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>
50 #include <net/netlabel.h>
51 #include <net/cipso_ipv4.h>
52 #include <linux/atomic.h>
53 #include <linux/bug.h>
54 #include <asm/unaligned.h>
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 {
73 struct list_head list;
76 struct cipso_v4_map_cache_entry {
81 struct netlbl_lsm_cache *lsm_data;
84 struct list_head list;
87 static struct cipso_v4_map_cache_bkt *cipso_v4_cache;
89 /* Restricted bitmap (tag #1) flags */
90 int cipso_v4_rbm_optfmt = 0;
91 int cipso_v4_rbm_strictvalid = 1;
97 /* Maximum size of the CIPSO IP option, derived from the fact that the maximum
98 * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
99 #define CIPSO_V4_OPT_LEN_MAX 40
101 /* Length of the base CIPSO option, this includes the option type (1 byte), the
102 * option length (1 byte), and the DOI (4 bytes). */
103 #define CIPSO_V4_HDR_LEN 6
105 /* Base length of the restrictive category bitmap tag (tag #1). */
106 #define CIPSO_V4_TAG_RBM_BLEN 4
108 /* Base length of the enumerated category tag (tag #2). */
109 #define CIPSO_V4_TAG_ENUM_BLEN 4
111 /* Base length of the ranged categories bitmap tag (tag #5). */
112 #define CIPSO_V4_TAG_RNG_BLEN 4
113 /* The maximum number of category ranges permitted in the ranged category tag
114 * (tag #5). You may note that the IETF draft states that the maximum number
115 * of category ranges is 7, but if the low end of the last category range is
116 * zero then it is possible to fit 8 category ranges because the zero should
118 #define CIPSO_V4_TAG_RNG_CAT_MAX 8
120 /* Base length of the local tag (non-standard tag).
121 * Tag definition (may change between kernel versions)
124 * +----------+----------+----------+----------+
125 * | 10000000 | 00000110 | 32-bit secid value |
126 * +----------+----------+----------+----------+
127 * | in (host byte order)|
128 * +----------+----------+
131 #define CIPSO_V4_TAG_LOC_BLEN 6
138 * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
139 * @bitmap: the bitmap
140 * @bitmap_len: length in bits
141 * @offset: starting offset
142 * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
145 * Starting at @offset, walk the bitmap from left to right until either the
146 * desired bit is found or we reach the end. Return the bit offset, -1 if
147 * not found, or -2 if error.
149 static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
156 unsigned char bitmask;
159 /* gcc always rounds to zero when doing integer division */
160 byte_offset = offset / 8;
161 byte = bitmap[byte_offset];
163 bitmask = 0x80 >> (offset % 8);
165 while (bit_spot < bitmap_len) {
166 if ((state && (byte & bitmask) == bitmask) ||
167 (state == 0 && (byte & bitmask) == 0))
173 byte = bitmap[++byte_offset];
182 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
183 * @bitmap: the bitmap
185 * @state: if non-zero, set the bit (1) else clear the bit (0)
188 * Set a single bit in the bitmask. Returns zero on success, negative values
191 static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
198 /* gcc always rounds to zero when doing integer division */
200 bitmask = 0x80 >> (bit % 8);
202 bitmap[byte_spot] |= bitmask;
204 bitmap[byte_spot] &= ~bitmask;
208 * cipso_v4_cache_entry_free - Frees a cache entry
209 * @entry: the entry to free
212 * This function frees the memory associated with a cache entry including the
213 * LSM cache data if there are no longer any users, i.e. reference count == 0.
216 static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
219 netlbl_secattr_cache_free(entry->lsm_data);
225 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
227 * @key_len: the length of the key in bytes
230 * The CIPSO tag hashing function. Returns a 32-bit hash value.
233 static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
235 return jhash(key, key_len, 0);
239 * Label Mapping Cache Functions
243 * cipso_v4_cache_init - Initialize the CIPSO cache
246 * Initializes the CIPSO label mapping cache, this function should be called
247 * before any of the other functions defined in this file. Returns zero on
248 * success, negative values on error.
251 static int __init cipso_v4_cache_init(void)
255 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
256 sizeof(struct cipso_v4_map_cache_bkt),
258 if (cipso_v4_cache == NULL)
261 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
262 spin_lock_init(&cipso_v4_cache[iter].lock);
263 cipso_v4_cache[iter].size = 0;
264 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
271 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
274 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
275 * success and negative values on failure.
278 void cipso_v4_cache_invalidate(void)
280 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
283 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
284 spin_lock_bh(&cipso_v4_cache[iter].lock);
285 list_for_each_entry_safe(entry,
287 &cipso_v4_cache[iter].list, list) {
288 list_del(&entry->list);
289 cipso_v4_cache_entry_free(entry);
291 cipso_v4_cache[iter].size = 0;
292 spin_unlock_bh(&cipso_v4_cache[iter].lock);
297 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
298 * @key: the buffer to check
299 * @key_len: buffer length in bytes
300 * @secattr: the security attribute struct to use
303 * This function checks the cache to see if a label mapping already exists for
304 * the given key. If there is a match then the cache is adjusted and the
305 * @secattr struct is populated with the correct LSM security attributes. The
306 * cache is adjusted in the following manner if the entry is not already the
307 * first in the cache bucket:
309 * 1. The cache entry's activity counter is incremented
310 * 2. The previous (higher ranking) entry's activity counter is decremented
311 * 3. If the difference between the two activity counters is geater than
312 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
314 * Returns zero on success, -ENOENT for a cache miss, and other negative values
318 static int cipso_v4_cache_check(const unsigned char *key,
320 struct netlbl_lsm_secattr *secattr)
323 struct cipso_v4_map_cache_entry *entry;
324 struct cipso_v4_map_cache_entry *prev_entry = NULL;
327 if (!cipso_v4_cache_enabled)
330 hash = cipso_v4_map_cache_hash(key, key_len);
331 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
332 spin_lock_bh(&cipso_v4_cache[bkt].lock);
333 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
334 if (entry->hash == hash &&
335 entry->key_len == key_len &&
336 memcmp(entry->key, key, key_len) == 0) {
337 entry->activity += 1;
338 atomic_inc(&entry->lsm_data->refcount);
339 secattr->cache = entry->lsm_data;
340 secattr->flags |= NETLBL_SECATTR_CACHE;
341 secattr->type = NETLBL_NLTYPE_CIPSOV4;
342 if (prev_entry == NULL) {
343 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
347 if (prev_entry->activity > 0)
348 prev_entry->activity -= 1;
349 if (entry->activity > prev_entry->activity &&
350 entry->activity - prev_entry->activity >
351 CIPSO_V4_CACHE_REORDERLIMIT) {
352 __list_del(entry->list.prev, entry->list.next);
353 __list_add(&entry->list,
354 prev_entry->list.prev,
358 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
363 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
369 * cipso_v4_cache_add - Add an entry to the CIPSO cache
371 * @secattr: the packet's security attributes
374 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
375 * head of the cache bucket's list, if the cache bucket is out of room remove
376 * the last entry in the list first. It is important to note that there is
377 * currently no checking for duplicate keys. Returns zero on success,
378 * negative values on failure.
381 int cipso_v4_cache_add(const struct sk_buff *skb,
382 const struct netlbl_lsm_secattr *secattr)
384 int ret_val = -EPERM;
386 struct cipso_v4_map_cache_entry *entry = NULL;
387 struct cipso_v4_map_cache_entry *old_entry = NULL;
388 unsigned char *cipso_ptr;
391 if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
394 cipso_ptr = CIPSO_V4_OPTPTR(skb);
395 cipso_ptr_len = cipso_ptr[1];
397 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
400 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
401 if (entry->key == NULL) {
403 goto cache_add_failure;
405 entry->key_len = cipso_ptr_len;
406 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
407 atomic_inc(&secattr->cache->refcount);
408 entry->lsm_data = secattr->cache;
410 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
411 spin_lock_bh(&cipso_v4_cache[bkt].lock);
412 if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
413 list_add(&entry->list, &cipso_v4_cache[bkt].list);
414 cipso_v4_cache[bkt].size += 1;
416 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
417 struct cipso_v4_map_cache_entry, list);
418 list_del(&old_entry->list);
419 list_add(&entry->list, &cipso_v4_cache[bkt].list);
420 cipso_v4_cache_entry_free(old_entry);
422 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
428 cipso_v4_cache_entry_free(entry);
437 * cipso_v4_doi_search - Searches for a DOI definition
438 * @doi: the DOI to search for
441 * Search the DOI definition list for a DOI definition with a DOI value that
442 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
443 * Returns a pointer to the DOI definition on success and NULL on failure.
445 static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
447 struct cipso_v4_doi *iter;
449 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
450 if (iter->doi == doi && atomic_read(&iter->refcount))
456 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
457 * @doi_def: the DOI structure
458 * @audit_info: NetLabel audit information
461 * The caller defines a new DOI for use by the CIPSO engine and calls this
462 * function to add it to the list of acceptable domains. The caller must
463 * ensure that the mapping table specified in @doi_def->map meets all of the
464 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
465 * zero on success and non-zero on failure.
468 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
469 struct netlbl_audit *audit_info)
471 int ret_val = -EINVAL;
475 struct audit_buffer *audit_buf;
478 doi_type = doi_def->type;
480 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
482 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
483 switch (doi_def->tags[iter]) {
484 case CIPSO_V4_TAG_RBITMAP:
486 case CIPSO_V4_TAG_RANGE:
487 case CIPSO_V4_TAG_ENUM:
488 if (doi_def->type != CIPSO_V4_MAP_PASS)
491 case CIPSO_V4_TAG_LOCAL:
492 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
495 case CIPSO_V4_TAG_INVALID:
504 atomic_set(&doi_def->refcount, 1);
506 spin_lock(&cipso_v4_doi_list_lock);
507 if (cipso_v4_doi_search(doi_def->doi) != NULL) {
508 spin_unlock(&cipso_v4_doi_list_lock);
512 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
513 spin_unlock(&cipso_v4_doi_list_lock);
517 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
518 if (audit_buf != NULL) {
519 const char *type_str;
521 case CIPSO_V4_MAP_TRANS:
524 case CIPSO_V4_MAP_PASS:
527 case CIPSO_V4_MAP_LOCAL:
531 type_str = "(unknown)";
533 audit_log_format(audit_buf,
534 " cipso_doi=%u cipso_type=%s res=%u",
535 doi, type_str, ret_val == 0 ? 1 : 0);
536 audit_log_end(audit_buf);
543 * cipso_v4_doi_free - Frees a DOI definition
544 * @doi_def: the DOI definition
547 * This function frees all of the memory associated with a DOI definition.
550 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
555 switch (doi_def->type) {
556 case CIPSO_V4_MAP_TRANS:
557 kfree(doi_def->map.std->lvl.cipso);
558 kfree(doi_def->map.std->lvl.local);
559 kfree(doi_def->map.std->cat.cipso);
560 kfree(doi_def->map.std->cat.local);
567 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
568 * @entry: the entry's RCU field
571 * This function is designed to be used as a callback to the call_rcu()
572 * function so that the memory allocated to the DOI definition can be released
576 static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
578 struct cipso_v4_doi *doi_def;
580 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
581 cipso_v4_doi_free(doi_def);
585 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
586 * @doi: the DOI value
587 * @audit_secid: the LSM secid to use in the audit message
590 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
591 * be called to release their own LSM domain mappings as well as our own
592 * domain list. Returns zero on success and negative values on failure.
595 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
598 struct cipso_v4_doi *doi_def;
599 struct audit_buffer *audit_buf;
601 spin_lock(&cipso_v4_doi_list_lock);
602 doi_def = cipso_v4_doi_search(doi);
603 if (doi_def == NULL) {
604 spin_unlock(&cipso_v4_doi_list_lock);
606 goto doi_remove_return;
608 if (!atomic_dec_and_test(&doi_def->refcount)) {
609 spin_unlock(&cipso_v4_doi_list_lock);
611 goto doi_remove_return;
613 list_del_rcu(&doi_def->list);
614 spin_unlock(&cipso_v4_doi_list_lock);
616 cipso_v4_cache_invalidate();
617 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
621 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
622 if (audit_buf != NULL) {
623 audit_log_format(audit_buf,
624 " cipso_doi=%u res=%u",
625 doi, ret_val == 0 ? 1 : 0);
626 audit_log_end(audit_buf);
633 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
634 * @doi: the DOI value
637 * Searches for a valid DOI definition and if one is found it is returned to
638 * the caller. Otherwise NULL is returned. The caller must ensure that
639 * rcu_read_lock() is held while accessing the returned definition and the DOI
640 * definition reference count is decremented when the caller is done.
643 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
645 struct cipso_v4_doi *doi_def;
648 doi_def = cipso_v4_doi_search(doi);
650 goto doi_getdef_return;
651 if (!atomic_inc_not_zero(&doi_def->refcount))
660 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
661 * @doi_def: the DOI definition
664 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
667 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
672 if (!atomic_dec_and_test(&doi_def->refcount))
674 spin_lock(&cipso_v4_doi_list_lock);
675 list_del_rcu(&doi_def->list);
676 spin_unlock(&cipso_v4_doi_list_lock);
678 cipso_v4_cache_invalidate();
679 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
683 * cipso_v4_doi_walk - Iterate through the DOI definitions
684 * @skip_cnt: skip past this number of DOI definitions, updated
685 * @callback: callback for each DOI definition
686 * @cb_arg: argument for the callback function
689 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
690 * For each entry call @callback, if @callback returns a negative value stop
691 * 'walking' through the list and return. Updates the value in @skip_cnt upon
692 * return. Returns zero on success, negative values on failure.
695 int cipso_v4_doi_walk(u32 *skip_cnt,
696 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
699 int ret_val = -ENOENT;
701 struct cipso_v4_doi *iter_doi;
704 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
705 if (atomic_read(&iter_doi->refcount) > 0) {
706 if (doi_cnt++ < *skip_cnt)
708 ret_val = callback(iter_doi, cb_arg);
711 goto doi_walk_return;
722 * Label Mapping Functions
726 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
727 * @doi_def: the DOI definition
728 * @level: the level to check
731 * Checks the given level against the given DOI definition and returns a
732 * negative value if the level does not have a valid mapping and a zero value
733 * if the level is defined by the DOI.
736 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
738 switch (doi_def->type) {
739 case CIPSO_V4_MAP_PASS:
741 case CIPSO_V4_MAP_TRANS:
742 if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
751 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
752 * @doi_def: the DOI definition
753 * @host_lvl: the host MLS level
754 * @net_lvl: the network/CIPSO MLS level
757 * Perform a label mapping to translate a local MLS level to the correct
758 * CIPSO level using the given DOI definition. Returns zero on success,
759 * negative values otherwise.
762 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
766 switch (doi_def->type) {
767 case CIPSO_V4_MAP_PASS:
770 case CIPSO_V4_MAP_TRANS:
771 if (host_lvl < doi_def->map.std->lvl.local_size &&
772 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
773 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
783 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
784 * @doi_def: the DOI definition
785 * @net_lvl: the network/CIPSO MLS level
786 * @host_lvl: the host MLS level
789 * Perform a label mapping to translate a CIPSO level to the correct local MLS
790 * level using the given DOI definition. Returns zero on success, negative
794 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
798 struct cipso_v4_std_map_tbl *map_tbl;
800 switch (doi_def->type) {
801 case CIPSO_V4_MAP_PASS:
804 case CIPSO_V4_MAP_TRANS:
805 map_tbl = doi_def->map.std;
806 if (net_lvl < map_tbl->lvl.cipso_size &&
807 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
808 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
818 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
819 * @doi_def: the DOI definition
820 * @bitmap: category bitmap
821 * @bitmap_len: bitmap length in bytes
824 * Checks the given category bitmap against the given DOI definition and
825 * returns a negative value if any of the categories in the bitmap do not have
826 * a valid mapping and a zero value if all of the categories are valid.
829 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
830 const unsigned char *bitmap,
834 u32 bitmap_len_bits = bitmap_len * 8;
838 switch (doi_def->type) {
839 case CIPSO_V4_MAP_PASS:
841 case CIPSO_V4_MAP_TRANS:
842 cipso_cat_size = doi_def->map.std->cat.cipso_size;
843 cipso_array = doi_def->map.std->cat.cipso;
845 cat = cipso_v4_bitmap_walk(bitmap,
851 if (cat >= cipso_cat_size ||
852 cipso_array[cat] >= CIPSO_V4_INV_CAT)
865 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
866 * @doi_def: the DOI definition
867 * @secattr: the security attributes
868 * @net_cat: the zero'd out category bitmap in network/CIPSO format
869 * @net_cat_len: the length of the CIPSO bitmap in bytes
872 * Perform a label mapping to translate a local MLS category bitmap to the
873 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
874 * size in bytes of the network bitmap on success, negative values otherwise.
877 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
878 const struct netlbl_lsm_secattr *secattr,
879 unsigned char *net_cat,
883 u32 net_spot = CIPSO_V4_INV_CAT;
884 u32 net_spot_max = 0;
885 u32 net_clen_bits = net_cat_len * 8;
886 u32 host_cat_size = 0;
887 u32 *host_cat_array = NULL;
889 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
890 host_cat_size = doi_def->map.std->cat.local_size;
891 host_cat_array = doi_def->map.std->cat.local;
895 host_spot = netlbl_catmap_walk(secattr->attr.mls.cat,
900 switch (doi_def->type) {
901 case CIPSO_V4_MAP_PASS:
902 net_spot = host_spot;
904 case CIPSO_V4_MAP_TRANS:
905 if (host_spot >= host_cat_size)
907 net_spot = host_cat_array[host_spot];
908 if (net_spot >= CIPSO_V4_INV_CAT)
912 if (net_spot >= net_clen_bits)
914 cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
916 if (net_spot > net_spot_max)
917 net_spot_max = net_spot;
920 if (++net_spot_max % 8)
921 return net_spot_max / 8 + 1;
922 return net_spot_max / 8;
926 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
927 * @doi_def: the DOI definition
928 * @net_cat: the category bitmap in network/CIPSO format
929 * @net_cat_len: the length of the CIPSO bitmap in bytes
930 * @secattr: the security attributes
933 * Perform a label mapping to translate a CIPSO bitmap to the correct local
934 * MLS category bitmap using the given DOI definition. Returns zero on
935 * success, negative values on failure.
938 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
939 const unsigned char *net_cat,
941 struct netlbl_lsm_secattr *secattr)
945 u32 host_spot = CIPSO_V4_INV_CAT;
946 u32 net_clen_bits = net_cat_len * 8;
947 u32 net_cat_size = 0;
948 u32 *net_cat_array = NULL;
950 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
951 net_cat_size = doi_def->map.std->cat.cipso_size;
952 net_cat_array = doi_def->map.std->cat.cipso;
956 net_spot = cipso_v4_bitmap_walk(net_cat,
966 switch (doi_def->type) {
967 case CIPSO_V4_MAP_PASS:
968 host_spot = net_spot;
970 case CIPSO_V4_MAP_TRANS:
971 if (net_spot >= net_cat_size)
973 host_spot = net_cat_array[net_spot];
974 if (host_spot >= CIPSO_V4_INV_CAT)
978 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
989 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
990 * @doi_def: the DOI definition
991 * @enumcat: category list
992 * @enumcat_len: length of the category list in bytes
995 * Checks the given categories against the given DOI definition and returns a
996 * negative value if any of the categories do not have a valid mapping and a
997 * zero value if all of the categories are valid.
1000 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
1001 const unsigned char *enumcat,
1008 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
1011 for (iter = 0; iter < enumcat_len; iter += 2) {
1012 cat = get_unaligned_be16(&enumcat[iter]);
1013 if (cat <= cat_prev)
1022 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
1023 * @doi_def: the DOI definition
1024 * @secattr: the security attributes
1025 * @net_cat: the zero'd out category list in network/CIPSO format
1026 * @net_cat_len: the length of the CIPSO category list in bytes
1029 * Perform a label mapping to translate a local MLS category bitmap to the
1030 * correct CIPSO category list using the given DOI definition. Returns the
1031 * size in bytes of the network category bitmap on success, negative values
1035 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
1036 const struct netlbl_lsm_secattr *secattr,
1037 unsigned char *net_cat,
1044 cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1);
1047 if ((cat_iter + 2) > net_cat_len)
1050 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
1058 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
1059 * @doi_def: the DOI definition
1060 * @net_cat: the category list in network/CIPSO format
1061 * @net_cat_len: the length of the CIPSO bitmap in bytes
1062 * @secattr: the security attributes
1065 * Perform a label mapping to translate a CIPSO category list to the correct
1066 * local MLS category bitmap using the given DOI definition. Returns zero on
1067 * success, negative values on failure.
1070 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
1071 const unsigned char *net_cat,
1073 struct netlbl_lsm_secattr *secattr)
1078 for (iter = 0; iter < net_cat_len; iter += 2) {
1079 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
1080 get_unaligned_be16(&net_cat[iter]),
1090 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
1091 * @doi_def: the DOI definition
1092 * @rngcat: category list
1093 * @rngcat_len: length of the category list in bytes
1096 * Checks the given categories against the given DOI definition and returns a
1097 * negative value if any of the categories do not have a valid mapping and a
1098 * zero value if all of the categories are valid.
1101 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1102 const unsigned char *rngcat,
1107 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1110 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1113 for (iter = 0; iter < rngcat_len; iter += 4) {
1114 cat_high = get_unaligned_be16(&rngcat[iter]);
1115 if ((iter + 4) <= rngcat_len)
1116 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
1120 if (cat_high > cat_prev)
1130 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1131 * @doi_def: the DOI definition
1132 * @secattr: the security attributes
1133 * @net_cat: the zero'd out category list in network/CIPSO format
1134 * @net_cat_len: the length of the CIPSO category list in bytes
1137 * Perform a label mapping to translate a local MLS category bitmap to the
1138 * correct CIPSO category list using the given DOI definition. Returns the
1139 * size in bytes of the network category bitmap on success, negative values
1143 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1144 const struct netlbl_lsm_secattr *secattr,
1145 unsigned char *net_cat,
1149 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1153 /* make sure we don't overflow the 'array[]' variable */
1155 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1159 iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1);
1162 cat_size += (iter == 0 ? 0 : sizeof(u16));
1163 if (cat_size > net_cat_len)
1165 array[array_cnt++] = iter;
1167 iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter);
1170 cat_size += sizeof(u16);
1171 if (cat_size > net_cat_len)
1173 array[array_cnt++] = iter;
1176 for (iter = 0; array_cnt > 0;) {
1177 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1180 if (array[array_cnt] != 0) {
1181 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1190 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1191 * @doi_def: the DOI definition
1192 * @net_cat: the category list in network/CIPSO format
1193 * @net_cat_len: the length of the CIPSO bitmap in bytes
1194 * @secattr: the security attributes
1197 * Perform a label mapping to translate a CIPSO category list to the correct
1198 * local MLS category bitmap using the given DOI definition. Returns zero on
1199 * success, negative values on failure.
1202 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1203 const unsigned char *net_cat,
1205 struct netlbl_lsm_secattr *secattr)
1212 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1213 cat_high = get_unaligned_be16(&net_cat[net_iter]);
1214 if ((net_iter + 4) <= net_cat_len)
1215 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
1219 ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat,
1231 * Protocol Handling Functions
1235 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1236 * @doi_def: the DOI definition
1237 * @len: the total tag length in bytes, not including this header
1238 * @buf: the CIPSO option buffer
1241 * Write a CIPSO header into the beginning of @buffer.
1244 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1248 buf[0] = IPOPT_CIPSO;
1249 buf[1] = CIPSO_V4_HDR_LEN + len;
1250 *(__be32 *)&buf[2] = htonl(doi_def->doi);
1254 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1255 * @doi_def: the DOI definition
1256 * @secattr: the security attributes
1257 * @buffer: the option buffer
1258 * @buffer_len: length of buffer in bytes
1261 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1262 * actual buffer length may be larger than the indicated size due to
1263 * translation between host and network category bitmaps. Returns the size of
1264 * the tag on success, negative values on failure.
1267 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1268 const struct netlbl_lsm_secattr *secattr,
1269 unsigned char *buffer,
1276 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1279 ret_val = cipso_v4_map_lvl_hton(doi_def,
1280 secattr->attr.mls.lvl,
1285 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1286 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1293 /* This will send packets using the "optimized" format when
1294 * possible as specified in section 3.4.2.6 of the
1296 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
1299 tag_len = 4 + ret_val;
1303 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1304 buffer[1] = tag_len;
1311 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1312 * @doi_def: the DOI definition
1313 * @tag: the CIPSO tag
1314 * @secattr: the security attributes
1317 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1318 * attributes in @secattr. Return zero on success, negatives values on
1322 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1323 const unsigned char *tag,
1324 struct netlbl_lsm_secattr *secattr)
1327 u8 tag_len = tag[1];
1330 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1333 secattr->attr.mls.lvl = level;
1334 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1337 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1342 netlbl_catmap_free(secattr->attr.mls.cat);
1346 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1353 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1354 * @doi_def: the DOI definition
1355 * @secattr: the security attributes
1356 * @buffer: the option buffer
1357 * @buffer_len: length of buffer in bytes
1360 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1361 * size of the tag on success, negative values on failure.
1364 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1365 const struct netlbl_lsm_secattr *secattr,
1366 unsigned char *buffer,
1373 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1376 ret_val = cipso_v4_map_lvl_hton(doi_def,
1377 secattr->attr.mls.lvl,
1382 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1383 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1390 tag_len = 4 + ret_val;
1394 buffer[0] = CIPSO_V4_TAG_ENUM;
1395 buffer[1] = tag_len;
1402 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1403 * @doi_def: the DOI definition
1404 * @tag: the CIPSO tag
1405 * @secattr: the security attributes
1408 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1409 * attributes in @secattr. Return zero on success, negatives values on
1413 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1414 const unsigned char *tag,
1415 struct netlbl_lsm_secattr *secattr)
1418 u8 tag_len = tag[1];
1421 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1424 secattr->attr.mls.lvl = level;
1425 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1428 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1433 netlbl_catmap_free(secattr->attr.mls.cat);
1437 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1444 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1445 * @doi_def: the DOI definition
1446 * @secattr: the security attributes
1447 * @buffer: the option buffer
1448 * @buffer_len: length of buffer in bytes
1451 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1452 * size of the tag on success, negative values on failure.
1455 static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1456 const struct netlbl_lsm_secattr *secattr,
1457 unsigned char *buffer,
1464 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1467 ret_val = cipso_v4_map_lvl_hton(doi_def,
1468 secattr->attr.mls.lvl,
1473 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1474 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1481 tag_len = 4 + ret_val;
1485 buffer[0] = CIPSO_V4_TAG_RANGE;
1486 buffer[1] = tag_len;
1493 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1494 * @doi_def: the DOI definition
1495 * @tag: the CIPSO tag
1496 * @secattr: the security attributes
1499 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1500 * in @secattr. Return zero on success, negatives values on failure.
1503 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1504 const unsigned char *tag,
1505 struct netlbl_lsm_secattr *secattr)
1508 u8 tag_len = tag[1];
1511 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1514 secattr->attr.mls.lvl = level;
1515 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1518 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1523 netlbl_catmap_free(secattr->attr.mls.cat);
1527 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1534 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1535 * @doi_def: the DOI definition
1536 * @secattr: the security attributes
1537 * @buffer: the option buffer
1538 * @buffer_len: length of buffer in bytes
1541 * Generate a CIPSO option using the local tag. Returns the size of the tag
1542 * on success, negative values on failure.
1545 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1546 const struct netlbl_lsm_secattr *secattr,
1547 unsigned char *buffer,
1550 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1553 buffer[0] = CIPSO_V4_TAG_LOCAL;
1554 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1555 *(u32 *)&buffer[2] = secattr->attr.secid;
1557 return CIPSO_V4_TAG_LOC_BLEN;
1561 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1562 * @doi_def: the DOI definition
1563 * @tag: the CIPSO tag
1564 * @secattr: the security attributes
1567 * Parse a CIPSO local tag and return the security attributes in @secattr.
1568 * Return zero on success, negatives values on failure.
1571 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1572 const unsigned char *tag,
1573 struct netlbl_lsm_secattr *secattr)
1575 secattr->attr.secid = *(u32 *)&tag[2];
1576 secattr->flags |= NETLBL_SECATTR_SECID;
1582 * cipso_v4_validate - Validate a CIPSO option
1583 * @option: the start of the option, on error it is set to point to the error
1586 * This routine is called to validate a CIPSO option, it checks all of the
1587 * fields to ensure that they are at least valid, see the draft snippet below
1588 * for details. If the option is valid then a zero value is returned and
1589 * the value of @option is unchanged. If the option is invalid then a
1590 * non-zero value is returned and @option is adjusted to point to the
1591 * offending portion of the option. From the IETF draft ...
1593 * "If any field within the CIPSO options, such as the DOI identifier, is not
1594 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1595 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1596 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1597 * that is unrecognized."
1600 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1602 unsigned char *opt = *option;
1604 unsigned char opt_iter;
1605 unsigned char err_offset = 0;
1608 struct cipso_v4_doi *doi_def = NULL;
1611 /* caller already checks for length values that are too large */
1615 goto validate_return;
1619 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1620 if (doi_def == NULL) {
1622 goto validate_return_locked;
1625 opt_iter = CIPSO_V4_HDR_LEN;
1626 tag = opt + opt_iter;
1627 while (opt_iter < opt_len) {
1628 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1629 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1630 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1631 err_offset = opt_iter;
1632 goto validate_return_locked;
1636 if (tag_len > (opt_len - opt_iter)) {
1637 err_offset = opt_iter + 1;
1638 goto validate_return_locked;
1642 case CIPSO_V4_TAG_RBITMAP:
1643 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1644 err_offset = opt_iter + 1;
1645 goto validate_return_locked;
1648 /* We are already going to do all the verification
1649 * necessary at the socket layer so from our point of
1650 * view it is safe to turn these checks off (and less
1651 * work), however, the CIPSO draft says we should do
1652 * all the CIPSO validations here but it doesn't
1653 * really specify _exactly_ what we need to validate
1654 * ... so, just make it a sysctl tunable. */
1655 if (cipso_v4_rbm_strictvalid) {
1656 if (cipso_v4_map_lvl_valid(doi_def,
1658 err_offset = opt_iter + 3;
1659 goto validate_return_locked;
1661 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1662 cipso_v4_map_cat_rbm_valid(doi_def,
1665 err_offset = opt_iter + 4;
1666 goto validate_return_locked;
1670 case CIPSO_V4_TAG_ENUM:
1671 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1672 err_offset = opt_iter + 1;
1673 goto validate_return_locked;
1676 if (cipso_v4_map_lvl_valid(doi_def,
1678 err_offset = opt_iter + 3;
1679 goto validate_return_locked;
1681 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1682 cipso_v4_map_cat_enum_valid(doi_def,
1685 err_offset = opt_iter + 4;
1686 goto validate_return_locked;
1689 case CIPSO_V4_TAG_RANGE:
1690 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1691 err_offset = opt_iter + 1;
1692 goto validate_return_locked;
1695 if (cipso_v4_map_lvl_valid(doi_def,
1697 err_offset = opt_iter + 3;
1698 goto validate_return_locked;
1700 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1701 cipso_v4_map_cat_rng_valid(doi_def,
1704 err_offset = opt_iter + 4;
1705 goto validate_return_locked;
1708 case CIPSO_V4_TAG_LOCAL:
1709 /* This is a non-standard tag that we only allow for
1710 * local connections, so if the incoming interface is
1711 * not the loopback device drop the packet. Further,
1712 * there is no legitimate reason for setting this from
1713 * userspace so reject it if skb is NULL. */
1714 if (skb == NULL || !(skb->dev->flags & IFF_LOOPBACK)) {
1715 err_offset = opt_iter;
1716 goto validate_return_locked;
1718 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1719 err_offset = opt_iter + 1;
1720 goto validate_return_locked;
1724 err_offset = opt_iter;
1725 goto validate_return_locked;
1729 opt_iter += tag_len;
1732 validate_return_locked:
1735 *option = opt + err_offset;
1740 * cipso_v4_error - Send the correct response for a bad packet
1742 * @error: the error code
1743 * @gateway: CIPSO gateway flag
1746 * Based on the error code given in @error, send an ICMP error message back to
1747 * the originating host. From the IETF draft ...
1749 * "If the contents of the CIPSO [option] are valid but the security label is
1750 * outside of the configured host or port label range, the datagram is
1751 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1752 * returned. The code field of the ICMP is set to 'communication with
1753 * destination network administratively prohibited' (code 9) or to
1754 * 'communication with destination host administratively prohibited'
1755 * (code 10). The value of the code is dependent on whether the originator
1756 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1757 * recipient of the ICMP message MUST be able to handle either value. The
1758 * same procedure is performed if a CIPSO [option] can not be added to an
1759 * IP packet because it is too large to fit in the IP options area."
1761 * "If the error is triggered by receipt of an ICMP message, the message is
1762 * discarded and no response is permitted (consistent with general ICMP
1763 * processing rules)."
1766 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1768 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1772 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
1774 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
1778 * cipso_v4_genopt - Generate a CIPSO option
1779 * @buf: the option buffer
1780 * @buf_len: the size of opt_buf
1781 * @doi_def: the CIPSO DOI to use
1782 * @secattr: the security attributes
1785 * Generate a CIPSO option using the DOI definition and security attributes
1786 * passed to the function. Returns the length of the option on success and
1787 * negative values on failure.
1790 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1791 const struct cipso_v4_doi *doi_def,
1792 const struct netlbl_lsm_secattr *secattr)
1797 if (buf_len <= CIPSO_V4_HDR_LEN)
1800 /* XXX - This code assumes only one tag per CIPSO option which isn't
1801 * really a good assumption to make but since we only support the MAC
1802 * tags right now it is a safe assumption. */
1805 memset(buf, 0, buf_len);
1806 switch (doi_def->tags[iter]) {
1807 case CIPSO_V4_TAG_RBITMAP:
1808 ret_val = cipso_v4_gentag_rbm(doi_def,
1810 &buf[CIPSO_V4_HDR_LEN],
1811 buf_len - CIPSO_V4_HDR_LEN);
1813 case CIPSO_V4_TAG_ENUM:
1814 ret_val = cipso_v4_gentag_enum(doi_def,
1816 &buf[CIPSO_V4_HDR_LEN],
1817 buf_len - CIPSO_V4_HDR_LEN);
1819 case CIPSO_V4_TAG_RANGE:
1820 ret_val = cipso_v4_gentag_rng(doi_def,
1822 &buf[CIPSO_V4_HDR_LEN],
1823 buf_len - CIPSO_V4_HDR_LEN);
1825 case CIPSO_V4_TAG_LOCAL:
1826 ret_val = cipso_v4_gentag_loc(doi_def,
1828 &buf[CIPSO_V4_HDR_LEN],
1829 buf_len - CIPSO_V4_HDR_LEN);
1836 } while (ret_val < 0 &&
1837 iter < CIPSO_V4_TAG_MAXCNT &&
1838 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1841 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1842 return CIPSO_V4_HDR_LEN + ret_val;
1846 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1848 * @doi_def: the CIPSO DOI to use
1849 * @secattr: the specific security attributes of the socket
1852 * Set the CIPSO option on the given socket using the DOI definition and
1853 * security attributes passed to the function. This function requires
1854 * exclusive access to @sk, which means it either needs to be in the
1855 * process of being created or locked. Returns zero on success and negative
1856 * values on failure.
1859 int cipso_v4_sock_setattr(struct sock *sk,
1860 const struct cipso_v4_doi *doi_def,
1861 const struct netlbl_lsm_secattr *secattr)
1863 int ret_val = -EPERM;
1864 unsigned char *buf = NULL;
1867 struct ip_options_rcu *old, *opt = NULL;
1868 struct inet_sock *sk_inet;
1869 struct inet_connection_sock *sk_conn;
1871 /* In the case of sock_create_lite(), the sock->sk field is not
1872 * defined yet but it is not a problem as the only users of these
1873 * "lite" PF_INET sockets are functions which do an accept() call
1874 * afterwards so we will label the socket as part of the accept(). */
1878 /* We allocate the maximum CIPSO option size here so we are probably
1879 * being a little wasteful, but it makes our life _much_ easier later
1880 * on and after all we are only talking about 40 bytes. */
1881 buf_len = CIPSO_V4_OPT_LEN_MAX;
1882 buf = kmalloc(buf_len, GFP_ATOMIC);
1885 goto socket_setattr_failure;
1888 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1890 goto socket_setattr_failure;
1893 /* We can't use ip_options_get() directly because it makes a call to
1894 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1895 * we won't always have CAP_NET_RAW even though we _always_ want to
1896 * set the IPOPT_CIPSO option. */
1897 opt_len = (buf_len + 3) & ~3;
1898 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1901 goto socket_setattr_failure;
1903 memcpy(opt->opt.__data, buf, buf_len);
1904 opt->opt.optlen = opt_len;
1905 opt->opt.cipso = sizeof(struct iphdr);
1909 sk_inet = inet_sk(sk);
1911 old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
1912 if (sk_inet->is_icsk) {
1913 sk_conn = inet_csk(sk);
1915 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1916 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1917 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1919 rcu_assign_pointer(sk_inet->inet_opt, opt);
1921 kfree_rcu(old, rcu);
1925 socket_setattr_failure:
1932 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1933 * @req: the connection request socket
1934 * @doi_def: the CIPSO DOI to use
1935 * @secattr: the specific security attributes of the socket
1938 * Set the CIPSO option on the given socket using the DOI definition and
1939 * security attributes passed to the function. Returns zero on success and
1940 * negative values on failure.
1943 int cipso_v4_req_setattr(struct request_sock *req,
1944 const struct cipso_v4_doi *doi_def,
1945 const struct netlbl_lsm_secattr *secattr)
1947 int ret_val = -EPERM;
1948 unsigned char *buf = NULL;
1951 struct ip_options_rcu *opt = NULL;
1952 struct inet_request_sock *req_inet;
1954 /* We allocate the maximum CIPSO option size here so we are probably
1955 * being a little wasteful, but it makes our life _much_ easier later
1956 * on and after all we are only talking about 40 bytes. */
1957 buf_len = CIPSO_V4_OPT_LEN_MAX;
1958 buf = kmalloc(buf_len, GFP_ATOMIC);
1961 goto req_setattr_failure;
1964 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1966 goto req_setattr_failure;
1969 /* We can't use ip_options_get() directly because it makes a call to
1970 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1971 * we won't always have CAP_NET_RAW even though we _always_ want to
1972 * set the IPOPT_CIPSO option. */
1973 opt_len = (buf_len + 3) & ~3;
1974 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1977 goto req_setattr_failure;
1979 memcpy(opt->opt.__data, buf, buf_len);
1980 opt->opt.optlen = opt_len;
1981 opt->opt.cipso = sizeof(struct iphdr);
1985 req_inet = inet_rsk(req);
1986 opt = xchg(&req_inet->opt, opt);
1988 kfree_rcu(opt, rcu);
1992 req_setattr_failure:
1999 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
2000 * @opt_ptr: IP option pointer
2003 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
2004 * adjustments to the IP option structure. Returns zero on success, negative
2005 * values on failure.
2008 static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr)
2011 struct ip_options_rcu *opt = *opt_ptr;
2013 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
2016 unsigned char *cipso_ptr;
2020 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
2021 cipso_ptr = &opt->opt.__data[cipso_off];
2022 cipso_len = cipso_ptr[1];
2024 if (opt->opt.srr > opt->opt.cipso)
2025 opt->opt.srr -= cipso_len;
2026 if (opt->opt.rr > opt->opt.cipso)
2027 opt->opt.rr -= cipso_len;
2028 if (opt->opt.ts > opt->opt.cipso)
2029 opt->opt.ts -= cipso_len;
2030 if (opt->opt.router_alert > opt->opt.cipso)
2031 opt->opt.router_alert -= cipso_len;
2034 memmove(cipso_ptr, cipso_ptr + cipso_len,
2035 opt->opt.optlen - cipso_off - cipso_len);
2037 /* determining the new total option length is tricky because of
2038 * the padding necessary, the only thing i can think to do at
2039 * this point is walk the options one-by-one, skipping the
2040 * padding at the end to determine the actual option size and
2041 * from there we can determine the new total option length */
2044 while (iter < opt->opt.optlen)
2045 if (opt->opt.__data[iter] != IPOPT_NOP) {
2046 iter += opt->opt.__data[iter + 1];
2050 hdr_delta = opt->opt.optlen;
2051 opt->opt.optlen = (optlen_new + 3) & ~3;
2052 hdr_delta -= opt->opt.optlen;
2054 /* only the cipso option was present on the socket so we can
2055 * remove the entire option struct */
2057 hdr_delta = opt->opt.optlen;
2058 kfree_rcu(opt, rcu);
2065 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2069 * Removes the CIPSO option from a socket, if present.
2072 void cipso_v4_sock_delattr(struct sock *sk)
2075 struct ip_options_rcu *opt;
2076 struct inet_sock *sk_inet;
2078 sk_inet = inet_sk(sk);
2079 opt = rcu_dereference_protected(sk_inet->inet_opt, 1);
2080 if (opt == NULL || opt->opt.cipso == 0)
2083 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2084 if (sk_inet->is_icsk && hdr_delta > 0) {
2085 struct inet_connection_sock *sk_conn = inet_csk(sk);
2086 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2087 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2092 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2093 * @reg: the request socket
2096 * Removes the CIPSO option from a request socket, if present.
2099 void cipso_v4_req_delattr(struct request_sock *req)
2101 struct ip_options_rcu *opt;
2102 struct inet_request_sock *req_inet;
2104 req_inet = inet_rsk(req);
2105 opt = req_inet->opt;
2106 if (opt == NULL || opt->opt.cipso == 0)
2109 cipso_v4_delopt(&req_inet->opt);
2113 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2114 * @cipso: the CIPSO v4 option
2115 * @secattr: the security attributes
2118 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2119 * on success and negative values on failure.
2122 static int cipso_v4_getattr(const unsigned char *cipso,
2123 struct netlbl_lsm_secattr *secattr)
2125 int ret_val = -ENOMSG;
2127 struct cipso_v4_doi *doi_def;
2129 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2132 doi = get_unaligned_be32(&cipso[2]);
2134 doi_def = cipso_v4_doi_search(doi);
2135 if (doi_def == NULL)
2136 goto getattr_return;
2137 /* XXX - This code assumes only one tag per CIPSO option which isn't
2138 * really a good assumption to make but since we only support the MAC
2139 * tags right now it is a safe assumption. */
2141 case CIPSO_V4_TAG_RBITMAP:
2142 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2144 case CIPSO_V4_TAG_ENUM:
2145 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2147 case CIPSO_V4_TAG_RANGE:
2148 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2150 case CIPSO_V4_TAG_LOCAL:
2151 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2155 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2163 * cipso_v4_sock_getattr - Get the security attributes from a sock
2165 * @secattr: the security attributes
2168 * Query @sk to see if there is a CIPSO option attached to the sock and if
2169 * there is return the CIPSO security attributes in @secattr. This function
2170 * requires that @sk be locked, or privately held, but it does not do any
2171 * locking itself. Returns zero on success and negative values on failure.
2174 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2176 struct ip_options_rcu *opt;
2180 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2181 if (opt && opt->opt.cipso)
2182 res = cipso_v4_getattr(opt->opt.__data +
2184 sizeof(struct iphdr),
2191 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2193 * @secattr: the security attributes
2196 * Set the CIPSO option on the given packet based on the security attributes.
2197 * Returns a pointer to the IP header on success and NULL on failure.
2200 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2201 const struct cipso_v4_doi *doi_def,
2202 const struct netlbl_lsm_secattr *secattr)
2206 struct ip_options *opt = &IPCB(skb)->opt;
2207 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2208 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2212 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2216 opt_len = (buf_len + 3) & ~3;
2218 /* we overwrite any existing options to ensure that we have enough
2219 * room for the CIPSO option, the reason is that we _need_ to guarantee
2220 * that the security label is applied to the packet - we do the same
2221 * thing when using the socket options and it hasn't caused a problem,
2222 * if we need to we can always revisit this choice later */
2224 len_delta = opt_len - opt->optlen;
2225 /* if we don't ensure enough headroom we could panic on the skb_push()
2226 * call below so make sure we have enough, we are also "mangling" the
2227 * packet so we should probably do a copy-on-write call anyway */
2228 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2232 if (len_delta > 0) {
2233 /* we assume that the header + opt->optlen have already been
2234 * "pushed" in ip_options_build() or similar */
2236 skb_push(skb, len_delta);
2237 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2238 skb_reset_network_header(skb);
2240 } else if (len_delta < 0) {
2242 memset(iph + 1, IPOPT_NOP, opt->optlen);
2246 if (opt->optlen > 0)
2247 memset(opt, 0, sizeof(*opt));
2248 opt->optlen = opt_len;
2249 opt->cipso = sizeof(struct iphdr);
2250 opt->is_changed = 1;
2252 /* we have to do the following because we are being called from a
2253 * netfilter hook which means the packet already has had the header
2254 * fields populated and the checksum calculated - yes this means we
2255 * are doing more work than needed but we do it to keep the core
2256 * stack clean and tidy */
2257 memcpy(iph + 1, buf, buf_len);
2258 if (opt_len > buf_len)
2259 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2260 if (len_delta != 0) {
2261 iph->ihl = 5 + (opt_len >> 2);
2262 iph->tot_len = htons(skb->len);
2270 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2274 * Removes any and all CIPSO options from the given packet. Returns zero on
2275 * success, negative values on failure.
2278 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2282 struct ip_options *opt = &IPCB(skb)->opt;
2283 unsigned char *cipso_ptr;
2285 if (opt->cipso == 0)
2288 /* since we are changing the packet we should make a copy */
2289 ret_val = skb_cow(skb, skb_headroom(skb));
2293 /* the easiest thing to do is just replace the cipso option with noop
2294 * options since we don't change the size of the packet, although we
2295 * still need to recalculate the checksum */
2298 cipso_ptr = (unsigned char *)iph + opt->cipso;
2299 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2301 opt->is_changed = 1;
2309 * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
2311 * @secattr: the security attributes
2314 * Parse the given packet's CIPSO option and return the security attributes.
2315 * Returns zero on success and negative values on failure.
2318 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
2319 struct netlbl_lsm_secattr *secattr)
2321 return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr);
2329 * cipso_v4_init - Initialize the CIPSO module
2332 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2333 * and negative values on failure.
2336 static int __init cipso_v4_init(void)
2340 ret_val = cipso_v4_cache_init();
2342 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2348 subsys_initcall(cipso_v4_init);