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);
566 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
567 * @entry: the entry's RCU field
570 * This function is designed to be used as a callback to the call_rcu()
571 * function so that the memory allocated to the DOI definition can be released
575 static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
577 struct cipso_v4_doi *doi_def;
579 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
580 cipso_v4_doi_free(doi_def);
584 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
585 * @doi: the DOI value
586 * @audit_secid: the LSM secid to use in the audit message
589 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
590 * be called to release their own LSM domain mappings as well as our own
591 * domain list. Returns zero on success and negative values on failure.
594 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
597 struct cipso_v4_doi *doi_def;
598 struct audit_buffer *audit_buf;
600 spin_lock(&cipso_v4_doi_list_lock);
601 doi_def = cipso_v4_doi_search(doi);
603 spin_unlock(&cipso_v4_doi_list_lock);
605 goto doi_remove_return;
607 if (!atomic_dec_and_test(&doi_def->refcount)) {
608 spin_unlock(&cipso_v4_doi_list_lock);
610 goto doi_remove_return;
612 list_del_rcu(&doi_def->list);
613 spin_unlock(&cipso_v4_doi_list_lock);
615 cipso_v4_cache_invalidate();
616 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
620 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
622 audit_log_format(audit_buf,
623 " cipso_doi=%u res=%u",
624 doi, ret_val == 0 ? 1 : 0);
625 audit_log_end(audit_buf);
632 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
633 * @doi: the DOI value
636 * Searches for a valid DOI definition and if one is found it is returned to
637 * the caller. Otherwise NULL is returned. The caller must ensure that
638 * rcu_read_lock() is held while accessing the returned definition and the DOI
639 * definition reference count is decremented when the caller is done.
642 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
644 struct cipso_v4_doi *doi_def;
647 doi_def = cipso_v4_doi_search(doi);
649 goto doi_getdef_return;
650 if (!atomic_inc_not_zero(&doi_def->refcount))
659 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
660 * @doi_def: the DOI definition
663 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
666 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
671 if (!atomic_dec_and_test(&doi_def->refcount))
673 spin_lock(&cipso_v4_doi_list_lock);
674 list_del_rcu(&doi_def->list);
675 spin_unlock(&cipso_v4_doi_list_lock);
677 cipso_v4_cache_invalidate();
678 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
682 * cipso_v4_doi_walk - Iterate through the DOI definitions
683 * @skip_cnt: skip past this number of DOI definitions, updated
684 * @callback: callback for each DOI definition
685 * @cb_arg: argument for the callback function
688 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
689 * For each entry call @callback, if @callback returns a negative value stop
690 * 'walking' through the list and return. Updates the value in @skip_cnt upon
691 * return. Returns zero on success, negative values on failure.
694 int cipso_v4_doi_walk(u32 *skip_cnt,
695 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
698 int ret_val = -ENOENT;
700 struct cipso_v4_doi *iter_doi;
703 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
704 if (atomic_read(&iter_doi->refcount) > 0) {
705 if (doi_cnt++ < *skip_cnt)
707 ret_val = callback(iter_doi, cb_arg);
710 goto doi_walk_return;
721 * Label Mapping Functions
725 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
726 * @doi_def: the DOI definition
727 * @level: the level to check
730 * Checks the given level against the given DOI definition and returns a
731 * negative value if the level does not have a valid mapping and a zero value
732 * if the level is defined by the DOI.
735 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
737 switch (doi_def->type) {
738 case CIPSO_V4_MAP_PASS:
740 case CIPSO_V4_MAP_TRANS:
741 if ((level < doi_def->map.std->lvl.cipso_size) &&
742 (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 if (secattr->attr.mls.cat)
1347 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1354 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1355 * @doi_def: the DOI definition
1356 * @secattr: the security attributes
1357 * @buffer: the option buffer
1358 * @buffer_len: length of buffer in bytes
1361 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1362 * size of the tag on success, negative values on failure.
1365 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1366 const struct netlbl_lsm_secattr *secattr,
1367 unsigned char *buffer,
1374 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1377 ret_val = cipso_v4_map_lvl_hton(doi_def,
1378 secattr->attr.mls.lvl,
1383 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1384 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1391 tag_len = 4 + ret_val;
1395 buffer[0] = CIPSO_V4_TAG_ENUM;
1396 buffer[1] = tag_len;
1403 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1404 * @doi_def: the DOI definition
1405 * @tag: the CIPSO tag
1406 * @secattr: the security attributes
1409 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1410 * attributes in @secattr. Return zero on success, negatives values on
1414 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1415 const unsigned char *tag,
1416 struct netlbl_lsm_secattr *secattr)
1419 u8 tag_len = tag[1];
1422 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1425 secattr->attr.mls.lvl = level;
1426 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1429 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1434 netlbl_catmap_free(secattr->attr.mls.cat);
1438 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1445 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1446 * @doi_def: the DOI definition
1447 * @secattr: the security attributes
1448 * @buffer: the option buffer
1449 * @buffer_len: length of buffer in bytes
1452 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1453 * size of the tag on success, negative values on failure.
1456 static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1457 const struct netlbl_lsm_secattr *secattr,
1458 unsigned char *buffer,
1465 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1468 ret_val = cipso_v4_map_lvl_hton(doi_def,
1469 secattr->attr.mls.lvl,
1474 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1475 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1482 tag_len = 4 + ret_val;
1486 buffer[0] = CIPSO_V4_TAG_RANGE;
1487 buffer[1] = tag_len;
1494 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1495 * @doi_def: the DOI definition
1496 * @tag: the CIPSO tag
1497 * @secattr: the security attributes
1500 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1501 * in @secattr. Return zero on success, negatives values on failure.
1504 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1505 const unsigned char *tag,
1506 struct netlbl_lsm_secattr *secattr)
1509 u8 tag_len = tag[1];
1512 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1515 secattr->attr.mls.lvl = level;
1516 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1519 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1524 netlbl_catmap_free(secattr->attr.mls.cat);
1528 if (secattr->attr.mls.cat)
1529 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1536 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1537 * @doi_def: the DOI definition
1538 * @secattr: the security attributes
1539 * @buffer: the option buffer
1540 * @buffer_len: length of buffer in bytes
1543 * Generate a CIPSO option using the local tag. Returns the size of the tag
1544 * on success, negative values on failure.
1547 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1548 const struct netlbl_lsm_secattr *secattr,
1549 unsigned char *buffer,
1552 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1555 buffer[0] = CIPSO_V4_TAG_LOCAL;
1556 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1557 *(u32 *)&buffer[2] = secattr->attr.secid;
1559 return CIPSO_V4_TAG_LOC_BLEN;
1563 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1564 * @doi_def: the DOI definition
1565 * @tag: the CIPSO tag
1566 * @secattr: the security attributes
1569 * Parse a CIPSO local tag and return the security attributes in @secattr.
1570 * Return zero on success, negatives values on failure.
1573 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1574 const unsigned char *tag,
1575 struct netlbl_lsm_secattr *secattr)
1577 secattr->attr.secid = *(u32 *)&tag[2];
1578 secattr->flags |= NETLBL_SECATTR_SECID;
1584 * cipso_v4_optptr - Find the CIPSO option in the packet
1588 * Parse the packet's IP header looking for a CIPSO option. Returns a pointer
1589 * to the start of the CIPSO option on success, NULL if one is not found.
1592 unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
1594 const struct iphdr *iph = ip_hdr(skb);
1595 unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]);
1599 for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
1600 switch (optptr[0]) {
1609 if (!taglen || taglen > optlen)
1611 if (optptr[0] == IPOPT_CIPSO)
1622 * cipso_v4_validate - Validate a CIPSO option
1623 * @option: the start of the option, on error it is set to point to the error
1626 * This routine is called to validate a CIPSO option, it checks all of the
1627 * fields to ensure that they are at least valid, see the draft snippet below
1628 * for details. If the option is valid then a zero value is returned and
1629 * the value of @option is unchanged. If the option is invalid then a
1630 * non-zero value is returned and @option is adjusted to point to the
1631 * offending portion of the option. From the IETF draft ...
1633 * "If any field within the CIPSO options, such as the DOI identifier, is not
1634 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1635 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1636 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1637 * that is unrecognized."
1640 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1642 unsigned char *opt = *option;
1644 unsigned char opt_iter;
1645 unsigned char err_offset = 0;
1648 struct cipso_v4_doi *doi_def = NULL;
1651 /* caller already checks for length values that are too large */
1655 goto validate_return;
1659 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1662 goto validate_return_locked;
1665 opt_iter = CIPSO_V4_HDR_LEN;
1666 tag = opt + opt_iter;
1667 while (opt_iter < opt_len) {
1668 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1669 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1670 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1671 err_offset = opt_iter;
1672 goto validate_return_locked;
1675 if (opt_iter + 1 == opt_len) {
1676 err_offset = opt_iter;
1677 goto validate_return_locked;
1680 if (tag_len > (opt_len - opt_iter)) {
1681 err_offset = opt_iter + 1;
1682 goto validate_return_locked;
1686 case CIPSO_V4_TAG_RBITMAP:
1687 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1688 err_offset = opt_iter + 1;
1689 goto validate_return_locked;
1692 /* We are already going to do all the verification
1693 * necessary at the socket layer so from our point of
1694 * view it is safe to turn these checks off (and less
1695 * work), however, the CIPSO draft says we should do
1696 * all the CIPSO validations here but it doesn't
1697 * really specify _exactly_ what we need to validate
1698 * ... so, just make it a sysctl tunable. */
1699 if (cipso_v4_rbm_strictvalid) {
1700 if (cipso_v4_map_lvl_valid(doi_def,
1702 err_offset = opt_iter + 3;
1703 goto validate_return_locked;
1705 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1706 cipso_v4_map_cat_rbm_valid(doi_def,
1709 err_offset = opt_iter + 4;
1710 goto validate_return_locked;
1714 case CIPSO_V4_TAG_ENUM:
1715 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1716 err_offset = opt_iter + 1;
1717 goto validate_return_locked;
1720 if (cipso_v4_map_lvl_valid(doi_def,
1722 err_offset = opt_iter + 3;
1723 goto validate_return_locked;
1725 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1726 cipso_v4_map_cat_enum_valid(doi_def,
1729 err_offset = opt_iter + 4;
1730 goto validate_return_locked;
1733 case CIPSO_V4_TAG_RANGE:
1734 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1735 err_offset = opt_iter + 1;
1736 goto validate_return_locked;
1739 if (cipso_v4_map_lvl_valid(doi_def,
1741 err_offset = opt_iter + 3;
1742 goto validate_return_locked;
1744 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1745 cipso_v4_map_cat_rng_valid(doi_def,
1748 err_offset = opt_iter + 4;
1749 goto validate_return_locked;
1752 case CIPSO_V4_TAG_LOCAL:
1753 /* This is a non-standard tag that we only allow for
1754 * local connections, so if the incoming interface is
1755 * not the loopback device drop the packet. Further,
1756 * there is no legitimate reason for setting this from
1757 * userspace so reject it if skb is NULL. */
1758 if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) {
1759 err_offset = opt_iter;
1760 goto validate_return_locked;
1762 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1763 err_offset = opt_iter + 1;
1764 goto validate_return_locked;
1768 err_offset = opt_iter;
1769 goto validate_return_locked;
1773 opt_iter += tag_len;
1776 validate_return_locked:
1779 *option = opt + err_offset;
1784 * cipso_v4_error - Send the correct response for a bad packet
1786 * @error: the error code
1787 * @gateway: CIPSO gateway flag
1790 * Based on the error code given in @error, send an ICMP error message back to
1791 * the originating host. From the IETF draft ...
1793 * "If the contents of the CIPSO [option] are valid but the security label is
1794 * outside of the configured host or port label range, the datagram is
1795 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1796 * returned. The code field of the ICMP is set to 'communication with
1797 * destination network administratively prohibited' (code 9) or to
1798 * 'communication with destination host administratively prohibited'
1799 * (code 10). The value of the code is dependent on whether the originator
1800 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1801 * recipient of the ICMP message MUST be able to handle either value. The
1802 * same procedure is performed if a CIPSO [option] can not be added to an
1803 * IP packet because it is too large to fit in the IP options area."
1805 * "If the error is triggered by receipt of an ICMP message, the message is
1806 * discarded and no response is permitted (consistent with general ICMP
1807 * processing rules)."
1810 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1812 unsigned char optbuf[sizeof(struct ip_options) + 40];
1813 struct ip_options *opt = (struct ip_options *)optbuf;
1816 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1820 * We might be called above the IP layer,
1821 * so we can not use icmp_send and IPCB here.
1824 memset(opt, 0, sizeof(struct ip_options));
1825 opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
1827 res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL);
1834 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
1836 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
1840 * cipso_v4_genopt - Generate a CIPSO option
1841 * @buf: the option buffer
1842 * @buf_len: the size of opt_buf
1843 * @doi_def: the CIPSO DOI to use
1844 * @secattr: the security attributes
1847 * Generate a CIPSO option using the DOI definition and security attributes
1848 * passed to the function. Returns the length of the option on success and
1849 * negative values on failure.
1852 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1853 const struct cipso_v4_doi *doi_def,
1854 const struct netlbl_lsm_secattr *secattr)
1859 if (buf_len <= CIPSO_V4_HDR_LEN)
1862 /* XXX - This code assumes only one tag per CIPSO option which isn't
1863 * really a good assumption to make but since we only support the MAC
1864 * tags right now it is a safe assumption. */
1867 memset(buf, 0, buf_len);
1868 switch (doi_def->tags[iter]) {
1869 case CIPSO_V4_TAG_RBITMAP:
1870 ret_val = cipso_v4_gentag_rbm(doi_def,
1872 &buf[CIPSO_V4_HDR_LEN],
1873 buf_len - CIPSO_V4_HDR_LEN);
1875 case CIPSO_V4_TAG_ENUM:
1876 ret_val = cipso_v4_gentag_enum(doi_def,
1878 &buf[CIPSO_V4_HDR_LEN],
1879 buf_len - CIPSO_V4_HDR_LEN);
1881 case CIPSO_V4_TAG_RANGE:
1882 ret_val = cipso_v4_gentag_rng(doi_def,
1884 &buf[CIPSO_V4_HDR_LEN],
1885 buf_len - CIPSO_V4_HDR_LEN);
1887 case CIPSO_V4_TAG_LOCAL:
1888 ret_val = cipso_v4_gentag_loc(doi_def,
1890 &buf[CIPSO_V4_HDR_LEN],
1891 buf_len - CIPSO_V4_HDR_LEN);
1898 } while (ret_val < 0 &&
1899 iter < CIPSO_V4_TAG_MAXCNT &&
1900 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1903 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1904 return CIPSO_V4_HDR_LEN + ret_val;
1908 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1910 * @doi_def: the CIPSO DOI to use
1911 * @secattr: the specific security attributes of the socket
1914 * Set the CIPSO option on the given socket using the DOI definition and
1915 * security attributes passed to the function. This function requires
1916 * exclusive access to @sk, which means it either needs to be in the
1917 * process of being created or locked. Returns zero on success and negative
1918 * values on failure.
1921 int cipso_v4_sock_setattr(struct sock *sk,
1922 const struct cipso_v4_doi *doi_def,
1923 const struct netlbl_lsm_secattr *secattr)
1925 int ret_val = -EPERM;
1926 unsigned char *buf = NULL;
1929 struct ip_options_rcu *old, *opt = NULL;
1930 struct inet_sock *sk_inet;
1931 struct inet_connection_sock *sk_conn;
1933 /* In the case of sock_create_lite(), the sock->sk field is not
1934 * defined yet but it is not a problem as the only users of these
1935 * "lite" PF_INET sockets are functions which do an accept() call
1936 * afterwards so we will label the socket as part of the accept(). */
1940 /* We allocate the maximum CIPSO option size here so we are probably
1941 * being a little wasteful, but it makes our life _much_ easier later
1942 * on and after all we are only talking about 40 bytes. */
1943 buf_len = CIPSO_V4_OPT_LEN_MAX;
1944 buf = kmalloc(buf_len, GFP_ATOMIC);
1947 goto socket_setattr_failure;
1950 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1952 goto socket_setattr_failure;
1955 /* We can't use ip_options_get() directly because it makes a call to
1956 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1957 * we won't always have CAP_NET_RAW even though we _always_ want to
1958 * set the IPOPT_CIPSO option. */
1959 opt_len = (buf_len + 3) & ~3;
1960 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1963 goto socket_setattr_failure;
1965 memcpy(opt->opt.__data, buf, buf_len);
1966 opt->opt.optlen = opt_len;
1967 opt->opt.cipso = sizeof(struct iphdr);
1971 sk_inet = inet_sk(sk);
1973 old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
1974 if (sk_inet->is_icsk) {
1975 sk_conn = inet_csk(sk);
1977 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1978 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1979 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1981 rcu_assign_pointer(sk_inet->inet_opt, opt);
1983 kfree_rcu(old, rcu);
1987 socket_setattr_failure:
1994 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1995 * @req: the connection request socket
1996 * @doi_def: the CIPSO DOI to use
1997 * @secattr: the specific security attributes of the socket
2000 * Set the CIPSO option on the given socket using the DOI definition and
2001 * security attributes passed to the function. Returns zero on success and
2002 * negative values on failure.
2005 int cipso_v4_req_setattr(struct request_sock *req,
2006 const struct cipso_v4_doi *doi_def,
2007 const struct netlbl_lsm_secattr *secattr)
2009 int ret_val = -EPERM;
2010 unsigned char *buf = NULL;
2013 struct ip_options_rcu *opt = NULL;
2014 struct inet_request_sock *req_inet;
2016 /* We allocate the maximum CIPSO option size here so we are probably
2017 * being a little wasteful, but it makes our life _much_ easier later
2018 * on and after all we are only talking about 40 bytes. */
2019 buf_len = CIPSO_V4_OPT_LEN_MAX;
2020 buf = kmalloc(buf_len, GFP_ATOMIC);
2023 goto req_setattr_failure;
2026 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2028 goto req_setattr_failure;
2031 /* We can't use ip_options_get() directly because it makes a call to
2032 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
2033 * we won't always have CAP_NET_RAW even though we _always_ want to
2034 * set the IPOPT_CIPSO option. */
2035 opt_len = (buf_len + 3) & ~3;
2036 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
2039 goto req_setattr_failure;
2041 memcpy(opt->opt.__data, buf, buf_len);
2042 opt->opt.optlen = opt_len;
2043 opt->opt.cipso = sizeof(struct iphdr);
2047 req_inet = inet_rsk(req);
2048 opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt);
2050 kfree_rcu(opt, rcu);
2054 req_setattr_failure:
2061 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
2062 * @opt_ptr: IP option pointer
2065 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
2066 * adjustments to the IP option structure. Returns zero on success, negative
2067 * values on failure.
2070 static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr)
2072 struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1);
2075 if (!opt || opt->opt.cipso == 0)
2077 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
2080 unsigned char *cipso_ptr;
2084 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
2085 cipso_ptr = &opt->opt.__data[cipso_off];
2086 cipso_len = cipso_ptr[1];
2088 if (opt->opt.srr > opt->opt.cipso)
2089 opt->opt.srr -= cipso_len;
2090 if (opt->opt.rr > opt->opt.cipso)
2091 opt->opt.rr -= cipso_len;
2092 if (opt->opt.ts > opt->opt.cipso)
2093 opt->opt.ts -= cipso_len;
2094 if (opt->opt.router_alert > opt->opt.cipso)
2095 opt->opt.router_alert -= cipso_len;
2098 memmove(cipso_ptr, cipso_ptr + cipso_len,
2099 opt->opt.optlen - cipso_off - cipso_len);
2101 /* determining the new total option length is tricky because of
2102 * the padding necessary, the only thing i can think to do at
2103 * this point is walk the options one-by-one, skipping the
2104 * padding at the end to determine the actual option size and
2105 * from there we can determine the new total option length */
2108 while (iter < opt->opt.optlen)
2109 if (opt->opt.__data[iter] != IPOPT_NOP) {
2110 iter += opt->opt.__data[iter + 1];
2114 hdr_delta = opt->opt.optlen;
2115 opt->opt.optlen = (optlen_new + 3) & ~3;
2116 hdr_delta -= opt->opt.optlen;
2118 /* only the cipso option was present on the socket so we can
2119 * remove the entire option struct */
2121 hdr_delta = opt->opt.optlen;
2122 kfree_rcu(opt, rcu);
2129 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2133 * Removes the CIPSO option from a socket, if present.
2136 void cipso_v4_sock_delattr(struct sock *sk)
2138 struct inet_sock *sk_inet;
2141 sk_inet = inet_sk(sk);
2143 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2144 if (sk_inet->is_icsk && hdr_delta > 0) {
2145 struct inet_connection_sock *sk_conn = inet_csk(sk);
2146 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2147 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2152 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2153 * @reg: the request socket
2156 * Removes the CIPSO option from a request socket, if present.
2159 void cipso_v4_req_delattr(struct request_sock *req)
2161 cipso_v4_delopt(&inet_rsk(req)->ireq_opt);
2165 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2166 * @cipso: the CIPSO v4 option
2167 * @secattr: the security attributes
2170 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2171 * on success and negative values on failure.
2174 int cipso_v4_getattr(const unsigned char *cipso,
2175 struct netlbl_lsm_secattr *secattr)
2177 int ret_val = -ENOMSG;
2179 struct cipso_v4_doi *doi_def;
2181 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2184 doi = get_unaligned_be32(&cipso[2]);
2186 doi_def = cipso_v4_doi_search(doi);
2188 goto getattr_return;
2189 /* XXX - This code assumes only one tag per CIPSO option which isn't
2190 * really a good assumption to make but since we only support the MAC
2191 * tags right now it is a safe assumption. */
2193 case CIPSO_V4_TAG_RBITMAP:
2194 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2196 case CIPSO_V4_TAG_ENUM:
2197 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2199 case CIPSO_V4_TAG_RANGE:
2200 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2202 case CIPSO_V4_TAG_LOCAL:
2203 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2207 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2215 * cipso_v4_sock_getattr - Get the security attributes from a sock
2217 * @secattr: the security attributes
2220 * Query @sk to see if there is a CIPSO option attached to the sock and if
2221 * there is return the CIPSO security attributes in @secattr. This function
2222 * requires that @sk be locked, or privately held, but it does not do any
2223 * locking itself. Returns zero on success and negative values on failure.
2226 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2228 struct ip_options_rcu *opt;
2232 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2233 if (opt && opt->opt.cipso)
2234 res = cipso_v4_getattr(opt->opt.__data +
2236 sizeof(struct iphdr),
2243 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2245 * @secattr: the security attributes
2248 * Set the CIPSO option on the given packet based on the security attributes.
2249 * Returns a pointer to the IP header on success and NULL on failure.
2252 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2253 const struct cipso_v4_doi *doi_def,
2254 const struct netlbl_lsm_secattr *secattr)
2258 struct ip_options *opt = &IPCB(skb)->opt;
2259 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2260 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2264 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2268 opt_len = (buf_len + 3) & ~3;
2270 /* we overwrite any existing options to ensure that we have enough
2271 * room for the CIPSO option, the reason is that we _need_ to guarantee
2272 * that the security label is applied to the packet - we do the same
2273 * thing when using the socket options and it hasn't caused a problem,
2274 * if we need to we can always revisit this choice later */
2276 len_delta = opt_len - opt->optlen;
2277 /* if we don't ensure enough headroom we could panic on the skb_push()
2278 * call below so make sure we have enough, we are also "mangling" the
2279 * packet so we should probably do a copy-on-write call anyway */
2280 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2284 if (len_delta > 0) {
2285 /* we assume that the header + opt->optlen have already been
2286 * "pushed" in ip_options_build() or similar */
2288 skb_push(skb, len_delta);
2289 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2290 skb_reset_network_header(skb);
2292 } else if (len_delta < 0) {
2294 memset(iph + 1, IPOPT_NOP, opt->optlen);
2298 if (opt->optlen > 0)
2299 memset(opt, 0, sizeof(*opt));
2300 opt->optlen = opt_len;
2301 opt->cipso = sizeof(struct iphdr);
2302 opt->is_changed = 1;
2304 /* we have to do the following because we are being called from a
2305 * netfilter hook which means the packet already has had the header
2306 * fields populated and the checksum calculated - yes this means we
2307 * are doing more work than needed but we do it to keep the core
2308 * stack clean and tidy */
2309 memcpy(iph + 1, buf, buf_len);
2310 if (opt_len > buf_len)
2311 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2312 if (len_delta != 0) {
2313 iph->ihl = 5 + (opt_len >> 2);
2314 iph->tot_len = htons(skb->len);
2322 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2326 * Removes any and all CIPSO options from the given packet. Returns zero on
2327 * success, negative values on failure.
2330 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2334 struct ip_options *opt = &IPCB(skb)->opt;
2335 unsigned char *cipso_ptr;
2337 if (opt->cipso == 0)
2340 /* since we are changing the packet we should make a copy */
2341 ret_val = skb_cow(skb, skb_headroom(skb));
2345 /* the easiest thing to do is just replace the cipso option with noop
2346 * options since we don't change the size of the packet, although we
2347 * still need to recalculate the checksum */
2350 cipso_ptr = (unsigned char *)iph + opt->cipso;
2351 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2353 opt->is_changed = 1;
2365 * cipso_v4_init - Initialize the CIPSO module
2368 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2369 * and negative values on failure.
2372 static int __init cipso_v4_init(void)
2376 ret_val = cipso_v4_cache_init();
2378 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2384 subsys_initcall(cipso_v4_init);