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 (!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 ret_val = -EPERM;
302 struct cipso_v4_map_cache_entry *entry = NULL;
303 struct cipso_v4_map_cache_entry *old_entry = NULL;
306 if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
309 cipso_ptr_len = cipso_ptr[1];
311 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
314 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
317 goto cache_add_failure;
319 entry->key_len = cipso_ptr_len;
320 entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
321 refcount_inc(&secattr->cache->refcount);
322 entry->lsm_data = secattr->cache;
324 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
325 spin_lock_bh(&cipso_v4_cache[bkt].lock);
326 if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
327 list_add(&entry->list, &cipso_v4_cache[bkt].list);
328 cipso_v4_cache[bkt].size += 1;
330 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
331 struct cipso_v4_map_cache_entry, list);
332 list_del(&old_entry->list);
333 list_add(&entry->list, &cipso_v4_cache[bkt].list);
334 cipso_v4_cache_entry_free(old_entry);
336 spin_unlock_bh(&cipso_v4_cache[bkt].lock);
342 cipso_v4_cache_entry_free(entry);
351 * cipso_v4_doi_search - Searches for a DOI definition
352 * @doi: the DOI to search for
355 * Search the DOI definition list for a DOI definition with a DOI value that
356 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
357 * Returns a pointer to the DOI definition on success and NULL on failure.
359 static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
361 struct cipso_v4_doi *iter;
363 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
364 if (iter->doi == doi && refcount_read(&iter->refcount))
370 * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
371 * @doi_def: the DOI structure
372 * @audit_info: NetLabel audit information
375 * The caller defines a new DOI for use by the CIPSO engine and calls this
376 * function to add it to the list of acceptable domains. The caller must
377 * ensure that the mapping table specified in @doi_def->map meets all of the
378 * requirements of the mapping type (see cipso_ipv4.h for details). Returns
379 * zero on success and non-zero on failure.
382 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
383 struct netlbl_audit *audit_info)
385 int ret_val = -EINVAL;
389 struct audit_buffer *audit_buf;
392 doi_type = doi_def->type;
394 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
396 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
397 switch (doi_def->tags[iter]) {
398 case CIPSO_V4_TAG_RBITMAP:
400 case CIPSO_V4_TAG_RANGE:
401 case CIPSO_V4_TAG_ENUM:
402 if (doi_def->type != CIPSO_V4_MAP_PASS)
405 case CIPSO_V4_TAG_LOCAL:
406 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
409 case CIPSO_V4_TAG_INVALID:
418 refcount_set(&doi_def->refcount, 1);
420 spin_lock(&cipso_v4_doi_list_lock);
421 if (cipso_v4_doi_search(doi_def->doi)) {
422 spin_unlock(&cipso_v4_doi_list_lock);
426 list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
427 spin_unlock(&cipso_v4_doi_list_lock);
431 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
433 const char *type_str;
435 case CIPSO_V4_MAP_TRANS:
438 case CIPSO_V4_MAP_PASS:
441 case CIPSO_V4_MAP_LOCAL:
445 type_str = "(unknown)";
447 audit_log_format(audit_buf,
448 " cipso_doi=%u cipso_type=%s res=%u",
449 doi, type_str, ret_val == 0 ? 1 : 0);
450 audit_log_end(audit_buf);
457 * cipso_v4_doi_free - Frees a DOI definition
458 * @doi_def: the DOI definition
461 * This function frees all of the memory associated with a DOI definition.
464 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
469 switch (doi_def->type) {
470 case CIPSO_V4_MAP_TRANS:
471 kfree(doi_def->map.std->lvl.cipso);
472 kfree(doi_def->map.std->lvl.local);
473 kfree(doi_def->map.std->cat.cipso);
474 kfree(doi_def->map.std->cat.local);
475 kfree(doi_def->map.std);
482 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
483 * @entry: the entry's RCU field
486 * This function is designed to be used as a callback to the call_rcu()
487 * function so that the memory allocated to the DOI definition can be released
491 static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
493 struct cipso_v4_doi *doi_def;
495 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
496 cipso_v4_doi_free(doi_def);
500 * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
501 * @doi: the DOI value
502 * @audit_info: NetLabel audit information
505 * Removes a DOI definition from the CIPSO engine. The NetLabel routines will
506 * be called to release their own LSM domain mappings as well as our own
507 * domain list. Returns zero on success and negative values on failure.
510 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
513 struct cipso_v4_doi *doi_def;
514 struct audit_buffer *audit_buf;
516 spin_lock(&cipso_v4_doi_list_lock);
517 doi_def = cipso_v4_doi_search(doi);
519 spin_unlock(&cipso_v4_doi_list_lock);
521 goto doi_remove_return;
523 list_del_rcu(&doi_def->list);
524 spin_unlock(&cipso_v4_doi_list_lock);
526 cipso_v4_doi_putdef(doi_def);
530 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
532 audit_log_format(audit_buf,
533 " cipso_doi=%u res=%u",
534 doi, ret_val == 0 ? 1 : 0);
535 audit_log_end(audit_buf);
542 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
543 * @doi: the DOI value
546 * Searches for a valid DOI definition and if one is found it is returned to
547 * the caller. Otherwise NULL is returned. The caller must ensure that
548 * rcu_read_lock() is held while accessing the returned definition and the DOI
549 * definition reference count is decremented when the caller is done.
552 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
554 struct cipso_v4_doi *doi_def;
557 doi_def = cipso_v4_doi_search(doi);
559 goto doi_getdef_return;
560 if (!refcount_inc_not_zero(&doi_def->refcount))
569 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
570 * @doi_def: the DOI definition
573 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
576 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
581 if (!refcount_dec_and_test(&doi_def->refcount))
584 cipso_v4_cache_invalidate();
585 call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
589 * cipso_v4_doi_walk - Iterate through the DOI definitions
590 * @skip_cnt: skip past this number of DOI definitions, updated
591 * @callback: callback for each DOI definition
592 * @cb_arg: argument for the callback function
595 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
596 * For each entry call @callback, if @callback returns a negative value stop
597 * 'walking' through the list and return. Updates the value in @skip_cnt upon
598 * return. Returns zero on success, negative values on failure.
601 int cipso_v4_doi_walk(u32 *skip_cnt,
602 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
605 int ret_val = -ENOENT;
607 struct cipso_v4_doi *iter_doi;
610 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
611 if (refcount_read(&iter_doi->refcount) > 0) {
612 if (doi_cnt++ < *skip_cnt)
614 ret_val = callback(iter_doi, cb_arg);
617 goto doi_walk_return;
628 * Label Mapping Functions
632 * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
633 * @doi_def: the DOI definition
634 * @level: the level to check
637 * Checks the given level against the given DOI definition and returns a
638 * negative value if the level does not have a valid mapping and a zero value
639 * if the level is defined by the DOI.
642 static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
644 switch (doi_def->type) {
645 case CIPSO_V4_MAP_PASS:
647 case CIPSO_V4_MAP_TRANS:
648 if ((level < doi_def->map.std->lvl.cipso_size) &&
649 (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL))
658 * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
659 * @doi_def: the DOI definition
660 * @host_lvl: the host MLS level
661 * @net_lvl: the network/CIPSO MLS level
664 * Perform a label mapping to translate a local MLS level to the correct
665 * CIPSO level using the given DOI definition. Returns zero on success,
666 * negative values otherwise.
669 static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
673 switch (doi_def->type) {
674 case CIPSO_V4_MAP_PASS:
677 case CIPSO_V4_MAP_TRANS:
678 if (host_lvl < doi_def->map.std->lvl.local_size &&
679 doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
680 *net_lvl = doi_def->map.std->lvl.local[host_lvl];
690 * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
691 * @doi_def: the DOI definition
692 * @net_lvl: the network/CIPSO MLS level
693 * @host_lvl: the host MLS level
696 * Perform a label mapping to translate a CIPSO level to the correct local MLS
697 * level using the given DOI definition. Returns zero on success, negative
701 static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
705 struct cipso_v4_std_map_tbl *map_tbl;
707 switch (doi_def->type) {
708 case CIPSO_V4_MAP_PASS:
711 case CIPSO_V4_MAP_TRANS:
712 map_tbl = doi_def->map.std;
713 if (net_lvl < map_tbl->lvl.cipso_size &&
714 map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
715 *host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
725 * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
726 * @doi_def: the DOI definition
727 * @bitmap: category bitmap
728 * @bitmap_len: bitmap length in bytes
731 * Checks the given category bitmap against the given DOI definition and
732 * returns a negative value if any of the categories in the bitmap do not have
733 * a valid mapping and a zero value if all of the categories are valid.
736 static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
737 const unsigned char *bitmap,
741 u32 bitmap_len_bits = bitmap_len * 8;
745 switch (doi_def->type) {
746 case CIPSO_V4_MAP_PASS:
748 case CIPSO_V4_MAP_TRANS:
749 cipso_cat_size = doi_def->map.std->cat.cipso_size;
750 cipso_array = doi_def->map.std->cat.cipso;
752 cat = netlbl_bitmap_walk(bitmap,
758 if (cat >= cipso_cat_size ||
759 cipso_array[cat] >= CIPSO_V4_INV_CAT)
772 * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
773 * @doi_def: the DOI definition
774 * @secattr: the security attributes
775 * @net_cat: the zero'd out category bitmap in network/CIPSO format
776 * @net_cat_len: the length of the CIPSO bitmap in bytes
779 * Perform a label mapping to translate a local MLS category bitmap to the
780 * correct CIPSO bitmap using the given DOI definition. Returns the minimum
781 * size in bytes of the network bitmap on success, negative values otherwise.
784 static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
785 const struct netlbl_lsm_secattr *secattr,
786 unsigned char *net_cat,
790 u32 net_spot = CIPSO_V4_INV_CAT;
791 u32 net_spot_max = 0;
792 u32 net_clen_bits = net_cat_len * 8;
793 u32 host_cat_size = 0;
794 u32 *host_cat_array = NULL;
796 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
797 host_cat_size = doi_def->map.std->cat.local_size;
798 host_cat_array = doi_def->map.std->cat.local;
802 host_spot = netlbl_catmap_walk(secattr->attr.mls.cat,
807 switch (doi_def->type) {
808 case CIPSO_V4_MAP_PASS:
809 net_spot = host_spot;
811 case CIPSO_V4_MAP_TRANS:
812 if (host_spot >= host_cat_size)
814 net_spot = host_cat_array[host_spot];
815 if (net_spot >= CIPSO_V4_INV_CAT)
819 if (net_spot >= net_clen_bits)
821 netlbl_bitmap_setbit(net_cat, net_spot, 1);
823 if (net_spot > net_spot_max)
824 net_spot_max = net_spot;
827 if (++net_spot_max % 8)
828 return net_spot_max / 8 + 1;
829 return net_spot_max / 8;
833 * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
834 * @doi_def: the DOI definition
835 * @net_cat: the category bitmap in network/CIPSO format
836 * @net_cat_len: the length of the CIPSO bitmap in bytes
837 * @secattr: the security attributes
840 * Perform a label mapping to translate a CIPSO bitmap to the correct local
841 * MLS category bitmap using the given DOI definition. Returns zero on
842 * success, negative values on failure.
845 static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
846 const unsigned char *net_cat,
848 struct netlbl_lsm_secattr *secattr)
852 u32 host_spot = CIPSO_V4_INV_CAT;
853 u32 net_clen_bits = net_cat_len * 8;
854 u32 net_cat_size = 0;
855 u32 *net_cat_array = NULL;
857 if (doi_def->type == CIPSO_V4_MAP_TRANS) {
858 net_cat_size = doi_def->map.std->cat.cipso_size;
859 net_cat_array = doi_def->map.std->cat.cipso;
863 net_spot = netlbl_bitmap_walk(net_cat,
873 switch (doi_def->type) {
874 case CIPSO_V4_MAP_PASS:
875 host_spot = net_spot;
877 case CIPSO_V4_MAP_TRANS:
878 if (net_spot >= net_cat_size)
880 host_spot = net_cat_array[net_spot];
881 if (host_spot >= CIPSO_V4_INV_CAT)
885 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
896 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
897 * @doi_def: the DOI definition
898 * @enumcat: category list
899 * @enumcat_len: length of the category list in bytes
902 * Checks the given categories against the given DOI definition and returns a
903 * negative value if any of the categories do not have a valid mapping and a
904 * zero value if all of the categories are valid.
907 static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
908 const unsigned char *enumcat,
915 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
918 for (iter = 0; iter < enumcat_len; iter += 2) {
919 cat = get_unaligned_be16(&enumcat[iter]);
929 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
930 * @doi_def: the DOI definition
931 * @secattr: the security attributes
932 * @net_cat: the zero'd out category list in network/CIPSO format
933 * @net_cat_len: the length of the CIPSO category list in bytes
936 * Perform a label mapping to translate a local MLS category bitmap to the
937 * correct CIPSO category list using the given DOI definition. Returns the
938 * size in bytes of the network category bitmap on success, negative values
942 static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
943 const struct netlbl_lsm_secattr *secattr,
944 unsigned char *net_cat,
951 cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1);
954 if ((cat_iter + 2) > net_cat_len)
957 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
965 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
966 * @doi_def: the DOI definition
967 * @net_cat: the category list in network/CIPSO format
968 * @net_cat_len: the length of the CIPSO bitmap in bytes
969 * @secattr: the security attributes
972 * Perform a label mapping to translate a CIPSO category list to the correct
973 * local MLS category bitmap using the given DOI definition. Returns zero on
974 * success, negative values on failure.
977 static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
978 const unsigned char *net_cat,
980 struct netlbl_lsm_secattr *secattr)
985 for (iter = 0; iter < net_cat_len; iter += 2) {
986 ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
987 get_unaligned_be16(&net_cat[iter]),
997 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
998 * @doi_def: the DOI definition
999 * @rngcat: category list
1000 * @rngcat_len: length of the category list in bytes
1003 * Checks the given categories against the given DOI definition and returns a
1004 * negative value if any of the categories do not have a valid mapping and a
1005 * zero value if all of the categories are valid.
1008 static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1009 const unsigned char *rngcat,
1014 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1017 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1020 for (iter = 0; iter < rngcat_len; iter += 4) {
1021 cat_high = get_unaligned_be16(&rngcat[iter]);
1022 if ((iter + 4) <= rngcat_len)
1023 cat_low = get_unaligned_be16(&rngcat[iter + 2]);
1027 if (cat_high > cat_prev)
1037 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1038 * @doi_def: the DOI definition
1039 * @secattr: the security attributes
1040 * @net_cat: the zero'd out category list in network/CIPSO format
1041 * @net_cat_len: the length of the CIPSO category list in bytes
1044 * Perform a label mapping to translate a local MLS category bitmap to the
1045 * correct CIPSO category list using the given DOI definition. Returns the
1046 * size in bytes of the network category bitmap on success, negative values
1050 static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1051 const struct netlbl_lsm_secattr *secattr,
1052 unsigned char *net_cat,
1056 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1060 /* make sure we don't overflow the 'array[]' variable */
1062 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1066 iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1);
1069 cat_size += (iter == 0 ? 0 : sizeof(u16));
1070 if (cat_size > net_cat_len)
1072 array[array_cnt++] = iter;
1074 iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter);
1077 cat_size += sizeof(u16);
1078 if (cat_size > net_cat_len)
1080 array[array_cnt++] = iter;
1083 for (iter = 0; array_cnt > 0;) {
1084 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1087 if (array[array_cnt] != 0) {
1088 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1097 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1098 * @doi_def: the DOI definition
1099 * @net_cat: the category list in network/CIPSO format
1100 * @net_cat_len: the length of the CIPSO bitmap in bytes
1101 * @secattr: the security attributes
1104 * Perform a label mapping to translate a CIPSO category list to the correct
1105 * local MLS category bitmap using the given DOI definition. Returns zero on
1106 * success, negative values on failure.
1109 static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1110 const unsigned char *net_cat,
1112 struct netlbl_lsm_secattr *secattr)
1119 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1120 cat_high = get_unaligned_be16(&net_cat[net_iter]);
1121 if ((net_iter + 4) <= net_cat_len)
1122 cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
1126 ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat,
1138 * Protocol Handling Functions
1142 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1143 * @doi_def: the DOI definition
1144 * @len: the total tag length in bytes, not including this header
1145 * @buf: the CIPSO option buffer
1148 * Write a CIPSO header into the beginning of @buffer.
1151 static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1155 buf[0] = IPOPT_CIPSO;
1156 buf[1] = CIPSO_V4_HDR_LEN + len;
1157 put_unaligned_be32(doi_def->doi, &buf[2]);
1161 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1162 * @doi_def: the DOI definition
1163 * @secattr: the security attributes
1164 * @buffer: the option buffer
1165 * @buffer_len: length of buffer in bytes
1168 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1169 * actual buffer length may be larger than the indicated size due to
1170 * translation between host and network category bitmaps. Returns the size of
1171 * the tag on success, negative values on failure.
1174 static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1175 const struct netlbl_lsm_secattr *secattr,
1176 unsigned char *buffer,
1183 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1186 ret_val = cipso_v4_map_lvl_hton(doi_def,
1187 secattr->attr.mls.lvl,
1192 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1193 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1200 /* This will send packets using the "optimized" format when
1201 * possible as specified in section 3.4.2.6 of the
1203 if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
1206 tag_len = 4 + ret_val;
1210 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1211 buffer[1] = tag_len;
1218 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1219 * @doi_def: the DOI definition
1220 * @tag: the CIPSO tag
1221 * @secattr: the security attributes
1224 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1225 * attributes in @secattr. Return zero on success, negatives values on
1229 static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1230 const unsigned char *tag,
1231 struct netlbl_lsm_secattr *secattr)
1234 u8 tag_len = tag[1];
1237 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1240 secattr->attr.mls.lvl = level;
1241 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1244 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1249 netlbl_catmap_free(secattr->attr.mls.cat);
1253 if (secattr->attr.mls.cat)
1254 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1261 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1262 * @doi_def: the DOI definition
1263 * @secattr: the security attributes
1264 * @buffer: the option buffer
1265 * @buffer_len: length of buffer in bytes
1268 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1269 * size of the tag on success, negative values on failure.
1272 static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1273 const struct netlbl_lsm_secattr *secattr,
1274 unsigned char *buffer,
1281 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1284 ret_val = cipso_v4_map_lvl_hton(doi_def,
1285 secattr->attr.mls.lvl,
1290 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1291 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1298 tag_len = 4 + ret_val;
1302 buffer[0] = CIPSO_V4_TAG_ENUM;
1303 buffer[1] = tag_len;
1310 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1311 * @doi_def: the DOI definition
1312 * @tag: the CIPSO tag
1313 * @secattr: the security attributes
1316 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1317 * attributes in @secattr. Return zero on success, negatives values on
1321 static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1322 const unsigned char *tag,
1323 struct netlbl_lsm_secattr *secattr)
1326 u8 tag_len = tag[1];
1329 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1332 secattr->attr.mls.lvl = level;
1333 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1336 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1341 netlbl_catmap_free(secattr->attr.mls.cat);
1345 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1352 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1353 * @doi_def: the DOI definition
1354 * @secattr: the security attributes
1355 * @buffer: the option buffer
1356 * @buffer_len: length of buffer in bytes
1359 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1360 * size of the tag on success, negative values on failure.
1363 static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1364 const struct netlbl_lsm_secattr *secattr,
1365 unsigned char *buffer,
1372 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1375 ret_val = cipso_v4_map_lvl_hton(doi_def,
1376 secattr->attr.mls.lvl,
1381 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1382 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1389 tag_len = 4 + ret_val;
1393 buffer[0] = CIPSO_V4_TAG_RANGE;
1394 buffer[1] = tag_len;
1401 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1402 * @doi_def: the DOI definition
1403 * @tag: the CIPSO tag
1404 * @secattr: the security attributes
1407 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1408 * in @secattr. Return zero on success, negatives values on failure.
1411 static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1412 const unsigned char *tag,
1413 struct netlbl_lsm_secattr *secattr)
1416 u8 tag_len = tag[1];
1419 ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
1422 secattr->attr.mls.lvl = level;
1423 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1426 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1431 netlbl_catmap_free(secattr->attr.mls.cat);
1435 if (secattr->attr.mls.cat)
1436 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1443 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1444 * @doi_def: the DOI definition
1445 * @secattr: the security attributes
1446 * @buffer: the option buffer
1447 * @buffer_len: length of buffer in bytes
1450 * Generate a CIPSO option using the local tag. Returns the size of the tag
1451 * on success, negative values on failure.
1454 static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1455 const struct netlbl_lsm_secattr *secattr,
1456 unsigned char *buffer,
1459 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1462 buffer[0] = CIPSO_V4_TAG_LOCAL;
1463 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1464 *(u32 *)&buffer[2] = secattr->attr.secid;
1466 return CIPSO_V4_TAG_LOC_BLEN;
1470 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1471 * @doi_def: the DOI definition
1472 * @tag: the CIPSO tag
1473 * @secattr: the security attributes
1476 * Parse a CIPSO local tag and return the security attributes in @secattr.
1477 * Return zero on success, negatives values on failure.
1480 static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1481 const unsigned char *tag,
1482 struct netlbl_lsm_secattr *secattr)
1484 secattr->attr.secid = *(u32 *)&tag[2];
1485 secattr->flags |= NETLBL_SECATTR_SECID;
1491 * cipso_v4_optptr - Find the CIPSO option in the packet
1495 * Parse the packet's IP header looking for a CIPSO option. Returns a pointer
1496 * to the start of the CIPSO option on success, NULL if one is not found.
1499 unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
1501 const struct iphdr *iph = ip_hdr(skb);
1502 unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]);
1506 for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
1507 switch (optptr[0]) {
1516 if (!taglen || taglen > optlen)
1518 if (optptr[0] == IPOPT_CIPSO)
1529 * cipso_v4_validate - Validate a CIPSO option
1531 * @option: the start of the option, on error it is set to point to the error
1534 * This routine is called to validate a CIPSO option, it checks all of the
1535 * fields to ensure that they are at least valid, see the draft snippet below
1536 * for details. If the option is valid then a zero value is returned and
1537 * the value of @option is unchanged. If the option is invalid then a
1538 * non-zero value is returned and @option is adjusted to point to the
1539 * offending portion of the option. From the IETF draft ...
1541 * "If any field within the CIPSO options, such as the DOI identifier, is not
1542 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1543 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1544 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1545 * that is unrecognized."
1548 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1550 unsigned char *opt = *option;
1552 unsigned char opt_iter;
1553 unsigned char err_offset = 0;
1556 struct cipso_v4_doi *doi_def = NULL;
1559 /* caller already checks for length values that are too large */
1563 goto validate_return;
1567 doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
1570 goto validate_return_locked;
1573 opt_iter = CIPSO_V4_HDR_LEN;
1574 tag = opt + opt_iter;
1575 while (opt_iter < opt_len) {
1576 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1577 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1578 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1579 err_offset = opt_iter;
1580 goto validate_return_locked;
1583 if (opt_iter + 1 == opt_len) {
1584 err_offset = opt_iter;
1585 goto validate_return_locked;
1588 if (tag_len > (opt_len - opt_iter)) {
1589 err_offset = opt_iter + 1;
1590 goto validate_return_locked;
1594 case CIPSO_V4_TAG_RBITMAP:
1595 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1596 err_offset = opt_iter + 1;
1597 goto validate_return_locked;
1600 /* We are already going to do all the verification
1601 * necessary at the socket layer so from our point of
1602 * view it is safe to turn these checks off (and less
1603 * work), however, the CIPSO draft says we should do
1604 * all the CIPSO validations here but it doesn't
1605 * really specify _exactly_ what we need to validate
1606 * ... so, just make it a sysctl tunable. */
1607 if (cipso_v4_rbm_strictvalid) {
1608 if (cipso_v4_map_lvl_valid(doi_def,
1610 err_offset = opt_iter + 3;
1611 goto validate_return_locked;
1613 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1614 cipso_v4_map_cat_rbm_valid(doi_def,
1617 err_offset = opt_iter + 4;
1618 goto validate_return_locked;
1622 case CIPSO_V4_TAG_ENUM:
1623 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1624 err_offset = opt_iter + 1;
1625 goto validate_return_locked;
1628 if (cipso_v4_map_lvl_valid(doi_def,
1630 err_offset = opt_iter + 3;
1631 goto validate_return_locked;
1633 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1634 cipso_v4_map_cat_enum_valid(doi_def,
1637 err_offset = opt_iter + 4;
1638 goto validate_return_locked;
1641 case CIPSO_V4_TAG_RANGE:
1642 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1643 err_offset = opt_iter + 1;
1644 goto validate_return_locked;
1647 if (cipso_v4_map_lvl_valid(doi_def,
1649 err_offset = opt_iter + 3;
1650 goto validate_return_locked;
1652 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1653 cipso_v4_map_cat_rng_valid(doi_def,
1656 err_offset = opt_iter + 4;
1657 goto validate_return_locked;
1660 case CIPSO_V4_TAG_LOCAL:
1661 /* This is a non-standard tag that we only allow for
1662 * local connections, so if the incoming interface is
1663 * not the loopback device drop the packet. Further,
1664 * there is no legitimate reason for setting this from
1665 * userspace so reject it if skb is NULL. */
1666 if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) {
1667 err_offset = opt_iter;
1668 goto validate_return_locked;
1670 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1671 err_offset = opt_iter + 1;
1672 goto validate_return_locked;
1676 err_offset = opt_iter;
1677 goto validate_return_locked;
1681 opt_iter += tag_len;
1684 validate_return_locked:
1687 *option = opt + err_offset;
1692 * cipso_v4_error - Send the correct response for a bad packet
1694 * @error: the error code
1695 * @gateway: CIPSO gateway flag
1698 * Based on the error code given in @error, send an ICMP error message back to
1699 * the originating host. From the IETF draft ...
1701 * "If the contents of the CIPSO [option] are valid but the security label is
1702 * outside of the configured host or port label range, the datagram is
1703 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1704 * returned. The code field of the ICMP is set to 'communication with
1705 * destination network administratively prohibited' (code 9) or to
1706 * 'communication with destination host administratively prohibited'
1707 * (code 10). The value of the code is dependent on whether the originator
1708 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1709 * recipient of the ICMP message MUST be able to handle either value. The
1710 * same procedure is performed if a CIPSO [option] can not be added to an
1711 * IP packet because it is too large to fit in the IP options area."
1713 * "If the error is triggered by receipt of an ICMP message, the message is
1714 * discarded and no response is permitted (consistent with general ICMP
1715 * processing rules)."
1718 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1720 unsigned char optbuf[sizeof(struct ip_options) + 40];
1721 struct ip_options *opt = (struct ip_options *)optbuf;
1724 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1728 * We might be called above the IP layer,
1729 * so we can not use icmp_send and IPCB here.
1732 memset(opt, 0, sizeof(struct ip_options));
1733 opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
1735 res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL);
1742 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
1744 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
1748 * cipso_v4_genopt - Generate a CIPSO option
1749 * @buf: the option buffer
1750 * @buf_len: the size of opt_buf
1751 * @doi_def: the CIPSO DOI to use
1752 * @secattr: the security attributes
1755 * Generate a CIPSO option using the DOI definition and security attributes
1756 * passed to the function. Returns the length of the option on success and
1757 * negative values on failure.
1760 static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1761 const struct cipso_v4_doi *doi_def,
1762 const struct netlbl_lsm_secattr *secattr)
1767 if (buf_len <= CIPSO_V4_HDR_LEN)
1770 /* XXX - This code assumes only one tag per CIPSO option which isn't
1771 * really a good assumption to make but since we only support the MAC
1772 * tags right now it is a safe assumption. */
1775 memset(buf, 0, buf_len);
1776 switch (doi_def->tags[iter]) {
1777 case CIPSO_V4_TAG_RBITMAP:
1778 ret_val = cipso_v4_gentag_rbm(doi_def,
1780 &buf[CIPSO_V4_HDR_LEN],
1781 buf_len - CIPSO_V4_HDR_LEN);
1783 case CIPSO_V4_TAG_ENUM:
1784 ret_val = cipso_v4_gentag_enum(doi_def,
1786 &buf[CIPSO_V4_HDR_LEN],
1787 buf_len - CIPSO_V4_HDR_LEN);
1789 case CIPSO_V4_TAG_RANGE:
1790 ret_val = cipso_v4_gentag_rng(doi_def,
1792 &buf[CIPSO_V4_HDR_LEN],
1793 buf_len - CIPSO_V4_HDR_LEN);
1795 case CIPSO_V4_TAG_LOCAL:
1796 ret_val = cipso_v4_gentag_loc(doi_def,
1798 &buf[CIPSO_V4_HDR_LEN],
1799 buf_len - CIPSO_V4_HDR_LEN);
1806 } while (ret_val < 0 &&
1807 iter < CIPSO_V4_TAG_MAXCNT &&
1808 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1811 cipso_v4_gentag_hdr(doi_def, buf, ret_val);
1812 return CIPSO_V4_HDR_LEN + ret_val;
1816 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1818 * @doi_def: the CIPSO DOI to use
1819 * @secattr: the specific security attributes of the socket
1822 * Set the CIPSO option on the given socket using the DOI definition and
1823 * security attributes passed to the function. This function requires
1824 * exclusive access to @sk, which means it either needs to be in the
1825 * process of being created or locked. Returns zero on success and negative
1826 * values on failure.
1829 int cipso_v4_sock_setattr(struct sock *sk,
1830 const struct cipso_v4_doi *doi_def,
1831 const struct netlbl_lsm_secattr *secattr)
1833 int ret_val = -EPERM;
1834 unsigned char *buf = NULL;
1837 struct ip_options_rcu *old, *opt = NULL;
1838 struct inet_sock *sk_inet;
1839 struct inet_connection_sock *sk_conn;
1841 /* In the case of sock_create_lite(), the sock->sk field is not
1842 * defined yet but it is not a problem as the only users of these
1843 * "lite" PF_INET sockets are functions which do an accept() call
1844 * afterwards so we will label the socket as part of the accept(). */
1848 /* We allocate the maximum CIPSO option size here so we are probably
1849 * being a little wasteful, but it makes our life _much_ easier later
1850 * on and after all we are only talking about 40 bytes. */
1851 buf_len = CIPSO_V4_OPT_LEN_MAX;
1852 buf = kmalloc(buf_len, GFP_ATOMIC);
1855 goto socket_setattr_failure;
1858 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1860 goto socket_setattr_failure;
1863 /* We can't use ip_options_get() directly because it makes a call to
1864 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1865 * we won't always have CAP_NET_RAW even though we _always_ want to
1866 * set the IPOPT_CIPSO option. */
1867 opt_len = (buf_len + 3) & ~3;
1868 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1871 goto socket_setattr_failure;
1873 memcpy(opt->opt.__data, buf, buf_len);
1874 opt->opt.optlen = opt_len;
1875 opt->opt.cipso = sizeof(struct iphdr);
1879 sk_inet = inet_sk(sk);
1881 old = rcu_dereference_protected(sk_inet->inet_opt,
1882 lockdep_sock_is_held(sk));
1883 if (sk_inet->is_icsk) {
1884 sk_conn = inet_csk(sk);
1886 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1887 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1888 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1890 rcu_assign_pointer(sk_inet->inet_opt, opt);
1892 kfree_rcu(old, rcu);
1896 socket_setattr_failure:
1903 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1904 * @req: the connection request socket
1905 * @doi_def: the CIPSO DOI to use
1906 * @secattr: the specific security attributes of the socket
1909 * Set the CIPSO option on the given socket using the DOI definition and
1910 * security attributes passed to the function. Returns zero on success and
1911 * negative values on failure.
1914 int cipso_v4_req_setattr(struct request_sock *req,
1915 const struct cipso_v4_doi *doi_def,
1916 const struct netlbl_lsm_secattr *secattr)
1918 int ret_val = -EPERM;
1919 unsigned char *buf = NULL;
1922 struct ip_options_rcu *opt = NULL;
1923 struct inet_request_sock *req_inet;
1925 /* We allocate the maximum CIPSO option size here so we are probably
1926 * being a little wasteful, but it makes our life _much_ easier later
1927 * on and after all we are only talking about 40 bytes. */
1928 buf_len = CIPSO_V4_OPT_LEN_MAX;
1929 buf = kmalloc(buf_len, GFP_ATOMIC);
1932 goto req_setattr_failure;
1935 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1937 goto req_setattr_failure;
1940 /* We can't use ip_options_get() directly because it makes a call to
1941 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1942 * we won't always have CAP_NET_RAW even though we _always_ want to
1943 * set the IPOPT_CIPSO option. */
1944 opt_len = (buf_len + 3) & ~3;
1945 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1948 goto req_setattr_failure;
1950 memcpy(opt->opt.__data, buf, buf_len);
1951 opt->opt.optlen = opt_len;
1952 opt->opt.cipso = sizeof(struct iphdr);
1956 req_inet = inet_rsk(req);
1957 opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt);
1959 kfree_rcu(opt, rcu);
1963 req_setattr_failure:
1970 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
1971 * @opt_ptr: IP option pointer
1974 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
1975 * adjustments to the IP option structure. Returns zero on success, negative
1976 * values on failure.
1979 static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr)
1981 struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1);
1984 if (!opt || opt->opt.cipso == 0)
1986 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
1989 unsigned char *cipso_ptr;
1993 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
1994 cipso_ptr = &opt->opt.__data[cipso_off];
1995 cipso_len = cipso_ptr[1];
1997 if (opt->opt.srr > opt->opt.cipso)
1998 opt->opt.srr -= cipso_len;
1999 if (opt->opt.rr > opt->opt.cipso)
2000 opt->opt.rr -= cipso_len;
2001 if (opt->opt.ts > opt->opt.cipso)
2002 opt->opt.ts -= cipso_len;
2003 if (opt->opt.router_alert > opt->opt.cipso)
2004 opt->opt.router_alert -= cipso_len;
2007 memmove(cipso_ptr, cipso_ptr + cipso_len,
2008 opt->opt.optlen - cipso_off - cipso_len);
2010 /* determining the new total option length is tricky because of
2011 * the padding necessary, the only thing i can think to do at
2012 * this point is walk the options one-by-one, skipping the
2013 * padding at the end to determine the actual option size and
2014 * from there we can determine the new total option length */
2017 while (iter < opt->opt.optlen)
2018 if (opt->opt.__data[iter] != IPOPT_NOP) {
2019 iter += opt->opt.__data[iter + 1];
2023 hdr_delta = opt->opt.optlen;
2024 opt->opt.optlen = (optlen_new + 3) & ~3;
2025 hdr_delta -= opt->opt.optlen;
2027 /* only the cipso option was present on the socket so we can
2028 * remove the entire option struct */
2030 hdr_delta = opt->opt.optlen;
2031 kfree_rcu(opt, rcu);
2038 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2042 * Removes the CIPSO option from a socket, if present.
2045 void cipso_v4_sock_delattr(struct sock *sk)
2047 struct inet_sock *sk_inet;
2050 sk_inet = inet_sk(sk);
2052 hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
2053 if (sk_inet->is_icsk && hdr_delta > 0) {
2054 struct inet_connection_sock *sk_conn = inet_csk(sk);
2055 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2056 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2061 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2062 * @req: the request socket
2065 * Removes the CIPSO option from a request socket, if present.
2068 void cipso_v4_req_delattr(struct request_sock *req)
2070 cipso_v4_delopt(&inet_rsk(req)->ireq_opt);
2074 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2075 * @cipso: the CIPSO v4 option
2076 * @secattr: the security attributes
2079 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2080 * on success and negative values on failure.
2083 int cipso_v4_getattr(const unsigned char *cipso,
2084 struct netlbl_lsm_secattr *secattr)
2086 int ret_val = -ENOMSG;
2088 struct cipso_v4_doi *doi_def;
2090 if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
2093 doi = get_unaligned_be32(&cipso[2]);
2095 doi_def = cipso_v4_doi_search(doi);
2097 goto getattr_return;
2098 /* XXX - This code assumes only one tag per CIPSO option which isn't
2099 * really a good assumption to make but since we only support the MAC
2100 * tags right now it is a safe assumption. */
2102 case CIPSO_V4_TAG_RBITMAP:
2103 ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
2105 case CIPSO_V4_TAG_ENUM:
2106 ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
2108 case CIPSO_V4_TAG_RANGE:
2109 ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
2111 case CIPSO_V4_TAG_LOCAL:
2112 ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
2116 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2124 * cipso_v4_sock_getattr - Get the security attributes from a sock
2126 * @secattr: the security attributes
2129 * Query @sk to see if there is a CIPSO option attached to the sock and if
2130 * there is return the CIPSO security attributes in @secattr. This function
2131 * requires that @sk be locked, or privately held, but it does not do any
2132 * locking itself. Returns zero on success and negative values on failure.
2135 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2137 struct ip_options_rcu *opt;
2141 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2142 if (opt && opt->opt.cipso)
2143 res = cipso_v4_getattr(opt->opt.__data +
2145 sizeof(struct iphdr),
2152 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2154 * @doi_def: the DOI structure
2155 * @secattr: the security attributes
2158 * Set the CIPSO option on the given packet based on the security attributes.
2159 * Returns a pointer to the IP header on success and NULL on failure.
2162 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2163 const struct cipso_v4_doi *doi_def,
2164 const struct netlbl_lsm_secattr *secattr)
2168 struct ip_options *opt = &IPCB(skb)->opt;
2169 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2170 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2174 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2178 opt_len = (buf_len + 3) & ~3;
2180 /* we overwrite any existing options to ensure that we have enough
2181 * room for the CIPSO option, the reason is that we _need_ to guarantee
2182 * that the security label is applied to the packet - we do the same
2183 * thing when using the socket options and it hasn't caused a problem,
2184 * if we need to we can always revisit this choice later */
2186 len_delta = opt_len - opt->optlen;
2187 /* if we don't ensure enough headroom we could panic on the skb_push()
2188 * call below so make sure we have enough, we are also "mangling" the
2189 * packet so we should probably do a copy-on-write call anyway */
2190 ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
2194 if (len_delta > 0) {
2195 /* we assume that the header + opt->optlen have already been
2196 * "pushed" in ip_options_build() or similar */
2198 skb_push(skb, len_delta);
2199 memmove((char *)iph - len_delta, iph, iph->ihl << 2);
2200 skb_reset_network_header(skb);
2202 } else if (len_delta < 0) {
2204 memset(iph + 1, IPOPT_NOP, opt->optlen);
2208 if (opt->optlen > 0)
2209 memset(opt, 0, sizeof(*opt));
2210 opt->optlen = opt_len;
2211 opt->cipso = sizeof(struct iphdr);
2212 opt->is_changed = 1;
2214 /* we have to do the following because we are being called from a
2215 * netfilter hook which means the packet already has had the header
2216 * fields populated and the checksum calculated - yes this means we
2217 * are doing more work than needed but we do it to keep the core
2218 * stack clean and tidy */
2219 memcpy(iph + 1, buf, buf_len);
2220 if (opt_len > buf_len)
2221 memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
2222 if (len_delta != 0) {
2223 iph->ihl = 5 + (opt_len >> 2);
2224 iph->tot_len = htons(skb->len);
2232 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2236 * Removes any and all CIPSO options from the given packet. Returns zero on
2237 * success, negative values on failure.
2240 int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2244 struct ip_options *opt = &IPCB(skb)->opt;
2245 unsigned char *cipso_ptr;
2247 if (opt->cipso == 0)
2250 /* since we are changing the packet we should make a copy */
2251 ret_val = skb_cow(skb, skb_headroom(skb));
2255 /* the easiest thing to do is just replace the cipso option with noop
2256 * options since we don't change the size of the packet, although we
2257 * still need to recalculate the checksum */
2260 cipso_ptr = (unsigned char *)iph + opt->cipso;
2261 memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
2263 opt->is_changed = 1;
2275 * cipso_v4_init - Initialize the CIPSO module
2278 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2279 * and negative values on failure.
2282 static int __init cipso_v4_init(void)
2286 ret_val = cipso_v4_cache_init();
2288 panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2294 subsys_initcall(cipso_v4_init);