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))
170 if (++bit_spot >= bitmap_len)
174 byte = bitmap[++byte_offset];
183 * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
184 * @bitmap: the bitmap
186 * @state: if non-zero, set the bit (1) else clear the bit (0)
189 * Set a single bit in the bitmask. Returns zero on success, negative values
192 static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
199 /* gcc always rounds to zero when doing integer division */
201 bitmask = 0x80 >> (bit % 8);
203 bitmap[byte_spot] |= bitmask;
205 bitmap[byte_spot] &= ~bitmask;
209 * cipso_v4_cache_entry_free - Frees a cache entry
210 * @entry: the entry to free
213 * This function frees the memory associated with a cache entry including the
214 * LSM cache data if there are no longer any users, i.e. reference count == 0.
217 static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
220 netlbl_secattr_cache_free(entry->lsm_data);
226 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
228 * @key_len: the length of the key in bytes
231 * The CIPSO tag hashing function. Returns a 32-bit hash value.
234 static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
236 return jhash(key, key_len, 0);
240 * Label Mapping Cache Functions
244 * cipso_v4_cache_init - Initialize the CIPSO cache
247 * Initializes the CIPSO label mapping cache, this function should be called
248 * before any of the other functions defined in this file. Returns zero on
249 * success, negative values on error.
252 static int __init cipso_v4_cache_init(void)
256 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
257 sizeof(struct cipso_v4_map_cache_bkt),
262 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
263 spin_lock_init(&cipso_v4_cache[iter].lock);
264 cipso_v4_cache[iter].size = 0;
265 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
272 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
275 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
276 * success and negative values on failure.
279 void cipso_v4_cache_invalidate(void)
281 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
284 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
285 spin_lock_bh(&cipso_v4_cache[iter].lock);
286 list_for_each_entry_safe(entry,
288 &cipso_v4_cache[iter].list, list) {
289 list_del(&entry->list);
290 cipso_v4_cache_entry_free(entry);
292 cipso_v4_cache[iter].size = 0;
293 spin_unlock_bh(&cipso_v4_cache[iter].lock);
298 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
299 * @key: the buffer to check
300 * @key_len: buffer length in bytes
301 * @secattr: the security attribute struct to use
304 * This function checks the cache to see if a label mapping already exists for
305 * the given key. If there is a match then the cache is adjusted and the
306 * @secattr struct is populated with the correct LSM security attributes. The
307 * cache is adjusted in the following manner if the entry is not already the
308 * first in the cache bucket:
310 * 1. The cache entry's activity counter is incremented
311 * 2. The previous (higher ranking) entry's activity counter is decremented
312 * 3. If the difference between the two activity counters is geater than
313 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
315 * Returns zero on success, -ENOENT for a cache miss, and other negative values
319 static int cipso_v4_cache_check(const unsigned char *key,
321 struct netlbl_lsm_secattr *secattr)
324 struct cipso_v4_map_cache_entry *entry;
325 struct cipso_v4_map_cache_entry *prev_entry = NULL;
328 if (!cipso_v4_cache_enabled)
331 hash = cipso_v4_map_cache_hash(key, key_len);
332 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
333 spin_lock_bh(&cipso_v4_cache[bkt].lock);
334 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
335 if (entry->hash == hash &&
336 entry->key_len == key_len &&
337 memcmp(entry->key, key, key_len) == 0) {
338 entry->activity += 1;
339 atomic_inc(&entry->lsm_data->refcount);
340 secattr->cache = entry->lsm_data;
341 secattr->flags |= NETLBL_SECATTR_CACHE;
342 secattr->type = NETLBL_NLTYPE_CIPSOV4;
344 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
348 if (prev_entry->activity > 0)
349 prev_entry->activity -= 1;
350 if (entry->activity > prev_entry->activity &&
351 entry->activity - prev_entry->activity >
352 CIPSO_V4_CACHE_REORDERLIMIT) {
353 __list_del(entry->list.prev, entry->list.next);
354 __list_add(&entry->list,
355 prev_entry->list.prev,
359 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
364 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
370 * cipso_v4_cache_add - Add an entry to the CIPSO cache
372 * @secattr: the packet's security attributes
375 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
376 * head of the cache bucket's list, if the cache bucket is out of room remove
377 * the last entry in the list first. It is important to note that there is
378 * currently no checking for duplicate keys. Returns zero on success,
379 * negative values on failure.
382 int cipso_v4_cache_add(const unsigned char *cipso_ptr,
383 const struct netlbl_lsm_secattr *secattr)
385 int ret_val = -EPERM;
387 struct cipso_v4_map_cache_entry *entry = NULL;
388 struct cipso_v4_map_cache_entry *old_entry = NULL;
391 if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
394 cipso_ptr_len = cipso_ptr[1];
396 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
399 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
402 goto cache_add_failure;
404 entry->key_len = cipso_ptr_len;
405 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
406 atomic_inc(&secattr->cache->refcount);
407 entry->lsm_data = secattr->cache;
409 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
410 spin_lock_bh(&cipso_v4_cache[bkt].lock);
411 if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
412 list_add(&entry->list, &cipso_v4_cache[bkt].list);
413 cipso_v4_cache[bkt].size += 1;
415 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
416 struct cipso_v4_map_cache_entry, list);
417 list_del(&old_entry->list);
418 list_add(&entry->list, &cipso_v4_cache[bkt].list);
419 cipso_v4_cache_entry_free(old_entry);
421 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
427 cipso_v4_cache_entry_free(entry);
436 * cipso_v4_doi_search - Searches for a DOI definition
437 * @doi: the DOI to search for
440 * Search the DOI definition list for a DOI definition with a DOI value that
441 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
442 * Returns a pointer to the DOI definition on success and NULL on failure.
444 static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
446 struct cipso_v4_doi *iter;
448 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
449 if (iter->doi == doi && atomic_read(&iter->refcount))
455 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
456 * @doi_def: the DOI structure
457 * @audit_info: NetLabel audit information
460 * The caller defines a new DOI for use by the CIPSO engine and calls this
461 * function to add it to the list of acceptable domains. The caller must
462 * ensure that the mapping table specified in @doi_def->map meets all of the
463 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
464 * zero on success and non-zero on failure.
467 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
468 struct netlbl_audit *audit_info)
470 int ret_val = -EINVAL;
474 struct audit_buffer *audit_buf;
477 doi_type = doi_def->type;
479 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
481 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
482 switch (doi_def->tags[iter]) {
483 case CIPSO_V4_TAG_RBITMAP:
485 case CIPSO_V4_TAG_RANGE:
486 case CIPSO_V4_TAG_ENUM:
487 if (doi_def->type != CIPSO_V4_MAP_PASS)
490 case CIPSO_V4_TAG_LOCAL:
491 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
494 case CIPSO_V4_TAG_INVALID:
503 atomic_set(&doi_def->refcount, 1);
505 spin_lock(&cipso_v4_doi_list_lock);
506 if (cipso_v4_doi_search(doi_def->doi)) {
507 spin_unlock(&cipso_v4_doi_list_lock);
511 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
512 spin_unlock(&cipso_v4_doi_list_lock);
516 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
518 const char *type_str;
520 case CIPSO_V4_MAP_TRANS:
523 case CIPSO_V4_MAP_PASS:
526 case CIPSO_V4_MAP_LOCAL:
530 type_str = "(unknown)";
532 audit_log_format(audit_buf,
533 " cipso_doi=%u cipso_type=%s res=%u",
534 doi, type_str, ret_val == 0 ? 1 : 0);
535 audit_log_end(audit_buf);
542 * cipso_v4_doi_free - Frees a DOI definition
543 * @doi_def: the DOI definition
546 * This function frees all of the memory associated with a DOI definition.
549 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
554 switch (doi_def->type) {
555 case CIPSO_V4_MAP_TRANS:
556 kfree(doi_def->map.std->lvl.cipso);
557 kfree(doi_def->map.std->lvl.local);
558 kfree(doi_def->map.std->cat.cipso);
559 kfree(doi_def->map.std->cat.local);
560 kfree(doi_def->map.std);
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);
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);
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 ((level < doi_def->map.std->lvl.cipso_size) &&
743 (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL))
752 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
753 * @doi_def: the DOI definition
754 * @host_lvl: the host MLS level
755 * @net_lvl: the network/CIPSO MLS level
758 * Perform a label mapping to translate a local MLS level to the correct
759 * CIPSO level using the given DOI definition. Returns zero on success,
760 * negative values otherwise.
763 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
767 switch (doi_def->type) {
768 case CIPSO_V4_MAP_PASS:
771 case CIPSO_V4_MAP_TRANS:
772 if (host_lvl < doi_def->map.std->lvl.local_size &&
773 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
774 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
784 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
785 * @doi_def: the DOI definition
786 * @net_lvl: the network/CIPSO MLS level
787 * @host_lvl: the host MLS level
790 * Perform a label mapping to translate a CIPSO level to the correct local MLS
791 * level using the given DOI definition. Returns zero on success, negative
795 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
799 struct cipso_v4_std_map_tbl *map_tbl;
801 switch (doi_def->type) {
802 case CIPSO_V4_MAP_PASS:
805 case CIPSO_V4_MAP_TRANS:
806 map_tbl = doi_def->map.std;
807 if (net_lvl < map_tbl->lvl.cipso_size &&
808 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
809 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
819 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
820 * @doi_def: the DOI definition
821 * @bitmap: category bitmap
822 * @bitmap_len: bitmap length in bytes
825 * Checks the given category bitmap against the given DOI definition and
826 * returns a negative value if any of the categories in the bitmap do not have
827 * a valid mapping and a zero value if all of the categories are valid.
830 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
831 const unsigned char *bitmap,
835 u32 bitmap_len_bits = bitmap_len * 8;
839 switch (doi_def->type) {
840 case CIPSO_V4_MAP_PASS:
842 case CIPSO_V4_MAP_TRANS:
843 cipso_cat_size = doi_def->map.std->cat.cipso_size;
844 cipso_array = doi_def->map.std->cat.cipso;
846 cat = cipso_v4_bitmap_walk(bitmap,
852 if (cat >= cipso_cat_size ||
853 cipso_array[cat] >= CIPSO_V4_INV_CAT)
866 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
867 * @doi_def: the DOI definition
868 * @secattr: the security attributes
869 * @net_cat: the zero'd out category bitmap in network/CIPSO format
870 * @net_cat_len: the length of the CIPSO bitmap in bytes
873 * Perform a label mapping to translate a local MLS category bitmap to the
874 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
875 * size in bytes of the network bitmap on success, negative values otherwise.
878 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
879 const struct netlbl_lsm_secattr *secattr,
880 unsigned char *net_cat,
884 u32 net_spot = CIPSO_V4_INV_CAT;
885 u32 net_spot_max = 0;
886 u32 net_clen_bits = net_cat_len * 8;
887 u32 host_cat_size = 0;
888 u32 *host_cat_array = NULL;
890 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
891 host_cat_size = doi_def->map.std->cat.local_size;
892 host_cat_array = doi_def->map.std->cat.local;
896 host_spot = netlbl_catmap_walk(secattr->attr.mls.cat,
901 switch (doi_def->type) {
902 case CIPSO_V4_MAP_PASS:
903 net_spot = host_spot;
905 case CIPSO_V4_MAP_TRANS:
906 if (host_spot >= host_cat_size)
908 net_spot = host_cat_array[host_spot];
909 if (net_spot >= CIPSO_V4_INV_CAT)
913 if (net_spot >= net_clen_bits)
915 cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
917 if (net_spot > net_spot_max)
918 net_spot_max = net_spot;
921 if (++net_spot_max % 8)
922 return net_spot_max / 8 + 1;
923 return net_spot_max / 8;
927 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
928 * @doi_def: the DOI definition
929 * @net_cat: the category bitmap in network/CIPSO format
930 * @net_cat_len: the length of the CIPSO bitmap in bytes
931 * @secattr: the security attributes
934 * Perform a label mapping to translate a CIPSO bitmap to the correct local
935 * MLS category bitmap using the given DOI definition. Returns zero on
936 * success, negative values on failure.
939 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
940 const unsigned char *net_cat,
942 struct netlbl_lsm_secattr *secattr)
946 u32 host_spot = CIPSO_V4_INV_CAT;
947 u32 net_clen_bits = net_cat_len * 8;
948 u32 net_cat_size = 0;
949 u32 *net_cat_array = NULL;
951 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
952 net_cat_size = doi_def->map.std->cat.cipso_size;
953 net_cat_array = doi_def->map.std->cat.cipso;
957 net_spot = cipso_v4_bitmap_walk(net_cat,
967 switch (doi_def->type) {
968 case CIPSO_V4_MAP_PASS:
969 host_spot = net_spot;
971 case CIPSO_V4_MAP_TRANS:
972 if (net_spot >= net_cat_size)
974 host_spot = net_cat_array[net_spot];
975 if (host_spot >= CIPSO_V4_INV_CAT)
979 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
990 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
991 * @doi_def: the DOI definition
992 * @enumcat: category list
993 * @enumcat_len: length of the category list in bytes
996 * Checks the given categories against the given DOI definition and returns a
997 * negative value if any of the categories do not have a valid mapping and a
998 * zero value if all of the categories are valid.
1001 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
1002 const unsigned char *enumcat,
1009 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
1012 for (iter = 0; iter < enumcat_len; iter += 2) {
1013 cat = get_unaligned_be16(&enumcat[iter]);
1014 if (cat <= cat_prev)
1023 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
1024 * @doi_def: the DOI definition
1025 * @secattr: the security attributes
1026 * @net_cat: the zero'd out category list in network/CIPSO format
1027 * @net_cat_len: the length of the CIPSO category list in bytes
1030 * Perform a label mapping to translate a local MLS category bitmap to the
1031 * correct CIPSO category list using the given DOI definition. Returns the
1032 * size in bytes of the network category bitmap on success, negative values
1036 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
1037 const struct netlbl_lsm_secattr *secattr,
1038 unsigned char *net_cat,
1045 cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1);
1048 if ((cat_iter + 2) > net_cat_len)
1051 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
1059 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
1060 * @doi_def: the DOI definition
1061 * @net_cat: the category list in network/CIPSO format
1062 * @net_cat_len: the length of the CIPSO bitmap in bytes
1063 * @secattr: the security attributes
1066 * Perform a label mapping to translate a CIPSO category list to the correct
1067 * local MLS category bitmap using the given DOI definition. Returns zero on
1068 * success, negative values on failure.
1071 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
1072 const unsigned char *net_cat,
1074 struct netlbl_lsm_secattr *secattr)
1079 for (iter = 0; iter < net_cat_len; iter += 2) {
1080 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
1081 get_unaligned_be16(&net_cat[iter]),
1091 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
1092 * @doi_def: the DOI definition
1093 * @rngcat: category list
1094 * @rngcat_len: length of the category list in bytes
1097 * Checks the given categories against the given DOI definition and returns a
1098 * negative value if any of the categories do not have a valid mapping and a
1099 * zero value if all of the categories are valid.
1102 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1103 const unsigned char *rngcat,
1108 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1111 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1114 for (iter = 0; iter < rngcat_len; iter += 4) {
1115 cat_high = get_unaligned_be16(&rngcat[iter]);
1116 if ((iter + 4) <= rngcat_len)
1117 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
1121 if (cat_high > cat_prev)
1131 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1132 * @doi_def: the DOI definition
1133 * @secattr: the security attributes
1134 * @net_cat: the zero'd out category list in network/CIPSO format
1135 * @net_cat_len: the length of the CIPSO category list in bytes
1138 * Perform a label mapping to translate a local MLS category bitmap to the
1139 * correct CIPSO category list using the given DOI definition. Returns the
1140 * size in bytes of the network category bitmap on success, negative values
1144 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1145 const struct netlbl_lsm_secattr *secattr,
1146 unsigned char *net_cat,
1150 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1154 /* make sure we don't overflow the 'array[]' variable */
1156 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1160 iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1);
1163 cat_size += (iter == 0 ? 0 : sizeof(u16));
1164 if (cat_size > net_cat_len)
1166 array[array_cnt++] = iter;
1168 iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter);
1171 cat_size += sizeof(u16);
1172 if (cat_size > net_cat_len)
1174 array[array_cnt++] = iter;
1177 for (iter = 0; array_cnt > 0;) {
1178 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1181 if (array[array_cnt] != 0) {
1182 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1191 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1192 * @doi_def: the DOI definition
1193 * @net_cat: the category list in network/CIPSO format
1194 * @net_cat_len: the length of the CIPSO bitmap in bytes
1195 * @secattr: the security attributes
1198 * Perform a label mapping to translate a CIPSO category list to the correct
1199 * local MLS category bitmap using the given DOI definition. Returns zero on
1200 * success, negative values on failure.
1203 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1204 const unsigned char *net_cat,
1206 struct netlbl_lsm_secattr *secattr)
1213 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1214 cat_high = get_unaligned_be16(&net_cat[net_iter]);
1215 if ((net_iter + 4) <= net_cat_len)
1216 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
1220 ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat,
1232 * Protocol Handling Functions
1236 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1237 * @doi_def: the DOI definition
1238 * @len: the total tag length in bytes, not including this header
1239 * @buf: the CIPSO option buffer
1242 * Write a CIPSO header into the beginning of @buffer.
1245 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1249 buf[0] = IPOPT_CIPSO;
1250 buf[1] = CIPSO_V4_HDR_LEN + len;
1251 *(__be32 *)&buf[2] = htonl(doi_def->doi);
1255 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1256 * @doi_def: the DOI definition
1257 * @secattr: the security attributes
1258 * @buffer: the option buffer
1259 * @buffer_len: length of buffer in bytes
1262 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1263 * actual buffer length may be larger than the indicated size due to
1264 * translation between host and network category bitmaps. Returns the size of
1265 * the tag on success, negative values on failure.
1268 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1269 const struct netlbl_lsm_secattr *secattr,
1270 unsigned char *buffer,
1277 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1280 ret_val = cipso_v4_map_lvl_hton(doi_def,
1281 secattr->attr.mls.lvl,
1286 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1287 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1294 /* This will send packets using the "optimized" format when
1295 * possible as specified in section 3.4.2.6 of the
1297 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
1300 tag_len = 4 + ret_val;
1304 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1305 buffer[1] = tag_len;
1312 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1313 * @doi_def: the DOI definition
1314 * @tag: the CIPSO tag
1315 * @secattr: the security attributes
1318 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1319 * attributes in @secattr. Return zero on success, negatives values on
1323 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1324 const unsigned char *tag,
1325 struct netlbl_lsm_secattr *secattr)
1328 u8 tag_len = tag[1];
1331 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1334 secattr->attr.mls.lvl = level;
1335 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1338 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1343 netlbl_catmap_free(secattr->attr.mls.cat);
1347 if (secattr->attr.mls.cat)
1348 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1355 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1356 * @doi_def: the DOI definition
1357 * @secattr: the security attributes
1358 * @buffer: the option buffer
1359 * @buffer_len: length of buffer in bytes
1362 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1363 * size of the tag on success, negative values on failure.
1366 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1367 const struct netlbl_lsm_secattr *secattr,
1368 unsigned char *buffer,
1375 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1378 ret_val = cipso_v4_map_lvl_hton(doi_def,
1379 secattr->attr.mls.lvl,
1384 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1385 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1392 tag_len = 4 + ret_val;
1396 buffer[0] = CIPSO_V4_TAG_ENUM;
1397 buffer[1] = tag_len;
1404 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1405 * @doi_def: the DOI definition
1406 * @tag: the CIPSO tag
1407 * @secattr: the security attributes
1410 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1411 * attributes in @secattr. Return zero on success, negatives values on
1415 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1416 const unsigned char *tag,
1417 struct netlbl_lsm_secattr *secattr)
1420 u8 tag_len = tag[1];
1423 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1426 secattr->attr.mls.lvl = level;
1427 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1430 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1435 netlbl_catmap_free(secattr->attr.mls.cat);
1439 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1446 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1447 * @doi_def: the DOI definition
1448 * @secattr: the security attributes
1449 * @buffer: the option buffer
1450 * @buffer_len: length of buffer in bytes
1453 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1454 * size of the tag on success, negative values on failure.
1457 static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1458 const struct netlbl_lsm_secattr *secattr,
1459 unsigned char *buffer,
1466 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1469 ret_val = cipso_v4_map_lvl_hton(doi_def,
1470 secattr->attr.mls.lvl,
1475 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1476 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1483 tag_len = 4 + ret_val;
1487 buffer[0] = CIPSO_V4_TAG_RANGE;
1488 buffer[1] = tag_len;
1495 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1496 * @doi_def: the DOI definition
1497 * @tag: the CIPSO tag
1498 * @secattr: the security attributes
1501 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1502 * in @secattr. Return zero on success, negatives values on failure.
1505 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1506 const unsigned char *tag,
1507 struct netlbl_lsm_secattr *secattr)
1510 u8 tag_len = tag[1];
1513 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1516 secattr->attr.mls.lvl = level;
1517 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1520 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1525 netlbl_catmap_free(secattr->attr.mls.cat);
1529 if (secattr->attr.mls.cat)
1530 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1537 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1538 * @doi_def: the DOI definition
1539 * @secattr: the security attributes
1540 * @buffer: the option buffer
1541 * @buffer_len: length of buffer in bytes
1544 * Generate a CIPSO option using the local tag. Returns the size of the tag
1545 * on success, negative values on failure.
1548 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1549 const struct netlbl_lsm_secattr *secattr,
1550 unsigned char *buffer,
1553 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1556 buffer[0] = CIPSO_V4_TAG_LOCAL;
1557 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1558 *(u32 *)&buffer[2] = secattr->attr.secid;
1560 return CIPSO_V4_TAG_LOC_BLEN;
1564 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1565 * @doi_def: the DOI definition
1566 * @tag: the CIPSO tag
1567 * @secattr: the security attributes
1570 * Parse a CIPSO local tag and return the security attributes in @secattr.
1571 * Return zero on success, negatives values on failure.
1574 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1575 const unsigned char *tag,
1576 struct netlbl_lsm_secattr *secattr)
1578 secattr->attr.secid = *(u32 *)&tag[2];
1579 secattr->flags |= NETLBL_SECATTR_SECID;
1585 * cipso_v4_optptr - Find the CIPSO option in the packet
1589 * Parse the packet's IP header looking for a CIPSO option. Returns a pointer
1590 * to the start of the CIPSO option on success, NULL if one is not found.
1593 unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
1595 const struct iphdr *iph = ip_hdr(skb);
1596 unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]);
1600 for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
1601 switch (optptr[0]) {
1610 if (!taglen || taglen > optlen)
1612 if (optptr[0] == IPOPT_CIPSO)
1623 * cipso_v4_validate - Validate a CIPSO option
1624 * @option: the start of the option, on error it is set to point to the error
1627 * This routine is called to validate a CIPSO option, it checks all of the
1628 * fields to ensure that they are at least valid, see the draft snippet below
1629 * for details. If the option is valid then a zero value is returned and
1630 * the value of @option is unchanged. If the option is invalid then a
1631 * non-zero value is returned and @option is adjusted to point to the
1632 * offending portion of the option. From the IETF draft ...
1634 * "If any field within the CIPSO options, such as the DOI identifier, is not
1635 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1636 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1637 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1638 * that is unrecognized."
1641 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1643 unsigned char *opt = *option;
1645 unsigned char opt_iter;
1646 unsigned char err_offset = 0;
1649 struct cipso_v4_doi *doi_def = NULL;
1652 /* caller already checks for length values that are too large */
1656 goto validate_return;
1660 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1663 goto validate_return_locked;
1666 opt_iter = CIPSO_V4_HDR_LEN;
1667 tag = opt + opt_iter;
1668 while (opt_iter < opt_len) {
1669 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1670 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1671 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1672 err_offset = opt_iter;
1673 goto validate_return_locked;
1676 if (opt_iter + 1 == opt_len) {
1677 err_offset = opt_iter;
1678 goto validate_return_locked;
1681 if (tag_len > (opt_len - opt_iter)) {
1682 err_offset = opt_iter + 1;
1683 goto validate_return_locked;
1687 case CIPSO_V4_TAG_RBITMAP:
1688 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1689 err_offset = opt_iter + 1;
1690 goto validate_return_locked;
1693 /* We are already going to do all the verification
1694 * necessary at the socket layer so from our point of
1695 * view it is safe to turn these checks off (and less
1696 * work), however, the CIPSO draft says we should do
1697 * all the CIPSO validations here but it doesn't
1698 * really specify _exactly_ what we need to validate
1699 * ... so, just make it a sysctl tunable. */
1700 if (cipso_v4_rbm_strictvalid) {
1701 if (cipso_v4_map_lvl_valid(doi_def,
1703 err_offset = opt_iter + 3;
1704 goto validate_return_locked;
1706 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1707 cipso_v4_map_cat_rbm_valid(doi_def,
1710 err_offset = opt_iter + 4;
1711 goto validate_return_locked;
1715 case CIPSO_V4_TAG_ENUM:
1716 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1717 err_offset = opt_iter + 1;
1718 goto validate_return_locked;
1721 if (cipso_v4_map_lvl_valid(doi_def,
1723 err_offset = opt_iter + 3;
1724 goto validate_return_locked;
1726 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1727 cipso_v4_map_cat_enum_valid(doi_def,
1730 err_offset = opt_iter + 4;
1731 goto validate_return_locked;
1734 case CIPSO_V4_TAG_RANGE:
1735 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1736 err_offset = opt_iter + 1;
1737 goto validate_return_locked;
1740 if (cipso_v4_map_lvl_valid(doi_def,
1742 err_offset = opt_iter + 3;
1743 goto validate_return_locked;
1745 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1746 cipso_v4_map_cat_rng_valid(doi_def,
1749 err_offset = opt_iter + 4;
1750 goto validate_return_locked;
1753 case CIPSO_V4_TAG_LOCAL:
1754 /* This is a non-standard tag that we only allow for
1755 * local connections, so if the incoming interface is
1756 * not the loopback device drop the packet. Further,
1757 * there is no legitimate reason for setting this from
1758 * userspace so reject it if skb is NULL. */
1759 if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) {
1760 err_offset = opt_iter;
1761 goto validate_return_locked;
1763 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1764 err_offset = opt_iter + 1;
1765 goto validate_return_locked;
1769 err_offset = opt_iter;
1770 goto validate_return_locked;
1774 opt_iter += tag_len;
1777 validate_return_locked:
1780 *option = opt + err_offset;
1785 * cipso_v4_error - Send the correct response for a bad packet
1787 * @error: the error code
1788 * @gateway: CIPSO gateway flag
1791 * Based on the error code given in @error, send an ICMP error message back to
1792 * the originating host. From the IETF draft ...
1794 * "If the contents of the CIPSO [option] are valid but the security label is
1795 * outside of the configured host or port label range, the datagram is
1796 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1797 * returned. The code field of the ICMP is set to 'communication with
1798 * destination network administratively prohibited' (code 9) or to
1799 * 'communication with destination host administratively prohibited'
1800 * (code 10). The value of the code is dependent on whether the originator
1801 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1802 * recipient of the ICMP message MUST be able to handle either value. The
1803 * same procedure is performed if a CIPSO [option] can not be added to an
1804 * IP packet because it is too large to fit in the IP options area."
1806 * "If the error is triggered by receipt of an ICMP message, the message is
1807 * discarded and no response is permitted (consistent with general ICMP
1808 * processing rules)."
1811 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1813 unsigned char optbuf[sizeof(struct ip_options) + 40];
1814 struct ip_options *opt = (struct ip_options *)optbuf;
1817 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1821 * We might be called above the IP layer,
1822 * so we can not use icmp_send and IPCB here.
1825 memset(opt, 0, sizeof(struct ip_options));
1826 opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
1828 res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL);
1835 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
1837 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
1841 * cipso_v4_genopt - Generate a CIPSO option
1842 * @buf: the option buffer
1843 * @buf_len: the size of opt_buf
1844 * @doi_def: the CIPSO DOI to use
1845 * @secattr: the security attributes
1848 * Generate a CIPSO option using the DOI definition and security attributes
1849 * passed to the function. Returns the length of the option on success and
1850 * negative values on failure.
1853 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1854 const struct cipso_v4_doi *doi_def,
1855 const struct netlbl_lsm_secattr *secattr)
1860 if (buf_len <= CIPSO_V4_HDR_LEN)
1863 /* XXX - This code assumes only one tag per CIPSO option which isn't
1864 * really a good assumption to make but since we only support the MAC
1865 * tags right now it is a safe assumption. */
1868 memset(buf, 0, buf_len);
1869 switch (doi_def->tags[iter]) {
1870 case CIPSO_V4_TAG_RBITMAP:
1871 ret_val = cipso_v4_gentag_rbm(doi_def,
1873 &buf[CIPSO_V4_HDR_LEN],
1874 buf_len - CIPSO_V4_HDR_LEN);
1876 case CIPSO_V4_TAG_ENUM:
1877 ret_val = cipso_v4_gentag_enum(doi_def,
1879 &buf[CIPSO_V4_HDR_LEN],
1880 buf_len - CIPSO_V4_HDR_LEN);
1882 case CIPSO_V4_TAG_RANGE:
1883 ret_val = cipso_v4_gentag_rng(doi_def,
1885 &buf[CIPSO_V4_HDR_LEN],
1886 buf_len - CIPSO_V4_HDR_LEN);
1888 case CIPSO_V4_TAG_LOCAL:
1889 ret_val = cipso_v4_gentag_loc(doi_def,
1891 &buf[CIPSO_V4_HDR_LEN],
1892 buf_len - CIPSO_V4_HDR_LEN);
1899 } while (ret_val < 0 &&
1900 iter < CIPSO_V4_TAG_MAXCNT &&
1901 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1904 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1905 return CIPSO_V4_HDR_LEN + ret_val;
1909 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1911 * @doi_def: the CIPSO DOI to use
1912 * @secattr: the specific security attributes of the socket
1915 * Set the CIPSO option on the given socket using the DOI definition and
1916 * security attributes passed to the function. This function requires
1917 * exclusive access to @sk, which means it either needs to be in the
1918 * process of being created or locked. Returns zero on success and negative
1919 * values on failure.
1922 int cipso_v4_sock_setattr(struct sock *sk,
1923 const struct cipso_v4_doi *doi_def,
1924 const struct netlbl_lsm_secattr *secattr)
1926 int ret_val = -EPERM;
1927 unsigned char *buf = NULL;
1930 struct ip_options_rcu *old, *opt = NULL;
1931 struct inet_sock *sk_inet;
1932 struct inet_connection_sock *sk_conn;
1934 /* In the case of sock_create_lite(), the sock->sk field is not
1935 * defined yet but it is not a problem as the only users of these
1936 * "lite" PF_INET sockets are functions which do an accept() call
1937 * afterwards so we will label the socket as part of the accept(). */
1941 /* We allocate the maximum CIPSO option size here so we are probably
1942 * being a little wasteful, but it makes our life _much_ easier later
1943 * on and after all we are only talking about 40 bytes. */
1944 buf_len = CIPSO_V4_OPT_LEN_MAX;
1945 buf = kmalloc(buf_len, GFP_ATOMIC);
1948 goto socket_setattr_failure;
1951 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1953 goto socket_setattr_failure;
1956 /* We can't use ip_options_get() directly because it makes a call to
1957 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1958 * we won't always have CAP_NET_RAW even though we _always_ want to
1959 * set the IPOPT_CIPSO option. */
1960 opt_len = (buf_len + 3) & ~3;
1961 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1964 goto socket_setattr_failure;
1966 memcpy(opt->opt.__data, buf, buf_len);
1967 opt->opt.optlen = opt_len;
1968 opt->opt.cipso = sizeof(struct iphdr);
1972 sk_inet = inet_sk(sk);
1974 old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
1975 if (sk_inet->is_icsk) {
1976 sk_conn = inet_csk(sk);
1978 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1979 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1980 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1982 rcu_assign_pointer(sk_inet->inet_opt, opt);
1984 kfree_rcu(old, rcu);
1988 socket_setattr_failure:
1995 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1996 * @req: the connection request socket
1997 * @doi_def: the CIPSO DOI to use
1998 * @secattr: the specific security attributes of the socket
2001 * Set the CIPSO option on the given socket using the DOI definition and
2002 * security attributes passed to the function. Returns zero on success and
2003 * negative values on failure.
2006 int cipso_v4_req_setattr(struct request_sock *req,
2007 const struct cipso_v4_doi *doi_def,
2008 const struct netlbl_lsm_secattr *secattr)
2010 int ret_val = -EPERM;
2011 unsigned char *buf = NULL;
2014 struct ip_options_rcu *opt = NULL;
2015 struct inet_request_sock *req_inet;
2017 /* We allocate the maximum CIPSO option size here so we are probably
2018 * being a little wasteful, but it makes our life _much_ easier later
2019 * on and after all we are only talking about 40 bytes. */
2020 buf_len = CIPSO_V4_OPT_LEN_MAX;
2021 buf = kmalloc(buf_len, GFP_ATOMIC);
2024 goto req_setattr_failure;
2027 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2029 goto req_setattr_failure;
2032 /* We can't use ip_options_get() directly because it makes a call to
2033 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
2034 * we won't always have CAP_NET_RAW even though we _always_ want to
2035 * set the IPOPT_CIPSO option. */
2036 opt_len = (buf_len + 3) & ~3;
2037 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
2040 goto req_setattr_failure;
2042 memcpy(opt->opt.__data, buf, buf_len);
2043 opt->opt.optlen = opt_len;
2044 opt->opt.cipso = sizeof(struct iphdr);
2048 req_inet = inet_rsk(req);
2049 opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt);
2051 kfree_rcu(opt, rcu);
2055 req_setattr_failure:
2062 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
2063 * @opt_ptr: IP option pointer
2066 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
2067 * adjustments to the IP option structure. Returns zero on success, negative
2068 * values on failure.
2071 static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr)
2073 struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1);
2076 if (!opt || opt->opt.cipso == 0)
2078 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
2081 unsigned char *cipso_ptr;
2085 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
2086 cipso_ptr = &opt->opt.__data[cipso_off];
2087 cipso_len = cipso_ptr[1];
2089 if (opt->opt.srr > opt->opt.cipso)
2090 opt->opt.srr -= cipso_len;
2091 if (opt->opt.rr > opt->opt.cipso)
2092 opt->opt.rr -= cipso_len;
2093 if (opt->opt.ts > opt->opt.cipso)
2094 opt->opt.ts -= cipso_len;
2095 if (opt->opt.router_alert > opt->opt.cipso)
2096 opt->opt.router_alert -= cipso_len;
2099 memmove(cipso_ptr, cipso_ptr + cipso_len,
2100 opt->opt.optlen - cipso_off - cipso_len);
2102 /* determining the new total option length is tricky because of
2103 * the padding necessary, the only thing i can think to do at
2104 * this point is walk the options one-by-one, skipping the
2105 * padding at the end to determine the actual option size and
2106 * from there we can determine the new total option length */
2109 while (iter < opt->opt.optlen)
2110 if (opt->opt.__data[iter] != IPOPT_NOP) {
2111 iter += opt->opt.__data[iter + 1];
2115 hdr_delta = opt->opt.optlen;
2116 opt->opt.optlen = (optlen_new + 3) & ~3;
2117 hdr_delta -= opt->opt.optlen;
2119 /* only the cipso option was present on the socket so we can
2120 * remove the entire option struct */
2122 hdr_delta = opt->opt.optlen;
2123 kfree_rcu(opt, rcu);
2130 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2134 * Removes the CIPSO option from a socket, if present.
2137 void cipso_v4_sock_delattr(struct sock *sk)
2139 struct inet_sock *sk_inet;
2142 sk_inet = inet_sk(sk);
2144 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2145 if (sk_inet->is_icsk && hdr_delta > 0) {
2146 struct inet_connection_sock *sk_conn = inet_csk(sk);
2147 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2148 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2153 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2154 * @reg: the request socket
2157 * Removes the CIPSO option from a request socket, if present.
2160 void cipso_v4_req_delattr(struct request_sock *req)
2162 cipso_v4_delopt(&inet_rsk(req)->ireq_opt);
2166 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2167 * @cipso: the CIPSO v4 option
2168 * @secattr: the security attributes
2171 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2172 * on success and negative values on failure.
2175 int cipso_v4_getattr(const unsigned char *cipso,
2176 struct netlbl_lsm_secattr *secattr)
2178 int ret_val = -ENOMSG;
2180 struct cipso_v4_doi *doi_def;
2182 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2185 doi = get_unaligned_be32(&cipso[2]);
2187 doi_def = cipso_v4_doi_search(doi);
2189 goto getattr_return;
2190 /* XXX - This code assumes only one tag per CIPSO option which isn't
2191 * really a good assumption to make but since we only support the MAC
2192 * tags right now it is a safe assumption. */
2194 case CIPSO_V4_TAG_RBITMAP:
2195 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2197 case CIPSO_V4_TAG_ENUM:
2198 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2200 case CIPSO_V4_TAG_RANGE:
2201 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2203 case CIPSO_V4_TAG_LOCAL:
2204 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2208 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2216 * cipso_v4_sock_getattr - Get the security attributes from a sock
2218 * @secattr: the security attributes
2221 * Query @sk to see if there is a CIPSO option attached to the sock and if
2222 * there is return the CIPSO security attributes in @secattr. This function
2223 * requires that @sk be locked, or privately held, but it does not do any
2224 * locking itself. Returns zero on success and negative values on failure.
2227 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2229 struct ip_options_rcu *opt;
2233 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2234 if (opt && opt->opt.cipso)
2235 res = cipso_v4_getattr(opt->opt.__data +
2237 sizeof(struct iphdr),
2244 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2246 * @secattr: the security attributes
2249 * Set the CIPSO option on the given packet based on the security attributes.
2250 * Returns a pointer to the IP header on success and NULL on failure.
2253 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2254 const struct cipso_v4_doi *doi_def,
2255 const struct netlbl_lsm_secattr *secattr)
2259 struct ip_options *opt = &IPCB(skb)->opt;
2260 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2261 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2265 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2269 opt_len = (buf_len + 3) & ~3;
2271 /* we overwrite any existing options to ensure that we have enough
2272 * room for the CIPSO option, the reason is that we _need_ to guarantee
2273 * that the security label is applied to the packet - we do the same
2274 * thing when using the socket options and it hasn't caused a problem,
2275 * if we need to we can always revisit this choice later */
2277 len_delta = opt_len - opt->optlen;
2278 /* if we don't ensure enough headroom we could panic on the skb_push()
2279 * call below so make sure we have enough, we are also "mangling" the
2280 * packet so we should probably do a copy-on-write call anyway */
2281 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2285 if (len_delta > 0) {
2286 /* we assume that the header + opt->optlen have already been
2287 * "pushed" in ip_options_build() or similar */
2289 skb_push(skb, len_delta);
2290 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2291 skb_reset_network_header(skb);
2293 } else if (len_delta < 0) {
2295 memset(iph + 1, IPOPT_NOP, opt->optlen);
2299 if (opt->optlen > 0)
2300 memset(opt, 0, sizeof(*opt));
2301 opt->optlen = opt_len;
2302 opt->cipso = sizeof(struct iphdr);
2303 opt->is_changed = 1;
2305 /* we have to do the following because we are being called from a
2306 * netfilter hook which means the packet already has had the header
2307 * fields populated and the checksum calculated - yes this means we
2308 * are doing more work than needed but we do it to keep the core
2309 * stack clean and tidy */
2310 memcpy(iph + 1, buf, buf_len);
2311 if (opt_len > buf_len)
2312 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2313 if (len_delta != 0) {
2314 iph->ihl = 5 + (opt_len >> 2);
2315 iph->tot_len = htons(skb->len);
2323 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2327 * Removes any and all CIPSO options from the given packet. Returns zero on
2328 * success, negative values on failure.
2331 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2335 struct ip_options *opt = &IPCB(skb)->opt;
2336 unsigned char *cipso_ptr;
2338 if (opt->cipso == 0)
2341 /* since we are changing the packet we should make a copy */
2342 ret_val = skb_cow(skb, skb_headroom(skb));
2346 /* the easiest thing to do is just replace the cipso option with noop
2347 * options since we don't change the size of the packet, although we
2348 * still need to recalculate the checksum */
2351 cipso_ptr = (unsigned char *)iph + opt->cipso;
2352 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2354 opt->is_changed = 1;
2366 * cipso_v4_init - Initialize the CIPSO module
2369 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2370 * and negative values on failure.
2373 static int __init cipso_v4_init(void)
2377 ret_val = cipso_v4_cache_init();
2379 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2385 subsys_initcall(cipso_v4_init);