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NetLabel: add tag verification when adding new CIPSOv4 DOI definitions
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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/*
16 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
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>
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47#include <asm/bug.h>
48
49struct cipso_v4_domhsh_entry {
50 char *domain;
51 u32 valid;
52 struct list_head list;
53 struct rcu_head rcu;
54};
55
56/* List of available DOI definitions */
57/* XXX - Updates should be minimal so having a single lock for the
58 * cipso_v4_doi_list and the cipso_v4_doi_list->dom_list should be
59 * okay. */
60/* XXX - This currently assumes a minimal number of different DOIs in use,
61 * if in practice there are a lot of different DOIs this list should
62 * probably be turned into a hash table or something similar so we
63 * can do quick lookups. */
8ce11e6a 64static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
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65static struct list_head cipso_v4_doi_list = LIST_HEAD_INIT(cipso_v4_doi_list);
66
67/* Label mapping cache */
68int cipso_v4_cache_enabled = 1;
69int cipso_v4_cache_bucketsize = 10;
70#define CIPSO_V4_CACHE_BUCKETBITS 7
71#define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS)
72#define CIPSO_V4_CACHE_REORDERLIMIT 10
73struct cipso_v4_map_cache_bkt {
74 spinlock_t lock;
75 u32 size;
76 struct list_head list;
77};
78struct cipso_v4_map_cache_entry {
79 u32 hash;
80 unsigned char *key;
81 size_t key_len;
82
ffb733c6 83 struct netlbl_lsm_cache *lsm_data;
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84
85 u32 activity;
86 struct list_head list;
87};
88static struct cipso_v4_map_cache_bkt *cipso_v4_cache = NULL;
89
90/* Restricted bitmap (tag #1) flags */
91int cipso_v4_rbm_optfmt = 0;
92int cipso_v4_rbm_strictvalid = 1;
93
94/*
95 * Helper Functions
96 */
97
98/**
99 * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
100 * @bitmap: the bitmap
101 * @bitmap_len: length in bits
102 * @offset: starting offset
103 * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
104 *
105 * Description:
106 * Starting at @offset, walk the bitmap from left to right until either the
107 * desired bit is found or we reach the end. Return the bit offset, -1 if
108 * not found, or -2 if error.
109 */
110static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
111 u32 bitmap_len,
112 u32 offset,
113 u8 state)
114{
115 u32 bit_spot;
116 u32 byte_offset;
117 unsigned char bitmask;
118 unsigned char byte;
119
120 /* gcc always rounds to zero when doing integer division */
121 byte_offset = offset / 8;
122 byte = bitmap[byte_offset];
123 bit_spot = offset;
124 bitmask = 0x80 >> (offset % 8);
125
126 while (bit_spot < bitmap_len) {
127 if ((state && (byte & bitmask) == bitmask) ||
128 (state == 0 && (byte & bitmask) == 0))
129 return bit_spot;
130
131 bit_spot++;
132 bitmask >>= 1;
133 if (bitmask == 0) {
134 byte = bitmap[++byte_offset];
135 bitmask = 0x80;
136 }
137 }
138
139 return -1;
140}
141
142/**
143 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
144 * @bitmap: the bitmap
145 * @bit: the bit
146 * @state: if non-zero, set the bit (1) else clear the bit (0)
147 *
148 * Description:
149 * Set a single bit in the bitmask. Returns zero on success, negative values
150 * on error.
151 */
152static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
153 u32 bit,
154 u8 state)
155{
156 u32 byte_spot;
157 u8 bitmask;
158
159 /* gcc always rounds to zero when doing integer division */
160 byte_spot = bit / 8;
161 bitmask = 0x80 >> (bit % 8);
162 if (state)
163 bitmap[byte_spot] |= bitmask;
164 else
165 bitmap[byte_spot] &= ~bitmask;
166}
167
168/**
169 * cipso_v4_doi_domhsh_free - Frees a domain list entry
170 * @entry: the entry's RCU field
171 *
172 * Description:
173 * This function is designed to be used as a callback to the call_rcu()
174 * function so that the memory allocated to a domain list entry can be released
175 * safely.
176 *
177 */
178static void cipso_v4_doi_domhsh_free(struct rcu_head *entry)
179{
180 struct cipso_v4_domhsh_entry *ptr;
181
182 ptr = container_of(entry, struct cipso_v4_domhsh_entry, rcu);
183 kfree(ptr->domain);
184 kfree(ptr);
185}
186
187/**
188 * cipso_v4_cache_entry_free - Frees a cache entry
189 * @entry: the entry to free
190 *
191 * Description:
ffb733c6 192 * This function frees the memory associated with a cache entry including the
193 * LSM cache data if there are no longer any users, i.e. reference count == 0.
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194 *
195 */
196static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
197{
ffb733c6 198 if (entry->lsm_data)
199 netlbl_secattr_cache_free(entry->lsm_data);
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200 kfree(entry->key);
201 kfree(entry);
202}
203
204/**
205 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
206 * @key: the hash key
207 * @key_len: the length of the key in bytes
208 *
209 * Description:
210 * The CIPSO tag hashing function. Returns a 32-bit hash value.
211 *
212 */
213static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
214{
215 return jhash(key, key_len, 0);
216}
217
218/*
219 * Label Mapping Cache Functions
220 */
221
222/**
223 * cipso_v4_cache_init - Initialize the CIPSO cache
224 *
225 * Description:
226 * Initializes the CIPSO label mapping cache, this function should be called
227 * before any of the other functions defined in this file. Returns zero on
228 * success, negative values on error.
229 *
230 */
231static int cipso_v4_cache_init(void)
232{
233 u32 iter;
234
235 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
236 sizeof(struct cipso_v4_map_cache_bkt),
237 GFP_KERNEL);
238 if (cipso_v4_cache == NULL)
239 return -ENOMEM;
240
241 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
242 spin_lock_init(&cipso_v4_cache[iter].lock);
243 cipso_v4_cache[iter].size = 0;
244 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
245 }
246
247 return 0;
248}
249
250/**
251 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
252 *
253 * Description:
254 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
255 * success and negative values on failure.
256 *
257 */
258void cipso_v4_cache_invalidate(void)
259{
260 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
261 u32 iter;
262
263 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
609c92fe 264 spin_lock_bh(&cipso_v4_cache[iter].lock);
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265 list_for_each_entry_safe(entry,
266 tmp_entry,
267 &cipso_v4_cache[iter].list, list) {
268 list_del(&entry->list);
269 cipso_v4_cache_entry_free(entry);
270 }
271 cipso_v4_cache[iter].size = 0;
609c92fe 272 spin_unlock_bh(&cipso_v4_cache[iter].lock);
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273 }
274
275 return;
276}
277
278/**
279 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
280 * @key: the buffer to check
281 * @key_len: buffer length in bytes
282 * @secattr: the security attribute struct to use
283 *
284 * Description:
285 * This function checks the cache to see if a label mapping already exists for
286 * the given key. If there is a match then the cache is adjusted and the
287 * @secattr struct is populated with the correct LSM security attributes. The
288 * cache is adjusted in the following manner if the entry is not already the
289 * first in the cache bucket:
290 *
291 * 1. The cache entry's activity counter is incremented
292 * 2. The previous (higher ranking) entry's activity counter is decremented
293 * 3. If the difference between the two activity counters is geater than
294 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
295 *
296 * Returns zero on success, -ENOENT for a cache miss, and other negative values
297 * on error.
298 *
299 */
300static int cipso_v4_cache_check(const unsigned char *key,
301 u32 key_len,
302 struct netlbl_lsm_secattr *secattr)
303{
304 u32 bkt;
305 struct cipso_v4_map_cache_entry *entry;
306 struct cipso_v4_map_cache_entry *prev_entry = NULL;
307 u32 hash;
308
309 if (!cipso_v4_cache_enabled)
310 return -ENOENT;
311
312 hash = cipso_v4_map_cache_hash(key, key_len);
313 bkt = hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
609c92fe 314 spin_lock_bh(&cipso_v4_cache[bkt].lock);
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315 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
316 if (entry->hash == hash &&
317 entry->key_len == key_len &&
318 memcmp(entry->key, key, key_len) == 0) {
319 entry->activity += 1;
ffb733c6 320 atomic_inc(&entry->lsm_data->refcount);
321 secattr->cache = entry->lsm_data;
701a90ba 322 secattr->flags |= NETLBL_SECATTR_CACHE;
446fda4f 323 if (prev_entry == NULL) {
609c92fe 324 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
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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);
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340 return 0;
341 }
342 prev_entry = entry;
343 }
609c92fe 344 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
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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 */
362int 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);
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382 if (entry->key == NULL) {
383 ret_val = -ENOMEM;
384 goto cache_add_failure;
385 }
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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;
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390
391 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
609c92fe 392 spin_lock_bh(&cipso_v4_cache[bkt].lock);
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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);
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404
405 return 0;
406
407cache_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 */
426static 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)
431 if (iter->doi == doi && iter->valid)
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 */
448int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
449{
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450 u32 iter;
451
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452 if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
453 return -EINVAL;
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454 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
455 switch (doi_def->tags[iter]) {
456 case CIPSO_V4_TAG_RBITMAP:
457 break;
458 case CIPSO_V4_TAG_INVALID:
459 if (iter == 0)
460 return -EINVAL;
461 break;
462 default:
463 return -EINVAL;
464 }
465 }
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466
467 doi_def->valid = 1;
468 INIT_RCU_HEAD(&doi_def->rcu);
469 INIT_LIST_HEAD(&doi_def->dom_list);
470
471 rcu_read_lock();
472 if (cipso_v4_doi_search(doi_def->doi) != NULL)
473 goto doi_add_failure_rlock;
474 spin_lock(&cipso_v4_doi_list_lock);
475 if (cipso_v4_doi_search(doi_def->doi) != NULL)
476 goto doi_add_failure_slock;
477 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
478 spin_unlock(&cipso_v4_doi_list_lock);
479 rcu_read_unlock();
480
481 return 0;
482
483doi_add_failure_slock:
484 spin_unlock(&cipso_v4_doi_list_lock);
485doi_add_failure_rlock:
486 rcu_read_unlock();
487 return -EEXIST;
488}
489
490/**
491 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
492 * @doi: the DOI value
32f50cde 493 * @audit_secid: the LSM secid to use in the audit message
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494 * @callback: the DOI cleanup/free callback
495 *
496 * Description:
497 * Removes a DOI definition from the CIPSO engine, @callback is called to
498 * free any memory. The NetLabel routines will be called to release their own
499 * LSM domain mappings as well as our own domain list. Returns zero on
500 * success and negative values on failure.
501 *
502 */
32f50cde 503int cipso_v4_doi_remove(u32 doi,
95d4e6be 504 struct netlbl_audit *audit_info,
32f50cde 505 void (*callback) (struct rcu_head * head))
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506{
507 struct cipso_v4_doi *doi_def;
508 struct cipso_v4_domhsh_entry *dom_iter;
509
510 rcu_read_lock();
511 if (cipso_v4_doi_search(doi) != NULL) {
512 spin_lock(&cipso_v4_doi_list_lock);
513 doi_def = cipso_v4_doi_search(doi);
514 if (doi_def == NULL) {
515 spin_unlock(&cipso_v4_doi_list_lock);
516 rcu_read_unlock();
517 return -ENOENT;
518 }
519 doi_def->valid = 0;
520 list_del_rcu(&doi_def->list);
521 spin_unlock(&cipso_v4_doi_list_lock);
522 list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list)
523 if (dom_iter->valid)
32f50cde 524 netlbl_domhsh_remove(dom_iter->domain,
95d4e6be 525 audit_info);
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526 cipso_v4_cache_invalidate();
527 rcu_read_unlock();
528
529 call_rcu(&doi_def->rcu, callback);
530 return 0;
531 }
532 rcu_read_unlock();
533
534 return -ENOENT;
535}
536
537/**
538 * cipso_v4_doi_getdef - Returns a pointer to a valid DOI definition
539 * @doi: the DOI value
540 *
541 * Description:
542 * Searches for a valid DOI definition and if one is found it is returned to
543 * the caller. Otherwise NULL is returned. The caller must ensure that
544 * rcu_read_lock() is held while accessing the returned definition.
545 *
546 */
547struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
548{
549 return cipso_v4_doi_search(doi);
550}
551
552/**
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553 * cipso_v4_doi_walk - Iterate through the DOI definitions
554 * @skip_cnt: skip past this number of DOI definitions, updated
555 * @callback: callback for each DOI definition
556 * @cb_arg: argument for the callback function
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557 *
558 * Description:
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559 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
560 * For each entry call @callback, if @callback returns a negative value stop
561 * 'walking' through the list and return. Updates the value in @skip_cnt upon
562 * return. Returns zero on success, negative values on failure.
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563 *
564 */
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565int cipso_v4_doi_walk(u32 *skip_cnt,
566 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
567 void *cb_arg)
446fda4f 568{
fcd48280 569 int ret_val = -ENOENT;
446fda4f 570 u32 doi_cnt = 0;
fcd48280 571 struct cipso_v4_doi *iter_doi;
446fda4f 572
446fda4f 573 rcu_read_lock();
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574 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
575 if (iter_doi->valid) {
576 if (doi_cnt++ < *skip_cnt)
577 continue;
578 ret_val = callback(iter_doi, cb_arg);
579 if (ret_val < 0) {
580 doi_cnt--;
581 goto doi_walk_return;
446fda4f 582 }
446fda4f 583 }
446fda4f 584
fcd48280 585doi_walk_return:
446fda4f 586 rcu_read_unlock();
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587 *skip_cnt = doi_cnt;
588 return ret_val;
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589}
590
591/**
592 * cipso_v4_doi_domhsh_add - Adds a domain entry to a DOI definition
593 * @doi_def: the DOI definition
594 * @domain: the domain to add
595 *
596 * Description:
597 * Adds the @domain to the the DOI specified by @doi_def, this function
598 * should only be called by external functions (i.e. NetLabel). This function
599 * does allocate memory. Returns zero on success, negative values on failure.
600 *
601 */
602int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def, const char *domain)
603{
604 struct cipso_v4_domhsh_entry *iter;
605 struct cipso_v4_domhsh_entry *new_dom;
606
607 new_dom = kzalloc(sizeof(*new_dom), GFP_KERNEL);
608 if (new_dom == NULL)
609 return -ENOMEM;
610 if (domain) {
611 new_dom->domain = kstrdup(domain, GFP_KERNEL);
612 if (new_dom->domain == NULL) {
613 kfree(new_dom);
614 return -ENOMEM;
615 }
616 }
617 new_dom->valid = 1;
618 INIT_RCU_HEAD(&new_dom->rcu);
619
620 rcu_read_lock();
621 spin_lock(&cipso_v4_doi_list_lock);
622 list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
623 if (iter->valid &&
624 ((domain != NULL && iter->domain != NULL &&
625 strcmp(iter->domain, domain) == 0) ||
626 (domain == NULL && iter->domain == NULL))) {
627 spin_unlock(&cipso_v4_doi_list_lock);
628 rcu_read_unlock();
629 kfree(new_dom->domain);
630 kfree(new_dom);
631 return -EEXIST;
632 }
633 list_add_tail_rcu(&new_dom->list, &doi_def->dom_list);
634 spin_unlock(&cipso_v4_doi_list_lock);
635 rcu_read_unlock();
636
637 return 0;
638}
639
640/**
641 * cipso_v4_doi_domhsh_remove - Removes a domain entry from a DOI definition
642 * @doi_def: the DOI definition
643 * @domain: the domain to remove
644 *
645 * Description:
646 * Removes the @domain from the DOI specified by @doi_def, this function
647 * should only be called by external functions (i.e. NetLabel). Returns zero
648 * on success and negative values on error.
649 *
650 */
651int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def,
652 const char *domain)
653{
654 struct cipso_v4_domhsh_entry *iter;
655
656 rcu_read_lock();
657 spin_lock(&cipso_v4_doi_list_lock);
658 list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
659 if (iter->valid &&
660 ((domain != NULL && iter->domain != NULL &&
661 strcmp(iter->domain, domain) == 0) ||
662 (domain == NULL && iter->domain == NULL))) {
663 iter->valid = 0;
664 list_del_rcu(&iter->list);
665 spin_unlock(&cipso_v4_doi_list_lock);
666 rcu_read_unlock();
667 call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free);
668
669 return 0;
670 }
671 spin_unlock(&cipso_v4_doi_list_lock);
672 rcu_read_unlock();
673
674 return -ENOENT;
675}
676
677/*
678 * Label Mapping Functions
679 */
680
681/**
682 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
683 * @doi_def: the DOI definition
684 * @level: the level to check
685 *
686 * Description:
687 * Checks the given level against the given DOI definition and returns a
688 * negative value if the level does not have a valid mapping and a zero value
689 * if the level is defined by the DOI.
690 *
691 */
692static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
693{
694 switch (doi_def->type) {
695 case CIPSO_V4_MAP_PASS:
696 return 0;
697 case CIPSO_V4_MAP_STD:
698 if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
699 return 0;
700 break;
701 }
702
703 return -EFAULT;
704}
705
706/**
707 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
708 * @doi_def: the DOI definition
709 * @host_lvl: the host MLS level
710 * @net_lvl: the network/CIPSO MLS level
711 *
712 * Description:
713 * Perform a label mapping to translate a local MLS level to the correct
714 * CIPSO level using the given DOI definition. Returns zero on success,
715 * negative values otherwise.
716 *
717 */
718static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
719 u32 host_lvl,
720 u32 *net_lvl)
721{
722 switch (doi_def->type) {
723 case CIPSO_V4_MAP_PASS:
724 *net_lvl = host_lvl;
725 return 0;
726 case CIPSO_V4_MAP_STD:
727 if (host_lvl < doi_def->map.std->lvl.local_size) {
728 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
729 return 0;
730 }
731 break;
732 }
733
734 return -EINVAL;
735}
736
737/**
738 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
739 * @doi_def: the DOI definition
740 * @net_lvl: the network/CIPSO MLS level
741 * @host_lvl: the host MLS level
742 *
743 * Description:
744 * Perform a label mapping to translate a CIPSO level to the correct local MLS
745 * level using the given DOI definition. Returns zero on success, negative
746 * values otherwise.
747 *
748 */
749static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
750 u32 net_lvl,
751 u32 *host_lvl)
752{
753 struct cipso_v4_std_map_tbl *map_tbl;
754
755 switch (doi_def->type) {
756 case CIPSO_V4_MAP_PASS:
757 *host_lvl = net_lvl;
758 return 0;
759 case CIPSO_V4_MAP_STD:
760 map_tbl = doi_def->map.std;
761 if (net_lvl < map_tbl->lvl.cipso_size &&
762 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
763 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
764 return 0;
765 }
766 break;
767 }
768
769 return -EINVAL;
770}
771
772/**
773 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
774 * @doi_def: the DOI definition
775 * @bitmap: category bitmap
776 * @bitmap_len: bitmap length in bytes
777 *
778 * Description:
779 * Checks the given category bitmap against the given DOI definition and
780 * returns a negative value if any of the categories in the bitmap do not have
781 * a valid mapping and a zero value if all of the categories are valid.
782 *
783 */
784static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
785 const unsigned char *bitmap,
786 u32 bitmap_len)
787{
788 int cat = -1;
789 u32 bitmap_len_bits = bitmap_len * 8;
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790 u32 cipso_cat_size;
791 u32 *cipso_array;
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792
793 switch (doi_def->type) {
794 case CIPSO_V4_MAP_PASS:
795 return 0;
796 case CIPSO_V4_MAP_STD:
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797 cipso_cat_size = doi_def->map.std->cat.cipso_size;
798 cipso_array = doi_def->map.std->cat.cipso;
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799 for (;;) {
800 cat = cipso_v4_bitmap_walk(bitmap,
801 bitmap_len_bits,
802 cat + 1,
803 1);
804 if (cat < 0)
805 break;
806 if (cat >= cipso_cat_size ||
807 cipso_array[cat] >= CIPSO_V4_INV_CAT)
808 return -EFAULT;
809 }
810
811 if (cat == -1)
812 return 0;
813 break;
814 }
815
816 return -EFAULT;
817}
818
819/**
820 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
821 * @doi_def: the DOI definition
822 * @host_cat: the category bitmap in host format
823 * @host_cat_len: the length of the host's category bitmap in bytes
824 * @net_cat: the zero'd out category bitmap in network/CIPSO format
825 * @net_cat_len: the length of the CIPSO bitmap in bytes
826 *
827 * Description:
828 * Perform a label mapping to translate a local MLS category bitmap to the
829 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
830 * size in bytes of the network bitmap on success, negative values otherwise.
831 *
832 */
833static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
834 const unsigned char *host_cat,
835 u32 host_cat_len,
836 unsigned char *net_cat,
837 u32 net_cat_len)
838{
839 int host_spot = -1;
840 u32 net_spot;
841 u32 net_spot_max = 0;
842 u32 host_clen_bits = host_cat_len * 8;
843 u32 net_clen_bits = net_cat_len * 8;
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844 u32 host_cat_size;
845 u32 *host_cat_array;
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846
847 switch (doi_def->type) {
848 case CIPSO_V4_MAP_PASS:
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849 net_spot_max = host_cat_len;
850 while (net_spot_max > 0 && host_cat[net_spot_max - 1] == 0)
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851 net_spot_max--;
852 if (net_spot_max > net_cat_len)
853 return -EINVAL;
854 memcpy(net_cat, host_cat, net_spot_max);
855 return net_spot_max;
856 case CIPSO_V4_MAP_STD:
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857 host_cat_size = doi_def->map.std->cat.local_size;
858 host_cat_array = doi_def->map.std->cat.local;
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859 for (;;) {
860 host_spot = cipso_v4_bitmap_walk(host_cat,
861 host_clen_bits,
862 host_spot + 1,
863 1);
864 if (host_spot < 0)
865 break;
866 if (host_spot >= host_cat_size)
867 return -EPERM;
868
869 net_spot = host_cat_array[host_spot];
870 if (net_spot >= net_clen_bits)
871 return -ENOSPC;
872 cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
873
874 if (net_spot > net_spot_max)
875 net_spot_max = net_spot;
876 }
877
878 if (host_spot == -2)
879 return -EFAULT;
880
881 if (++net_spot_max % 8)
882 return net_spot_max / 8 + 1;
883 return net_spot_max / 8;
884 }
885
886 return -EINVAL;
887}
888
889/**
890 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
891 * @doi_def: the DOI definition
892 * @net_cat: the category bitmap in network/CIPSO format
893 * @net_cat_len: the length of the CIPSO bitmap in bytes
894 * @host_cat: the zero'd out category bitmap in host format
895 * @host_cat_len: the length of the host's category bitmap in bytes
896 *
897 * Description:
898 * Perform a label mapping to translate a CIPSO bitmap to the correct local
899 * MLS category bitmap using the given DOI definition. Returns the minimum
900 * size in bytes of the host bitmap on success, negative values otherwise.
901 *
902 */
903static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
904 const unsigned char *net_cat,
905 u32 net_cat_len,
906 unsigned char *host_cat,
907 u32 host_cat_len)
908{
909 u32 host_spot;
910 u32 host_spot_max = 0;
911 int net_spot = -1;
912 u32 net_clen_bits = net_cat_len * 8;
913 u32 host_clen_bits = host_cat_len * 8;
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914 u32 net_cat_size;
915 u32 *net_cat_array;
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916
917 switch (doi_def->type) {
918 case CIPSO_V4_MAP_PASS:
919 if (net_cat_len > host_cat_len)
920 return -EINVAL;
921 memcpy(host_cat, net_cat, net_cat_len);
922 return net_cat_len;
923 case CIPSO_V4_MAP_STD:
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924 net_cat_size = doi_def->map.std->cat.cipso_size;
925 net_cat_array = doi_def->map.std->cat.cipso;
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926 for (;;) {
927 net_spot = cipso_v4_bitmap_walk(net_cat,
928 net_clen_bits,
929 net_spot + 1,
930 1);
931 if (net_spot < 0)
932 break;
933 if (net_spot >= net_cat_size ||
934 net_cat_array[net_spot] >= CIPSO_V4_INV_CAT)
935 return -EPERM;
936
937 host_spot = net_cat_array[net_spot];
938 if (host_spot >= host_clen_bits)
939 return -ENOSPC;
940 cipso_v4_bitmap_setbit(host_cat, host_spot, 1);
941
942 if (host_spot > host_spot_max)
943 host_spot_max = host_spot;
944 }
945
946 if (net_spot == -2)
947 return -EFAULT;
948
949 if (++host_spot_max % 8)
950 return host_spot_max / 8 + 1;
951 return host_spot_max / 8;
952 }
953
954 return -EINVAL;
955}
956
957/*
958 * Protocol Handling Functions
959 */
960
961#define CIPSO_V4_HDR_LEN 6
962
963/**
964 * cipso_v4_gentag_hdr - Generate a CIPSO option header
965 * @doi_def: the DOI definition
966 * @len: the total tag length in bytes
967 * @buf: the CIPSO option buffer
968 *
969 * Description:
970 * Write a CIPSO header into the beginning of @buffer. Return zero on success,
971 * negative values on failure.
972 *
973 */
974static int cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
975 u32 len,
976 unsigned char *buf)
977{
978 if (CIPSO_V4_HDR_LEN + len > 40)
979 return -ENOSPC;
980
981 buf[0] = IPOPT_CIPSO;
982 buf[1] = CIPSO_V4_HDR_LEN + len;
714e85be 983 *(__be32 *)&buf[2] = htonl(doi_def->doi);
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984
985 return 0;
986}
987
988#define CIPSO_V4_TAG1_CAT_LEN 30
989
990/**
991 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
992 * @doi_def: the DOI definition
993 * @secattr: the security attributes
994 * @buffer: the option buffer
995 * @buffer_len: length of buffer in bytes
996 *
997 * Description:
998 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
999 * actual buffer length may be larger than the indicated size due to
1000 * translation between host and network category bitmaps. Returns zero on
1001 * success, negative values on failure.
1002 *
1003 */
1004static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1005 const struct netlbl_lsm_secattr *secattr,
1006 unsigned char **buffer,
1007 u32 *buffer_len)
1008{
701a90ba 1009 int ret_val;
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1010 unsigned char *buf = NULL;
1011 u32 buf_len;
1012 u32 level;
1013
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1014 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1015 return -EPERM;
1016
1017 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
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1018 buf = kzalloc(CIPSO_V4_HDR_LEN + 4 + CIPSO_V4_TAG1_CAT_LEN,
1019 GFP_ATOMIC);
1020 if (buf == NULL)
1021 return -ENOMEM;
1022
1023 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1024 secattr->mls_cat,
1025 secattr->mls_cat_len,
1026 &buf[CIPSO_V4_HDR_LEN + 4],
1027 CIPSO_V4_TAG1_CAT_LEN);
1028 if (ret_val < 0)
1029 goto gentag_failure;
1030
1031 /* This will send packets using the "optimized" format when
1032 * possibile as specified in section 3.4.2.6 of the
1033 * CIPSO draft. */
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1034 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
1035 buf_len = 14;
1036 else
1037 buf_len = 4 + ret_val;
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1038 } else {
1039 buf = kzalloc(CIPSO_V4_HDR_LEN + 4, GFP_ATOMIC);
1040 if (buf == NULL)
1041 return -ENOMEM;
1042 buf_len = 4;
1043 }
1044
1045 ret_val = cipso_v4_map_lvl_hton(doi_def, secattr->mls_lvl, &level);
1046 if (ret_val != 0)
1047 goto gentag_failure;
1048
1049 ret_val = cipso_v4_gentag_hdr(doi_def, buf_len, buf);
1050 if (ret_val != 0)
1051 goto gentag_failure;
1052
1053 buf[CIPSO_V4_HDR_LEN] = 0x01;
1054 buf[CIPSO_V4_HDR_LEN + 1] = buf_len;
1055 buf[CIPSO_V4_HDR_LEN + 3] = level;
1056
1057 *buffer = buf;
1058 *buffer_len = CIPSO_V4_HDR_LEN + buf_len;
1059
1060 return 0;
1061
1062gentag_failure:
1063 kfree(buf);
1064 return ret_val;
1065}
1066
1067/**
1068 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1069 * @doi_def: the DOI definition
1070 * @tag: the CIPSO tag
1071 * @secattr: the security attributes
1072 *
1073 * Description:
1074 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1075 * attributes in @secattr. Return zero on success, negatives values on
1076 * failure.
1077 *
1078 */
1079static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1080 const unsigned char *tag,
1081 struct netlbl_lsm_secattr *secattr)
1082{
1083 int ret_val;
1084 u8 tag_len = tag[1];
1085 u32 level;
1086
1087 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1088 if (ret_val != 0)
1089 return ret_val;
1090 secattr->mls_lvl = level;
701a90ba 1091 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
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1092
1093 if (tag_len > 4) {
1094 switch (doi_def->type) {
1095 case CIPSO_V4_MAP_PASS:
1096 secattr->mls_cat_len = tag_len - 4;
1097 break;
1098 case CIPSO_V4_MAP_STD:
1099 secattr->mls_cat_len =
1100 doi_def->map.std->cat.local_size;
1101 break;
1102 }
1103 secattr->mls_cat = kzalloc(secattr->mls_cat_len, GFP_ATOMIC);
1104 if (secattr->mls_cat == NULL)
1105 return -ENOMEM;
1106
1107 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1108 &tag[4],
1109 tag_len - 4,
1110 secattr->mls_cat,
1111 secattr->mls_cat_len);
1112 if (ret_val < 0) {
1113 kfree(secattr->mls_cat);
1114 return ret_val;
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1115 } else if (ret_val > 0) {
1116 secattr->mls_cat_len = ret_val;
1117 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
446fda4f 1118 }
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1119 }
1120
1121 return 0;
1122}
1123
1124/**
1125 * cipso_v4_validate - Validate a CIPSO option
1126 * @option: the start of the option, on error it is set to point to the error
1127 *
1128 * Description:
1129 * This routine is called to validate a CIPSO option, it checks all of the
1130 * fields to ensure that they are at least valid, see the draft snippet below
1131 * for details. If the option is valid then a zero value is returned and
1132 * the value of @option is unchanged. If the option is invalid then a
1133 * non-zero value is returned and @option is adjusted to point to the
1134 * offending portion of the option. From the IETF draft ...
1135 *
1136 * "If any field within the CIPSO options, such as the DOI identifier, is not
1137 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1138 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1139 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1140 * that is unrecognized."
1141 *
1142 */
1143int cipso_v4_validate(unsigned char **option)
1144{
1145 unsigned char *opt = *option;
1146 unsigned char *tag;
1147 unsigned char opt_iter;
1148 unsigned char err_offset = 0;
1149 u8 opt_len;
1150 u8 tag_len;
1151 struct cipso_v4_doi *doi_def = NULL;
1152 u32 tag_iter;
1153
1154 /* caller already checks for length values that are too large */
1155 opt_len = opt[1];
1156 if (opt_len < 8) {
1157 err_offset = 1;
1158 goto validate_return;
1159 }
1160
1161 rcu_read_lock();
714e85be 1162 doi_def = cipso_v4_doi_getdef(ntohl(*((__be32 *)&opt[2])));
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1163 if (doi_def == NULL) {
1164 err_offset = 2;
1165 goto validate_return_locked;
1166 }
1167
1168 opt_iter = 6;
1169 tag = opt + opt_iter;
1170 while (opt_iter < opt_len) {
1171 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1172 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1173 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1174 err_offset = opt_iter;
1175 goto validate_return_locked;
1176 }
1177
1178 tag_len = tag[1];
1179 if (tag_len > (opt_len - opt_iter)) {
1180 err_offset = opt_iter + 1;
1181 goto validate_return_locked;
1182 }
1183
1184 switch (tag[0]) {
1185 case CIPSO_V4_TAG_RBITMAP:
1186 if (tag_len < 4) {
1187 err_offset = opt_iter + 1;
1188 goto validate_return_locked;
1189 }
1190
1191 /* We are already going to do all the verification
1192 * necessary at the socket layer so from our point of
1193 * view it is safe to turn these checks off (and less
1194 * work), however, the CIPSO draft says we should do
1195 * all the CIPSO validations here but it doesn't
1196 * really specify _exactly_ what we need to validate
1197 * ... so, just make it a sysctl tunable. */
1198 if (cipso_v4_rbm_strictvalid) {
1199 if (cipso_v4_map_lvl_valid(doi_def,
1200 tag[3]) < 0) {
1201 err_offset = opt_iter + 3;
1202 goto validate_return_locked;
1203 }
1204 if (tag_len > 4 &&
1205 cipso_v4_map_cat_rbm_valid(doi_def,
1206 &tag[4],
1207 tag_len - 4) < 0) {
1208 err_offset = opt_iter + 4;
1209 goto validate_return_locked;
1210 }
1211 }
1212 break;
1213 default:
1214 err_offset = opt_iter;
1215 goto validate_return_locked;
1216 }
1217
1218 tag += tag_len;
1219 opt_iter += tag_len;
1220 }
1221
1222validate_return_locked:
1223 rcu_read_unlock();
1224validate_return:
1225 *option = opt + err_offset;
1226 return err_offset;
1227}
1228
1229/**
1230 * cipso_v4_error - Send the correct reponse for a bad packet
1231 * @skb: the packet
1232 * @error: the error code
1233 * @gateway: CIPSO gateway flag
1234 *
1235 * Description:
1236 * Based on the error code given in @error, send an ICMP error message back to
1237 * the originating host. From the IETF draft ...
1238 *
1239 * "If the contents of the CIPSO [option] are valid but the security label is
1240 * outside of the configured host or port label range, the datagram is
1241 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1242 * returned. The code field of the ICMP is set to 'communication with
1243 * destination network administratively prohibited' (code 9) or to
1244 * 'communication with destination host administratively prohibited'
1245 * (code 10). The value of the code is dependent on whether the originator
1246 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1247 * recipient of the ICMP message MUST be able to handle either value. The
1248 * same procedure is performed if a CIPSO [option] can not be added to an
1249 * IP packet because it is too large to fit in the IP options area."
1250 *
1251 * "If the error is triggered by receipt of an ICMP message, the message is
1252 * discarded and no response is permitted (consistent with general ICMP
1253 * processing rules)."
1254 *
1255 */
1256void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1257{
1258 if (skb->nh.iph->protocol == IPPROTO_ICMP || error != -EACCES)
1259 return;
1260
1261 if (gateway)
1262 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
1263 else
1264 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
1265}
1266
1267/**
1268 * cipso_v4_socket_setattr - Add a CIPSO option to a socket
1269 * @sock: the socket
1270 * @doi_def: the CIPSO DOI to use
1271 * @secattr: the specific security attributes of the socket
1272 *
1273 * Description:
1274 * Set the CIPSO option on the given socket using the DOI definition and
1275 * security attributes passed to the function. This function requires
1276 * exclusive access to @sock->sk, which means it either needs to be in the
1277 * process of being created or locked via lock_sock(sock->sk). Returns zero on
1278 * success and negative values on failure.
1279 *
1280 */
1281int cipso_v4_socket_setattr(const struct socket *sock,
1282 const struct cipso_v4_doi *doi_def,
1283 const struct netlbl_lsm_secattr *secattr)
1284{
1285 int ret_val = -EPERM;
1286 u32 iter;
1287 unsigned char *buf = NULL;
1288 u32 buf_len = 0;
1289 u32 opt_len;
1290 struct ip_options *opt = NULL;
1291 struct sock *sk;
1292 struct inet_sock *sk_inet;
1293 struct inet_connection_sock *sk_conn;
1294
1295 /* In the case of sock_create_lite(), the sock->sk field is not
1296 * defined yet but it is not a problem as the only users of these
1297 * "lite" PF_INET sockets are functions which do an accept() call
1298 * afterwards so we will label the socket as part of the accept(). */
1299 sk = sock->sk;
1300 if (sk == NULL)
1301 return 0;
1302
1303 /* XXX - This code assumes only one tag per CIPSO option which isn't
1304 * really a good assumption to make but since we only support the MAC
1305 * tags right now it is a safe assumption. */
1306 iter = 0;
1307 do {
1308 switch (doi_def->tags[iter]) {
1309 case CIPSO_V4_TAG_RBITMAP:
1310 ret_val = cipso_v4_gentag_rbm(doi_def,
1311 secattr,
1312 &buf,
1313 &buf_len);
1314 break;
1315 default:
1316 ret_val = -EPERM;
1317 goto socket_setattr_failure;
1318 }
1319
1320 iter++;
1321 } while (ret_val != 0 &&
1322 iter < CIPSO_V4_TAG_MAXCNT &&
1323 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1324 if (ret_val != 0)
1325 goto socket_setattr_failure;
1326
1327 /* We can't use ip_options_get() directly because it makes a call to
1328 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
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1329 * we won't always have CAP_NET_RAW even though we _always_ want to
1330 * set the IPOPT_CIPSO option. */
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1331 opt_len = (buf_len + 3) & ~3;
1332 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1333 if (opt == NULL) {
1334 ret_val = -ENOMEM;
1335 goto socket_setattr_failure;
1336 }
1337 memcpy(opt->__data, buf, buf_len);
1338 opt->optlen = opt_len;
1339 opt->is_data = 1;
f8687afe 1340 opt->cipso = sizeof(struct iphdr);
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1341 kfree(buf);
1342 buf = NULL;
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1343
1344 sk_inet = inet_sk(sk);
1345 if (sk_inet->is_icsk) {
1346 sk_conn = inet_csk(sk);
1347 if (sk_inet->opt)
1348 sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen;
1349 sk_conn->icsk_ext_hdr_len += opt->optlen;
1350 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1351 }
1352 opt = xchg(&sk_inet->opt, opt);
1353 kfree(opt);
1354
1355 return 0;
1356
1357socket_setattr_failure:
1358 kfree(buf);
1359 kfree(opt);
1360 return ret_val;
1361}
1362
1363/**
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1364 * cipso_v4_sock_getattr - Get the security attributes from a sock
1365 * @sk: the sock
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1366 * @secattr: the security attributes
1367 *
1368 * Description:
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1369 * Query @sk to see if there is a CIPSO option attached to the sock and if
1370 * there is return the CIPSO security attributes in @secattr. This function
1371 * requires that @sk be locked, or privately held, but it does not do any
1372 * locking itself. Returns zero on success and negative values on failure.
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1373 *
1374 */
14a72f53 1375int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
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1376{
1377 int ret_val = -ENOMSG;
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1378 struct inet_sock *sk_inet;
1379 unsigned char *cipso_ptr;
1380 u32 doi;
1381 struct cipso_v4_doi *doi_def;
1382
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1383 sk_inet = inet_sk(sk);
1384 if (sk_inet->opt == NULL || sk_inet->opt->cipso == 0)
14a72f53 1385 return -ENOMSG;
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1386 cipso_ptr = sk_inet->opt->__data + sk_inet->opt->cipso -
1387 sizeof(struct iphdr);
1388 ret_val = cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr);
1389 if (ret_val == 0)
14a72f53 1390 return ret_val;
446fda4f 1391
714e85be 1392 doi = ntohl(*(__be32 *)&cipso_ptr[2]);
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1393 rcu_read_lock();
1394 doi_def = cipso_v4_doi_getdef(doi);
1395 if (doi_def == NULL) {
1396 rcu_read_unlock();
14a72f53 1397 return -ENOMSG;
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1398 }
1399 switch (cipso_ptr[6]) {
1400 case CIPSO_V4_TAG_RBITMAP:
1401 ret_val = cipso_v4_parsetag_rbm(doi_def,
1402 &cipso_ptr[6],
1403 secattr);
1404 break;
1405 }
1406 rcu_read_unlock();
1407
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1408 return ret_val;
1409}
1410
1411/**
1412 * cipso_v4_socket_getattr - Get the security attributes from a socket
1413 * @sock: the socket
1414 * @secattr: the security attributes
1415 *
1416 * Description:
1417 * Query @sock to see if there is a CIPSO option attached to the socket and if
1418 * there is return the CIPSO security attributes in @secattr. Returns zero on
1419 * success and negative values on failure.
1420 *
1421 */
1422int cipso_v4_socket_getattr(const struct socket *sock,
1423 struct netlbl_lsm_secattr *secattr)
1424{
1425 int ret_val;
1426
1427 lock_sock(sock->sk);
1428 ret_val = cipso_v4_sock_getattr(sock->sk, secattr);
1429 release_sock(sock->sk);
1430
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1431 return ret_val;
1432}
1433
1434/**
1435 * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
1436 * @skb: the packet
1437 * @secattr: the security attributes
1438 *
1439 * Description:
1440 * Parse the given packet's CIPSO option and return the security attributes.
1441 * Returns zero on success and negative values on failure.
1442 *
1443 */
1444int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
1445 struct netlbl_lsm_secattr *secattr)
1446{
1447 int ret_val = -ENOMSG;
1448 unsigned char *cipso_ptr;
1449 u32 doi;
1450 struct cipso_v4_doi *doi_def;
1451
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1452 cipso_ptr = CIPSO_V4_OPTPTR(skb);
1453 if (cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr) == 0)
1454 return 0;
1455
714e85be 1456 doi = ntohl(*(__be32 *)&cipso_ptr[2]);
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1457 rcu_read_lock();
1458 doi_def = cipso_v4_doi_getdef(doi);
1459 if (doi_def == NULL)
1460 goto skbuff_getattr_return;
1461 switch (cipso_ptr[6]) {
1462 case CIPSO_V4_TAG_RBITMAP:
1463 ret_val = cipso_v4_parsetag_rbm(doi_def,
1464 &cipso_ptr[6],
1465 secattr);
1466 break;
1467 }
1468
1469skbuff_getattr_return:
1470 rcu_read_unlock();
1471 return ret_val;
1472}
1473
1474/*
1475 * Setup Functions
1476 */
1477
1478/**
1479 * cipso_v4_init - Initialize the CIPSO module
1480 *
1481 * Description:
1482 * Initialize the CIPSO module and prepare it for use. Returns zero on success
1483 * and negative values on failure.
1484 *
1485 */
1486static int __init cipso_v4_init(void)
1487{
1488 int ret_val;
1489
1490 ret_val = cipso_v4_cache_init();
1491 if (ret_val != 0)
1492 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
1493 ret_val);
1494
1495 return 0;
1496}
1497
1498subsys_initcall(cipso_v4_init);