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, 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.
11 * Author: Paul Moore <paul.moore@hp.com>
16 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
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.
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.
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
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>
44 #include <net/netlabel.h>
45 #include <net/cipso_ipv4.h>
46 #include <asm/atomic.h>
48 #include <asm/unaligned.h>
50 /* List of available DOI definitions */
51 /* XXX - This currently assumes a minimal number of different DOIs in use,
52 * if in practice there are a lot of different DOIs this list should
53 * probably be turned into a hash table or something similar so we
54 * can do quick lookups. */
55 static DEFINE_SPINLOCK(cipso_v4_doi_list_lock
);
56 static LIST_HEAD(cipso_v4_doi_list
);
58 /* Label mapping cache */
59 int cipso_v4_cache_enabled
= 1;
60 int cipso_v4_cache_bucketsize
= 10;
61 #define CIPSO_V4_CACHE_BUCKETBITS 7
62 #define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS)
63 #define CIPSO_V4_CACHE_REORDERLIMIT 10
64 struct cipso_v4_map_cache_bkt
{
67 struct list_head list
;
69 struct cipso_v4_map_cache_entry
{
74 struct netlbl_lsm_cache
*lsm_data
;
77 struct list_head list
;
79 static struct cipso_v4_map_cache_bkt
*cipso_v4_cache
= NULL
;
81 /* Restricted bitmap (tag #1) flags */
82 int cipso_v4_rbm_optfmt
= 0;
83 int cipso_v4_rbm_strictvalid
= 1;
89 /* Maximum size of the CIPSO IP option, derived from the fact that the maximum
90 * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
91 #define CIPSO_V4_OPT_LEN_MAX 40
93 /* Length of the base CIPSO option, this includes the option type (1 byte), the
94 * option length (1 byte), and the DOI (4 bytes). */
95 #define CIPSO_V4_HDR_LEN 6
97 /* Base length of the restrictive category bitmap tag (tag #1). */
98 #define CIPSO_V4_TAG_RBM_BLEN 4
100 /* Base length of the enumerated category tag (tag #2). */
101 #define CIPSO_V4_TAG_ENUM_BLEN 4
103 /* Base length of the ranged categories bitmap tag (tag #5). */
104 #define CIPSO_V4_TAG_RNG_BLEN 4
105 /* The maximum number of category ranges permitted in the ranged category tag
106 * (tag #5). You may note that the IETF draft states that the maximum number
107 * of category ranges is 7, but if the low end of the last category range is
108 * zero then it is possibile to fit 8 category ranges because the zero should
110 #define CIPSO_V4_TAG_RNG_CAT_MAX 8
112 /* Base length of the local tag (non-standard tag).
113 * Tag definition (may change between kernel versions)
116 * +----------+----------+----------+----------+
117 * | 10000000 | 00000110 | 32-bit secid value |
118 * +----------+----------+----------+----------+
119 * | in (host byte order)|
120 * +----------+----------+
123 #define CIPSO_V4_TAG_LOC_BLEN 6
130 * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
131 * @bitmap: the bitmap
132 * @bitmap_len: length in bits
133 * @offset: starting offset
134 * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
137 * Starting at @offset, walk the bitmap from left to right until either the
138 * desired bit is found or we reach the end. Return the bit offset, -1 if
139 * not found, or -2 if error.
141 static int cipso_v4_bitmap_walk(const unsigned char *bitmap
,
148 unsigned char bitmask
;
151 /* gcc always rounds to zero when doing integer division */
152 byte_offset
= offset
/ 8;
153 byte
= bitmap
[byte_offset
];
155 bitmask
= 0x80 >> (offset
% 8);
157 while (bit_spot
< bitmap_len
) {
158 if ((state
&& (byte
& bitmask
) == bitmask
) ||
159 (state
== 0 && (byte
& bitmask
) == 0))
165 byte
= bitmap
[++byte_offset
];
174 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
175 * @bitmap: the bitmap
177 * @state: if non-zero, set the bit (1) else clear the bit (0)
180 * Set a single bit in the bitmask. Returns zero on success, negative values
183 static void cipso_v4_bitmap_setbit(unsigned char *bitmap
,
190 /* gcc always rounds to zero when doing integer division */
192 bitmask
= 0x80 >> (bit
% 8);
194 bitmap
[byte_spot
] |= bitmask
;
196 bitmap
[byte_spot
] &= ~bitmask
;
200 * cipso_v4_cache_entry_free - Frees a cache entry
201 * @entry: the entry to free
204 * This function frees the memory associated with a cache entry including the
205 * LSM cache data if there are no longer any users, i.e. reference count == 0.
208 static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry
*entry
)
211 netlbl_secattr_cache_free(entry
->lsm_data
);
217 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
219 * @key_len: the length of the key in bytes
222 * The CIPSO tag hashing function. Returns a 32-bit hash value.
225 static u32
cipso_v4_map_cache_hash(const unsigned char *key
, u32 key_len
)
227 return jhash(key
, key_len
, 0);
231 * Label Mapping Cache Functions
235 * cipso_v4_cache_init - Initialize the CIPSO cache
238 * Initializes the CIPSO label mapping cache, this function should be called
239 * before any of the other functions defined in this file. Returns zero on
240 * success, negative values on error.
243 static int cipso_v4_cache_init(void)
247 cipso_v4_cache
= kcalloc(CIPSO_V4_CACHE_BUCKETS
,
248 sizeof(struct cipso_v4_map_cache_bkt
),
250 if (cipso_v4_cache
== NULL
)
253 for (iter
= 0; iter
< CIPSO_V4_CACHE_BUCKETS
; iter
++) {
254 spin_lock_init(&cipso_v4_cache
[iter
].lock
);
255 cipso_v4_cache
[iter
].size
= 0;
256 INIT_LIST_HEAD(&cipso_v4_cache
[iter
].list
);
263 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
266 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
267 * success and negative values on failure.
270 void cipso_v4_cache_invalidate(void)
272 struct cipso_v4_map_cache_entry
*entry
, *tmp_entry
;
275 for (iter
= 0; iter
< CIPSO_V4_CACHE_BUCKETS
; iter
++) {
276 spin_lock_bh(&cipso_v4_cache
[iter
].lock
);
277 list_for_each_entry_safe(entry
,
279 &cipso_v4_cache
[iter
].list
, list
) {
280 list_del(&entry
->list
);
281 cipso_v4_cache_entry_free(entry
);
283 cipso_v4_cache
[iter
].size
= 0;
284 spin_unlock_bh(&cipso_v4_cache
[iter
].lock
);
291 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
292 * @key: the buffer to check
293 * @key_len: buffer length in bytes
294 * @secattr: the security attribute struct to use
297 * This function checks the cache to see if a label mapping already exists for
298 * the given key. If there is a match then the cache is adjusted and the
299 * @secattr struct is populated with the correct LSM security attributes. The
300 * cache is adjusted in the following manner if the entry is not already the
301 * first in the cache bucket:
303 * 1. The cache entry's activity counter is incremented
304 * 2. The previous (higher ranking) entry's activity counter is decremented
305 * 3. If the difference between the two activity counters is geater than
306 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
308 * Returns zero on success, -ENOENT for a cache miss, and other negative values
312 static int cipso_v4_cache_check(const unsigned char *key
,
314 struct netlbl_lsm_secattr
*secattr
)
317 struct cipso_v4_map_cache_entry
*entry
;
318 struct cipso_v4_map_cache_entry
*prev_entry
= NULL
;
321 if (!cipso_v4_cache_enabled
)
324 hash
= cipso_v4_map_cache_hash(key
, key_len
);
325 bkt
= hash
& (CIPSO_V4_CACHE_BUCKETS
- 1);
326 spin_lock_bh(&cipso_v4_cache
[bkt
].lock
);
327 list_for_each_entry(entry
, &cipso_v4_cache
[bkt
].list
, list
) {
328 if (entry
->hash
== hash
&&
329 entry
->key_len
== key_len
&&
330 memcmp(entry
->key
, key
, key_len
) == 0) {
331 entry
->activity
+= 1;
332 atomic_inc(&entry
->lsm_data
->refcount
);
333 secattr
->cache
= entry
->lsm_data
;
334 secattr
->flags
|= NETLBL_SECATTR_CACHE
;
335 secattr
->type
= NETLBL_NLTYPE_CIPSOV4
;
336 if (prev_entry
== NULL
) {
337 spin_unlock_bh(&cipso_v4_cache
[bkt
].lock
);
341 if (prev_entry
->activity
> 0)
342 prev_entry
->activity
-= 1;
343 if (entry
->activity
> prev_entry
->activity
&&
344 entry
->activity
- prev_entry
->activity
>
345 CIPSO_V4_CACHE_REORDERLIMIT
) {
346 __list_del(entry
->list
.prev
, entry
->list
.next
);
347 __list_add(&entry
->list
,
348 prev_entry
->list
.prev
,
352 spin_unlock_bh(&cipso_v4_cache
[bkt
].lock
);
357 spin_unlock_bh(&cipso_v4_cache
[bkt
].lock
);
363 * cipso_v4_cache_add - Add an entry to the CIPSO cache
365 * @secattr: the packet's security attributes
368 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
369 * head of the cache bucket's list, if the cache bucket is out of room remove
370 * the last entry in the list first. It is important to note that there is
371 * currently no checking for duplicate keys. Returns zero on success,
372 * negative values on failure.
375 int cipso_v4_cache_add(const struct sk_buff
*skb
,
376 const struct netlbl_lsm_secattr
*secattr
)
378 int ret_val
= -EPERM
;
380 struct cipso_v4_map_cache_entry
*entry
= NULL
;
381 struct cipso_v4_map_cache_entry
*old_entry
= NULL
;
382 unsigned char *cipso_ptr
;
385 if (!cipso_v4_cache_enabled
|| cipso_v4_cache_bucketsize
<= 0)
388 cipso_ptr
= CIPSO_V4_OPTPTR(skb
);
389 cipso_ptr_len
= cipso_ptr
[1];
391 entry
= kzalloc(sizeof(*entry
), GFP_ATOMIC
);
394 entry
->key
= kmemdup(cipso_ptr
, cipso_ptr_len
, GFP_ATOMIC
);
395 if (entry
->key
== NULL
) {
397 goto cache_add_failure
;
399 entry
->key_len
= cipso_ptr_len
;
400 entry
->hash
= cipso_v4_map_cache_hash(cipso_ptr
, cipso_ptr_len
);
401 atomic_inc(&secattr
->cache
->refcount
);
402 entry
->lsm_data
= secattr
->cache
;
404 bkt
= entry
->hash
& (CIPSO_V4_CACHE_BUCKETS
- 1);
405 spin_lock_bh(&cipso_v4_cache
[bkt
].lock
);
406 if (cipso_v4_cache
[bkt
].size
< cipso_v4_cache_bucketsize
) {
407 list_add(&entry
->list
, &cipso_v4_cache
[bkt
].list
);
408 cipso_v4_cache
[bkt
].size
+= 1;
410 old_entry
= list_entry(cipso_v4_cache
[bkt
].list
.prev
,
411 struct cipso_v4_map_cache_entry
, list
);
412 list_del(&old_entry
->list
);
413 list_add(&entry
->list
, &cipso_v4_cache
[bkt
].list
);
414 cipso_v4_cache_entry_free(old_entry
);
416 spin_unlock_bh(&cipso_v4_cache
[bkt
].lock
);
422 cipso_v4_cache_entry_free(entry
);
431 * cipso_v4_doi_search - Searches for a DOI definition
432 * @doi: the DOI to search for
435 * Search the DOI definition list for a DOI definition with a DOI value that
436 * matches @doi. The caller is responsibile for calling rcu_read_[un]lock().
437 * Returns a pointer to the DOI definition on success and NULL on failure.
439 static struct cipso_v4_doi
*cipso_v4_doi_search(u32 doi
)
441 struct cipso_v4_doi
*iter
;
443 list_for_each_entry_rcu(iter
, &cipso_v4_doi_list
, list
)
444 if (iter
->doi
== doi
&& atomic_read(&iter
->refcount
))
450 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
451 * @doi_def: the DOI structure
454 * The caller defines a new DOI for use by the CIPSO engine and calls this
455 * function to add it to the list of acceptable domains. The caller must
456 * ensure that the mapping table specified in @doi_def->map meets all of the
457 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
458 * zero on success and non-zero on failure.
461 int cipso_v4_doi_add(struct cipso_v4_doi
*doi_def
)
465 if (doi_def
== NULL
|| doi_def
->doi
== CIPSO_V4_DOI_UNKNOWN
)
467 for (iter
= 0; iter
< CIPSO_V4_TAG_MAXCNT
; iter
++) {
468 switch (doi_def
->tags
[iter
]) {
469 case CIPSO_V4_TAG_RBITMAP
:
471 case CIPSO_V4_TAG_RANGE
:
472 if (doi_def
->type
!= CIPSO_V4_MAP_PASS
)
475 case CIPSO_V4_TAG_INVALID
:
479 case CIPSO_V4_TAG_ENUM
:
480 if (doi_def
->type
!= CIPSO_V4_MAP_PASS
)
483 case CIPSO_V4_TAG_LOCAL
:
484 if (doi_def
->type
!= CIPSO_V4_MAP_LOCAL
)
492 atomic_set(&doi_def
->refcount
, 1);
493 INIT_RCU_HEAD(&doi_def
->rcu
);
495 spin_lock(&cipso_v4_doi_list_lock
);
496 if (cipso_v4_doi_search(doi_def
->doi
) != NULL
)
497 goto doi_add_failure
;
498 list_add_tail_rcu(&doi_def
->list
, &cipso_v4_doi_list
);
499 spin_unlock(&cipso_v4_doi_list_lock
);
504 spin_unlock(&cipso_v4_doi_list_lock
);
509 * cipso_v4_doi_free - Frees a DOI definition
510 * @entry: the entry's RCU field
513 * This function frees all of the memory associated with a DOI definition.
516 void cipso_v4_doi_free(struct cipso_v4_doi
*doi_def
)
521 switch (doi_def
->type
) {
522 case CIPSO_V4_MAP_TRANS
:
523 kfree(doi_def
->map
.std
->lvl
.cipso
);
524 kfree(doi_def
->map
.std
->lvl
.local
);
525 kfree(doi_def
->map
.std
->cat
.cipso
);
526 kfree(doi_def
->map
.std
->cat
.local
);
533 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
534 * @entry: the entry's RCU field
537 * This function is designed to be used as a callback to the call_rcu()
538 * function so that the memory allocated to the DOI definition can be released
542 static void cipso_v4_doi_free_rcu(struct rcu_head
*entry
)
544 struct cipso_v4_doi
*doi_def
;
546 doi_def
= container_of(entry
, struct cipso_v4_doi
, rcu
);
547 cipso_v4_doi_free(doi_def
);
551 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
552 * @doi: the DOI value
553 * @audit_secid: the LSM secid to use in the audit message
556 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
557 * be called to release their own LSM domain mappings as well as our own
558 * domain list. Returns zero on success and negative values on failure.
561 int cipso_v4_doi_remove(u32 doi
, struct netlbl_audit
*audit_info
)
563 struct cipso_v4_doi
*doi_def
;
565 spin_lock(&cipso_v4_doi_list_lock
);
566 doi_def
= cipso_v4_doi_search(doi
);
567 if (doi_def
== NULL
) {
568 spin_unlock(&cipso_v4_doi_list_lock
);
571 if (!atomic_dec_and_test(&doi_def
->refcount
)) {
572 spin_unlock(&cipso_v4_doi_list_lock
);
575 list_del_rcu(&doi_def
->list
);
576 spin_unlock(&cipso_v4_doi_list_lock
);
578 cipso_v4_cache_invalidate();
579 call_rcu(&doi_def
->rcu
, cipso_v4_doi_free_rcu
);
585 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
586 * @doi: the DOI value
589 * Searches for a valid DOI definition and if one is found it is returned to
590 * the caller. Otherwise NULL is returned. The caller must ensure that
591 * rcu_read_lock() is held while accessing the returned definition and the DOI
592 * definition reference count is decremented when the caller is done.
595 struct cipso_v4_doi
*cipso_v4_doi_getdef(u32 doi
)
597 struct cipso_v4_doi
*doi_def
;
600 doi_def
= cipso_v4_doi_search(doi
);
602 goto doi_getdef_return
;
603 if (!atomic_inc_not_zero(&doi_def
->refcount
))
612 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
613 * @doi_def: the DOI definition
616 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
619 void cipso_v4_doi_putdef(struct cipso_v4_doi
*doi_def
)
624 if (!atomic_dec_and_test(&doi_def
->refcount
))
626 spin_lock(&cipso_v4_doi_list_lock
);
627 list_del_rcu(&doi_def
->list
);
628 spin_unlock(&cipso_v4_doi_list_lock
);
630 cipso_v4_cache_invalidate();
631 call_rcu(&doi_def
->rcu
, cipso_v4_doi_free_rcu
);
635 * cipso_v4_doi_walk - Iterate through the DOI definitions
636 * @skip_cnt: skip past this number of DOI definitions, updated
637 * @callback: callback for each DOI definition
638 * @cb_arg: argument for the callback function
641 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
642 * For each entry call @callback, if @callback returns a negative value stop
643 * 'walking' through the list and return. Updates the value in @skip_cnt upon
644 * return. Returns zero on success, negative values on failure.
647 int cipso_v4_doi_walk(u32
*skip_cnt
,
648 int (*callback
) (struct cipso_v4_doi
*doi_def
, void *arg
),
651 int ret_val
= -ENOENT
;
653 struct cipso_v4_doi
*iter_doi
;
656 list_for_each_entry_rcu(iter_doi
, &cipso_v4_doi_list
, list
)
657 if (atomic_read(&iter_doi
->refcount
) > 0) {
658 if (doi_cnt
++ < *skip_cnt
)
660 ret_val
= callback(iter_doi
, cb_arg
);
663 goto doi_walk_return
;
674 * Label Mapping Functions
678 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
679 * @doi_def: the DOI definition
680 * @level: the level to check
683 * Checks the given level against the given DOI definition and returns a
684 * negative value if the level does not have a valid mapping and a zero value
685 * if the level is defined by the DOI.
688 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi
*doi_def
, u8 level
)
690 switch (doi_def
->type
) {
691 case CIPSO_V4_MAP_PASS
:
693 case CIPSO_V4_MAP_TRANS
:
694 if (doi_def
->map
.std
->lvl
.cipso
[level
] < CIPSO_V4_INV_LVL
)
703 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
704 * @doi_def: the DOI definition
705 * @host_lvl: the host MLS level
706 * @net_lvl: the network/CIPSO MLS level
709 * Perform a label mapping to translate a local MLS level to the correct
710 * CIPSO level using the given DOI definition. Returns zero on success,
711 * negative values otherwise.
714 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi
*doi_def
,
718 switch (doi_def
->type
) {
719 case CIPSO_V4_MAP_PASS
:
722 case CIPSO_V4_MAP_TRANS
:
723 if (host_lvl
< doi_def
->map
.std
->lvl
.local_size
&&
724 doi_def
->map
.std
->lvl
.local
[host_lvl
] < CIPSO_V4_INV_LVL
) {
725 *net_lvl
= doi_def
->map
.std
->lvl
.local
[host_lvl
];
735 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
736 * @doi_def: the DOI definition
737 * @net_lvl: the network/CIPSO MLS level
738 * @host_lvl: the host MLS level
741 * Perform a label mapping to translate a CIPSO level to the correct local MLS
742 * level using the given DOI definition. Returns zero on success, negative
746 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi
*doi_def
,
750 struct cipso_v4_std_map_tbl
*map_tbl
;
752 switch (doi_def
->type
) {
753 case CIPSO_V4_MAP_PASS
:
756 case CIPSO_V4_MAP_TRANS
:
757 map_tbl
= doi_def
->map
.std
;
758 if (net_lvl
< map_tbl
->lvl
.cipso_size
&&
759 map_tbl
->lvl
.cipso
[net_lvl
] < CIPSO_V4_INV_LVL
) {
760 *host_lvl
= doi_def
->map
.std
->lvl
.cipso
[net_lvl
];
770 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
771 * @doi_def: the DOI definition
772 * @bitmap: category bitmap
773 * @bitmap_len: bitmap length in bytes
776 * Checks the given category bitmap against the given DOI definition and
777 * returns a negative value if any of the categories in the bitmap do not have
778 * a valid mapping and a zero value if all of the categories are valid.
781 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi
*doi_def
,
782 const unsigned char *bitmap
,
786 u32 bitmap_len_bits
= bitmap_len
* 8;
790 switch (doi_def
->type
) {
791 case CIPSO_V4_MAP_PASS
:
793 case CIPSO_V4_MAP_TRANS
:
794 cipso_cat_size
= doi_def
->map
.std
->cat
.cipso_size
;
795 cipso_array
= doi_def
->map
.std
->cat
.cipso
;
797 cat
= cipso_v4_bitmap_walk(bitmap
,
803 if (cat
>= cipso_cat_size
||
804 cipso_array
[cat
] >= CIPSO_V4_INV_CAT
)
817 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
818 * @doi_def: the DOI definition
819 * @secattr: the security attributes
820 * @net_cat: the zero'd out category bitmap in network/CIPSO format
821 * @net_cat_len: the length of the CIPSO bitmap in bytes
824 * Perform a label mapping to translate a local MLS category bitmap to the
825 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
826 * size in bytes of the network bitmap on success, negative values otherwise.
829 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi
*doi_def
,
830 const struct netlbl_lsm_secattr
*secattr
,
831 unsigned char *net_cat
,
835 u32 net_spot
= CIPSO_V4_INV_CAT
;
836 u32 net_spot_max
= 0;
837 u32 net_clen_bits
= net_cat_len
* 8;
838 u32 host_cat_size
= 0;
839 u32
*host_cat_array
= NULL
;
841 if (doi_def
->type
== CIPSO_V4_MAP_TRANS
) {
842 host_cat_size
= doi_def
->map
.std
->cat
.local_size
;
843 host_cat_array
= doi_def
->map
.std
->cat
.local
;
847 host_spot
= netlbl_secattr_catmap_walk(secattr
->attr
.mls
.cat
,
852 switch (doi_def
->type
) {
853 case CIPSO_V4_MAP_PASS
:
854 net_spot
= host_spot
;
856 case CIPSO_V4_MAP_TRANS
:
857 if (host_spot
>= host_cat_size
)
859 net_spot
= host_cat_array
[host_spot
];
860 if (net_spot
>= CIPSO_V4_INV_CAT
)
864 if (net_spot
>= net_clen_bits
)
866 cipso_v4_bitmap_setbit(net_cat
, net_spot
, 1);
868 if (net_spot
> net_spot_max
)
869 net_spot_max
= net_spot
;
872 if (++net_spot_max
% 8)
873 return net_spot_max
/ 8 + 1;
874 return net_spot_max
/ 8;
878 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
879 * @doi_def: the DOI definition
880 * @net_cat: the category bitmap in network/CIPSO format
881 * @net_cat_len: the length of the CIPSO bitmap in bytes
882 * @secattr: the security attributes
885 * Perform a label mapping to translate a CIPSO bitmap to the correct local
886 * MLS category bitmap using the given DOI definition. Returns zero on
887 * success, negative values on failure.
890 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi
*doi_def
,
891 const unsigned char *net_cat
,
893 struct netlbl_lsm_secattr
*secattr
)
897 u32 host_spot
= CIPSO_V4_INV_CAT
;
898 u32 net_clen_bits
= net_cat_len
* 8;
899 u32 net_cat_size
= 0;
900 u32
*net_cat_array
= NULL
;
902 if (doi_def
->type
== CIPSO_V4_MAP_TRANS
) {
903 net_cat_size
= doi_def
->map
.std
->cat
.cipso_size
;
904 net_cat_array
= doi_def
->map
.std
->cat
.cipso
;
908 net_spot
= cipso_v4_bitmap_walk(net_cat
,
918 switch (doi_def
->type
) {
919 case CIPSO_V4_MAP_PASS
:
920 host_spot
= net_spot
;
922 case CIPSO_V4_MAP_TRANS
:
923 if (net_spot
>= net_cat_size
)
925 host_spot
= net_cat_array
[net_spot
];
926 if (host_spot
>= CIPSO_V4_INV_CAT
)
930 ret_val
= netlbl_secattr_catmap_setbit(secattr
->attr
.mls
.cat
,
941 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
942 * @doi_def: the DOI definition
943 * @enumcat: category list
944 * @enumcat_len: length of the category list in bytes
947 * Checks the given categories against the given DOI definition and returns a
948 * negative value if any of the categories do not have a valid mapping and a
949 * zero value if all of the categories are valid.
952 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi
*doi_def
,
953 const unsigned char *enumcat
,
960 if (doi_def
->type
!= CIPSO_V4_MAP_PASS
|| enumcat_len
& 0x01)
963 for (iter
= 0; iter
< enumcat_len
; iter
+= 2) {
964 cat
= get_unaligned_be16(&enumcat
[iter
]);
974 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
975 * @doi_def: the DOI definition
976 * @secattr: the security attributes
977 * @net_cat: the zero'd out category list in network/CIPSO format
978 * @net_cat_len: the length of the CIPSO category list in bytes
981 * Perform a label mapping to translate a local MLS category bitmap to the
982 * correct CIPSO category list using the given DOI definition. Returns the
983 * size in bytes of the network category bitmap on success, negative values
987 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi
*doi_def
,
988 const struct netlbl_lsm_secattr
*secattr
,
989 unsigned char *net_cat
,
996 cat
= netlbl_secattr_catmap_walk(secattr
->attr
.mls
.cat
,
1000 if ((cat_iter
+ 2) > net_cat_len
)
1003 *((__be16
*)&net_cat
[cat_iter
]) = htons(cat
);
1011 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
1012 * @doi_def: the DOI definition
1013 * @net_cat: the category list in network/CIPSO format
1014 * @net_cat_len: the length of the CIPSO bitmap in bytes
1015 * @secattr: the security attributes
1018 * Perform a label mapping to translate a CIPSO category list to the correct
1019 * local MLS category bitmap using the given DOI definition. Returns zero on
1020 * success, negative values on failure.
1023 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi
*doi_def
,
1024 const unsigned char *net_cat
,
1026 struct netlbl_lsm_secattr
*secattr
)
1031 for (iter
= 0; iter
< net_cat_len
; iter
+= 2) {
1032 ret_val
= netlbl_secattr_catmap_setbit(secattr
->attr
.mls
.cat
,
1033 get_unaligned_be16(&net_cat
[iter
]),
1043 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
1044 * @doi_def: the DOI definition
1045 * @rngcat: category list
1046 * @rngcat_len: length of the category list in bytes
1049 * Checks the given categories against the given DOI definition and returns a
1050 * negative value if any of the categories do not have a valid mapping and a
1051 * zero value if all of the categories are valid.
1054 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi
*doi_def
,
1055 const unsigned char *rngcat
,
1060 u32 cat_prev
= CIPSO_V4_MAX_REM_CATS
+ 1;
1063 if (doi_def
->type
!= CIPSO_V4_MAP_PASS
|| rngcat_len
& 0x01)
1066 for (iter
= 0; iter
< rngcat_len
; iter
+= 4) {
1067 cat_high
= get_unaligned_be16(&rngcat
[iter
]);
1068 if ((iter
+ 4) <= rngcat_len
)
1069 cat_low
= get_unaligned_be16(&rngcat
[iter
+ 2]);
1073 if (cat_high
> cat_prev
)
1083 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1084 * @doi_def: the DOI definition
1085 * @secattr: the security attributes
1086 * @net_cat: the zero'd out category list in network/CIPSO format
1087 * @net_cat_len: the length of the CIPSO category list in bytes
1090 * Perform a label mapping to translate a local MLS category bitmap to the
1091 * correct CIPSO category list using the given DOI definition. Returns the
1092 * size in bytes of the network category bitmap on success, negative values
1096 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi
*doi_def
,
1097 const struct netlbl_lsm_secattr
*secattr
,
1098 unsigned char *net_cat
,
1102 u16 array
[CIPSO_V4_TAG_RNG_CAT_MAX
* 2];
1106 /* make sure we don't overflow the 'array[]' variable */
1108 (CIPSO_V4_OPT_LEN_MAX
- CIPSO_V4_HDR_LEN
- CIPSO_V4_TAG_RNG_BLEN
))
1112 iter
= netlbl_secattr_catmap_walk(secattr
->attr
.mls
.cat
,
1116 cat_size
+= (iter
== 0 ? 0 : sizeof(u16
));
1117 if (cat_size
> net_cat_len
)
1119 array
[array_cnt
++] = iter
;
1121 iter
= netlbl_secattr_catmap_walk_rng(secattr
->attr
.mls
.cat
,
1125 cat_size
+= sizeof(u16
);
1126 if (cat_size
> net_cat_len
)
1128 array
[array_cnt
++] = iter
;
1131 for (iter
= 0; array_cnt
> 0;) {
1132 *((__be16
*)&net_cat
[iter
]) = htons(array
[--array_cnt
]);
1135 if (array
[array_cnt
] != 0) {
1136 *((__be16
*)&net_cat
[iter
]) = htons(array
[array_cnt
]);
1145 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1146 * @doi_def: the DOI definition
1147 * @net_cat: the category list in network/CIPSO format
1148 * @net_cat_len: the length of the CIPSO bitmap in bytes
1149 * @secattr: the security attributes
1152 * Perform a label mapping to translate a CIPSO category list to the correct
1153 * local MLS category bitmap using the given DOI definition. Returns zero on
1154 * success, negative values on failure.
1157 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi
*doi_def
,
1158 const unsigned char *net_cat
,
1160 struct netlbl_lsm_secattr
*secattr
)
1167 for (net_iter
= 0; net_iter
< net_cat_len
; net_iter
+= 4) {
1168 cat_high
= get_unaligned_be16(&net_cat
[net_iter
]);
1169 if ((net_iter
+ 4) <= net_cat_len
)
1170 cat_low
= get_unaligned_be16(&net_cat
[net_iter
+ 2]);
1174 ret_val
= netlbl_secattr_catmap_setrng(secattr
->attr
.mls
.cat
,
1186 * Protocol Handling Functions
1190 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1191 * @doi_def: the DOI definition
1192 * @len: the total tag length in bytes, not including this header
1193 * @buf: the CIPSO option buffer
1196 * Write a CIPSO header into the beginning of @buffer.
1199 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi
*doi_def
,
1203 buf
[0] = IPOPT_CIPSO
;
1204 buf
[1] = CIPSO_V4_HDR_LEN
+ len
;
1205 *(__be32
*)&buf
[2] = htonl(doi_def
->doi
);
1209 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1210 * @doi_def: the DOI definition
1211 * @secattr: the security attributes
1212 * @buffer: the option buffer
1213 * @buffer_len: length of buffer in bytes
1216 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1217 * actual buffer length may be larger than the indicated size due to
1218 * translation between host and network category bitmaps. Returns the size of
1219 * the tag on success, negative values on failure.
1222 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi
*doi_def
,
1223 const struct netlbl_lsm_secattr
*secattr
,
1224 unsigned char *buffer
,
1231 if ((secattr
->flags
& NETLBL_SECATTR_MLS_LVL
) == 0)
1234 ret_val
= cipso_v4_map_lvl_hton(doi_def
,
1235 secattr
->attr
.mls
.lvl
,
1240 if (secattr
->flags
& NETLBL_SECATTR_MLS_CAT
) {
1241 ret_val
= cipso_v4_map_cat_rbm_hton(doi_def
,
1248 /* This will send packets using the "optimized" format when
1249 * possibile as specified in section 3.4.2.6 of the
1251 if (cipso_v4_rbm_optfmt
&& ret_val
> 0 && ret_val
<= 10)
1254 tag_len
= 4 + ret_val
;
1258 buffer
[0] = CIPSO_V4_TAG_RBITMAP
;
1259 buffer
[1] = tag_len
;
1266 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1267 * @doi_def: the DOI definition
1268 * @tag: the CIPSO tag
1269 * @secattr: the security attributes
1272 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1273 * attributes in @secattr. Return zero on success, negatives values on
1277 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi
*doi_def
,
1278 const unsigned char *tag
,
1279 struct netlbl_lsm_secattr
*secattr
)
1282 u8 tag_len
= tag
[1];
1285 ret_val
= cipso_v4_map_lvl_ntoh(doi_def
, tag
[3], &level
);
1288 secattr
->attr
.mls
.lvl
= level
;
1289 secattr
->flags
|= NETLBL_SECATTR_MLS_LVL
;
1292 secattr
->attr
.mls
.cat
=
1293 netlbl_secattr_catmap_alloc(GFP_ATOMIC
);
1294 if (secattr
->attr
.mls
.cat
== NULL
)
1297 ret_val
= cipso_v4_map_cat_rbm_ntoh(doi_def
,
1302 netlbl_secattr_catmap_free(secattr
->attr
.mls
.cat
);
1306 secattr
->flags
|= NETLBL_SECATTR_MLS_CAT
;
1313 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1314 * @doi_def: the DOI definition
1315 * @secattr: the security attributes
1316 * @buffer: the option buffer
1317 * @buffer_len: length of buffer in bytes
1320 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1321 * size of the tag on success, negative values on failure.
1324 static int cipso_v4_gentag_enum(const struct cipso_v4_doi
*doi_def
,
1325 const struct netlbl_lsm_secattr
*secattr
,
1326 unsigned char *buffer
,
1333 if (!(secattr
->flags
& NETLBL_SECATTR_MLS_LVL
))
1336 ret_val
= cipso_v4_map_lvl_hton(doi_def
,
1337 secattr
->attr
.mls
.lvl
,
1342 if (secattr
->flags
& NETLBL_SECATTR_MLS_CAT
) {
1343 ret_val
= cipso_v4_map_cat_enum_hton(doi_def
,
1350 tag_len
= 4 + ret_val
;
1354 buffer
[0] = CIPSO_V4_TAG_ENUM
;
1355 buffer
[1] = tag_len
;
1362 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1363 * @doi_def: the DOI definition
1364 * @tag: the CIPSO tag
1365 * @secattr: the security attributes
1368 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1369 * attributes in @secattr. Return zero on success, negatives values on
1373 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi
*doi_def
,
1374 const unsigned char *tag
,
1375 struct netlbl_lsm_secattr
*secattr
)
1378 u8 tag_len
= tag
[1];
1381 ret_val
= cipso_v4_map_lvl_ntoh(doi_def
, tag
[3], &level
);
1384 secattr
->attr
.mls
.lvl
= level
;
1385 secattr
->flags
|= NETLBL_SECATTR_MLS_LVL
;
1388 secattr
->attr
.mls
.cat
=
1389 netlbl_secattr_catmap_alloc(GFP_ATOMIC
);
1390 if (secattr
->attr
.mls
.cat
== NULL
)
1393 ret_val
= cipso_v4_map_cat_enum_ntoh(doi_def
,
1398 netlbl_secattr_catmap_free(secattr
->attr
.mls
.cat
);
1402 secattr
->flags
|= NETLBL_SECATTR_MLS_CAT
;
1409 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1410 * @doi_def: the DOI definition
1411 * @secattr: the security attributes
1412 * @buffer: the option buffer
1413 * @buffer_len: length of buffer in bytes
1416 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1417 * size of the tag on success, negative values on failure.
1420 static int cipso_v4_gentag_rng(const struct cipso_v4_doi
*doi_def
,
1421 const struct netlbl_lsm_secattr
*secattr
,
1422 unsigned char *buffer
,
1429 if (!(secattr
->flags
& NETLBL_SECATTR_MLS_LVL
))
1432 ret_val
= cipso_v4_map_lvl_hton(doi_def
,
1433 secattr
->attr
.mls
.lvl
,
1438 if (secattr
->flags
& NETLBL_SECATTR_MLS_CAT
) {
1439 ret_val
= cipso_v4_map_cat_rng_hton(doi_def
,
1446 tag_len
= 4 + ret_val
;
1450 buffer
[0] = CIPSO_V4_TAG_RANGE
;
1451 buffer
[1] = tag_len
;
1458 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1459 * @doi_def: the DOI definition
1460 * @tag: the CIPSO tag
1461 * @secattr: the security attributes
1464 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1465 * in @secattr. Return zero on success, negatives values on failure.
1468 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi
*doi_def
,
1469 const unsigned char *tag
,
1470 struct netlbl_lsm_secattr
*secattr
)
1473 u8 tag_len
= tag
[1];
1476 ret_val
= cipso_v4_map_lvl_ntoh(doi_def
, tag
[3], &level
);
1479 secattr
->attr
.mls
.lvl
= level
;
1480 secattr
->flags
|= NETLBL_SECATTR_MLS_LVL
;
1483 secattr
->attr
.mls
.cat
=
1484 netlbl_secattr_catmap_alloc(GFP_ATOMIC
);
1485 if (secattr
->attr
.mls
.cat
== NULL
)
1488 ret_val
= cipso_v4_map_cat_rng_ntoh(doi_def
,
1493 netlbl_secattr_catmap_free(secattr
->attr
.mls
.cat
);
1497 secattr
->flags
|= NETLBL_SECATTR_MLS_CAT
;
1504 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1505 * @doi_def: the DOI definition
1506 * @secattr: the security attributes
1507 * @buffer: the option buffer
1508 * @buffer_len: length of buffer in bytes
1511 * Generate a CIPSO option using the local tag. Returns the size of the tag
1512 * on success, negative values on failure.
1515 static int cipso_v4_gentag_loc(const struct cipso_v4_doi
*doi_def
,
1516 const struct netlbl_lsm_secattr
*secattr
,
1517 unsigned char *buffer
,
1520 if (!(secattr
->flags
& NETLBL_SECATTR_SECID
))
1523 buffer
[0] = CIPSO_V4_TAG_LOCAL
;
1524 buffer
[1] = CIPSO_V4_TAG_LOC_BLEN
;
1525 *(u32
*)&buffer
[2] = secattr
->attr
.secid
;
1527 return CIPSO_V4_TAG_LOC_BLEN
;
1531 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1532 * @doi_def: the DOI definition
1533 * @tag: the CIPSO tag
1534 * @secattr: the security attributes
1537 * Parse a CIPSO local tag and return the security attributes in @secattr.
1538 * Return zero on success, negatives values on failure.
1541 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi
*doi_def
,
1542 const unsigned char *tag
,
1543 struct netlbl_lsm_secattr
*secattr
)
1545 secattr
->attr
.secid
= *(u32
*)&tag
[2];
1546 secattr
->flags
|= NETLBL_SECATTR_SECID
;
1552 * cipso_v4_validate - Validate a CIPSO option
1553 * @option: the start of the option, on error it is set to point to the error
1556 * This routine is called to validate a CIPSO option, it checks all of the
1557 * fields to ensure that they are at least valid, see the draft snippet below
1558 * for details. If the option is valid then a zero value is returned and
1559 * the value of @option is unchanged. If the option is invalid then a
1560 * non-zero value is returned and @option is adjusted to point to the
1561 * offending portion of the option. From the IETF draft ...
1563 * "If any field within the CIPSO options, such as the DOI identifier, is not
1564 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1565 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1566 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1567 * that is unrecognized."
1570 int cipso_v4_validate(const struct sk_buff
*skb
, unsigned char **option
)
1572 unsigned char *opt
= *option
;
1574 unsigned char opt_iter
;
1575 unsigned char err_offset
= 0;
1578 struct cipso_v4_doi
*doi_def
= NULL
;
1581 /* caller already checks for length values that are too large */
1585 goto validate_return
;
1589 doi_def
= cipso_v4_doi_search(get_unaligned_be32(&opt
[2]));
1590 if (doi_def
== NULL
) {
1592 goto validate_return_locked
;
1595 opt_iter
= CIPSO_V4_HDR_LEN
;
1596 tag
= opt
+ opt_iter
;
1597 while (opt_iter
< opt_len
) {
1598 for (tag_iter
= 0; doi_def
->tags
[tag_iter
] != tag
[0];)
1599 if (doi_def
->tags
[tag_iter
] == CIPSO_V4_TAG_INVALID
||
1600 ++tag_iter
== CIPSO_V4_TAG_MAXCNT
) {
1601 err_offset
= opt_iter
;
1602 goto validate_return_locked
;
1606 if (tag_len
> (opt_len
- opt_iter
)) {
1607 err_offset
= opt_iter
+ 1;
1608 goto validate_return_locked
;
1612 case CIPSO_V4_TAG_RBITMAP
:
1613 if (tag_len
< CIPSO_V4_TAG_RBM_BLEN
) {
1614 err_offset
= opt_iter
+ 1;
1615 goto validate_return_locked
;
1618 /* We are already going to do all the verification
1619 * necessary at the socket layer so from our point of
1620 * view it is safe to turn these checks off (and less
1621 * work), however, the CIPSO draft says we should do
1622 * all the CIPSO validations here but it doesn't
1623 * really specify _exactly_ what we need to validate
1624 * ... so, just make it a sysctl tunable. */
1625 if (cipso_v4_rbm_strictvalid
) {
1626 if (cipso_v4_map_lvl_valid(doi_def
,
1628 err_offset
= opt_iter
+ 3;
1629 goto validate_return_locked
;
1631 if (tag_len
> CIPSO_V4_TAG_RBM_BLEN
&&
1632 cipso_v4_map_cat_rbm_valid(doi_def
,
1635 err_offset
= opt_iter
+ 4;
1636 goto validate_return_locked
;
1640 case CIPSO_V4_TAG_ENUM
:
1641 if (tag_len
< CIPSO_V4_TAG_ENUM_BLEN
) {
1642 err_offset
= opt_iter
+ 1;
1643 goto validate_return_locked
;
1646 if (cipso_v4_map_lvl_valid(doi_def
,
1648 err_offset
= opt_iter
+ 3;
1649 goto validate_return_locked
;
1651 if (tag_len
> CIPSO_V4_TAG_ENUM_BLEN
&&
1652 cipso_v4_map_cat_enum_valid(doi_def
,
1655 err_offset
= opt_iter
+ 4;
1656 goto validate_return_locked
;
1659 case CIPSO_V4_TAG_RANGE
:
1660 if (tag_len
< CIPSO_V4_TAG_RNG_BLEN
) {
1661 err_offset
= opt_iter
+ 1;
1662 goto validate_return_locked
;
1665 if (cipso_v4_map_lvl_valid(doi_def
,
1667 err_offset
= opt_iter
+ 3;
1668 goto validate_return_locked
;
1670 if (tag_len
> CIPSO_V4_TAG_RNG_BLEN
&&
1671 cipso_v4_map_cat_rng_valid(doi_def
,
1674 err_offset
= opt_iter
+ 4;
1675 goto validate_return_locked
;
1678 case CIPSO_V4_TAG_LOCAL
:
1679 /* This is a non-standard tag that we only allow for
1680 * local connections, so if the incoming interface is
1681 * not the loopback device drop the packet. */
1682 if (!(skb
->dev
->flags
& IFF_LOOPBACK
)) {
1683 err_offset
= opt_iter
;
1684 goto validate_return_locked
;
1686 if (tag_len
!= CIPSO_V4_TAG_LOC_BLEN
) {
1687 err_offset
= opt_iter
+ 1;
1688 goto validate_return_locked
;
1692 err_offset
= opt_iter
;
1693 goto validate_return_locked
;
1697 opt_iter
+= tag_len
;
1700 validate_return_locked
:
1703 *option
= opt
+ err_offset
;
1708 * cipso_v4_error - Send the correct reponse for a bad packet
1710 * @error: the error code
1711 * @gateway: CIPSO gateway flag
1714 * Based on the error code given in @error, send an ICMP error message back to
1715 * the originating host. From the IETF draft ...
1717 * "If the contents of the CIPSO [option] are valid but the security label is
1718 * outside of the configured host or port label range, the datagram is
1719 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1720 * returned. The code field of the ICMP is set to 'communication with
1721 * destination network administratively prohibited' (code 9) or to
1722 * 'communication with destination host administratively prohibited'
1723 * (code 10). The value of the code is dependent on whether the originator
1724 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1725 * recipient of the ICMP message MUST be able to handle either value. The
1726 * same procedure is performed if a CIPSO [option] can not be added to an
1727 * IP packet because it is too large to fit in the IP options area."
1729 * "If the error is triggered by receipt of an ICMP message, the message is
1730 * discarded and no response is permitted (consistent with general ICMP
1731 * processing rules)."
1734 void cipso_v4_error(struct sk_buff
*skb
, int error
, u32 gateway
)
1736 if (ip_hdr(skb
)->protocol
== IPPROTO_ICMP
|| error
!= -EACCES
)
1740 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_NET_ANO
, 0);
1742 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_ANO
, 0);
1746 * cipso_v4_genopt - Generate a CIPSO option
1747 * @buf: the option buffer
1748 * @buf_len: the size of opt_buf
1749 * @doi_def: the CIPSO DOI to use
1750 * @secattr: the security attributes
1753 * Generate a CIPSO option using the DOI definition and security attributes
1754 * passed to the function. Returns the length of the option on success and
1755 * negative values on failure.
1758 static int cipso_v4_genopt(unsigned char *buf
, u32 buf_len
,
1759 const struct cipso_v4_doi
*doi_def
,
1760 const struct netlbl_lsm_secattr
*secattr
)
1765 if (buf_len
<= CIPSO_V4_HDR_LEN
)
1768 /* XXX - This code assumes only one tag per CIPSO option which isn't
1769 * really a good assumption to make but since we only support the MAC
1770 * tags right now it is a safe assumption. */
1773 memset(buf
, 0, buf_len
);
1774 switch (doi_def
->tags
[iter
]) {
1775 case CIPSO_V4_TAG_RBITMAP
:
1776 ret_val
= cipso_v4_gentag_rbm(doi_def
,
1778 &buf
[CIPSO_V4_HDR_LEN
],
1779 buf_len
- CIPSO_V4_HDR_LEN
);
1781 case CIPSO_V4_TAG_ENUM
:
1782 ret_val
= cipso_v4_gentag_enum(doi_def
,
1784 &buf
[CIPSO_V4_HDR_LEN
],
1785 buf_len
- CIPSO_V4_HDR_LEN
);
1787 case CIPSO_V4_TAG_RANGE
:
1788 ret_val
= cipso_v4_gentag_rng(doi_def
,
1790 &buf
[CIPSO_V4_HDR_LEN
],
1791 buf_len
- CIPSO_V4_HDR_LEN
);
1793 case CIPSO_V4_TAG_LOCAL
:
1794 ret_val
= cipso_v4_gentag_loc(doi_def
,
1796 &buf
[CIPSO_V4_HDR_LEN
],
1797 buf_len
- CIPSO_V4_HDR_LEN
);
1804 } while (ret_val
< 0 &&
1805 iter
< CIPSO_V4_TAG_MAXCNT
&&
1806 doi_def
->tags
[iter
] != CIPSO_V4_TAG_INVALID
);
1809 cipso_v4_gentag_hdr(doi_def
, buf
, ret_val
);
1810 return CIPSO_V4_HDR_LEN
+ ret_val
;
1814 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1816 * @doi_def: the CIPSO DOI to use
1817 * @secattr: the specific security attributes of the socket
1820 * Set the CIPSO option on the given socket using the DOI definition and
1821 * security attributes passed to the function. This function requires
1822 * exclusive access to @sk, which means it either needs to be in the
1823 * process of being created or locked. Returns zero on success and negative
1824 * values on failure.
1827 int cipso_v4_sock_setattr(struct sock
*sk
,
1828 const struct cipso_v4_doi
*doi_def
,
1829 const struct netlbl_lsm_secattr
*secattr
)
1831 int ret_val
= -EPERM
;
1832 unsigned char *buf
= NULL
;
1835 struct ip_options
*opt
= NULL
;
1836 struct inet_sock
*sk_inet
;
1837 struct inet_connection_sock
*sk_conn
;
1839 /* In the case of sock_create_lite(), the sock->sk field is not
1840 * defined yet but it is not a problem as the only users of these
1841 * "lite" PF_INET sockets are functions which do an accept() call
1842 * afterwards so we will label the socket as part of the accept(). */
1846 /* We allocate the maximum CIPSO option size here so we are probably
1847 * being a little wasteful, but it makes our life _much_ easier later
1848 * on and after all we are only talking about 40 bytes. */
1849 buf_len
= CIPSO_V4_OPT_LEN_MAX
;
1850 buf
= kmalloc(buf_len
, GFP_ATOMIC
);
1853 goto socket_setattr_failure
;
1856 ret_val
= cipso_v4_genopt(buf
, buf_len
, doi_def
, secattr
);
1858 goto socket_setattr_failure
;
1861 /* We can't use ip_options_get() directly because it makes a call to
1862 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1863 * we won't always have CAP_NET_RAW even though we _always_ want to
1864 * set the IPOPT_CIPSO option. */
1865 opt_len
= (buf_len
+ 3) & ~3;
1866 opt
= kzalloc(sizeof(*opt
) + opt_len
, GFP_ATOMIC
);
1869 goto socket_setattr_failure
;
1871 memcpy(opt
->__data
, buf
, buf_len
);
1872 opt
->optlen
= opt_len
;
1873 opt
->cipso
= sizeof(struct iphdr
);
1877 sk_inet
= inet_sk(sk
);
1878 if (sk_inet
->is_icsk
) {
1879 sk_conn
= inet_csk(sk
);
1881 sk_conn
->icsk_ext_hdr_len
-= sk_inet
->opt
->optlen
;
1882 sk_conn
->icsk_ext_hdr_len
+= opt
->optlen
;
1883 sk_conn
->icsk_sync_mss(sk
, sk_conn
->icsk_pmtu_cookie
);
1885 opt
= xchg(&sk_inet
->opt
, opt
);
1890 socket_setattr_failure
:
1897 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
1901 * Removes the CIPSO option from a socket, if present.
1904 void cipso_v4_sock_delattr(struct sock
*sk
)
1907 struct ip_options
*opt
;
1908 struct inet_sock
*sk_inet
;
1910 sk_inet
= inet_sk(sk
);
1912 if (opt
== NULL
|| opt
->cipso
== 0)
1915 if (opt
->srr
|| opt
->rr
|| opt
->ts
|| opt
->router_alert
) {
1918 unsigned char *cipso_ptr
;
1922 cipso_off
= opt
->cipso
- sizeof(struct iphdr
);
1923 cipso_ptr
= &opt
->__data
[cipso_off
];
1924 cipso_len
= cipso_ptr
[1];
1926 if (opt
->srr
> opt
->cipso
)
1927 opt
->srr
-= cipso_len
;
1928 if (opt
->rr
> opt
->cipso
)
1929 opt
->rr
-= cipso_len
;
1930 if (opt
->ts
> opt
->cipso
)
1931 opt
->ts
-= cipso_len
;
1932 if (opt
->router_alert
> opt
->cipso
)
1933 opt
->router_alert
-= cipso_len
;
1936 memmove(cipso_ptr
, cipso_ptr
+ cipso_len
,
1937 opt
->optlen
- cipso_off
- cipso_len
);
1939 /* determining the new total option length is tricky because of
1940 * the padding necessary, the only thing i can think to do at
1941 * this point is walk the options one-by-one, skipping the
1942 * padding at the end to determine the actual option size and
1943 * from there we can determine the new total option length */
1946 while (iter
< opt
->optlen
)
1947 if (opt
->__data
[iter
] != IPOPT_NOP
) {
1948 iter
+= opt
->__data
[iter
+ 1];
1952 hdr_delta
= opt
->optlen
;
1953 opt
->optlen
= (optlen_new
+ 3) & ~3;
1954 hdr_delta
-= opt
->optlen
;
1956 /* only the cipso option was present on the socket so we can
1957 * remove the entire option struct */
1958 sk_inet
->opt
= NULL
;
1959 hdr_delta
= opt
->optlen
;
1963 if (sk_inet
->is_icsk
&& hdr_delta
> 0) {
1964 struct inet_connection_sock
*sk_conn
= inet_csk(sk
);
1965 sk_conn
->icsk_ext_hdr_len
-= hdr_delta
;
1966 sk_conn
->icsk_sync_mss(sk
, sk_conn
->icsk_pmtu_cookie
);
1971 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
1972 * @cipso: the CIPSO v4 option
1973 * @secattr: the security attributes
1976 * Inspect @cipso and return the security attributes in @secattr. Returns zero
1977 * on success and negative values on failure.
1980 static int cipso_v4_getattr(const unsigned char *cipso
,
1981 struct netlbl_lsm_secattr
*secattr
)
1983 int ret_val
= -ENOMSG
;
1985 struct cipso_v4_doi
*doi_def
;
1987 if (cipso_v4_cache_check(cipso
, cipso
[1], secattr
) == 0)
1990 doi
= get_unaligned_be32(&cipso
[2]);
1992 doi_def
= cipso_v4_doi_search(doi
);
1993 if (doi_def
== NULL
)
1994 goto getattr_return
;
1995 /* XXX - This code assumes only one tag per CIPSO option which isn't
1996 * really a good assumption to make but since we only support the MAC
1997 * tags right now it is a safe assumption. */
1999 case CIPSO_V4_TAG_RBITMAP
:
2000 ret_val
= cipso_v4_parsetag_rbm(doi_def
, &cipso
[6], secattr
);
2002 case CIPSO_V4_TAG_ENUM
:
2003 ret_val
= cipso_v4_parsetag_enum(doi_def
, &cipso
[6], secattr
);
2005 case CIPSO_V4_TAG_RANGE
:
2006 ret_val
= cipso_v4_parsetag_rng(doi_def
, &cipso
[6], secattr
);
2008 case CIPSO_V4_TAG_LOCAL
:
2009 ret_val
= cipso_v4_parsetag_loc(doi_def
, &cipso
[6], secattr
);
2013 secattr
->type
= NETLBL_NLTYPE_CIPSOV4
;
2021 * cipso_v4_sock_getattr - Get the security attributes from a sock
2023 * @secattr: the security attributes
2026 * Query @sk to see if there is a CIPSO option attached to the sock and if
2027 * there is return the CIPSO security attributes in @secattr. This function
2028 * requires that @sk be locked, or privately held, but it does not do any
2029 * locking itself. Returns zero on success and negative values on failure.
2032 int cipso_v4_sock_getattr(struct sock
*sk
, struct netlbl_lsm_secattr
*secattr
)
2034 struct ip_options
*opt
;
2036 opt
= inet_sk(sk
)->opt
;
2037 if (opt
== NULL
|| opt
->cipso
== 0)
2040 return cipso_v4_getattr(opt
->__data
+ opt
->cipso
- sizeof(struct iphdr
),
2045 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2047 * @secattr: the security attributes
2050 * Set the CIPSO option on the given packet based on the security attributes.
2051 * Returns a pointer to the IP header on success and NULL on failure.
2054 int cipso_v4_skbuff_setattr(struct sk_buff
*skb
,
2055 const struct cipso_v4_doi
*doi_def
,
2056 const struct netlbl_lsm_secattr
*secattr
)
2060 struct ip_options
*opt
= &IPCB(skb
)->opt
;
2061 unsigned char buf
[CIPSO_V4_OPT_LEN_MAX
];
2062 u32 buf_len
= CIPSO_V4_OPT_LEN_MAX
;
2066 buf_len
= cipso_v4_genopt(buf
, buf_len
, doi_def
, secattr
);
2069 opt_len
= (buf_len
+ 3) & ~3;
2071 /* we overwrite any existing options to ensure that we have enough
2072 * room for the CIPSO option, the reason is that we _need_ to guarantee
2073 * that the security label is applied to the packet - we do the same
2074 * thing when using the socket options and it hasn't caused a problem,
2075 * if we need to we can always revisit this choice later */
2077 len_delta
= opt_len
- opt
->optlen
;
2078 /* if we don't ensure enough headroom we could panic on the skb_push()
2079 * call below so make sure we have enough, we are also "mangling" the
2080 * packet so we should probably do a copy-on-write call anyway */
2081 ret_val
= skb_cow(skb
, skb_headroom(skb
) + len_delta
);
2085 if (len_delta
> 0) {
2086 /* we assume that the header + opt->optlen have already been
2087 * "pushed" in ip_options_build() or similar */
2089 skb_push(skb
, len_delta
);
2090 memmove((char *)iph
- len_delta
, iph
, iph
->ihl
<< 2);
2091 skb_reset_network_header(skb
);
2093 } else if (len_delta
< 0) {
2095 memset(iph
+ 1, IPOPT_NOP
, opt
->optlen
);
2099 if (opt
->optlen
> 0)
2100 memset(opt
, 0, sizeof(*opt
));
2101 opt
->optlen
= opt_len
;
2102 opt
->cipso
= sizeof(struct iphdr
);
2103 opt
->is_changed
= 1;
2105 /* we have to do the following because we are being called from a
2106 * netfilter hook which means the packet already has had the header
2107 * fields populated and the checksum calculated - yes this means we
2108 * are doing more work than needed but we do it to keep the core
2109 * stack clean and tidy */
2110 memcpy(iph
+ 1, buf
, buf_len
);
2111 if (opt_len
> buf_len
)
2112 memset((char *)(iph
+ 1) + buf_len
, 0, opt_len
- buf_len
);
2113 if (len_delta
!= 0) {
2114 iph
->ihl
= 5 + (opt_len
>> 2);
2115 iph
->tot_len
= htons(skb
->len
);
2123 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2127 * Removes any and all CIPSO options from the given packet. Returns zero on
2128 * success, negative values on failure.
2131 int cipso_v4_skbuff_delattr(struct sk_buff
*skb
)
2135 struct ip_options
*opt
= &IPCB(skb
)->opt
;
2136 unsigned char *cipso_ptr
;
2138 if (opt
->cipso
== 0)
2141 /* since we are changing the packet we should make a copy */
2142 ret_val
= skb_cow(skb
, skb_headroom(skb
));
2146 /* the easiest thing to do is just replace the cipso option with noop
2147 * options since we don't change the size of the packet, although we
2148 * still need to recalculate the checksum */
2151 cipso_ptr
= (unsigned char *)iph
+ opt
->cipso
;
2152 memset(cipso_ptr
, IPOPT_NOOP
, cipso_ptr
[1]);
2154 opt
->is_changed
= 1;
2162 * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
2164 * @secattr: the security attributes
2167 * Parse the given packet's CIPSO option and return the security attributes.
2168 * Returns zero on success and negative values on failure.
2171 int cipso_v4_skbuff_getattr(const struct sk_buff
*skb
,
2172 struct netlbl_lsm_secattr
*secattr
)
2174 return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb
), secattr
);
2182 * cipso_v4_init - Initialize the CIPSO module
2185 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2186 * and negative values on failure.
2189 static int __init
cipso_v4_init(void)
2193 ret_val
= cipso_v4_cache_init();
2195 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2201 subsys_initcall(cipso_v4_init
);