | validate_return: |
1706 | *option = opt + err_offset; |
1707 | return err_offset; |
1708 | } |
1709 | |
1710 | /** |
1711 | * cipso_v4_error - Send the correct response for a bad packet |
1712 | * @skb: the packet |
1713 | * @error: the error code |
1714 | * @gateway: CIPSO gateway flag |
1715 | * |
1716 | * Description: |
1717 | * Based on the error code given in @error, send an ICMP error message back to |
1718 | * the originating host. From the IETF draft ... |
1719 | * |
1720 | * "If the contents of the CIPSO [option] are valid but the security label is |
1721 | * outside of the configured host or port label range, the datagram is |
1722 | * discarded and an ICMP 'destination unreachable' (type 3) is generated and |
1723 | * returned. The code field of the ICMP is set to 'communication with |
1724 | * destination network administratively prohibited' (code 9) or to |
1725 | * 'communication with destination host administratively prohibited' |
1726 | * (code 10). The value of the code is dependent on whether the originator |
1727 | * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The |
1728 | * recipient of the ICMP message MUST be able to handle either value. The |
1729 | * same procedure is performed if a CIPSO [option] can not be added to an |
1730 | * IP packet because it is too large to fit in the IP options area." |
1731 | * |
1732 | * "If the error is triggered by receipt of an ICMP message, the message is |
1733 | * discarded and no response is permitted (consistent with general ICMP |
1734 | * processing rules)." |
1735 | * |
1736 | */ |
1737 | void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) |
1738 | { |
1739 | unsigned char optbuf[sizeof(struct ip_options) + 40]; |
1740 | struct ip_options *opt = (struct ip_options *)optbuf; |
1741 | |
1742 | if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES) |
1743 | return; |
1744 | |
1745 | /* |
1746 | * We might be called above the IP layer, |
1747 | * so we can not use icmp_send and IPCB here. |
1748 | */ |
1749 | |
1750 | memset(opt, 0, sizeof(struct ip_options)); |
1751 | opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr); |
1752 | if (__ip_options_compile(dev_net(skb->dev), opt, skb, NULL)) |
1753 | return; |
1754 | |
1755 | if (gateway) |
1756 | __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt); |
1757 | else |
1758 | __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt); |
1759 | } |
1760 | |
1761 | /** |
1762 | * cipso_v4_genopt - Generate a CIPSO option |
1763 | * @buf: the option buffer |
1764 | * @buf_len: the size of opt_buf |
1765 | * @doi_def: the CIPSO DOI to use |
1766 | * @secattr: the security attributes |
1767 | * |
1768 | * Description: |
1769 | * Generate a CIPSO option using the DOI definition and security attributes |
1770 | * passed to the function. Returns the length of the option on success and |
1771 | * negative values on failure. |
1772 | * |
1773 | */ |
1774 | static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, |
1775 | const struct cipso_v4_doi *doi_def, |
1776 | const struct netlbl_lsm_secattr *secattr) |
1777 | { |
1778 | int ret_val; |
1779 | u32 iter; |
1780 | |
1781 | if (buf_len <= CIPSO_V4_HDR_LEN) |
1782 | return -ENOSPC; |
1783 | |
1784 | /* XXX - This code assumes only one tag per CIPSO option which isn't |
1785 | * really a good assumption to make but since we only support the MAC |
1786 | * tags right now it is a safe assumption. */ |
1787 | iter = 0; |
1788 | do { |
1789 | memset(buf, 0, buf_len); |
1790 | switch (doi_def->tags[iter]) { |
1791 | case CIPSO_V4_TAG_RBITMAP: |
1792 | ret_val = cipso_v4_gentag_rbm(doi_def, |
1793 | secattr, |
1794 | &buf[CIPSO_V4_HDR_LEN], |
1795 | buf_len - CIPSO_V4_HDR_LEN); |
1796 | break; |
1797 | case CIPSO_V4_TAG_ENUM: |
1798 | ret_val = cipso_v4_gentag_enum(doi_def, |
1799 | secattr, |
1800 | &buf[CIPSO_V4_HDR_LEN], |
1801 | buf_len - CIPSO_V4_HDR_LEN); |
1802 | break; |
1803 | case CIPSO_V4_TAG_RANGE: |
1804 | ret_val = cipso_v4_gentag_rng(doi_def, |
1805 | secattr, |
1806 | &buf[CIPSO_V4_HDR_LEN], |
1807 | buf_len - CIPSO_V4_HDR_LEN); |
1808 | break; |
1809 | case CIPSO_V4_TAG_LOCAL: |
1810 | ret_val = cipso_v4_gentag_loc(doi_def, |
1811 | secattr, |
1812 | &buf[CIPSO_V4_HDR_LEN], |
1813 | buf_len - CIPSO_V4_HDR_LEN); |
1814 | break; |
1815 | default: |
1816 | return -EPERM; |
1817 | } |
1818 | |
1819 | iter++; |
1820 | } while (ret_val < 0 && |
1821 | iter < CIPSO_V4_TAG_MAXCNT && |
1822 | doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); |
1823 | if (ret_val < 0) |
1824 | return ret_val; |
1825 | cipso_v4_gentag_hdr(doi_def, buf, ret_val); |
1826 | return CIPSO_V4_HDR_LEN + ret_val; |
1827 | } |
1828 | |
1829 | /** |
1830 | * cipso_v4_sock_setattr - Add a CIPSO option to a socket |
1831 | * @sk: the socket |
1832 | * @doi_def: the CIPSO DOI to use |
1833 | * @secattr: the specific security attributes of the socket |
1834 | * |
1835 | * Description: |
1836 | * Set the CIPSO option on the given socket using the DOI definition and |
1837 | * security attributes passed to the function. This function requires |
1838 | * exclusive access to @sk, which means it either needs to be in the |
1839 | * process of being created or locked. Returns zero on success and negative |
1840 | * values on failure. |
1841 | * |
1842 | */ |
1843 | int cipso_v4_sock_setattr(struct sock *sk, |
1844 | const struct cipso_v4_doi *doi_def, |
1845 | const struct netlbl_lsm_secattr *secattr) |
1846 | { |
1847 | int ret_val = -EPERM; |
1848 | unsigned char *buf = NULL; |
1849 | u32 buf_len; |
1850 | u32 opt_len; |
1851 | struct ip_options_rcu *old, *opt = NULL; |
1852 | struct inet_sock *sk_inet; |
1853 | struct inet_connection_sock *sk_conn; |
1854 | |
1855 | /* In the case of sock_create_lite(), the sock->sk field is not |
1856 | * defined yet but it is not a problem as the only users of these |
1857 | * "lite" PF_INET sockets are functions which do an accept() call |
1858 | * afterwards so we will label the socket as part of the accept(). */ |
1859 | if (!sk) |
1860 | return 0; |
1861 | |
1862 | /* We allocate the maximum CIPSO option size here so we are probably |
1863 | * being a little wasteful, but it makes our life _much_ easier later |
1864 | * on and after all we are only talking about 40 bytes. */ |
1865 | buf_len = CIPSO_V4_OPT_LEN_MAX; |
1866 | buf = kmalloc(buf_len, GFP_ATOMIC); |
1867 | if (!buf) { |
1868 | ret_val = -ENOMEM; |
1869 | goto socket_setattr_failure; |
1870 | } |
1871 | |
1872 | ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
1873 | if (ret_val < 0) |
1874 | goto socket_setattr_failure; |
1875 | buf_len = ret_val; |
1876 | |
1877 | /* We can't use ip_options_get() directly because it makes a call to |
1878 | * ip_options_get_alloc() which allocates memory with GFP_KERNEL and |
1879 | * we won't always have CAP_NET_RAW even though we _always_ want to |
1880 | * set the IPOPT_CIPSO option. */ |
1881 | opt_len = (buf_len + 3) & ~3; |
1882 | opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); |
1883 | if (!opt) { |
1884 | ret_val = -ENOMEM; |
1885 | goto socket_setattr_failure; |
1886 | } |
1887 | memcpy(opt->opt.__data, buf, buf_len); |
1888 | opt->opt.optlen = opt_len; |
1889 | opt->opt.cipso = sizeof(struct iphdr); |
1890 | kfree(buf); |
1891 | buf = NULL; |
1892 | |
1893 | sk_inet = inet_sk(sk); |
1894 | |
1895 | old = rcu_dereference_protected(sk_inet->inet_opt, |
1896 | lockdep_sock_is_held(sk)); |
1897 | if (sk_inet->is_icsk) { |
1898 | sk_conn = inet_csk(sk); |
1899 | if (old) |
1900 | sk_conn->icsk_ext_hdr_len -= old->opt.optlen; |
1901 | sk_conn->icsk_ext_hdr_len += opt->opt.optlen; |
1902 | sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); |
1903 | } |
1904 | rcu_assign_pointer(sk_inet->inet_opt, opt); |
1905 | if (old) |
1906 | kfree_rcu(old, rcu); |
1907 | |
1908 | return 0; |
1909 | |
1910 | socket_setattr_failure: |
1911 | kfree(buf); |
1912 | kfree(opt); |
1913 | return ret_val; |
1914 | } |
1915 | |
1916 | /** |
1917 | * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket |
1918 | * @req: the connection request socket |
1919 | * @doi_def: the CIPSO DOI to use |
1920 | * @secattr: the specific security attributes of the socket |
1921 | * |
1922 | * Description: |
1923 | * Set the CIPSO option on the given socket using the DOI definition and |
1924 | * security attributes passed to the function. Returns zero on success and |
1925 | * negative values on failure. |
1926 | * |
1927 | */ |
1928 | int cipso_v4_req_setattr(struct request_sock *req, |
1929 | const struct cipso_v4_doi *doi_def, |
1930 | const struct netlbl_lsm_secattr *secattr) |
1931 | { |
1932 | int ret_val = -EPERM; |
1933 | unsigned char *buf = NULL; |
1934 | u32 buf_len; |
1935 | u32 opt_len; |
1936 | struct ip_options_rcu *opt = NULL; |
1937 | struct inet_request_sock *req_inet; |
1938 | |
1939 | /* We allocate the maximum CIPSO option size here so we are probably |
1940 | * being a little wasteful, but it makes our life _much_ easier later |
1941 | * on and after all we are only talking about 40 bytes. */ |
1942 | buf_len = CIPSO_V4_OPT_LEN_MAX; |
1943 | buf = kmalloc(buf_len, GFP_ATOMIC); |
1944 | if (!buf) { |
1945 | ret_val = -ENOMEM; |
1946 | goto req_setattr_failure; |
1947 | } |
1948 | |
1949 | ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
1950 | if (ret_val < 0) |
1951 | goto req_setattr_failure; |
1952 | buf_len = ret_val; |
1953 | |
1954 | /* We can't use ip_options_get() directly because it makes a call to |
1955 | * ip_options_get_alloc() which allocates memory with GFP_KERNEL and |
1956 | * we won't always have CAP_NET_RAW even though we _always_ want to |
1957 | * set the IPOPT_CIPSO option. */ |
1958 | opt_len = (buf_len + 3) & ~3; |
1959 | opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); |
1960 | if (!opt) { |
1961 | ret_val = -ENOMEM; |
1962 | goto req_setattr_failure; |
1963 | } |
1964 | memcpy(opt->opt.__data, buf, buf_len); |
1965 | opt->opt.optlen = opt_len; |
1966 | opt->opt.cipso = sizeof(struct iphdr); |
1967 | kfree(buf); |
1968 | buf = NULL; |
1969 | |
1970 | req_inet = inet_rsk(req); |
1971 | opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt); |
1972 | if (opt) |
1973 | kfree_rcu(opt, rcu); |
1974 | |
1975 | return 0; |
1976 | |
1977 | req_setattr_failure: |
1978 | kfree(buf); |
1979 | kfree(opt); |
1980 | return ret_val; |
1981 | } |
1982 | |
1983 | /** |
1984 | * cipso_v4_delopt - Delete the CIPSO option from a set of IP options |
1985 | * @opt_ptr: IP option pointer |
1986 | * |
1987 | * Description: |
1988 | * Deletes the CIPSO IP option from a set of IP options and makes the necessary |
1989 | * adjustments to the IP option structure. Returns zero on success, negative |
1990 | * values on failure. |
1991 | * |
1992 | */ |
1993 | static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr) |
1994 | { |
1995 | struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1); |
1996 | int hdr_delta = 0; |
1997 | |
1998 | if (!opt || opt->opt.cipso == 0) |
1999 | return 0; |
2000 | if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) { |
2001 | u8 cipso_len; |
2002 | u8 cipso_off; |
2003 | unsigned char *cipso_ptr; |
2004 | int iter; |
2005 | int optlen_new; |
2006 | |
2007 | cipso_off = opt->opt.cipso - sizeof(struct iphdr); |
2008 | cipso_ptr = &opt->opt.__data[cipso_off]; |
2009 | cipso_len = cipso_ptr[1]; |
2010 | |
2011 | if (opt->opt.srr > opt->opt.cipso) |
2012 | opt->opt.srr -= cipso_len; |
2013 | if (opt->opt.rr > opt->opt.cipso) |
2014 | opt->opt.rr -= cipso_len; |
2015 | if (opt->opt.ts > opt->opt.cipso) |
2016 | opt->opt.ts -= cipso_len; |
2017 | if (opt->opt.router_alert > opt->opt.cipso) |
2018 | opt->opt.router_alert -= cipso_len; |
2019 | opt->opt.cipso = 0; |
2020 | |
2021 | memmove(cipso_ptr, cipso_ptr + cipso_len, |
2022 | opt->opt.optlen - cipso_off - cipso_len); |
2023 | |
2024 | /* determining the new total option length is tricky because of |
2025 | * the padding necessary, the only thing i can think to do at |
2026 | * this point is walk the options one-by-one, skipping the |
2027 | * padding at the end to determine the actual option size and |
2028 | * from there we can determine the new total option length */ |
2029 | iter = 0; |
2030 | optlen_new = 0; |
2031 | while (iter < opt->opt.optlen) |
2032 | if (opt->opt.__data[iter] != IPOPT_NOP) { |
2033 | iter += opt->opt.__data[iter + 1]; |
2034 | optlen_new = iter; |
2035 | } else |
2036 | iter++; |
2037 | hdr_delta = opt->opt.optlen; |
2038 | opt->opt.optlen = (optlen_new + 3) & ~3; |
2039 | hdr_delta -= opt->opt.optlen; |
2040 | } else { |
2041 | /* only the cipso option was present on the socket so we can |
2042 | * remove the entire option struct */ |
2043 | *opt_ptr = NULL; |
2044 | hdr_delta = opt->opt.optlen; |
2045 | kfree_rcu(opt, rcu); |
2046 | } |
2047 | |
2048 | return hdr_delta; |
2049 | } |
2050 | |
2051 | /** |
2052 | * cipso_v4_sock_delattr - Delete the CIPSO option from a socket |
2053 | * @sk: the socket |
2054 | * |
2055 | * Description: |
2056 | * Removes the CIPSO option from a socket, if present. |
2057 | * |
2058 | */ |
2059 | void cipso_v4_sock_delattr(struct sock *sk) |
2060 | { |
2061 | struct inet_sock *sk_inet; |
2062 | int hdr_delta; |
2063 | |
2064 | sk_inet = inet_sk(sk); |
2065 | |
2066 | hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt); |
2067 | if (sk_inet->is_icsk && hdr_delta > 0) { |
2068 | struct inet_connection_sock *sk_conn = inet_csk(sk); |
2069 | sk_conn->icsk_ext_hdr_len -= hdr_delta; |
2070 | sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); |
2071 | } |
2072 | } |
2073 | |
2074 | /** |
2075 | * cipso_v4_req_delattr - Delete the CIPSO option from a request socket |
2076 | * @reg: the request socket |
2077 | * |
2078 | * Description: |
2079 | * Removes the CIPSO option from a request socket, if present. |
2080 | * |
2081 | */ |
2082 | void cipso_v4_req_delattr(struct request_sock *req) |
2083 | { |
2084 | cipso_v4_delopt(&inet_rsk(req)->ireq_opt); |
2085 | } |
2086 | |
2087 | /** |
2088 | * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions |
2089 | * @cipso: the CIPSO v4 option |
2090 | * @secattr: the security attributes |
2091 | * |
2092 | * Description: |
2093 | * Inspect @cipso and return the security attributes in @secattr. Returns zero |
2094 | * on success and negative values on failure. |
2095 | * |
2096 | */ |
2097 | int cipso_v4_getattr(const unsigned char *cipso, |
2098 | struct netlbl_lsm_secattr *secattr) |
2099 | { |
2100 | int ret_val = -ENOMSG; |
2101 | u32 doi; |
2102 | struct cipso_v4_doi *doi_def; |
2103 | |
2104 | if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0) |
2105 | return 0; |
2106 | |
2107 | doi = get_unaligned_be32(&cipso[2]); |
2108 | rcu_read_lock(); |
2109 | doi_def = cipso_v4_doi_search(doi); |
2110 | if (!doi_def) |
2111 | goto getattr_return; |
2112 | /* XXX - This code assumes only one tag per CIPSO option which isn't |
2113 | * really a good assumption to make but since we only support the MAC |
2114 | * tags right now it is a safe assumption. */ |
2115 | switch (cipso[6]) { |
2116 | case CIPSO_V4_TAG_RBITMAP: |
2117 | ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr); |
2118 | break; |
2119 | case CIPSO_V4_TAG_ENUM: |
2120 | ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr); |
2121 | break; |
2122 | case CIPSO_V4_TAG_RANGE: |
2123 | ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr); |
2124 | break; |
2125 | case CIPSO_V4_TAG_LOCAL: |
2126 | ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr); |
2127 | break; |
2128 | } |
2129 | if (ret_val == 0) |
2130 | secattr->type = NETLBL_NLTYPE_CIPSOV4; |
2131 | |
2132 | getattr_return: |
2133 | rcu_read_unlock(); |
2134 | return ret_val; |
2135 | } |
2136 | |
2137 | /** |
2138 | * cipso_v4_sock_getattr - Get the security attributes from a sock |
2139 | * @sk: the sock |
2140 | * @secattr: the security attributes |
2141 | * |
2142 | * Description: |
2143 | * Query @sk to see if there is a CIPSO option attached to the sock and if |
2144 | * there is return the CIPSO security attributes in @secattr. This function |
2145 | * requires that @sk be locked, or privately held, but it does not do any |
2146 | * locking itself. Returns zero on success and negative values on failure. |
2147 | * |
2148 | */ |
2149 | int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) |
2150 | { |
2151 | struct ip_options_rcu *opt; |
2152 | int res = -ENOMSG; |
2153 | |
2154 | rcu_read_lock(); |
2155 | opt = rcu_dereference(inet_sk(sk)->inet_opt); |
2156 | if (opt && opt->opt.cipso) |
2157 | res = cipso_v4_getattr(opt->opt.__data + |
2158 | opt->opt.cipso - |
2159 | sizeof(struct iphdr), |
2160 | secattr); |
2161 | rcu_read_unlock(); |
2162 | return res; |
2163 | } |
2164 | |
2165 | /** |
2166 | * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet |
2167 | * @skb: the packet |
2168 | * @secattr: the security attributes |
2169 | * |
2170 | * Description: |
2171 | * Set the CIPSO option on the given packet based on the security attributes. |
2172 | * Returns a pointer to the IP header on success and NULL on failure. |
2173 | * |
2174 | */ |
2175 | int cipso_v4_skbuff_setattr(struct sk_buff *skb, |
2176 | const struct cipso_v4_doi *doi_def, |
2177 | const struct netlbl_lsm_secattr *secattr) |
2178 | { |
2179 | int ret_val; |
2180 | struct iphdr *iph; |
2181 | struct ip_options *opt = &IPCB(skb)->opt; |
2182 | unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; |
2183 | u32 buf_len = CIPSO_V4_OPT_LEN_MAX; |
2184 | u32 opt_len; |
2185 | int len_delta; |
2186 | |
2187 | ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
2188 | if (ret_val < 0) |
2189 | return ret_val; |
2190 | buf_len = ret_val; |
2191 | opt_len = (buf_len + 3) & ~3; |
2192 | |
2193 | /* we overwrite any existing options to ensure that we have enough |
2194 | * room for the CIPSO option, the reason is that we _need_ to guarantee |
2195 | * that the security label is applied to the packet - we do the same |
2196 | * thing when using the socket options and it hasn't caused a problem, |
2197 | * if we need to we can always revisit this choice later */ |
2198 | |
2199 | len_delta = opt_len - opt->optlen; |
2200 | /* if we don't ensure enough headroom we could panic on the skb_push() |
2201 | * call below so make sure we have enough, we are also "mangling" the |
2202 | * packet so we should probably do a copy-on-write call anyway */ |
2203 | ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); |
2204 | if (ret_val < 0) |
2205 | return ret_val; |
2206 | |
2207 | if (len_delta > 0) { |
2208 | /* we assume that the header + opt->optlen have already been |
2209 | * "pushed" in ip_options_build() or similar */ |
2210 | iph = ip_hdr(skb); |
2211 | skb_push(skb, len_delta); |
2212 | memmove((char *)iph - len_delta, iph, iph->ihl << 2); |
2213 | skb_reset_network_header(skb); |
2214 | iph = ip_hdr(skb); |
2215 | } else if (len_delta < 0) { |
2216 | iph = ip_hdr(skb); |
2217 | memset(iph + 1, IPOPT_NOP, opt->optlen); |
2218 | } else |
2219 | iph = ip_hdr(skb); |
2220 | |
2221 | if (opt->optlen > 0) |
2222 | memset(opt, 0, sizeof(*opt)); |
2223 | opt->optlen = opt_len; |
2224 | opt->cipso = sizeof(struct iphdr); |
2225 | opt->is_changed = 1; |
2226 | |
2227 | /* we have to do the following because we are being called from a |
2228 | * netfilter hook which means the packet already has had the header |
2229 | * fields populated and the checksum calculated - yes this means we |
2230 | * are doing more work than needed but we do it to keep the core |
2231 | * stack clean and tidy */ |
2232 | memcpy(iph + 1, buf, buf_len); |
2233 | if (opt_len > buf_len) |
2234 | memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); |
2235 | if (len_delta != 0) { |
2236 | iph->ihl = 5 + (opt_len >> 2); |
2237 | iph->tot_len = htons(skb->len); |
2238 | } |
2239 | ip_send_check(iph); |
2240 | |
2241 | return 0; |
2242 | } |
2243 | |
2244 | /** |
2245 | * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet |
2246 | * @skb: the packet |
2247 | * |
2248 | * Description: |
2249 | * Removes any and all CIPSO options from the given packet. Returns zero on |
2250 | * success, negative values on failure. |
2251 | * |
2252 | */ |
2253 | int cipso_v4_skbuff_delattr(struct sk_buff *skb) |
2254 | { |
2255 | int ret_val; |
2256 | struct iphdr *iph; |
2257 | struct ip_options *opt = &IPCB(skb)->opt; |
2258 | unsigned char *cipso_ptr; |
2259 | |
2260 | if (opt->cipso == 0) |
2261 | return 0; |
2262 | |
2263 | /* since we are changing the packet we should make a copy */ |
2264 | ret_val = skb_cow(skb, skb_headroom(skb)); |
2265 | if (ret_val < 0) |
2266 | return ret_val; |
2267 | |
2268 | /* the easiest thing to do is just replace the cipso option with noop |
2269 | * options since we don't change the size of the packet, although we |
2270 | * still need to recalculate the checksum */ |
2271 | |
2272 | iph = ip_hdr(skb); |
2273 | cipso_ptr = (unsigned char *)iph + opt->cipso; |
2274 | memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); |
2275 | opt->cipso = 0; |
2276 | opt->is_changed = 1; |
2277 | |
2278 | ip_send_check(iph); |
2279 | |
2280 | return 0; |
2281 | } |
2282 | |
2283 | /* |
2284 | * Setup Functions |
2285 | */ |
2286 | |
2287 | /** |
2288 | * cipso_v4_init - Initialize the CIPSO module |
2289 | * |
2290 | * Description: |
2291 | * Initialize the CIPSO module and prepare it for use. Returns zero on success |
2292 | * and negative values on failure. |
2293 | * |
2294 | */ |
2295 | static int __init cipso_v4_init(void) |
2296 | { |
2297 | int ret_val; |
2298 | |
2299 | ret_val = cipso_v4_cache_init(); |
2300 | if (ret_val != 0) |
2301 | panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n" , |
2302 | ret_val); |
2303 | |
2304 | return 0; |
2305 | } |
2306 | |
2307 | subsys_initcall(cipso_v4_init); |
2308 | |