tracing: Use helper functions in event assignment to shrink macro size
[linux/fpc-iii.git] / net / ipv4 / cipso_ipv4.c
blob69e77c8ff285c74a3743cd10b95cfd04a45bf687
1 /*
2 * CIPSO - Commercial IP Security Option
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.
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
16 * Author: Paul Moore <paul.moore@hp.com>
21 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
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.
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.
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/>.
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 <asm/bug.h>
54 #include <asm/unaligned.h>
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);
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;
75 struct cipso_v4_map_cache_entry {
76 u32 hash;
77 unsigned char *key;
78 size_t key_len;
80 struct netlbl_lsm_cache *lsm_data;
82 u32 activity;
83 struct list_head list;
85 static struct cipso_v4_map_cache_bkt *cipso_v4_cache = NULL;
87 /* Restricted bitmap (tag #1) flags */
88 int cipso_v4_rbm_optfmt = 0;
89 int cipso_v4_rbm_strictvalid = 1;
92 * Protocol Constants
95 /* Maximum size of the CIPSO IP option, derived from the fact that the maximum
96 * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
97 #define CIPSO_V4_OPT_LEN_MAX 40
99 /* Length of the base CIPSO option, this includes the option type (1 byte), the
100 * option length (1 byte), and the DOI (4 bytes). */
101 #define CIPSO_V4_HDR_LEN 6
103 /* Base length of the restrictive category bitmap tag (tag #1). */
104 #define CIPSO_V4_TAG_RBM_BLEN 4
106 /* Base length of the enumerated category tag (tag #2). */
107 #define CIPSO_V4_TAG_ENUM_BLEN 4
109 /* Base length of the ranged categories bitmap tag (tag #5). */
110 #define CIPSO_V4_TAG_RNG_BLEN 4
111 /* The maximum number of category ranges permitted in the ranged category tag
112 * (tag #5). You may note that the IETF draft states that the maximum number
113 * of category ranges is 7, but if the low end of the last category range is
114 * zero then it is possible to fit 8 category ranges because the zero should
115 * be omitted. */
116 #define CIPSO_V4_TAG_RNG_CAT_MAX 8
118 /* Base length of the local tag (non-standard tag).
119 * Tag definition (may change between kernel versions)
121 * 0 8 16 24 32
122 * +----------+----------+----------+----------+
123 * | 10000000 | 00000110 | 32-bit secid value |
124 * +----------+----------+----------+----------+
125 * | in (host byte order)|
126 * +----------+----------+
129 #define CIPSO_V4_TAG_LOC_BLEN 6
132 * Helper Functions
136 * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
137 * @bitmap: the bitmap
138 * @bitmap_len: length in bits
139 * @offset: starting offset
140 * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
142 * Description:
143 * Starting at @offset, walk the bitmap from left to right until either the
144 * desired bit is found or we reach the end. Return the bit offset, -1 if
145 * not found, or -2 if error.
147 static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
148 u32 bitmap_len,
149 u32 offset,
150 u8 state)
152 u32 bit_spot;
153 u32 byte_offset;
154 unsigned char bitmask;
155 unsigned char byte;
157 /* gcc always rounds to zero when doing integer division */
158 byte_offset = offset / 8;
159 byte = bitmap[byte_offset];
160 bit_spot = offset;
161 bitmask = 0x80 >> (offset % 8);
163 while (bit_spot < bitmap_len) {
164 if ((state && (byte & bitmask) == bitmask) ||
165 (state == 0 && (byte & bitmask) == 0))
166 return bit_spot;
168 bit_spot++;
169 bitmask >>= 1;
170 if (bitmask == 0) {
171 byte = bitmap[++byte_offset];
172 bitmask = 0x80;
176 return -1;
180 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
181 * @bitmap: the bitmap
182 * @bit: the bit
183 * @state: if non-zero, set the bit (1) else clear the bit (0)
185 * Description:
186 * Set a single bit in the bitmask. Returns zero on success, negative values
187 * on error.
189 static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
190 u32 bit,
191 u8 state)
193 u32 byte_spot;
194 u8 bitmask;
196 /* gcc always rounds to zero when doing integer division */
197 byte_spot = bit / 8;
198 bitmask = 0x80 >> (bit % 8);
199 if (state)
200 bitmap[byte_spot] |= bitmask;
201 else
202 bitmap[byte_spot] &= ~bitmask;
206 * cipso_v4_cache_entry_free - Frees a cache entry
207 * @entry: the entry to free
209 * Description:
210 * This function frees the memory associated with a cache entry including the
211 * LSM cache data if there are no longer any users, i.e. reference count == 0.
214 static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
216 if (entry->lsm_data)
217 netlbl_secattr_cache_free(entry->lsm_data);
218 kfree(entry->key);
219 kfree(entry);
223 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
224 * @key: the hash key
225 * @key_len: the length of the key in bytes
227 * Description:
228 * The CIPSO tag hashing function. Returns a 32-bit hash value.
231 static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
233 return jhash(key, key_len, 0);
237 * Label Mapping Cache Functions
241 * cipso_v4_cache_init - Initialize the CIPSO cache
243 * Description:
244 * Initializes the CIPSO label mapping cache, this function should be called
245 * before any of the other functions defined in this file. Returns zero on
246 * success, negative values on error.
249 static int cipso_v4_cache_init(void)
251 u32 iter;
253 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
254 sizeof(struct cipso_v4_map_cache_bkt),
255 GFP_KERNEL);
256 if (cipso_v4_cache == NULL)
257 return -ENOMEM;
259 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
260 spin_lock_init(&cipso_v4_cache[iter].lock);
261 cipso_v4_cache[iter].size = 0;
262 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
265 return 0;
269 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
271 * Description:
272 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
273 * success and negative values on failure.
276 void cipso_v4_cache_invalidate(void)
278 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
279 u32 iter;
281 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
282 spin_lock_bh(&cipso_v4_cache[iter].lock);
283 list_for_each_entry_safe(entry,
284 tmp_entry,
285 &cipso_v4_cache[iter].list, list) {
286 list_del(&entry->list);
287 cipso_v4_cache_entry_free(entry);
289 cipso_v4_cache[iter].size = 0;
290 spin_unlock_bh(&cipso_v4_cache[iter].lock);
295 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
296 * @key: the buffer to check
297 * @key_len: buffer length in bytes
298 * @secattr: the security attribute struct to use
300 * Description:
301 * This function checks the cache to see if a label mapping already exists for
302 * the given key. If there is a match then the cache is adjusted and the
303 * @secattr struct is populated with the correct LSM security attributes. The
304 * cache is adjusted in the following manner if the entry is not already the
305 * first in the cache bucket:
307 * 1. The cache entry's activity counter is incremented
308 * 2. The previous (higher ranking) entry's activity counter is decremented
309 * 3. If the difference between the two activity counters is geater than
310 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
312 * Returns zero on success, -ENOENT for a cache miss, and other negative values
313 * on error.
316 static int cipso_v4_cache_check(const unsigned char *key,
317 u32 key_len,
318 struct netlbl_lsm_secattr *secattr)
320 u32 bkt;
321 struct cipso_v4_map_cache_entry *entry;
322 struct cipso_v4_map_cache_entry *prev_entry = NULL;
323 u32 hash;
325 if (!cipso_v4_cache_enabled)
326 return -ENOENT;
328 hash = cipso_v4_map_cache_hash(key, key_len);
329 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
330 spin_lock_bh(&cipso_v4_cache[bkt].lock);
331 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
332 if (entry->hash == hash &&
333 entry->key_len == key_len &&
334 memcmp(entry->key, key, key_len) == 0) {
335 entry->activity += 1;
336 atomic_inc(&entry->lsm_data->refcount);
337 secattr->cache = entry->lsm_data;
338 secattr->flags |= NETLBL_SECATTR_CACHE;
339 secattr->type = NETLBL_NLTYPE_CIPSOV4;
340 if (prev_entry == NULL) {
341 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
342 return 0;
345 if (prev_entry->activity > 0)
346 prev_entry->activity -= 1;
347 if (entry->activity > prev_entry->activity &&
348 entry->activity - prev_entry->activity >
349 CIPSO_V4_CACHE_REORDERLIMIT) {
350 __list_del(entry->list.prev, entry->list.next);
351 __list_add(&entry->list,
352 prev_entry->list.prev,
353 &prev_entry->list);
356 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
357 return 0;
359 prev_entry = entry;
361 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
363 return -ENOENT;
367 * cipso_v4_cache_add - Add an entry to the CIPSO cache
368 * @skb: the packet
369 * @secattr: the packet's security attributes
371 * Description:
372 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
373 * head of the cache bucket's list, if the cache bucket is out of room remove
374 * the last entry in the list first. It is important to note that there is
375 * currently no checking for duplicate keys. Returns zero on success,
376 * negative values on failure.
379 int cipso_v4_cache_add(const struct sk_buff *skb,
380 const struct netlbl_lsm_secattr *secattr)
382 int ret_val = -EPERM;
383 u32 bkt;
384 struct cipso_v4_map_cache_entry *entry = NULL;
385 struct cipso_v4_map_cache_entry *old_entry = NULL;
386 unsigned char *cipso_ptr;
387 u32 cipso_ptr_len;
389 if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
390 return 0;
392 cipso_ptr = CIPSO_V4_OPTPTR(skb);
393 cipso_ptr_len = cipso_ptr[1];
395 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
396 if (entry == NULL)
397 return -ENOMEM;
398 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
399 if (entry->key == NULL) {
400 ret_val = -ENOMEM;
401 goto cache_add_failure;
403 entry->key_len = cipso_ptr_len;
404 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
405 atomic_inc(&secattr->cache->refcount);
406 entry->lsm_data = secattr->cache;
408 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
409 spin_lock_bh(&cipso_v4_cache[bkt].lock);
410 if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
411 list_add(&entry->list, &cipso_v4_cache[bkt].list);
412 cipso_v4_cache[bkt].size += 1;
413 } else {
414 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
415 struct cipso_v4_map_cache_entry, list);
416 list_del(&old_entry->list);
417 list_add(&entry->list, &cipso_v4_cache[bkt].list);
418 cipso_v4_cache_entry_free(old_entry);
420 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
422 return 0;
424 cache_add_failure:
425 if (entry)
426 cipso_v4_cache_entry_free(entry);
427 return ret_val;
431 * DOI List Functions
435 * cipso_v4_doi_search - Searches for a DOI definition
436 * @doi: the DOI to search for
438 * Description:
439 * Search the DOI definition list for a DOI definition with a DOI value that
440 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
441 * Returns a pointer to the DOI definition on success and NULL on failure.
443 static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
445 struct cipso_v4_doi *iter;
447 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
448 if (iter->doi == doi && atomic_read(&iter->refcount))
449 return iter;
450 return NULL;
454 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
455 * @doi_def: the DOI structure
456 * @audit_info: NetLabel audit information
458 * Description:
459 * The caller defines a new DOI for use by the CIPSO engine and calls this
460 * function to add it to the list of acceptable domains. The caller must
461 * ensure that the mapping table specified in @doi_def->map meets all of the
462 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
463 * zero on success and non-zero on failure.
466 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
467 struct netlbl_audit *audit_info)
469 int ret_val = -EINVAL;
470 u32 iter;
471 u32 doi;
472 u32 doi_type;
473 struct audit_buffer *audit_buf;
475 doi = doi_def->doi;
476 doi_type = doi_def->type;
478 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
479 goto doi_add_return;
480 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
481 switch (doi_def->tags[iter]) {
482 case CIPSO_V4_TAG_RBITMAP:
483 break;
484 case CIPSO_V4_TAG_RANGE:
485 case CIPSO_V4_TAG_ENUM:
486 if (doi_def->type != CIPSO_V4_MAP_PASS)
487 goto doi_add_return;
488 break;
489 case CIPSO_V4_TAG_LOCAL:
490 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
491 goto doi_add_return;
492 break;
493 case CIPSO_V4_TAG_INVALID:
494 if (iter == 0)
495 goto doi_add_return;
496 break;
497 default:
498 goto doi_add_return;
502 atomic_set(&doi_def->refcount, 1);
504 spin_lock(&cipso_v4_doi_list_lock);
505 if (cipso_v4_doi_search(doi_def->doi) != NULL) {
506 spin_unlock(&cipso_v4_doi_list_lock);
507 ret_val = -EEXIST;
508 goto doi_add_return;
510 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
511 spin_unlock(&cipso_v4_doi_list_lock);
512 ret_val = 0;
514 doi_add_return:
515 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
516 if (audit_buf != NULL) {
517 const char *type_str;
518 switch (doi_type) {
519 case CIPSO_V4_MAP_TRANS:
520 type_str = "trans";
521 break;
522 case CIPSO_V4_MAP_PASS:
523 type_str = "pass";
524 break;
525 case CIPSO_V4_MAP_LOCAL:
526 type_str = "local";
527 break;
528 default:
529 type_str = "(unknown)";
531 audit_log_format(audit_buf,
532 " cipso_doi=%u cipso_type=%s res=%u",
533 doi, type_str, ret_val == 0 ? 1 : 0);
534 audit_log_end(audit_buf);
537 return ret_val;
541 * cipso_v4_doi_free - Frees a DOI definition
542 * @entry: the entry's RCU field
544 * Description:
545 * This function frees all of the memory associated with a DOI definition.
548 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
550 if (doi_def == NULL)
551 return;
553 switch (doi_def->type) {
554 case CIPSO_V4_MAP_TRANS:
555 kfree(doi_def->map.std->lvl.cipso);
556 kfree(doi_def->map.std->lvl.local);
557 kfree(doi_def->map.std->cat.cipso);
558 kfree(doi_def->map.std->cat.local);
559 break;
561 kfree(doi_def);
565 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
566 * @entry: the entry's RCU field
568 * Description:
569 * This function is designed to be used as a callback to the call_rcu()
570 * function so that the memory allocated to the DOI definition can be released
571 * safely.
574 static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
576 struct cipso_v4_doi *doi_def;
578 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
579 cipso_v4_doi_free(doi_def);
583 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
584 * @doi: the DOI value
585 * @audit_secid: the LSM secid to use in the audit message
587 * Description:
588 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
589 * be called to release their own LSM domain mappings as well as our own
590 * domain list. Returns zero on success and negative values on failure.
593 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
595 int ret_val;
596 struct cipso_v4_doi *doi_def;
597 struct audit_buffer *audit_buf;
599 spin_lock(&cipso_v4_doi_list_lock);
600 doi_def = cipso_v4_doi_search(doi);
601 if (doi_def == NULL) {
602 spin_unlock(&cipso_v4_doi_list_lock);
603 ret_val = -ENOENT;
604 goto doi_remove_return;
606 if (!atomic_dec_and_test(&doi_def->refcount)) {
607 spin_unlock(&cipso_v4_doi_list_lock);
608 ret_val = -EBUSY;
609 goto doi_remove_return;
611 list_del_rcu(&doi_def->list);
612 spin_unlock(&cipso_v4_doi_list_lock);
614 cipso_v4_cache_invalidate();
615 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
616 ret_val = 0;
618 doi_remove_return:
619 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
620 if (audit_buf != NULL) {
621 audit_log_format(audit_buf,
622 " cipso_doi=%u res=%u",
623 doi, ret_val == 0 ? 1 : 0);
624 audit_log_end(audit_buf);
627 return ret_val;
631 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
632 * @doi: the DOI value
634 * Description:
635 * Searches for a valid DOI definition and if one is found it is returned to
636 * the caller. Otherwise NULL is returned. The caller must ensure that
637 * rcu_read_lock() is held while accessing the returned definition and the DOI
638 * definition reference count is decremented when the caller is done.
641 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
643 struct cipso_v4_doi *doi_def;
645 rcu_read_lock();
646 doi_def = cipso_v4_doi_search(doi);
647 if (doi_def == NULL)
648 goto doi_getdef_return;
649 if (!atomic_inc_not_zero(&doi_def->refcount))
650 doi_def = NULL;
652 doi_getdef_return:
653 rcu_read_unlock();
654 return doi_def;
658 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
659 * @doi_def: the DOI definition
661 * Description:
662 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
665 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
667 if (doi_def == NULL)
668 return;
670 if (!atomic_dec_and_test(&doi_def->refcount))
671 return;
672 spin_lock(&cipso_v4_doi_list_lock);
673 list_del_rcu(&doi_def->list);
674 spin_unlock(&cipso_v4_doi_list_lock);
676 cipso_v4_cache_invalidate();
677 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
681 * cipso_v4_doi_walk - Iterate through the DOI definitions
682 * @skip_cnt: skip past this number of DOI definitions, updated
683 * @callback: callback for each DOI definition
684 * @cb_arg: argument for the callback function
686 * Description:
687 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
688 * For each entry call @callback, if @callback returns a negative value stop
689 * 'walking' through the list and return. Updates the value in @skip_cnt upon
690 * return. Returns zero on success, negative values on failure.
693 int cipso_v4_doi_walk(u32 *skip_cnt,
694 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
695 void *cb_arg)
697 int ret_val = -ENOENT;
698 u32 doi_cnt = 0;
699 struct cipso_v4_doi *iter_doi;
701 rcu_read_lock();
702 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
703 if (atomic_read(&iter_doi->refcount) > 0) {
704 if (doi_cnt++ < *skip_cnt)
705 continue;
706 ret_val = callback(iter_doi, cb_arg);
707 if (ret_val < 0) {
708 doi_cnt--;
709 goto doi_walk_return;
713 doi_walk_return:
714 rcu_read_unlock();
715 *skip_cnt = doi_cnt;
716 return ret_val;
720 * Label Mapping Functions
724 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
725 * @doi_def: the DOI definition
726 * @level: the level to check
728 * Description:
729 * Checks the given level against the given DOI definition and returns a
730 * negative value if the level does not have a valid mapping and a zero value
731 * if the level is defined by the DOI.
734 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
736 switch (doi_def->type) {
737 case CIPSO_V4_MAP_PASS:
738 return 0;
739 case CIPSO_V4_MAP_TRANS:
740 if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
741 return 0;
742 break;
745 return -EFAULT;
749 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
750 * @doi_def: the DOI definition
751 * @host_lvl: the host MLS level
752 * @net_lvl: the network/CIPSO MLS level
754 * Description:
755 * Perform a label mapping to translate a local MLS level to the correct
756 * CIPSO level using the given DOI definition. Returns zero on success,
757 * negative values otherwise.
760 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
761 u32 host_lvl,
762 u32 *net_lvl)
764 switch (doi_def->type) {
765 case CIPSO_V4_MAP_PASS:
766 *net_lvl = host_lvl;
767 return 0;
768 case CIPSO_V4_MAP_TRANS:
769 if (host_lvl < doi_def->map.std->lvl.local_size &&
770 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
771 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
772 return 0;
774 return -EPERM;
777 return -EINVAL;
781 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
782 * @doi_def: the DOI definition
783 * @net_lvl: the network/CIPSO MLS level
784 * @host_lvl: the host MLS level
786 * Description:
787 * Perform a label mapping to translate a CIPSO level to the correct local MLS
788 * level using the given DOI definition. Returns zero on success, negative
789 * values otherwise.
792 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
793 u32 net_lvl,
794 u32 *host_lvl)
796 struct cipso_v4_std_map_tbl *map_tbl;
798 switch (doi_def->type) {
799 case CIPSO_V4_MAP_PASS:
800 *host_lvl = net_lvl;
801 return 0;
802 case CIPSO_V4_MAP_TRANS:
803 map_tbl = doi_def->map.std;
804 if (net_lvl < map_tbl->lvl.cipso_size &&
805 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
806 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
807 return 0;
809 return -EPERM;
812 return -EINVAL;
816 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
817 * @doi_def: the DOI definition
818 * @bitmap: category bitmap
819 * @bitmap_len: bitmap length in bytes
821 * Description:
822 * Checks the given category bitmap against the given DOI definition and
823 * returns a negative value if any of the categories in the bitmap do not have
824 * a valid mapping and a zero value if all of the categories are valid.
827 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
828 const unsigned char *bitmap,
829 u32 bitmap_len)
831 int cat = -1;
832 u32 bitmap_len_bits = bitmap_len * 8;
833 u32 cipso_cat_size;
834 u32 *cipso_array;
836 switch (doi_def->type) {
837 case CIPSO_V4_MAP_PASS:
838 return 0;
839 case CIPSO_V4_MAP_TRANS:
840 cipso_cat_size = doi_def->map.std->cat.cipso_size;
841 cipso_array = doi_def->map.std->cat.cipso;
842 for (;;) {
843 cat = cipso_v4_bitmap_walk(bitmap,
844 bitmap_len_bits,
845 cat + 1,
847 if (cat < 0)
848 break;
849 if (cat >= cipso_cat_size ||
850 cipso_array[cat] >= CIPSO_V4_INV_CAT)
851 return -EFAULT;
854 if (cat == -1)
855 return 0;
856 break;
859 return -EFAULT;
863 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
864 * @doi_def: the DOI definition
865 * @secattr: the security attributes
866 * @net_cat: the zero'd out category bitmap in network/CIPSO format
867 * @net_cat_len: the length of the CIPSO bitmap in bytes
869 * Description:
870 * Perform a label mapping to translate a local MLS category bitmap to the
871 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
872 * size in bytes of the network bitmap on success, negative values otherwise.
875 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
876 const struct netlbl_lsm_secattr *secattr,
877 unsigned char *net_cat,
878 u32 net_cat_len)
880 int host_spot = -1;
881 u32 net_spot = CIPSO_V4_INV_CAT;
882 u32 net_spot_max = 0;
883 u32 net_clen_bits = net_cat_len * 8;
884 u32 host_cat_size = 0;
885 u32 *host_cat_array = NULL;
887 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
888 host_cat_size = doi_def->map.std->cat.local_size;
889 host_cat_array = doi_def->map.std->cat.local;
892 for (;;) {
893 host_spot = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
894 host_spot + 1);
895 if (host_spot < 0)
896 break;
898 switch (doi_def->type) {
899 case CIPSO_V4_MAP_PASS:
900 net_spot = host_spot;
901 break;
902 case CIPSO_V4_MAP_TRANS:
903 if (host_spot >= host_cat_size)
904 return -EPERM;
905 net_spot = host_cat_array[host_spot];
906 if (net_spot >= CIPSO_V4_INV_CAT)
907 return -EPERM;
908 break;
910 if (net_spot >= net_clen_bits)
911 return -ENOSPC;
912 cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
914 if (net_spot > net_spot_max)
915 net_spot_max = net_spot;
918 if (++net_spot_max % 8)
919 return net_spot_max / 8 + 1;
920 return net_spot_max / 8;
924 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
925 * @doi_def: the DOI definition
926 * @net_cat: the category bitmap in network/CIPSO format
927 * @net_cat_len: the length of the CIPSO bitmap in bytes
928 * @secattr: the security attributes
930 * Description:
931 * Perform a label mapping to translate a CIPSO bitmap to the correct local
932 * MLS category bitmap using the given DOI definition. Returns zero on
933 * success, negative values on failure.
936 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
937 const unsigned char *net_cat,
938 u32 net_cat_len,
939 struct netlbl_lsm_secattr *secattr)
941 int ret_val;
942 int net_spot = -1;
943 u32 host_spot = CIPSO_V4_INV_CAT;
944 u32 net_clen_bits = net_cat_len * 8;
945 u32 net_cat_size = 0;
946 u32 *net_cat_array = NULL;
948 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
949 net_cat_size = doi_def->map.std->cat.cipso_size;
950 net_cat_array = doi_def->map.std->cat.cipso;
953 for (;;) {
954 net_spot = cipso_v4_bitmap_walk(net_cat,
955 net_clen_bits,
956 net_spot + 1,
958 if (net_spot < 0) {
959 if (net_spot == -2)
960 return -EFAULT;
961 return 0;
964 switch (doi_def->type) {
965 case CIPSO_V4_MAP_PASS:
966 host_spot = net_spot;
967 break;
968 case CIPSO_V4_MAP_TRANS:
969 if (net_spot >= net_cat_size)
970 return -EPERM;
971 host_spot = net_cat_array[net_spot];
972 if (host_spot >= CIPSO_V4_INV_CAT)
973 return -EPERM;
974 break;
976 ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
977 host_spot,
978 GFP_ATOMIC);
979 if (ret_val != 0)
980 return ret_val;
983 return -EINVAL;
987 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
988 * @doi_def: the DOI definition
989 * @enumcat: category list
990 * @enumcat_len: length of the category list in bytes
992 * Description:
993 * Checks the given categories against the given DOI definition and returns a
994 * negative value if any of the categories do not have a valid mapping and a
995 * zero value if all of the categories are valid.
998 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
999 const unsigned char *enumcat,
1000 u32 enumcat_len)
1002 u16 cat;
1003 int cat_prev = -1;
1004 u32 iter;
1006 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
1007 return -EFAULT;
1009 for (iter = 0; iter < enumcat_len; iter += 2) {
1010 cat = get_unaligned_be16(&enumcat[iter]);
1011 if (cat <= cat_prev)
1012 return -EFAULT;
1013 cat_prev = cat;
1016 return 0;
1020 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
1021 * @doi_def: the DOI definition
1022 * @secattr: the security attributes
1023 * @net_cat: the zero'd out category list in network/CIPSO format
1024 * @net_cat_len: the length of the CIPSO category list in bytes
1026 * Description:
1027 * Perform a label mapping to translate a local MLS category bitmap to the
1028 * correct CIPSO category list using the given DOI definition. Returns the
1029 * size in bytes of the network category bitmap on success, negative values
1030 * otherwise.
1033 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
1034 const struct netlbl_lsm_secattr *secattr,
1035 unsigned char *net_cat,
1036 u32 net_cat_len)
1038 int cat = -1;
1039 u32 cat_iter = 0;
1041 for (;;) {
1042 cat = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
1043 cat + 1);
1044 if (cat < 0)
1045 break;
1046 if ((cat_iter + 2) > net_cat_len)
1047 return -ENOSPC;
1049 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
1050 cat_iter += 2;
1053 return cat_iter;
1057 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
1058 * @doi_def: the DOI definition
1059 * @net_cat: the category list in network/CIPSO format
1060 * @net_cat_len: the length of the CIPSO bitmap in bytes
1061 * @secattr: the security attributes
1063 * Description:
1064 * Perform a label mapping to translate a CIPSO category list to the correct
1065 * local MLS category bitmap using the given DOI definition. Returns zero on
1066 * success, negative values on failure.
1069 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
1070 const unsigned char *net_cat,
1071 u32 net_cat_len,
1072 struct netlbl_lsm_secattr *secattr)
1074 int ret_val;
1075 u32 iter;
1077 for (iter = 0; iter < net_cat_len; iter += 2) {
1078 ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
1079 get_unaligned_be16(&net_cat[iter]),
1080 GFP_ATOMIC);
1081 if (ret_val != 0)
1082 return ret_val;
1085 return 0;
1089 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
1090 * @doi_def: the DOI definition
1091 * @rngcat: category list
1092 * @rngcat_len: length of the category list in bytes
1094 * Description:
1095 * Checks the given categories against the given DOI definition and returns a
1096 * negative value if any of the categories do not have a valid mapping and a
1097 * zero value if all of the categories are valid.
1100 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1101 const unsigned char *rngcat,
1102 u32 rngcat_len)
1104 u16 cat_high;
1105 u16 cat_low;
1106 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1107 u32 iter;
1109 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1110 return -EFAULT;
1112 for (iter = 0; iter < rngcat_len; iter += 4) {
1113 cat_high = get_unaligned_be16(&rngcat[iter]);
1114 if ((iter + 4) <= rngcat_len)
1115 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
1116 else
1117 cat_low = 0;
1119 if (cat_high > cat_prev)
1120 return -EFAULT;
1122 cat_prev = cat_low;
1125 return 0;
1129 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1130 * @doi_def: the DOI definition
1131 * @secattr: the security attributes
1132 * @net_cat: the zero'd out category list in network/CIPSO format
1133 * @net_cat_len: the length of the CIPSO category list in bytes
1135 * Description:
1136 * Perform a label mapping to translate a local MLS category bitmap to the
1137 * correct CIPSO category list using the given DOI definition. Returns the
1138 * size in bytes of the network category bitmap on success, negative values
1139 * otherwise.
1142 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1143 const struct netlbl_lsm_secattr *secattr,
1144 unsigned char *net_cat,
1145 u32 net_cat_len)
1147 int iter = -1;
1148 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1149 u32 array_cnt = 0;
1150 u32 cat_size = 0;
1152 /* make sure we don't overflow the 'array[]' variable */
1153 if (net_cat_len >
1154 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1155 return -ENOSPC;
1157 for (;;) {
1158 iter = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
1159 iter + 1);
1160 if (iter < 0)
1161 break;
1162 cat_size += (iter == 0 ? 0 : sizeof(u16));
1163 if (cat_size > net_cat_len)
1164 return -ENOSPC;
1165 array[array_cnt++] = iter;
1167 iter = netlbl_secattr_catmap_walk_rng(secattr->attr.mls.cat,
1168 iter);
1169 if (iter < 0)
1170 return -EFAULT;
1171 cat_size += sizeof(u16);
1172 if (cat_size > net_cat_len)
1173 return -ENOSPC;
1174 array[array_cnt++] = iter;
1177 for (iter = 0; array_cnt > 0;) {
1178 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1179 iter += 2;
1180 array_cnt--;
1181 if (array[array_cnt] != 0) {
1182 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1183 iter += 2;
1187 return cat_size;
1191 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1192 * @doi_def: the DOI definition
1193 * @net_cat: the category list in network/CIPSO format
1194 * @net_cat_len: the length of the CIPSO bitmap in bytes
1195 * @secattr: the security attributes
1197 * Description:
1198 * Perform a label mapping to translate a CIPSO category list to the correct
1199 * local MLS category bitmap using the given DOI definition. Returns zero on
1200 * success, negative values on failure.
1203 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1204 const unsigned char *net_cat,
1205 u32 net_cat_len,
1206 struct netlbl_lsm_secattr *secattr)
1208 int ret_val;
1209 u32 net_iter;
1210 u16 cat_low;
1211 u16 cat_high;
1213 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1214 cat_high = get_unaligned_be16(&net_cat[net_iter]);
1215 if ((net_iter + 4) <= net_cat_len)
1216 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
1217 else
1218 cat_low = 0;
1220 ret_val = netlbl_secattr_catmap_setrng(secattr->attr.mls.cat,
1221 cat_low,
1222 cat_high,
1223 GFP_ATOMIC);
1224 if (ret_val != 0)
1225 return ret_val;
1228 return 0;
1232 * Protocol Handling Functions
1236 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1237 * @doi_def: the DOI definition
1238 * @len: the total tag length in bytes, not including this header
1239 * @buf: the CIPSO option buffer
1241 * Description:
1242 * Write a CIPSO header into the beginning of @buffer.
1245 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1246 unsigned char *buf,
1247 u32 len)
1249 buf[0] = IPOPT_CIPSO;
1250 buf[1] = CIPSO_V4_HDR_LEN + len;
1251 *(__be32 *)&buf[2] = htonl(doi_def->doi);
1255 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1256 * @doi_def: the DOI definition
1257 * @secattr: the security attributes
1258 * @buffer: the option buffer
1259 * @buffer_len: length of buffer in bytes
1261 * Description:
1262 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1263 * actual buffer length may be larger than the indicated size due to
1264 * translation between host and network category bitmaps. Returns the size of
1265 * the tag on success, negative values on failure.
1268 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1269 const struct netlbl_lsm_secattr *secattr,
1270 unsigned char *buffer,
1271 u32 buffer_len)
1273 int ret_val;
1274 u32 tag_len;
1275 u32 level;
1277 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1278 return -EPERM;
1280 ret_val = cipso_v4_map_lvl_hton(doi_def,
1281 secattr->attr.mls.lvl,
1282 &level);
1283 if (ret_val != 0)
1284 return ret_val;
1286 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1287 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1288 secattr,
1289 &buffer[4],
1290 buffer_len - 4);
1291 if (ret_val < 0)
1292 return ret_val;
1294 /* This will send packets using the "optimized" format when
1295 * possible as specified in section 3.4.2.6 of the
1296 * CIPSO draft. */
1297 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
1298 tag_len = 14;
1299 else
1300 tag_len = 4 + ret_val;
1301 } else
1302 tag_len = 4;
1304 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1305 buffer[1] = tag_len;
1306 buffer[3] = level;
1308 return tag_len;
1312 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1313 * @doi_def: the DOI definition
1314 * @tag: the CIPSO tag
1315 * @secattr: the security attributes
1317 * Description:
1318 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1319 * attributes in @secattr. Return zero on success, negatives values on
1320 * failure.
1323 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1324 const unsigned char *tag,
1325 struct netlbl_lsm_secattr *secattr)
1327 int ret_val;
1328 u8 tag_len = tag[1];
1329 u32 level;
1331 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1332 if (ret_val != 0)
1333 return ret_val;
1334 secattr->attr.mls.lvl = level;
1335 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1337 if (tag_len > 4) {
1338 secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1339 if (secattr->attr.mls.cat == NULL)
1340 return -ENOMEM;
1342 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1343 &tag[4],
1344 tag_len - 4,
1345 secattr);
1346 if (ret_val != 0) {
1347 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
1348 return ret_val;
1351 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1354 return 0;
1358 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1359 * @doi_def: the DOI definition
1360 * @secattr: the security attributes
1361 * @buffer: the option buffer
1362 * @buffer_len: length of buffer in bytes
1364 * Description:
1365 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1366 * size of the tag on success, negative values on failure.
1369 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1370 const struct netlbl_lsm_secattr *secattr,
1371 unsigned char *buffer,
1372 u32 buffer_len)
1374 int ret_val;
1375 u32 tag_len;
1376 u32 level;
1378 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1379 return -EPERM;
1381 ret_val = cipso_v4_map_lvl_hton(doi_def,
1382 secattr->attr.mls.lvl,
1383 &level);
1384 if (ret_val != 0)
1385 return ret_val;
1387 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1388 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1389 secattr,
1390 &buffer[4],
1391 buffer_len - 4);
1392 if (ret_val < 0)
1393 return ret_val;
1395 tag_len = 4 + ret_val;
1396 } else
1397 tag_len = 4;
1399 buffer[0] = CIPSO_V4_TAG_ENUM;
1400 buffer[1] = tag_len;
1401 buffer[3] = level;
1403 return tag_len;
1407 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1408 * @doi_def: the DOI definition
1409 * @tag: the CIPSO tag
1410 * @secattr: the security attributes
1412 * Description:
1413 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1414 * attributes in @secattr. Return zero on success, negatives values on
1415 * failure.
1418 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1419 const unsigned char *tag,
1420 struct netlbl_lsm_secattr *secattr)
1422 int ret_val;
1423 u8 tag_len = tag[1];
1424 u32 level;
1426 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1427 if (ret_val != 0)
1428 return ret_val;
1429 secattr->attr.mls.lvl = level;
1430 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1432 if (tag_len > 4) {
1433 secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1434 if (secattr->attr.mls.cat == NULL)
1435 return -ENOMEM;
1437 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1438 &tag[4],
1439 tag_len - 4,
1440 secattr);
1441 if (ret_val != 0) {
1442 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
1443 return ret_val;
1446 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1449 return 0;
1453 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1454 * @doi_def: the DOI definition
1455 * @secattr: the security attributes
1456 * @buffer: the option buffer
1457 * @buffer_len: length of buffer in bytes
1459 * Description:
1460 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1461 * size of the tag on success, negative values on failure.
1464 static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1465 const struct netlbl_lsm_secattr *secattr,
1466 unsigned char *buffer,
1467 u32 buffer_len)
1469 int ret_val;
1470 u32 tag_len;
1471 u32 level;
1473 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1474 return -EPERM;
1476 ret_val = cipso_v4_map_lvl_hton(doi_def,
1477 secattr->attr.mls.lvl,
1478 &level);
1479 if (ret_val != 0)
1480 return ret_val;
1482 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1483 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1484 secattr,
1485 &buffer[4],
1486 buffer_len - 4);
1487 if (ret_val < 0)
1488 return ret_val;
1490 tag_len = 4 + ret_val;
1491 } else
1492 tag_len = 4;
1494 buffer[0] = CIPSO_V4_TAG_RANGE;
1495 buffer[1] = tag_len;
1496 buffer[3] = level;
1498 return tag_len;
1502 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1503 * @doi_def: the DOI definition
1504 * @tag: the CIPSO tag
1505 * @secattr: the security attributes
1507 * Description:
1508 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1509 * in @secattr. Return zero on success, negatives values on failure.
1512 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1513 const unsigned char *tag,
1514 struct netlbl_lsm_secattr *secattr)
1516 int ret_val;
1517 u8 tag_len = tag[1];
1518 u32 level;
1520 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1521 if (ret_val != 0)
1522 return ret_val;
1523 secattr->attr.mls.lvl = level;
1524 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1526 if (tag_len > 4) {
1527 secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1528 if (secattr->attr.mls.cat == NULL)
1529 return -ENOMEM;
1531 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1532 &tag[4],
1533 tag_len - 4,
1534 secattr);
1535 if (ret_val != 0) {
1536 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
1537 return ret_val;
1540 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1543 return 0;
1547 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1548 * @doi_def: the DOI definition
1549 * @secattr: the security attributes
1550 * @buffer: the option buffer
1551 * @buffer_len: length of buffer in bytes
1553 * Description:
1554 * Generate a CIPSO option using the local tag. Returns the size of the tag
1555 * on success, negative values on failure.
1558 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1559 const struct netlbl_lsm_secattr *secattr,
1560 unsigned char *buffer,
1561 u32 buffer_len)
1563 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1564 return -EPERM;
1566 buffer[0] = CIPSO_V4_TAG_LOCAL;
1567 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1568 *(u32 *)&buffer[2] = secattr->attr.secid;
1570 return CIPSO_V4_TAG_LOC_BLEN;
1574 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1575 * @doi_def: the DOI definition
1576 * @tag: the CIPSO tag
1577 * @secattr: the security attributes
1579 * Description:
1580 * Parse a CIPSO local tag and return the security attributes in @secattr.
1581 * Return zero on success, negatives values on failure.
1584 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1585 const unsigned char *tag,
1586 struct netlbl_lsm_secattr *secattr)
1588 secattr->attr.secid = *(u32 *)&tag[2];
1589 secattr->flags |= NETLBL_SECATTR_SECID;
1591 return 0;
1595 * cipso_v4_validate - Validate a CIPSO option
1596 * @option: the start of the option, on error it is set to point to the error
1598 * Description:
1599 * This routine is called to validate a CIPSO option, it checks all of the
1600 * fields to ensure that they are at least valid, see the draft snippet below
1601 * for details. If the option is valid then a zero value is returned and
1602 * the value of @option is unchanged. If the option is invalid then a
1603 * non-zero value is returned and @option is adjusted to point to the
1604 * offending portion of the option. From the IETF draft ...
1606 * "If any field within the CIPSO options, such as the DOI identifier, is not
1607 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1608 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1609 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1610 * that is unrecognized."
1613 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1615 unsigned char *opt = *option;
1616 unsigned char *tag;
1617 unsigned char opt_iter;
1618 unsigned char err_offset = 0;
1619 u8 opt_len;
1620 u8 tag_len;
1621 struct cipso_v4_doi *doi_def = NULL;
1622 u32 tag_iter;
1624 /* caller already checks for length values that are too large */
1625 opt_len = opt[1];
1626 if (opt_len < 8) {
1627 err_offset = 1;
1628 goto validate_return;
1631 rcu_read_lock();
1632 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1633 if (doi_def == NULL) {
1634 err_offset = 2;
1635 goto validate_return_locked;
1638 opt_iter = CIPSO_V4_HDR_LEN;
1639 tag = opt + opt_iter;
1640 while (opt_iter < opt_len) {
1641 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1642 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1643 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1644 err_offset = opt_iter;
1645 goto validate_return_locked;
1648 tag_len = tag[1];
1649 if (tag_len > (opt_len - opt_iter)) {
1650 err_offset = opt_iter + 1;
1651 goto validate_return_locked;
1654 switch (tag[0]) {
1655 case CIPSO_V4_TAG_RBITMAP:
1656 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1657 err_offset = opt_iter + 1;
1658 goto validate_return_locked;
1661 /* We are already going to do all the verification
1662 * necessary at the socket layer so from our point of
1663 * view it is safe to turn these checks off (and less
1664 * work), however, the CIPSO draft says we should do
1665 * all the CIPSO validations here but it doesn't
1666 * really specify _exactly_ what we need to validate
1667 * ... so, just make it a sysctl tunable. */
1668 if (cipso_v4_rbm_strictvalid) {
1669 if (cipso_v4_map_lvl_valid(doi_def,
1670 tag[3]) < 0) {
1671 err_offset = opt_iter + 3;
1672 goto validate_return_locked;
1674 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1675 cipso_v4_map_cat_rbm_valid(doi_def,
1676 &tag[4],
1677 tag_len - 4) < 0) {
1678 err_offset = opt_iter + 4;
1679 goto validate_return_locked;
1682 break;
1683 case CIPSO_V4_TAG_ENUM:
1684 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1685 err_offset = opt_iter + 1;
1686 goto validate_return_locked;
1689 if (cipso_v4_map_lvl_valid(doi_def,
1690 tag[3]) < 0) {
1691 err_offset = opt_iter + 3;
1692 goto validate_return_locked;
1694 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1695 cipso_v4_map_cat_enum_valid(doi_def,
1696 &tag[4],
1697 tag_len - 4) < 0) {
1698 err_offset = opt_iter + 4;
1699 goto validate_return_locked;
1701 break;
1702 case CIPSO_V4_TAG_RANGE:
1703 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1704 err_offset = opt_iter + 1;
1705 goto validate_return_locked;
1708 if (cipso_v4_map_lvl_valid(doi_def,
1709 tag[3]) < 0) {
1710 err_offset = opt_iter + 3;
1711 goto validate_return_locked;
1713 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1714 cipso_v4_map_cat_rng_valid(doi_def,
1715 &tag[4],
1716 tag_len - 4) < 0) {
1717 err_offset = opt_iter + 4;
1718 goto validate_return_locked;
1720 break;
1721 case CIPSO_V4_TAG_LOCAL:
1722 /* This is a non-standard tag that we only allow for
1723 * local connections, so if the incoming interface is
1724 * not the loopback device drop the packet. Further,
1725 * there is no legitimate reason for setting this from
1726 * userspace so reject it if skb is NULL. */
1727 if (skb == NULL || !(skb->dev->flags & IFF_LOOPBACK)) {
1728 err_offset = opt_iter;
1729 goto validate_return_locked;
1731 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1732 err_offset = opt_iter + 1;
1733 goto validate_return_locked;
1735 break;
1736 default:
1737 err_offset = opt_iter;
1738 goto validate_return_locked;
1741 tag += tag_len;
1742 opt_iter += tag_len;
1745 validate_return_locked:
1746 rcu_read_unlock();
1747 validate_return:
1748 *option = opt + err_offset;
1749 return err_offset;
1753 * cipso_v4_error - Send the correct response for a bad packet
1754 * @skb: the packet
1755 * @error: the error code
1756 * @gateway: CIPSO gateway flag
1758 * Description:
1759 * Based on the error code given in @error, send an ICMP error message back to
1760 * the originating host. From the IETF draft ...
1762 * "If the contents of the CIPSO [option] are valid but the security label is
1763 * outside of the configured host or port label range, the datagram is
1764 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1765 * returned. The code field of the ICMP is set to 'communication with
1766 * destination network administratively prohibited' (code 9) or to
1767 * 'communication with destination host administratively prohibited'
1768 * (code 10). The value of the code is dependent on whether the originator
1769 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1770 * recipient of the ICMP message MUST be able to handle either value. The
1771 * same procedure is performed if a CIPSO [option] can not be added to an
1772 * IP packet because it is too large to fit in the IP options area."
1774 * "If the error is triggered by receipt of an ICMP message, the message is
1775 * discarded and no response is permitted (consistent with general ICMP
1776 * processing rules)."
1779 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1781 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1782 return;
1784 if (gateway)
1785 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
1786 else
1787 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
1791 * cipso_v4_genopt - Generate a CIPSO option
1792 * @buf: the option buffer
1793 * @buf_len: the size of opt_buf
1794 * @doi_def: the CIPSO DOI to use
1795 * @secattr: the security attributes
1797 * Description:
1798 * Generate a CIPSO option using the DOI definition and security attributes
1799 * passed to the function. Returns the length of the option on success and
1800 * negative values on failure.
1803 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1804 const struct cipso_v4_doi *doi_def,
1805 const struct netlbl_lsm_secattr *secattr)
1807 int ret_val;
1808 u32 iter;
1810 if (buf_len <= CIPSO_V4_HDR_LEN)
1811 return -ENOSPC;
1813 /* XXX - This code assumes only one tag per CIPSO option which isn't
1814 * really a good assumption to make but since we only support the MAC
1815 * tags right now it is a safe assumption. */
1816 iter = 0;
1817 do {
1818 memset(buf, 0, buf_len);
1819 switch (doi_def->tags[iter]) {
1820 case CIPSO_V4_TAG_RBITMAP:
1821 ret_val = cipso_v4_gentag_rbm(doi_def,
1822 secattr,
1823 &buf[CIPSO_V4_HDR_LEN],
1824 buf_len - CIPSO_V4_HDR_LEN);
1825 break;
1826 case CIPSO_V4_TAG_ENUM:
1827 ret_val = cipso_v4_gentag_enum(doi_def,
1828 secattr,
1829 &buf[CIPSO_V4_HDR_LEN],
1830 buf_len - CIPSO_V4_HDR_LEN);
1831 break;
1832 case CIPSO_V4_TAG_RANGE:
1833 ret_val = cipso_v4_gentag_rng(doi_def,
1834 secattr,
1835 &buf[CIPSO_V4_HDR_LEN],
1836 buf_len - CIPSO_V4_HDR_LEN);
1837 break;
1838 case CIPSO_V4_TAG_LOCAL:
1839 ret_val = cipso_v4_gentag_loc(doi_def,
1840 secattr,
1841 &buf[CIPSO_V4_HDR_LEN],
1842 buf_len - CIPSO_V4_HDR_LEN);
1843 break;
1844 default:
1845 return -EPERM;
1848 iter++;
1849 } while (ret_val < 0 &&
1850 iter < CIPSO_V4_TAG_MAXCNT &&
1851 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1852 if (ret_val < 0)
1853 return ret_val;
1854 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1855 return CIPSO_V4_HDR_LEN + ret_val;
1859 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1860 * @sk: the socket
1861 * @doi_def: the CIPSO DOI to use
1862 * @secattr: the specific security attributes of the socket
1864 * Description:
1865 * Set the CIPSO option on the given socket using the DOI definition and
1866 * security attributes passed to the function. This function requires
1867 * exclusive access to @sk, which means it either needs to be in the
1868 * process of being created or locked. Returns zero on success and negative
1869 * values on failure.
1872 int cipso_v4_sock_setattr(struct sock *sk,
1873 const struct cipso_v4_doi *doi_def,
1874 const struct netlbl_lsm_secattr *secattr)
1876 int ret_val = -EPERM;
1877 unsigned char *buf = NULL;
1878 u32 buf_len;
1879 u32 opt_len;
1880 struct ip_options_rcu *old, *opt = NULL;
1881 struct inet_sock *sk_inet;
1882 struct inet_connection_sock *sk_conn;
1884 /* In the case of sock_create_lite(), the sock->sk field is not
1885 * defined yet but it is not a problem as the only users of these
1886 * "lite" PF_INET sockets are functions which do an accept() call
1887 * afterwards so we will label the socket as part of the accept(). */
1888 if (sk == NULL)
1889 return 0;
1891 /* We allocate the maximum CIPSO option size here so we are probably
1892 * being a little wasteful, but it makes our life _much_ easier later
1893 * on and after all we are only talking about 40 bytes. */
1894 buf_len = CIPSO_V4_OPT_LEN_MAX;
1895 buf = kmalloc(buf_len, GFP_ATOMIC);
1896 if (buf == NULL) {
1897 ret_val = -ENOMEM;
1898 goto socket_setattr_failure;
1901 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1902 if (ret_val < 0)
1903 goto socket_setattr_failure;
1904 buf_len = ret_val;
1906 /* We can't use ip_options_get() directly because it makes a call to
1907 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1908 * we won't always have CAP_NET_RAW even though we _always_ want to
1909 * set the IPOPT_CIPSO option. */
1910 opt_len = (buf_len + 3) & ~3;
1911 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1912 if (opt == NULL) {
1913 ret_val = -ENOMEM;
1914 goto socket_setattr_failure;
1916 memcpy(opt->opt.__data, buf, buf_len);
1917 opt->opt.optlen = opt_len;
1918 opt->opt.cipso = sizeof(struct iphdr);
1919 kfree(buf);
1920 buf = NULL;
1922 sk_inet = inet_sk(sk);
1924 old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
1925 if (sk_inet->is_icsk) {
1926 sk_conn = inet_csk(sk);
1927 if (old)
1928 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1929 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1930 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1932 rcu_assign_pointer(sk_inet->inet_opt, opt);
1933 if (old)
1934 kfree_rcu(old, rcu);
1936 return 0;
1938 socket_setattr_failure:
1939 kfree(buf);
1940 kfree(opt);
1941 return ret_val;
1945 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1946 * @req: the connection request socket
1947 * @doi_def: the CIPSO DOI to use
1948 * @secattr: the specific security attributes of the socket
1950 * Description:
1951 * Set the CIPSO option on the given socket using the DOI definition and
1952 * security attributes passed to the function. Returns zero on success and
1953 * negative values on failure.
1956 int cipso_v4_req_setattr(struct request_sock *req,
1957 const struct cipso_v4_doi *doi_def,
1958 const struct netlbl_lsm_secattr *secattr)
1960 int ret_val = -EPERM;
1961 unsigned char *buf = NULL;
1962 u32 buf_len;
1963 u32 opt_len;
1964 struct ip_options_rcu *opt = NULL;
1965 struct inet_request_sock *req_inet;
1967 /* We allocate the maximum CIPSO option size here so we are probably
1968 * being a little wasteful, but it makes our life _much_ easier later
1969 * on and after all we are only talking about 40 bytes. */
1970 buf_len = CIPSO_V4_OPT_LEN_MAX;
1971 buf = kmalloc(buf_len, GFP_ATOMIC);
1972 if (buf == NULL) {
1973 ret_val = -ENOMEM;
1974 goto req_setattr_failure;
1977 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1978 if (ret_val < 0)
1979 goto req_setattr_failure;
1980 buf_len = ret_val;
1982 /* We can't use ip_options_get() directly because it makes a call to
1983 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1984 * we won't always have CAP_NET_RAW even though we _always_ want to
1985 * set the IPOPT_CIPSO option. */
1986 opt_len = (buf_len + 3) & ~3;
1987 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1988 if (opt == NULL) {
1989 ret_val = -ENOMEM;
1990 goto req_setattr_failure;
1992 memcpy(opt->opt.__data, buf, buf_len);
1993 opt->opt.optlen = opt_len;
1994 opt->opt.cipso = sizeof(struct iphdr);
1995 kfree(buf);
1996 buf = NULL;
1998 req_inet = inet_rsk(req);
1999 opt = xchg(&req_inet->opt, opt);
2000 if (opt)
2001 kfree_rcu(opt, rcu);
2003 return 0;
2005 req_setattr_failure:
2006 kfree(buf);
2007 kfree(opt);
2008 return ret_val;
2012 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
2013 * @opt_ptr: IP option pointer
2015 * Description:
2016 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
2017 * adjustments to the IP option structure. Returns zero on success, negative
2018 * values on failure.
2021 static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr)
2023 int hdr_delta = 0;
2024 struct ip_options_rcu *opt = *opt_ptr;
2026 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
2027 u8 cipso_len;
2028 u8 cipso_off;
2029 unsigned char *cipso_ptr;
2030 int iter;
2031 int optlen_new;
2033 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
2034 cipso_ptr = &opt->opt.__data[cipso_off];
2035 cipso_len = cipso_ptr[1];
2037 if (opt->opt.srr > opt->opt.cipso)
2038 opt->opt.srr -= cipso_len;
2039 if (opt->opt.rr > opt->opt.cipso)
2040 opt->opt.rr -= cipso_len;
2041 if (opt->opt.ts > opt->opt.cipso)
2042 opt->opt.ts -= cipso_len;
2043 if (opt->opt.router_alert > opt->opt.cipso)
2044 opt->opt.router_alert -= cipso_len;
2045 opt->opt.cipso = 0;
2047 memmove(cipso_ptr, cipso_ptr + cipso_len,
2048 opt->opt.optlen - cipso_off - cipso_len);
2050 /* determining the new total option length is tricky because of
2051 * the padding necessary, the only thing i can think to do at
2052 * this point is walk the options one-by-one, skipping the
2053 * padding at the end to determine the actual option size and
2054 * from there we can determine the new total option length */
2055 iter = 0;
2056 optlen_new = 0;
2057 while (iter < opt->opt.optlen)
2058 if (opt->opt.__data[iter] != IPOPT_NOP) {
2059 iter += opt->opt.__data[iter + 1];
2060 optlen_new = iter;
2061 } else
2062 iter++;
2063 hdr_delta = opt->opt.optlen;
2064 opt->opt.optlen = (optlen_new + 3) & ~3;
2065 hdr_delta -= opt->opt.optlen;
2066 } else {
2067 /* only the cipso option was present on the socket so we can
2068 * remove the entire option struct */
2069 *opt_ptr = NULL;
2070 hdr_delta = opt->opt.optlen;
2071 kfree_rcu(opt, rcu);
2074 return hdr_delta;
2078 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2079 * @sk: the socket
2081 * Description:
2082 * Removes the CIPSO option from a socket, if present.
2085 void cipso_v4_sock_delattr(struct sock *sk)
2087 int hdr_delta;
2088 struct ip_options_rcu *opt;
2089 struct inet_sock *sk_inet;
2091 sk_inet = inet_sk(sk);
2092 opt = rcu_dereference_protected(sk_inet->inet_opt, 1);
2093 if (opt == NULL || opt->opt.cipso == 0)
2094 return;
2096 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2097 if (sk_inet->is_icsk && hdr_delta > 0) {
2098 struct inet_connection_sock *sk_conn = inet_csk(sk);
2099 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2100 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2105 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2106 * @reg: the request socket
2108 * Description:
2109 * Removes the CIPSO option from a request socket, if present.
2112 void cipso_v4_req_delattr(struct request_sock *req)
2114 struct ip_options_rcu *opt;
2115 struct inet_request_sock *req_inet;
2117 req_inet = inet_rsk(req);
2118 opt = req_inet->opt;
2119 if (opt == NULL || opt->opt.cipso == 0)
2120 return;
2122 cipso_v4_delopt(&req_inet->opt);
2126 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2127 * @cipso: the CIPSO v4 option
2128 * @secattr: the security attributes
2130 * Description:
2131 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2132 * on success and negative values on failure.
2135 static int cipso_v4_getattr(const unsigned char *cipso,
2136 struct netlbl_lsm_secattr *secattr)
2138 int ret_val = -ENOMSG;
2139 u32 doi;
2140 struct cipso_v4_doi *doi_def;
2142 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2143 return 0;
2145 doi = get_unaligned_be32(&cipso[2]);
2146 rcu_read_lock();
2147 doi_def = cipso_v4_doi_search(doi);
2148 if (doi_def == NULL)
2149 goto getattr_return;
2150 /* XXX - This code assumes only one tag per CIPSO option which isn't
2151 * really a good assumption to make but since we only support the MAC
2152 * tags right now it is a safe assumption. */
2153 switch (cipso[6]) {
2154 case CIPSO_V4_TAG_RBITMAP:
2155 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2156 break;
2157 case CIPSO_V4_TAG_ENUM:
2158 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2159 break;
2160 case CIPSO_V4_TAG_RANGE:
2161 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2162 break;
2163 case CIPSO_V4_TAG_LOCAL:
2164 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2165 break;
2167 if (ret_val == 0)
2168 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2170 getattr_return:
2171 rcu_read_unlock();
2172 return ret_val;
2176 * cipso_v4_sock_getattr - Get the security attributes from a sock
2177 * @sk: the sock
2178 * @secattr: the security attributes
2180 * Description:
2181 * Query @sk to see if there is a CIPSO option attached to the sock and if
2182 * there is return the CIPSO security attributes in @secattr. This function
2183 * requires that @sk be locked, or privately held, but it does not do any
2184 * locking itself. Returns zero on success and negative values on failure.
2187 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2189 struct ip_options_rcu *opt;
2190 int res = -ENOMSG;
2192 rcu_read_lock();
2193 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2194 if (opt && opt->opt.cipso)
2195 res = cipso_v4_getattr(opt->opt.__data +
2196 opt->opt.cipso -
2197 sizeof(struct iphdr),
2198 secattr);
2199 rcu_read_unlock();
2200 return res;
2204 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2205 * @skb: the packet
2206 * @secattr: the security attributes
2208 * Description:
2209 * Set the CIPSO option on the given packet based on the security attributes.
2210 * Returns a pointer to the IP header on success and NULL on failure.
2213 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2214 const struct cipso_v4_doi *doi_def,
2215 const struct netlbl_lsm_secattr *secattr)
2217 int ret_val;
2218 struct iphdr *iph;
2219 struct ip_options *opt = &IPCB(skb)->opt;
2220 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2221 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2222 u32 opt_len;
2223 int len_delta;
2225 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2226 if (ret_val < 0)
2227 return ret_val;
2228 buf_len = ret_val;
2229 opt_len = (buf_len + 3) & ~3;
2231 /* we overwrite any existing options to ensure that we have enough
2232 * room for the CIPSO option, the reason is that we _need_ to guarantee
2233 * that the security label is applied to the packet - we do the same
2234 * thing when using the socket options and it hasn't caused a problem,
2235 * if we need to we can always revisit this choice later */
2237 len_delta = opt_len - opt->optlen;
2238 /* if we don't ensure enough headroom we could panic on the skb_push()
2239 * call below so make sure we have enough, we are also "mangling" the
2240 * packet so we should probably do a copy-on-write call anyway */
2241 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2242 if (ret_val < 0)
2243 return ret_val;
2245 if (len_delta > 0) {
2246 /* we assume that the header + opt->optlen have already been
2247 * "pushed" in ip_options_build() or similar */
2248 iph = ip_hdr(skb);
2249 skb_push(skb, len_delta);
2250 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2251 skb_reset_network_header(skb);
2252 iph = ip_hdr(skb);
2253 } else if (len_delta < 0) {
2254 iph = ip_hdr(skb);
2255 memset(iph + 1, IPOPT_NOP, opt->optlen);
2256 } else
2257 iph = ip_hdr(skb);
2259 if (opt->optlen > 0)
2260 memset(opt, 0, sizeof(*opt));
2261 opt->optlen = opt_len;
2262 opt->cipso = sizeof(struct iphdr);
2263 opt->is_changed = 1;
2265 /* we have to do the following because we are being called from a
2266 * netfilter hook which means the packet already has had the header
2267 * fields populated and the checksum calculated - yes this means we
2268 * are doing more work than needed but we do it to keep the core
2269 * stack clean and tidy */
2270 memcpy(iph + 1, buf, buf_len);
2271 if (opt_len > buf_len)
2272 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2273 if (len_delta != 0) {
2274 iph->ihl = 5 + (opt_len >> 2);
2275 iph->tot_len = htons(skb->len);
2277 ip_send_check(iph);
2279 return 0;
2283 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2284 * @skb: the packet
2286 * Description:
2287 * Removes any and all CIPSO options from the given packet. Returns zero on
2288 * success, negative values on failure.
2291 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2293 int ret_val;
2294 struct iphdr *iph;
2295 struct ip_options *opt = &IPCB(skb)->opt;
2296 unsigned char *cipso_ptr;
2298 if (opt->cipso == 0)
2299 return 0;
2301 /* since we are changing the packet we should make a copy */
2302 ret_val = skb_cow(skb, skb_headroom(skb));
2303 if (ret_val < 0)
2304 return ret_val;
2306 /* the easiest thing to do is just replace the cipso option with noop
2307 * options since we don't change the size of the packet, although we
2308 * still need to recalculate the checksum */
2310 iph = ip_hdr(skb);
2311 cipso_ptr = (unsigned char *)iph + opt->cipso;
2312 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2313 opt->cipso = 0;
2314 opt->is_changed = 1;
2316 ip_send_check(iph);
2318 return 0;
2322 * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
2323 * @skb: the packet
2324 * @secattr: the security attributes
2326 * Description:
2327 * Parse the given packet's CIPSO option and return the security attributes.
2328 * Returns zero on success and negative values on failure.
2331 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
2332 struct netlbl_lsm_secattr *secattr)
2334 return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr);
2338 * Setup Functions
2342 * cipso_v4_init - Initialize the CIPSO module
2344 * Description:
2345 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2346 * and negative values on failure.
2349 static int __init cipso_v4_init(void)
2351 int ret_val;
2353 ret_val = cipso_v4_cache_init();
2354 if (ret_val != 0)
2355 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2356 ret_val);
2358 return 0;
2361 subsys_initcall(cipso_v4_init);