1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * CIPSO - Commercial IP Security Option
5 * This is an implementation of the CIPSO 2.2 protocol as specified in
6 * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
7 * FIPS-188. While CIPSO never became a full IETF RFC standard many vendors
8 * have chosen to adopt the protocol and over the years it has become a
9 * de-facto standard for labeled networking.
11 * The CIPSO draft specification can be found in the kernel's Documentation
12 * directory as well as the following URL:
13 * https://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt
14 * The FIPS-188 specification can be found at the following URL:
15 * https://www.itl.nist.gov/fipspubs/fip188.htm
17 * Author: Paul Moore <paul.moore@hp.com>
21 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
24 #include <linux/init.h>
25 #include <linux/types.h>
26 #include <linux/rcupdate.h>
27 #include <linux/list.h>
28 #include <linux/spinlock.h>
29 #include <linux/string.h>
30 #include <linux/jhash.h>
31 #include <linux/audit.h>
32 #include <linux/slab.h>
36 #include <net/netlabel.h>
37 #include <net/cipso_ipv4.h>
38 #include <linux/atomic.h>
39 #include <linux/bug.h>
40 #include <asm/unaligned.h>
42 /* List of available DOI definitions */
43 /* XXX - This currently assumes a minimal number of different DOIs in use,
44 * if in practice there are a lot of different DOIs this list should
45 * probably be turned into a hash table or something similar so we
46 * can do quick lookups. */
47 static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
48 static LIST_HEAD(cipso_v4_doi_list);
50 /* Label mapping cache */
51 int cipso_v4_cache_enabled = 1;
52 int cipso_v4_cache_bucketsize = 10;
53 #define CIPSO_V4_CACHE_BUCKETBITS 7
54 #define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS)
55 #define CIPSO_V4_CACHE_REORDERLIMIT 10
56 struct cipso_v4_map_cache_bkt {
59 struct list_head list;
62 struct cipso_v4_map_cache_entry {
67 struct netlbl_lsm_cache *lsm_data;
70 struct list_head list;
73 static struct cipso_v4_map_cache_bkt *cipso_v4_cache;
75 /* Restricted bitmap (tag #1) flags */
76 int cipso_v4_rbm_optfmt = 0;
77 int cipso_v4_rbm_strictvalid = 1;
83 /* Maximum size of the CIPSO IP option, derived from the fact that the maximum
84 * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
85 #define CIPSO_V4_OPT_LEN_MAX 40
87 /* Length of the base CIPSO option, this includes the option type (1 byte), the
88 * option length (1 byte), and the DOI (4 bytes). */
89 #define CIPSO_V4_HDR_LEN 6
91 /* Base length of the restrictive category bitmap tag (tag #1). */
92 #define CIPSO_V4_TAG_RBM_BLEN 4
94 /* Base length of the enumerated category tag (tag #2). */
95 #define CIPSO_V4_TAG_ENUM_BLEN 4
97 /* Base length of the ranged categories bitmap tag (tag #5). */
98 #define CIPSO_V4_TAG_RNG_BLEN 4
99 /* The maximum number of category ranges permitted in the ranged category tag
100 * (tag #5). You may note that the IETF draft states that the maximum number
101 * of category ranges is 7, but if the low end of the last category range is
102 * zero then it is possible to fit 8 category ranges because the zero should
104 #define CIPSO_V4_TAG_RNG_CAT_MAX 8
106 /* Base length of the local tag (non-standard tag).
107 * Tag definition (may change between kernel versions)
110 * +----------+----------+----------+----------+
111 * | 10000000 | 00000110 | 32-bit secid value |
112 * +----------+----------+----------+----------+
113 * | in (host byte order)|
114 * +----------+----------+
117 #define CIPSO_V4_TAG_LOC_BLEN 6
124 * cipso_v4_cache_entry_free - Frees a cache entry
125 * @entry: the entry to free
128 * This function frees the memory associated with a cache entry including the
129 * LSM cache data if there are no longer any users, i.e. reference count == 0.
132 static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
135 netlbl_secattr_cache_free(entry->lsm_data);
141 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
143 * @key_len: the length of the key in bytes
146 * The CIPSO tag hashing function. Returns a 32-bit hash value.
149 static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
151 return jhash(key, key_len, 0);
155 * Label Mapping Cache Functions
159 * cipso_v4_cache_init - Initialize the CIPSO cache
162 * Initializes the CIPSO label mapping cache, this function should be called
163 * before any of the other functions defined in this file. Returns zero on
164 * success, negative values on error.
167 static int __init cipso_v4_cache_init(void)
171 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
172 sizeof(struct cipso_v4_map_cache_bkt),
177 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
178 spin_lock_init(&cipso_v4_cache[iter].lock);
179 cipso_v4_cache[iter].size = 0;
180 INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
187 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
190 * Invalidates and frees any entries in the CIPSO cache. Returns zero on
191 * success and negative values on failure.
194 void cipso_v4_cache_invalidate(void)
196 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
199 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
200 spin_lock_bh(&cipso_v4_cache[iter].lock);
201 list_for_each_entry_safe(entry,
203 &cipso_v4_cache[iter].list, list) {
204 list_del(&entry->list);
205 cipso_v4_cache_entry_free(entry);
207 cipso_v4_cache[iter].size = 0;
208 spin_unlock_bh(&cipso_v4_cache[iter].lock);
213 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
214 * @key: the buffer to check
215 * @key_len: buffer length in bytes
216 * @secattr: the security attribute struct to use
219 * This function checks the cache to see if a label mapping already exists for
220 * the given key. If there is a match then the cache is adjusted and the
221 * @secattr struct is populated with the correct LSM security attributes. The
222 * cache is adjusted in the following manner if the entry is not already the
223 * first in the cache bucket:
225 * 1. The cache entry's activity counter is incremented
226 * 2. The previous (higher ranking) entry's activity counter is decremented
227 * 3. If the difference between the two activity counters is geater than
228 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
230 * Returns zero on success, -ENOENT for a cache miss, and other negative values
234 static int cipso_v4_cache_check(const unsigned char *key,
236 struct netlbl_lsm_secattr *secattr)
239 struct cipso_v4_map_cache_entry *entry;
240 struct cipso_v4_map_cache_entry *prev_entry = NULL;
243 if (!READ_ONCE(cipso_v4_cache_enabled))
246 hash = cipso_v4_map_cache_hash(key, key_len);
247 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
248 spin_lock_bh(&cipso_v4_cache[bkt].lock);
249 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
250 if (entry->hash == hash &&
251 entry->key_len == key_len &&
252 memcmp(entry->key, key, key_len) == 0) {
253 entry->activity += 1;
254 refcount_inc(&entry->lsm_data->refcount);
255 secattr->cache = entry->lsm_data;
256 secattr->flags |= NETLBL_SECATTR_CACHE;
257 secattr->type = NETLBL_NLTYPE_CIPSOV4;
259 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
263 if (prev_entry->activity > 0)
264 prev_entry->activity -= 1;
265 if (entry->activity > prev_entry->activity &&
266 entry->activity - prev_entry->activity >
267 CIPSO_V4_CACHE_REORDERLIMIT) {
268 __list_del(entry->list.prev, entry->list.next);
269 __list_add(&entry->list,
270 prev_entry->list.prev,
274 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
279 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
285 * cipso_v4_cache_add - Add an entry to the CIPSO cache
286 * @cipso_ptr: pointer to CIPSO IP option
287 * @secattr: the packet's security attributes
290 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
291 * head of the cache bucket's list, if the cache bucket is out of room remove
292 * the last entry in the list first. It is important to note that there is
293 * currently no checking for duplicate keys. Returns zero on success,
294 * negative values on failure.
297 int cipso_v4_cache_add(const unsigned char *cipso_ptr,
298 const struct netlbl_lsm_secattr *secattr)
300 int bkt_size = READ_ONCE(cipso_v4_cache_bucketsize);
301 int ret_val = -EPERM;
303 struct cipso_v4_map_cache_entry *entry = NULL;
304 struct cipso_v4_map_cache_entry *old_entry = NULL;
307 if (!READ_ONCE(cipso_v4_cache_enabled) || bkt_size <= 0)
310 cipso_ptr_len = cipso_ptr[1];
312 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
315 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
318 goto cache_add_failure;
320 entry->key_len = cipso_ptr_len;
321 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
322 refcount_inc(&secattr->cache->refcount);
323 entry->lsm_data = secattr->cache;
325 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
326 spin_lock_bh(&cipso_v4_cache[bkt].lock);
327 if (cipso_v4_cache[bkt].size < bkt_size) {
328 list_add(&entry->list, &cipso_v4_cache[bkt].list);
329 cipso_v4_cache[bkt].size += 1;
331 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
332 struct cipso_v4_map_cache_entry, list);
333 list_del(&old_entry->list);
334 list_add(&entry->list, &cipso_v4_cache[bkt].list);
335 cipso_v4_cache_entry_free(old_entry);
337 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
343 cipso_v4_cache_entry_free(entry);
352 * cipso_v4_doi_search - Searches for a DOI definition
353 * @doi: the DOI to search for
356 * Search the DOI definition list for a DOI definition with a DOI value that
357 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
358 * Returns a pointer to the DOI definition on success and NULL on failure.
360 static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
362 struct cipso_v4_doi *iter;
364 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
365 if (iter->doi == doi && refcount_read(&iter->refcount))
371 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
372 * @doi_def: the DOI structure
373 * @audit_info: NetLabel audit information
376 * The caller defines a new DOI for use by the CIPSO engine and calls this
377 * function to add it to the list of acceptable domains. The caller must
378 * ensure that the mapping table specified in @doi_def->map meets all of the
379 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
380 * zero on success and non-zero on failure.
383 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
384 struct netlbl_audit *audit_info)
386 int ret_val = -EINVAL;
390 struct audit_buffer *audit_buf;
393 doi_type = doi_def->type;
395 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
397 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
398 switch (doi_def->tags[iter]) {
399 case CIPSO_V4_TAG_RBITMAP:
401 case CIPSO_V4_TAG_RANGE:
402 case CIPSO_V4_TAG_ENUM:
403 if (doi_def->type != CIPSO_V4_MAP_PASS)
406 case CIPSO_V4_TAG_LOCAL:
407 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
410 case CIPSO_V4_TAG_INVALID:
419 refcount_set(&doi_def->refcount, 1);
421 spin_lock(&cipso_v4_doi_list_lock);
422 if (cipso_v4_doi_search(doi_def->doi)) {
423 spin_unlock(&cipso_v4_doi_list_lock);
427 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
428 spin_unlock(&cipso_v4_doi_list_lock);
432 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
434 const char *type_str;
436 case CIPSO_V4_MAP_TRANS:
439 case CIPSO_V4_MAP_PASS:
442 case CIPSO_V4_MAP_LOCAL:
446 type_str = "(unknown)";
448 audit_log_format(audit_buf,
449 " cipso_doi=%u cipso_type=%s res=%u",
450 doi, type_str, ret_val == 0 ? 1 : 0);
451 audit_log_end(audit_buf);
458 * cipso_v4_doi_free - Frees a DOI definition
459 * @doi_def: the DOI definition
462 * This function frees all of the memory associated with a DOI definition.
465 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
470 switch (doi_def->type) {
471 case CIPSO_V4_MAP_TRANS:
472 kfree(doi_def->map.std->lvl.cipso);
473 kfree(doi_def->map.std->lvl.local);
474 kfree(doi_def->map.std->cat.cipso);
475 kfree(doi_def->map.std->cat.local);
476 kfree(doi_def->map.std);
483 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
484 * @entry: the entry's RCU field
487 * This function is designed to be used as a callback to the call_rcu()
488 * function so that the memory allocated to the DOI definition can be released
492 static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
494 struct cipso_v4_doi *doi_def;
496 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
497 cipso_v4_doi_free(doi_def);
501 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
502 * @doi: the DOI value
503 * @audit_info: NetLabel audit information
506 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
507 * be called to release their own LSM domain mappings as well as our own
508 * domain list. Returns zero on success and negative values on failure.
511 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
514 struct cipso_v4_doi *doi_def;
515 struct audit_buffer *audit_buf;
517 spin_lock(&cipso_v4_doi_list_lock);
518 doi_def = cipso_v4_doi_search(doi);
520 spin_unlock(&cipso_v4_doi_list_lock);
522 goto doi_remove_return;
524 list_del_rcu(&doi_def->list);
525 spin_unlock(&cipso_v4_doi_list_lock);
527 cipso_v4_doi_putdef(doi_def);
531 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
533 audit_log_format(audit_buf,
534 " cipso_doi=%u res=%u",
535 doi, ret_val == 0 ? 1 : 0);
536 audit_log_end(audit_buf);
543 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
544 * @doi: the DOI value
547 * Searches for a valid DOI definition and if one is found it is returned to
548 * the caller. Otherwise NULL is returned. The caller must ensure that
549 * rcu_read_lock() is held while accessing the returned definition and the DOI
550 * definition reference count is decremented when the caller is done.
553 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
555 struct cipso_v4_doi *doi_def;
558 doi_def = cipso_v4_doi_search(doi);
560 goto doi_getdef_return;
561 if (!refcount_inc_not_zero(&doi_def->refcount))
570 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
571 * @doi_def: the DOI definition
574 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
577 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
582 if (!refcount_dec_and_test(&doi_def->refcount))
585 cipso_v4_cache_invalidate();
586 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
590 * cipso_v4_doi_walk - Iterate through the DOI definitions
591 * @skip_cnt: skip past this number of DOI definitions, updated
592 * @callback: callback for each DOI definition
593 * @cb_arg: argument for the callback function
596 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
597 * For each entry call @callback, if @callback returns a negative value stop
598 * 'walking' through the list and return. Updates the value in @skip_cnt upon
599 * return. Returns zero on success, negative values on failure.
602 int cipso_v4_doi_walk(u32 *skip_cnt,
603 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
606 int ret_val = -ENOENT;
608 struct cipso_v4_doi *iter_doi;
611 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
612 if (refcount_read(&iter_doi->refcount) > 0) {
613 if (doi_cnt++ < *skip_cnt)
615 ret_val = callback(iter_doi, cb_arg);
618 goto doi_walk_return;
629 * Label Mapping Functions
633 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
634 * @doi_def: the DOI definition
635 * @level: the level to check
638 * Checks the given level against the given DOI definition and returns a
639 * negative value if the level does not have a valid mapping and a zero value
640 * if the level is defined by the DOI.
643 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
645 switch (doi_def->type) {
646 case CIPSO_V4_MAP_PASS:
648 case CIPSO_V4_MAP_TRANS:
649 if ((level < doi_def->map.std->lvl.cipso_size) &&
650 (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL))
659 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
660 * @doi_def: the DOI definition
661 * @host_lvl: the host MLS level
662 * @net_lvl: the network/CIPSO MLS level
665 * Perform a label mapping to translate a local MLS level to the correct
666 * CIPSO level using the given DOI definition. Returns zero on success,
667 * negative values otherwise.
670 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
674 switch (doi_def->type) {
675 case CIPSO_V4_MAP_PASS:
678 case CIPSO_V4_MAP_TRANS:
679 if (host_lvl < doi_def->map.std->lvl.local_size &&
680 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
681 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
691 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
692 * @doi_def: the DOI definition
693 * @net_lvl: the network/CIPSO MLS level
694 * @host_lvl: the host MLS level
697 * Perform a label mapping to translate a CIPSO level to the correct local MLS
698 * level using the given DOI definition. Returns zero on success, negative
702 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
706 struct cipso_v4_std_map_tbl *map_tbl;
708 switch (doi_def->type) {
709 case CIPSO_V4_MAP_PASS:
712 case CIPSO_V4_MAP_TRANS:
713 map_tbl = doi_def->map.std;
714 if (net_lvl < map_tbl->lvl.cipso_size &&
715 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
716 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
726 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
727 * @doi_def: the DOI definition
728 * @bitmap: category bitmap
729 * @bitmap_len: bitmap length in bytes
732 * Checks the given category bitmap against the given DOI definition and
733 * returns a negative value if any of the categories in the bitmap do not have
734 * a valid mapping and a zero value if all of the categories are valid.
737 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
738 const unsigned char *bitmap,
742 u32 bitmap_len_bits = bitmap_len * 8;
746 switch (doi_def->type) {
747 case CIPSO_V4_MAP_PASS:
749 case CIPSO_V4_MAP_TRANS:
750 cipso_cat_size = doi_def->map.std->cat.cipso_size;
751 cipso_array = doi_def->map.std->cat.cipso;
753 cat = netlbl_bitmap_walk(bitmap,
759 if (cat >= cipso_cat_size ||
760 cipso_array[cat] >= CIPSO_V4_INV_CAT)
773 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
774 * @doi_def: the DOI definition
775 * @secattr: the security attributes
776 * @net_cat: the zero'd out category bitmap in network/CIPSO format
777 * @net_cat_len: the length of the CIPSO bitmap in bytes
780 * Perform a label mapping to translate a local MLS category bitmap to the
781 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
782 * size in bytes of the network bitmap on success, negative values otherwise.
785 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
786 const struct netlbl_lsm_secattr *secattr,
787 unsigned char *net_cat,
791 u32 net_spot = CIPSO_V4_INV_CAT;
792 u32 net_spot_max = 0;
793 u32 net_clen_bits = net_cat_len * 8;
794 u32 host_cat_size = 0;
795 u32 *host_cat_array = NULL;
797 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
798 host_cat_size = doi_def->map.std->cat.local_size;
799 host_cat_array = doi_def->map.std->cat.local;
803 host_spot = netlbl_catmap_walk(secattr->attr.mls.cat,
808 switch (doi_def->type) {
809 case CIPSO_V4_MAP_PASS:
810 net_spot = host_spot;
812 case CIPSO_V4_MAP_TRANS:
813 if (host_spot >= host_cat_size)
815 net_spot = host_cat_array[host_spot];
816 if (net_spot >= CIPSO_V4_INV_CAT)
820 if (net_spot >= net_clen_bits)
822 netlbl_bitmap_setbit(net_cat, net_spot, 1);
824 if (net_spot > net_spot_max)
825 net_spot_max = net_spot;
828 if (++net_spot_max % 8)
829 return net_spot_max / 8 + 1;
830 return net_spot_max / 8;
834 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
835 * @doi_def: the DOI definition
836 * @net_cat: the category bitmap in network/CIPSO format
837 * @net_cat_len: the length of the CIPSO bitmap in bytes
838 * @secattr: the security attributes
841 * Perform a label mapping to translate a CIPSO bitmap to the correct local
842 * MLS category bitmap using the given DOI definition. Returns zero on
843 * success, negative values on failure.
846 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
847 const unsigned char *net_cat,
849 struct netlbl_lsm_secattr *secattr)
853 u32 host_spot = CIPSO_V4_INV_CAT;
854 u32 net_clen_bits = net_cat_len * 8;
855 u32 net_cat_size = 0;
856 u32 *net_cat_array = NULL;
858 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
859 net_cat_size = doi_def->map.std->cat.cipso_size;
860 net_cat_array = doi_def->map.std->cat.cipso;
864 net_spot = netlbl_bitmap_walk(net_cat,
874 switch (doi_def->type) {
875 case CIPSO_V4_MAP_PASS:
876 host_spot = net_spot;
878 case CIPSO_V4_MAP_TRANS:
879 if (net_spot >= net_cat_size)
881 host_spot = net_cat_array[net_spot];
882 if (host_spot >= CIPSO_V4_INV_CAT)
886 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
897 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
898 * @doi_def: the DOI definition
899 * @enumcat: category list
900 * @enumcat_len: length of the category list in bytes
903 * Checks the given categories against the given DOI definition and returns a
904 * negative value if any of the categories do not have a valid mapping and a
905 * zero value if all of the categories are valid.
908 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
909 const unsigned char *enumcat,
916 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
919 for (iter = 0; iter < enumcat_len; iter += 2) {
920 cat = get_unaligned_be16(&enumcat[iter]);
930 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
931 * @doi_def: the DOI definition
932 * @secattr: the security attributes
933 * @net_cat: the zero'd out category list in network/CIPSO format
934 * @net_cat_len: the length of the CIPSO category list in bytes
937 * Perform a label mapping to translate a local MLS category bitmap to the
938 * correct CIPSO category list using the given DOI definition. Returns the
939 * size in bytes of the network category bitmap on success, negative values
943 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
944 const struct netlbl_lsm_secattr *secattr,
945 unsigned char *net_cat,
952 cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1);
955 if ((cat_iter + 2) > net_cat_len)
958 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
966 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
967 * @doi_def: the DOI definition
968 * @net_cat: the category list in network/CIPSO format
969 * @net_cat_len: the length of the CIPSO bitmap in bytes
970 * @secattr: the security attributes
973 * Perform a label mapping to translate a CIPSO category list to the correct
974 * local MLS category bitmap using the given DOI definition. Returns zero on
975 * success, negative values on failure.
978 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
979 const unsigned char *net_cat,
981 struct netlbl_lsm_secattr *secattr)
986 for (iter = 0; iter < net_cat_len; iter += 2) {
987 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
988 get_unaligned_be16(&net_cat[iter]),
998 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
999 * @doi_def: the DOI definition
1000 * @rngcat: category list
1001 * @rngcat_len: length of the category list in bytes
1004 * Checks the given categories against the given DOI definition and returns a
1005 * negative value if any of the categories do not have a valid mapping and a
1006 * zero value if all of the categories are valid.
1009 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1010 const unsigned char *rngcat,
1015 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1018 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1021 for (iter = 0; iter < rngcat_len; iter += 4) {
1022 cat_high = get_unaligned_be16(&rngcat[iter]);
1023 if ((iter + 4) <= rngcat_len)
1024 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
1028 if (cat_high > cat_prev)
1038 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1039 * @doi_def: the DOI definition
1040 * @secattr: the security attributes
1041 * @net_cat: the zero'd out category list in network/CIPSO format
1042 * @net_cat_len: the length of the CIPSO category list in bytes
1045 * Perform a label mapping to translate a local MLS category bitmap to the
1046 * correct CIPSO category list using the given DOI definition. Returns the
1047 * size in bytes of the network category bitmap on success, negative values
1051 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1052 const struct netlbl_lsm_secattr *secattr,
1053 unsigned char *net_cat,
1057 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1061 /* make sure we don't overflow the 'array[]' variable */
1063 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1067 iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1);
1070 cat_size += (iter == 0 ? 0 : sizeof(u16));
1071 if (cat_size > net_cat_len)
1073 array[array_cnt++] = iter;
1075 iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter);
1078 cat_size += sizeof(u16);
1079 if (cat_size > net_cat_len)
1081 array[array_cnt++] = iter;
1084 for (iter = 0; array_cnt > 0;) {
1085 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1088 if (array[array_cnt] != 0) {
1089 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1098 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1099 * @doi_def: the DOI definition
1100 * @net_cat: the category list in network/CIPSO format
1101 * @net_cat_len: the length of the CIPSO bitmap in bytes
1102 * @secattr: the security attributes
1105 * Perform a label mapping to translate a CIPSO category list to the correct
1106 * local MLS category bitmap using the given DOI definition. Returns zero on
1107 * success, negative values on failure.
1110 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1111 const unsigned char *net_cat,
1113 struct netlbl_lsm_secattr *secattr)
1120 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1121 cat_high = get_unaligned_be16(&net_cat[net_iter]);
1122 if ((net_iter + 4) <= net_cat_len)
1123 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
1127 ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat,
1139 * Protocol Handling Functions
1143 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1144 * @doi_def: the DOI definition
1145 * @len: the total tag length in bytes, not including this header
1146 * @buf: the CIPSO option buffer
1149 * Write a CIPSO header into the beginning of @buffer.
1152 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1156 buf[0] = IPOPT_CIPSO;
1157 buf[1] = CIPSO_V4_HDR_LEN + len;
1158 *(__be32 *)&buf[2] = htonl(doi_def->doi);
1162 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1163 * @doi_def: the DOI definition
1164 * @secattr: the security attributes
1165 * @buffer: the option buffer
1166 * @buffer_len: length of buffer in bytes
1169 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1170 * actual buffer length may be larger than the indicated size due to
1171 * translation between host and network category bitmaps. Returns the size of
1172 * the tag on success, negative values on failure.
1175 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1176 const struct netlbl_lsm_secattr *secattr,
1177 unsigned char *buffer,
1184 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1187 ret_val = cipso_v4_map_lvl_hton(doi_def,
1188 secattr->attr.mls.lvl,
1193 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1194 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1201 /* This will send packets using the "optimized" format when
1202 * possible as specified in section 3.4.2.6 of the
1204 if (READ_ONCE(cipso_v4_rbm_optfmt) && ret_val > 0 &&
1208 tag_len = 4 + ret_val;
1212 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1213 buffer[1] = tag_len;
1220 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1221 * @doi_def: the DOI definition
1222 * @tag: the CIPSO tag
1223 * @secattr: the security attributes
1226 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1227 * attributes in @secattr. Return zero on success, negatives values on
1231 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1232 const unsigned char *tag,
1233 struct netlbl_lsm_secattr *secattr)
1236 u8 tag_len = tag[1];
1239 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1242 secattr->attr.mls.lvl = level;
1243 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1246 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1251 netlbl_catmap_free(secattr->attr.mls.cat);
1255 if (secattr->attr.mls.cat)
1256 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1263 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1264 * @doi_def: the DOI definition
1265 * @secattr: the security attributes
1266 * @buffer: the option buffer
1267 * @buffer_len: length of buffer in bytes
1270 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1271 * size of the tag on success, negative values on failure.
1274 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1275 const struct netlbl_lsm_secattr *secattr,
1276 unsigned char *buffer,
1283 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1286 ret_val = cipso_v4_map_lvl_hton(doi_def,
1287 secattr->attr.mls.lvl,
1292 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1293 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1300 tag_len = 4 + ret_val;
1304 buffer[0] = CIPSO_V4_TAG_ENUM;
1305 buffer[1] = tag_len;
1312 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1313 * @doi_def: the DOI definition
1314 * @tag: the CIPSO tag
1315 * @secattr: the security attributes
1318 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1319 * attributes in @secattr. Return zero on success, negatives values on
1323 static int cipso_v4_parsetag_enum(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_enum_ntoh(doi_def,
1343 netlbl_catmap_free(secattr->attr.mls.cat);
1347 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1354 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
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 ranged tag, tag type #5. Returns the
1362 * size of the tag on success, negative values on failure.
1365 static int cipso_v4_gentag_rng(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_rng_hton(doi_def,
1391 tag_len = 4 + ret_val;
1395 buffer[0] = CIPSO_V4_TAG_RANGE;
1396 buffer[1] = tag_len;
1403 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1404 * @doi_def: the DOI definition
1405 * @tag: the CIPSO tag
1406 * @secattr: the security attributes
1409 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1410 * in @secattr. Return zero on success, negatives values on failure.
1413 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1414 const unsigned char *tag,
1415 struct netlbl_lsm_secattr *secattr)
1418 u8 tag_len = tag[1];
1421 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1424 secattr->attr.mls.lvl = level;
1425 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1428 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1433 netlbl_catmap_free(secattr->attr.mls.cat);
1437 if (secattr->attr.mls.cat)
1438 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1445 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
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 local tag. Returns the size of the tag
1453 * on success, negative values on failure.
1456 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1457 const struct netlbl_lsm_secattr *secattr,
1458 unsigned char *buffer,
1461 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1464 buffer[0] = CIPSO_V4_TAG_LOCAL;
1465 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1466 *(u32 *)&buffer[2] = secattr->attr.secid;
1468 return CIPSO_V4_TAG_LOC_BLEN;
1472 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1473 * @doi_def: the DOI definition
1474 * @tag: the CIPSO tag
1475 * @secattr: the security attributes
1478 * Parse a CIPSO local tag and return the security attributes in @secattr.
1479 * Return zero on success, negatives values on failure.
1482 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1483 const unsigned char *tag,
1484 struct netlbl_lsm_secattr *secattr)
1486 secattr->attr.secid = *(u32 *)&tag[2];
1487 secattr->flags |= NETLBL_SECATTR_SECID;
1493 * cipso_v4_optptr - Find the CIPSO option in the packet
1497 * Parse the packet's IP header looking for a CIPSO option. Returns a pointer
1498 * to the start of the CIPSO option on success, NULL if one is not found.
1501 unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
1503 const struct iphdr *iph = ip_hdr(skb);
1504 unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]);
1508 for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
1509 switch (optptr[0]) {
1518 if (!taglen || taglen > optlen)
1520 if (optptr[0] == IPOPT_CIPSO)
1531 * cipso_v4_validate - Validate a CIPSO option
1533 * @option: the start of the option, on error it is set to point to the error
1536 * This routine is called to validate a CIPSO option, it checks all of the
1537 * fields to ensure that they are at least valid, see the draft snippet below
1538 * for details. If the option is valid then a zero value is returned and
1539 * the value of @option is unchanged. If the option is invalid then a
1540 * non-zero value is returned and @option is adjusted to point to the
1541 * offending portion of the option. From the IETF draft ...
1543 * "If any field within the CIPSO options, such as the DOI identifier, is not
1544 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1545 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1546 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1547 * that is unrecognized."
1550 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1552 unsigned char *opt = *option;
1554 unsigned char opt_iter;
1555 unsigned char err_offset = 0;
1558 struct cipso_v4_doi *doi_def = NULL;
1561 /* caller already checks for length values that are too large */
1565 goto validate_return;
1569 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1572 goto validate_return_locked;
1575 opt_iter = CIPSO_V4_HDR_LEN;
1576 tag = opt + opt_iter;
1577 while (opt_iter < opt_len) {
1578 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1579 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1580 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1581 err_offset = opt_iter;
1582 goto validate_return_locked;
1585 if (opt_iter + 1 == opt_len) {
1586 err_offset = opt_iter;
1587 goto validate_return_locked;
1590 if (tag_len > (opt_len - opt_iter)) {
1591 err_offset = opt_iter + 1;
1592 goto validate_return_locked;
1596 case CIPSO_V4_TAG_RBITMAP:
1597 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1598 err_offset = opt_iter + 1;
1599 goto validate_return_locked;
1602 /* We are already going to do all the verification
1603 * necessary at the socket layer so from our point of
1604 * view it is safe to turn these checks off (and less
1605 * work), however, the CIPSO draft says we should do
1606 * all the CIPSO validations here but it doesn't
1607 * really specify _exactly_ what we need to validate
1608 * ... so, just make it a sysctl tunable. */
1609 if (READ_ONCE(cipso_v4_rbm_strictvalid)) {
1610 if (cipso_v4_map_lvl_valid(doi_def,
1612 err_offset = opt_iter + 3;
1613 goto validate_return_locked;
1615 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1616 cipso_v4_map_cat_rbm_valid(doi_def,
1619 err_offset = opt_iter + 4;
1620 goto validate_return_locked;
1624 case CIPSO_V4_TAG_ENUM:
1625 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1626 err_offset = opt_iter + 1;
1627 goto validate_return_locked;
1630 if (cipso_v4_map_lvl_valid(doi_def,
1632 err_offset = opt_iter + 3;
1633 goto validate_return_locked;
1635 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1636 cipso_v4_map_cat_enum_valid(doi_def,
1639 err_offset = opt_iter + 4;
1640 goto validate_return_locked;
1643 case CIPSO_V4_TAG_RANGE:
1644 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1645 err_offset = opt_iter + 1;
1646 goto validate_return_locked;
1649 if (cipso_v4_map_lvl_valid(doi_def,
1651 err_offset = opt_iter + 3;
1652 goto validate_return_locked;
1654 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1655 cipso_v4_map_cat_rng_valid(doi_def,
1658 err_offset = opt_iter + 4;
1659 goto validate_return_locked;
1662 case CIPSO_V4_TAG_LOCAL:
1663 /* This is a non-standard tag that we only allow for
1664 * local connections, so if the incoming interface is
1665 * not the loopback device drop the packet. Further,
1666 * there is no legitimate reason for setting this from
1667 * userspace so reject it if skb is NULL. */
1668 if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) {
1669 err_offset = opt_iter;
1670 goto validate_return_locked;
1672 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1673 err_offset = opt_iter + 1;
1674 goto validate_return_locked;
1678 err_offset = opt_iter;
1679 goto validate_return_locked;
1683 opt_iter += tag_len;
1686 validate_return_locked:
1689 *option = opt + err_offset;
1694 * cipso_v4_error - Send the correct response for a bad packet
1696 * @error: the error code
1697 * @gateway: CIPSO gateway flag
1700 * Based on the error code given in @error, send an ICMP error message back to
1701 * the originating host. From the IETF draft ...
1703 * "If the contents of the CIPSO [option] are valid but the security label is
1704 * outside of the configured host or port label range, the datagram is
1705 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1706 * returned. The code field of the ICMP is set to 'communication with
1707 * destination network administratively prohibited' (code 9) or to
1708 * 'communication with destination host administratively prohibited'
1709 * (code 10). The value of the code is dependent on whether the originator
1710 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1711 * recipient of the ICMP message MUST be able to handle either value. The
1712 * same procedure is performed if a CIPSO [option] can not be added to an
1713 * IP packet because it is too large to fit in the IP options area."
1715 * "If the error is triggered by receipt of an ICMP message, the message is
1716 * discarded and no response is permitted (consistent with general ICMP
1717 * processing rules)."
1720 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1722 unsigned char optbuf[sizeof(struct ip_options) + 40];
1723 struct ip_options *opt = (struct ip_options *)optbuf;
1726 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1730 * We might be called above the IP layer,
1731 * so we can not use icmp_send and IPCB here.
1734 memset(opt, 0, sizeof(struct ip_options));
1735 opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
1737 res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL);
1744 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
1746 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
1750 * cipso_v4_genopt - Generate a CIPSO option
1751 * @buf: the option buffer
1752 * @buf_len: the size of opt_buf
1753 * @doi_def: the CIPSO DOI to use
1754 * @secattr: the security attributes
1757 * Generate a CIPSO option using the DOI definition and security attributes
1758 * passed to the function. Returns the length of the option on success and
1759 * negative values on failure.
1762 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1763 const struct cipso_v4_doi *doi_def,
1764 const struct netlbl_lsm_secattr *secattr)
1769 if (buf_len <= CIPSO_V4_HDR_LEN)
1772 /* XXX - This code assumes only one tag per CIPSO option which isn't
1773 * really a good assumption to make but since we only support the MAC
1774 * tags right now it is a safe assumption. */
1777 memset(buf, 0, buf_len);
1778 switch (doi_def->tags[iter]) {
1779 case CIPSO_V4_TAG_RBITMAP:
1780 ret_val = cipso_v4_gentag_rbm(doi_def,
1782 &buf[CIPSO_V4_HDR_LEN],
1783 buf_len - CIPSO_V4_HDR_LEN);
1785 case CIPSO_V4_TAG_ENUM:
1786 ret_val = cipso_v4_gentag_enum(doi_def,
1788 &buf[CIPSO_V4_HDR_LEN],
1789 buf_len - CIPSO_V4_HDR_LEN);
1791 case CIPSO_V4_TAG_RANGE:
1792 ret_val = cipso_v4_gentag_rng(doi_def,
1794 &buf[CIPSO_V4_HDR_LEN],
1795 buf_len - CIPSO_V4_HDR_LEN);
1797 case CIPSO_V4_TAG_LOCAL:
1798 ret_val = cipso_v4_gentag_loc(doi_def,
1800 &buf[CIPSO_V4_HDR_LEN],
1801 buf_len - CIPSO_V4_HDR_LEN);
1808 } while (ret_val < 0 &&
1809 iter < CIPSO_V4_TAG_MAXCNT &&
1810 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1813 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1814 return CIPSO_V4_HDR_LEN + ret_val;
1818 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1820 * @doi_def: the CIPSO DOI to use
1821 * @secattr: the specific security attributes of the socket
1824 * Set the CIPSO option on the given socket using the DOI definition and
1825 * security attributes passed to the function. This function requires
1826 * exclusive access to @sk, which means it either needs to be in the
1827 * process of being created or locked. Returns zero on success and negative
1828 * values on failure.
1831 int cipso_v4_sock_setattr(struct sock *sk,
1832 const struct cipso_v4_doi *doi_def,
1833 const struct netlbl_lsm_secattr *secattr)
1835 int ret_val = -EPERM;
1836 unsigned char *buf = NULL;
1839 struct ip_options_rcu *old, *opt = NULL;
1840 struct inet_sock *sk_inet;
1841 struct inet_connection_sock *sk_conn;
1843 /* In the case of sock_create_lite(), the sock->sk field is not
1844 * defined yet but it is not a problem as the only users of these
1845 * "lite" PF_INET sockets are functions which do an accept() call
1846 * afterwards so we will label the socket as part of the accept(). */
1850 /* We allocate the maximum CIPSO option size here so we are probably
1851 * being a little wasteful, but it makes our life _much_ easier later
1852 * on and after all we are only talking about 40 bytes. */
1853 buf_len = CIPSO_V4_OPT_LEN_MAX;
1854 buf = kmalloc(buf_len, GFP_ATOMIC);
1857 goto socket_setattr_failure;
1860 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1862 goto socket_setattr_failure;
1865 /* We can't use ip_options_get() directly because it makes a call to
1866 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1867 * we won't always have CAP_NET_RAW even though we _always_ want to
1868 * set the IPOPT_CIPSO option. */
1869 opt_len = (buf_len + 3) & ~3;
1870 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1873 goto socket_setattr_failure;
1875 memcpy(opt->opt.__data, buf, buf_len);
1876 opt->opt.optlen = opt_len;
1877 opt->opt.cipso = sizeof(struct iphdr);
1881 sk_inet = inet_sk(sk);
1883 old = rcu_dereference_protected(sk_inet->inet_opt,
1884 lockdep_sock_is_held(sk));
1885 if (sk_inet->is_icsk) {
1886 sk_conn = inet_csk(sk);
1888 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1889 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1890 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1892 rcu_assign_pointer(sk_inet->inet_opt, opt);
1894 kfree_rcu(old, rcu);
1898 socket_setattr_failure:
1905 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1906 * @req: the connection request socket
1907 * @doi_def: the CIPSO DOI to use
1908 * @secattr: the specific security attributes of the socket
1911 * Set the CIPSO option on the given socket using the DOI definition and
1912 * security attributes passed to the function. Returns zero on success and
1913 * negative values on failure.
1916 int cipso_v4_req_setattr(struct request_sock *req,
1917 const struct cipso_v4_doi *doi_def,
1918 const struct netlbl_lsm_secattr *secattr)
1920 int ret_val = -EPERM;
1921 unsigned char *buf = NULL;
1924 struct ip_options_rcu *opt = NULL;
1925 struct inet_request_sock *req_inet;
1927 /* We allocate the maximum CIPSO option size here so we are probably
1928 * being a little wasteful, but it makes our life _much_ easier later
1929 * on and after all we are only talking about 40 bytes. */
1930 buf_len = CIPSO_V4_OPT_LEN_MAX;
1931 buf = kmalloc(buf_len, GFP_ATOMIC);
1934 goto req_setattr_failure;
1937 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1939 goto req_setattr_failure;
1942 /* We can't use ip_options_get() directly because it makes a call to
1943 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1944 * we won't always have CAP_NET_RAW even though we _always_ want to
1945 * set the IPOPT_CIPSO option. */
1946 opt_len = (buf_len + 3) & ~3;
1947 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1950 goto req_setattr_failure;
1952 memcpy(opt->opt.__data, buf, buf_len);
1953 opt->opt.optlen = opt_len;
1954 opt->opt.cipso = sizeof(struct iphdr);
1958 req_inet = inet_rsk(req);
1959 opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt);
1961 kfree_rcu(opt, rcu);
1965 req_setattr_failure:
1972 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
1973 * @opt_ptr: IP option pointer
1976 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
1977 * adjustments to the IP option structure. Returns zero on success, negative
1978 * values on failure.
1981 static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr)
1983 struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1);
1986 if (!opt || opt->opt.cipso == 0)
1988 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
1991 unsigned char *cipso_ptr;
1995 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
1996 cipso_ptr = &opt->opt.__data[cipso_off];
1997 cipso_len = cipso_ptr[1];
1999 if (opt->opt.srr > opt->opt.cipso)
2000 opt->opt.srr -= cipso_len;
2001 if (opt->opt.rr > opt->opt.cipso)
2002 opt->opt.rr -= cipso_len;
2003 if (opt->opt.ts > opt->opt.cipso)
2004 opt->opt.ts -= cipso_len;
2005 if (opt->opt.router_alert > opt->opt.cipso)
2006 opt->opt.router_alert -= cipso_len;
2009 memmove(cipso_ptr, cipso_ptr + cipso_len,
2010 opt->opt.optlen - cipso_off - cipso_len);
2012 /* determining the new total option length is tricky because of
2013 * the padding necessary, the only thing i can think to do at
2014 * this point is walk the options one-by-one, skipping the
2015 * padding at the end to determine the actual option size and
2016 * from there we can determine the new total option length */
2019 while (iter < opt->opt.optlen)
2020 if (opt->opt.__data[iter] != IPOPT_NOP) {
2021 iter += opt->opt.__data[iter + 1];
2025 hdr_delta = opt->opt.optlen;
2026 opt->opt.optlen = (optlen_new + 3) & ~3;
2027 hdr_delta -= opt->opt.optlen;
2029 /* only the cipso option was present on the socket so we can
2030 * remove the entire option struct */
2032 hdr_delta = opt->opt.optlen;
2033 kfree_rcu(opt, rcu);
2040 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2044 * Removes the CIPSO option from a socket, if present.
2047 void cipso_v4_sock_delattr(struct sock *sk)
2049 struct inet_sock *sk_inet;
2052 sk_inet = inet_sk(sk);
2054 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2055 if (sk_inet->is_icsk && hdr_delta > 0) {
2056 struct inet_connection_sock *sk_conn = inet_csk(sk);
2057 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2058 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2063 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2064 * @req: the request socket
2067 * Removes the CIPSO option from a request socket, if present.
2070 void cipso_v4_req_delattr(struct request_sock *req)
2072 cipso_v4_delopt(&inet_rsk(req)->ireq_opt);
2076 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2077 * @cipso: the CIPSO v4 option
2078 * @secattr: the security attributes
2081 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2082 * on success and negative values on failure.
2085 int cipso_v4_getattr(const unsigned char *cipso,
2086 struct netlbl_lsm_secattr *secattr)
2088 int ret_val = -ENOMSG;
2090 struct cipso_v4_doi *doi_def;
2092 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2095 doi = get_unaligned_be32(&cipso[2]);
2097 doi_def = cipso_v4_doi_search(doi);
2099 goto getattr_return;
2100 /* XXX - This code assumes only one tag per CIPSO option which isn't
2101 * really a good assumption to make but since we only support the MAC
2102 * tags right now it is a safe assumption. */
2104 case CIPSO_V4_TAG_RBITMAP:
2105 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2107 case CIPSO_V4_TAG_ENUM:
2108 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2110 case CIPSO_V4_TAG_RANGE:
2111 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2113 case CIPSO_V4_TAG_LOCAL:
2114 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2118 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2126 * cipso_v4_sock_getattr - Get the security attributes from a sock
2128 * @secattr: the security attributes
2131 * Query @sk to see if there is a CIPSO option attached to the sock and if
2132 * there is return the CIPSO security attributes in @secattr. This function
2133 * requires that @sk be locked, or privately held, but it does not do any
2134 * locking itself. Returns zero on success and negative values on failure.
2137 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2139 struct ip_options_rcu *opt;
2143 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2144 if (opt && opt->opt.cipso)
2145 res = cipso_v4_getattr(opt->opt.__data +
2147 sizeof(struct iphdr),
2154 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2156 * @doi_def: the DOI structure
2157 * @secattr: the security attributes
2160 * Set the CIPSO option on the given packet based on the security attributes.
2161 * Returns a pointer to the IP header on success and NULL on failure.
2164 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2165 const struct cipso_v4_doi *doi_def,
2166 const struct netlbl_lsm_secattr *secattr)
2170 struct ip_options *opt = &IPCB(skb)->opt;
2171 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2172 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2176 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2180 opt_len = (buf_len + 3) & ~3;
2182 /* we overwrite any existing options to ensure that we have enough
2183 * room for the CIPSO option, the reason is that we _need_ to guarantee
2184 * that the security label is applied to the packet - we do the same
2185 * thing when using the socket options and it hasn't caused a problem,
2186 * if we need to we can always revisit this choice later */
2188 len_delta = opt_len - opt->optlen;
2189 /* if we don't ensure enough headroom we could panic on the skb_push()
2190 * call below so make sure we have enough, we are also "mangling" the
2191 * packet so we should probably do a copy-on-write call anyway */
2192 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2196 if (len_delta > 0) {
2197 /* we assume that the header + opt->optlen have already been
2198 * "pushed" in ip_options_build() or similar */
2200 skb_push(skb, len_delta);
2201 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2202 skb_reset_network_header(skb);
2204 } else if (len_delta < 0) {
2206 memset(iph + 1, IPOPT_NOP, opt->optlen);
2210 if (opt->optlen > 0)
2211 memset(opt, 0, sizeof(*opt));
2212 opt->optlen = opt_len;
2213 opt->cipso = sizeof(struct iphdr);
2214 opt->is_changed = 1;
2216 /* we have to do the following because we are being called from a
2217 * netfilter hook which means the packet already has had the header
2218 * fields populated and the checksum calculated - yes this means we
2219 * are doing more work than needed but we do it to keep the core
2220 * stack clean and tidy */
2221 memcpy(iph + 1, buf, buf_len);
2222 if (opt_len > buf_len)
2223 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2224 if (len_delta != 0) {
2225 iph->ihl = 5 + (opt_len >> 2);
2226 iph->tot_len = htons(skb->len);
2234 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2238 * Removes any and all CIPSO options from the given packet. Returns zero on
2239 * success, negative values on failure.
2242 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2246 struct ip_options *opt = &IPCB(skb)->opt;
2247 unsigned char *cipso_ptr;
2249 if (opt->cipso == 0)
2252 /* since we are changing the packet we should make a copy */
2253 ret_val = skb_cow(skb, skb_headroom(skb));
2257 /* the easiest thing to do is just replace the cipso option with noop
2258 * options since we don't change the size of the packet, although we
2259 * still need to recalculate the checksum */
2262 cipso_ptr = (unsigned char *)iph + opt->cipso;
2263 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2265 opt->is_changed = 1;
2277 * cipso_v4_init - Initialize the CIPSO module
2280 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2281 * and negative values on failure.
2284 static int __init cipso_v4_init(void)
2288 ret_val = cipso_v4_cache_init();
2290 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2296 subsys_initcall(cipso_v4_init);