1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CIPSO - Commercial IP Security Option
4 *
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.
10 *
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
16 *
17 * Author: Paul Moore <paul.moore@hp.com>
18 */
19
20/*
21 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
22 */
23
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>
33#include <net/ip.h>
34#include <net/icmp.h>
35#include <net/tcp.h>
36#include <net/netlabel.h>
37#include <net/cipso_ipv4.h>
38#include <linux/atomic.h>
39#include <linux/bug.h>
40#include <linux/unaligned.h>
41
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. */
47static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
48static LIST_HEAD(cipso_v4_doi_list);
49
50/* Label mapping cache */
51int cipso_v4_cache_enabled = 1;
52int 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
56struct cipso_v4_map_cache_bkt {
57 spinlock_t lock;
58 u32 size;
59 struct list_head list;
60};
61
62struct cipso_v4_map_cache_entry {
63 u32 hash;
64 unsigned char *key;
65 size_t key_len;
66
67 struct netlbl_lsm_cache *lsm_data;
68
69 u32 activity;
70 struct list_head list;
71};
72
73static struct cipso_v4_map_cache_bkt *cipso_v4_cache;
74
75/* Restricted bitmap (tag #1) flags */
76int cipso_v4_rbm_optfmt;
77int cipso_v4_rbm_strictvalid = 1;
78
79/*
80 * Protocol Constants
81 */
82
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
86
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
90
91/* Base length of the restrictive category bitmap tag (tag #1). */
92#define CIPSO_V4_TAG_RBM_BLEN 4
93
94/* Base length of the enumerated category tag (tag #2). */
95#define CIPSO_V4_TAG_ENUM_BLEN 4
96
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
103 * be omitted. */
104#define CIPSO_V4_TAG_RNG_CAT_MAX 8
105
106/* Base length of the local tag (non-standard tag).
107 * Tag definition (may change between kernel versions)
108 *
109 * 0 8 16 24 32
110 * +----------+----------+----------+----------+
111 * | 10000000 | 00000110 | 32-bit secid value |
112 * +----------+----------+----------+----------+
113 * | in (host byte order)|
114 * +----------+----------+
115 *
116 */
117#define CIPSO_V4_TAG_LOC_BLEN 6
118
119/*
120 * Helper Functions
121 */
122
123/**
124 * cipso_v4_cache_entry_free - Frees a cache entry
125 * @entry: the entry to free
126 *
127 * Description:
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.
130 *
131 */
132static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
133{
134 if (entry->lsm_data)
135 netlbl_secattr_cache_free(cache: entry->lsm_data);
136 kfree(objp: entry->key);
137 kfree(objp: entry);
138}
139
140/**
141 * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
142 * @key: the hash key
143 * @key_len: the length of the key in bytes
144 *
145 * Description:
146 * The CIPSO tag hashing function. Returns a 32-bit hash value.
147 *
148 */
149static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
150{
151 return jhash(key, length: key_len, initval: 0);
152}
153
154/*
155 * Label Mapping Cache Functions
156 */
157
158/**
159 * cipso_v4_cache_init - Initialize the CIPSO cache
160 *
161 * Description:
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.
165 *
166 */
167static int __init cipso_v4_cache_init(void)
168{
169 u32 iter;
170
171 cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
172 sizeof(struct cipso_v4_map_cache_bkt),
173 GFP_KERNEL);
174 if (!cipso_v4_cache)
175 return -ENOMEM;
176
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(list: &cipso_v4_cache[iter].list);
181 }
182
183 return 0;
184}
185
186/**
187 * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
188 *
189 * Description:
190 * Invalidates and frees any entries in the CIPSO cache.
191 *
192 */
193void cipso_v4_cache_invalidate(void)
194{
195 struct cipso_v4_map_cache_entry *entry, *tmp_entry;
196 u32 iter;
197
198 for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
199 spin_lock_bh(lock: &cipso_v4_cache[iter].lock);
200 list_for_each_entry_safe(entry,
201 tmp_entry,
202 &cipso_v4_cache[iter].list, list) {
203 list_del(entry: &entry->list);
204 cipso_v4_cache_entry_free(entry);
205 }
206 cipso_v4_cache[iter].size = 0;
207 spin_unlock_bh(lock: &cipso_v4_cache[iter].lock);
208 }
209}
210
211/**
212 * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
213 * @key: the buffer to check
214 * @key_len: buffer length in bytes
215 * @secattr: the security attribute struct to use
216 *
217 * Description:
218 * This function checks the cache to see if a label mapping already exists for
219 * the given key. If there is a match then the cache is adjusted and the
220 * @secattr struct is populated with the correct LSM security attributes. The
221 * cache is adjusted in the following manner if the entry is not already the
222 * first in the cache bucket:
223 *
224 * 1. The cache entry's activity counter is incremented
225 * 2. The previous (higher ranking) entry's activity counter is decremented
226 * 3. If the difference between the two activity counters is geater than
227 * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
228 *
229 * Returns zero on success, -ENOENT for a cache miss, and other negative values
230 * on error.
231 *
232 */
233static int cipso_v4_cache_check(const unsigned char *key,
234 u32 key_len,
235 struct netlbl_lsm_secattr *secattr)
236{
237 u32 bkt;
238 struct cipso_v4_map_cache_entry *entry;
239 struct cipso_v4_map_cache_entry *prev_entry = NULL;
240 u32 hash;
241
242 if (!READ_ONCE(cipso_v4_cache_enabled))
243 return -ENOENT;
244
245 hash = cipso_v4_map_cache_hash(key, key_len);
246 bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
247 spin_lock_bh(lock: &cipso_v4_cache[bkt].lock);
248 list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
249 if (entry->hash == hash &&
250 entry->key_len == key_len &&
251 memcmp(entry->key, key, key_len) == 0) {
252 entry->activity += 1;
253 refcount_inc(r: &entry->lsm_data->refcount);
254 secattr->cache = entry->lsm_data;
255 secattr->flags |= NETLBL_SECATTR_CACHE;
256 secattr->type = NETLBL_NLTYPE_CIPSOV4;
257 if (!prev_entry) {
258 spin_unlock_bh(lock: &cipso_v4_cache[bkt].lock);
259 return 0;
260 }
261
262 if (prev_entry->activity > 0)
263 prev_entry->activity -= 1;
264 if (entry->activity > prev_entry->activity &&
265 entry->activity - prev_entry->activity >
266 CIPSO_V4_CACHE_REORDERLIMIT) {
267 __list_del(prev: entry->list.prev, next: entry->list.next);
268 __list_add(new: &entry->list,
269 prev: prev_entry->list.prev,
270 next: &prev_entry->list);
271 }
272
273 spin_unlock_bh(lock: &cipso_v4_cache[bkt].lock);
274 return 0;
275 }
276 prev_entry = entry;
277 }
278 spin_unlock_bh(lock: &cipso_v4_cache[bkt].lock);
279
280 return -ENOENT;
281}
282
283/**
284 * cipso_v4_cache_add - Add an entry to the CIPSO cache
285 * @cipso_ptr: pointer to CIPSO IP option
286 * @secattr: the packet's security attributes
287 *
288 * Description:
289 * Add a new entry into the CIPSO label mapping cache. Add the new entry to
290 * head of the cache bucket's list, if the cache bucket is out of room remove
291 * the last entry in the list first. It is important to note that there is
292 * currently no checking for duplicate keys. Returns zero on success,
293 * negative values on failure.
294 *
295 */
296int cipso_v4_cache_add(const unsigned char *cipso_ptr,
297 const struct netlbl_lsm_secattr *secattr)
298{
299 int bkt_size = READ_ONCE(cipso_v4_cache_bucketsize);
300 int ret_val = -EPERM;
301 u32 bkt;
302 struct cipso_v4_map_cache_entry *entry = NULL;
303 struct cipso_v4_map_cache_entry *old_entry = NULL;
304 u32 cipso_ptr_len;
305
306 if (!READ_ONCE(cipso_v4_cache_enabled) || bkt_size <= 0)
307 return 0;
308
309 cipso_ptr_len = cipso_ptr[1];
310
311 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
312 if (!entry)
313 return -ENOMEM;
314 entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
315 if (!entry->key) {
316 ret_val = -ENOMEM;
317 goto cache_add_failure;
318 }
319 entry->key_len = cipso_ptr_len;
320 entry->hash = cipso_v4_map_cache_hash(key: cipso_ptr, key_len: cipso_ptr_len);
321 refcount_inc(r: &secattr->cache->refcount);
322 entry->lsm_data = secattr->cache;
323
324 bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
325 spin_lock_bh(lock: &cipso_v4_cache[bkt].lock);
326 if (cipso_v4_cache[bkt].size < bkt_size) {
327 list_add(new: &entry->list, head: &cipso_v4_cache[bkt].list);
328 cipso_v4_cache[bkt].size += 1;
329 } else {
330 old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
331 struct cipso_v4_map_cache_entry, list);
332 list_del(entry: &old_entry->list);
333 list_add(new: &entry->list, head: &cipso_v4_cache[bkt].list);
334 cipso_v4_cache_entry_free(entry: old_entry);
335 }
336 spin_unlock_bh(lock: &cipso_v4_cache[bkt].lock);
337
338 return 0;
339
340cache_add_failure:
341 if (entry)
342 cipso_v4_cache_entry_free(entry);
343 return ret_val;
344}
345
346/*
347 * DOI List Functions
348 */
349
350/**
351 * cipso_v4_doi_search - Searches for a DOI definition
352 * @doi: the DOI to search for
353 *
354 * Description:
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.
358 */
359static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
360{
361 struct cipso_v4_doi *iter;
362
363 list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
364 if (iter->doi == doi && refcount_read(r: &iter->refcount))
365 return iter;
366 return NULL;
367}
368
369/**
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
373 *
374 * Description:
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.
380 *
381 */
382int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
383 struct netlbl_audit *audit_info)
384{
385 int ret_val = -EINVAL;
386 u32 iter;
387 u32 doi;
388 u32 doi_type;
389 struct audit_buffer *audit_buf;
390
391 doi = doi_def->doi;
392 doi_type = doi_def->type;
393
394 if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
395 goto doi_add_return;
396 for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
397 switch (doi_def->tags[iter]) {
398 case CIPSO_V4_TAG_RBITMAP:
399 break;
400 case CIPSO_V4_TAG_RANGE:
401 case CIPSO_V4_TAG_ENUM:
402 if (doi_def->type != CIPSO_V4_MAP_PASS)
403 goto doi_add_return;
404 break;
405 case CIPSO_V4_TAG_LOCAL:
406 if (doi_def->type != CIPSO_V4_MAP_LOCAL)
407 goto doi_add_return;
408 break;
409 case CIPSO_V4_TAG_INVALID:
410 if (iter == 0)
411 goto doi_add_return;
412 break;
413 default:
414 goto doi_add_return;
415 }
416 }
417
418 refcount_set(r: &doi_def->refcount, n: 1);
419
420 spin_lock(lock: &cipso_v4_doi_list_lock);
421 if (cipso_v4_doi_search(doi: doi_def->doi)) {
422 spin_unlock(lock: &cipso_v4_doi_list_lock);
423 ret_val = -EEXIST;
424 goto doi_add_return;
425 }
426 list_add_tail_rcu(new: &doi_def->list, head: &cipso_v4_doi_list);
427 spin_unlock(lock: &cipso_v4_doi_list_lock);
428 ret_val = 0;
429
430doi_add_return:
431 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
432 if (audit_buf) {
433 const char *type_str;
434 switch (doi_type) {
435 case CIPSO_V4_MAP_TRANS:
436 type_str = "trans";
437 break;
438 case CIPSO_V4_MAP_PASS:
439 type_str = "pass";
440 break;
441 case CIPSO_V4_MAP_LOCAL:
442 type_str = "local";
443 break;
444 default:
445 type_str = "(unknown)";
446 }
447 audit_log_format(ab: audit_buf,
448 fmt: " cipso_doi=%u cipso_type=%s res=%u",
449 doi, type_str, ret_val == 0 ? 1 : 0);
450 audit_log_end(ab: audit_buf);
451 }
452
453 return ret_val;
454}
455
456/**
457 * cipso_v4_doi_free - Frees a DOI definition
458 * @doi_def: the DOI definition
459 *
460 * Description:
461 * This function frees all of the memory associated with a DOI definition.
462 *
463 */
464void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
465{
466 if (!doi_def)
467 return;
468
469 switch (doi_def->type) {
470 case CIPSO_V4_MAP_TRANS:
471 kfree(objp: doi_def->map.std->lvl.cipso);
472 kfree(objp: doi_def->map.std->lvl.local);
473 kfree(objp: doi_def->map.std->cat.cipso);
474 kfree(objp: doi_def->map.std->cat.local);
475 kfree(objp: doi_def->map.std);
476 break;
477 }
478 kfree(objp: doi_def);
479}
480
481/**
482 * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
483 * @entry: the entry's RCU field
484 *
485 * Description:
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
488 * safely.
489 *
490 */
491static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
492{
493 struct cipso_v4_doi *doi_def;
494
495 doi_def = container_of(entry, struct cipso_v4_doi, rcu);
496 cipso_v4_doi_free(doi_def);
497}
498
499/**
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
503 *
504 * Description:
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.
508 *
509 */
510int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
511{
512 int ret_val;
513 struct cipso_v4_doi *doi_def;
514 struct audit_buffer *audit_buf;
515
516 spin_lock(lock: &cipso_v4_doi_list_lock);
517 doi_def = cipso_v4_doi_search(doi);
518 if (!doi_def) {
519 spin_unlock(lock: &cipso_v4_doi_list_lock);
520 ret_val = -ENOENT;
521 goto doi_remove_return;
522 }
523 list_del_rcu(entry: &doi_def->list);
524 spin_unlock(lock: &cipso_v4_doi_list_lock);
525
526 cipso_v4_doi_putdef(doi_def);
527 ret_val = 0;
528
529doi_remove_return:
530 audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
531 if (audit_buf) {
532 audit_log_format(ab: audit_buf,
533 fmt: " cipso_doi=%u res=%u",
534 doi, ret_val == 0 ? 1 : 0);
535 audit_log_end(ab: audit_buf);
536 }
537
538 return ret_val;
539}
540
541/**
542 * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
543 * @doi: the DOI value
544 *
545 * Description:
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.
550 *
551 */
552struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
553{
554 struct cipso_v4_doi *doi_def;
555
556 rcu_read_lock();
557 doi_def = cipso_v4_doi_search(doi);
558 if (!doi_def)
559 goto doi_getdef_return;
560 if (!refcount_inc_not_zero(r: &doi_def->refcount))
561 doi_def = NULL;
562
563doi_getdef_return:
564 rcu_read_unlock();
565 return doi_def;
566}
567
568/**
569 * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
570 * @doi_def: the DOI definition
571 *
572 * Description:
573 * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
574 *
575 */
576void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
577{
578 if (!doi_def)
579 return;
580
581 if (!refcount_dec_and_test(r: &doi_def->refcount))
582 return;
583
584 cipso_v4_cache_invalidate();
585 call_rcu(head: &doi_def->rcu, func: cipso_v4_doi_free_rcu);
586}
587
588/**
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
593 *
594 * Description:
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.
599 *
600 */
601int cipso_v4_doi_walk(u32 *skip_cnt,
602 int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
603 void *cb_arg)
604{
605 int ret_val = -ENOENT;
606 u32 doi_cnt = 0;
607 struct cipso_v4_doi *iter_doi;
608
609 rcu_read_lock();
610 list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
611 if (refcount_read(r: &iter_doi->refcount) > 0) {
612 if (doi_cnt++ < *skip_cnt)
613 continue;
614 ret_val = callback(iter_doi, cb_arg);
615 if (ret_val < 0) {
616 doi_cnt--;
617 goto doi_walk_return;
618 }
619 }
620
621doi_walk_return:
622 rcu_read_unlock();
623 *skip_cnt = doi_cnt;
624 return ret_val;
625}
626
627/*
628 * Label Mapping Functions
629 */
630
631/**
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
635 *
636 * Description:
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.
640 *
641 */
642static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
643{
644 switch (doi_def->type) {
645 case CIPSO_V4_MAP_PASS:
646 return 0;
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))
650 return 0;
651 break;
652 }
653
654 return -EFAULT;
655}
656
657/**
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
662 *
663 * Description:
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.
667 *
668 */
669static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
670 u32 host_lvl,
671 u32 *net_lvl)
672{
673 switch (doi_def->type) {
674 case CIPSO_V4_MAP_PASS:
675 *net_lvl = host_lvl;
676 return 0;
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];
681 return 0;
682 }
683 return -EPERM;
684 }
685
686 return -EINVAL;
687}
688
689/**
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
694 *
695 * Description:
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
698 * values otherwise.
699 *
700 */
701static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
702 u32 net_lvl,
703 u32 *host_lvl)
704{
705 struct cipso_v4_std_map_tbl *map_tbl;
706
707 switch (doi_def->type) {
708 case CIPSO_V4_MAP_PASS:
709 *host_lvl = net_lvl;
710 return 0;
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];
716 return 0;
717 }
718 return -EPERM;
719 }
720
721 return -EINVAL;
722}
723
724/**
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
729 *
730 * Description:
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.
734 *
735 */
736static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
737 const unsigned char *bitmap,
738 u32 bitmap_len)
739{
740 int cat = -1;
741 u32 bitmap_len_bits = bitmap_len * 8;
742 u32 cipso_cat_size;
743 u32 *cipso_array;
744
745 switch (doi_def->type) {
746 case CIPSO_V4_MAP_PASS:
747 return 0;
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;
751 for (;;) {
752 cat = netlbl_bitmap_walk(bitmap,
753 bitmap_len: bitmap_len_bits,
754 offset: cat + 1,
755 state: 1);
756 if (cat < 0)
757 break;
758 if (cat >= cipso_cat_size ||
759 cipso_array[cat] >= CIPSO_V4_INV_CAT)
760 return -EFAULT;
761 }
762
763 if (cat == -1)
764 return 0;
765 break;
766 }
767
768 return -EFAULT;
769}
770
771/**
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
777 *
778 * Description:
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.
782 *
783 */
784static 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,
787 u32 net_cat_len)
788{
789 int host_spot = -1;
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;
795
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;
799 }
800
801 for (;;) {
802 host_spot = netlbl_catmap_walk(catmap: secattr->attr.mls.cat,
803 offset: host_spot + 1);
804 if (host_spot < 0)
805 break;
806
807 switch (doi_def->type) {
808 case CIPSO_V4_MAP_PASS:
809 net_spot = host_spot;
810 break;
811 case CIPSO_V4_MAP_TRANS:
812 if (host_spot >= host_cat_size)
813 return -EPERM;
814 net_spot = host_cat_array[host_spot];
815 if (net_spot >= CIPSO_V4_INV_CAT)
816 return -EPERM;
817 break;
818 }
819 if (net_spot >= net_clen_bits)
820 return -ENOSPC;
821 netlbl_bitmap_setbit(bitmap: net_cat, bit: net_spot, state: 1);
822
823 if (net_spot > net_spot_max)
824 net_spot_max = net_spot;
825 }
826
827 if (++net_spot_max % 8)
828 return net_spot_max / 8 + 1;
829 return net_spot_max / 8;
830}
831
832/**
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
838 *
839 * Description:
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.
843 *
844 */
845static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
846 const unsigned char *net_cat,
847 u32 net_cat_len,
848 struct netlbl_lsm_secattr *secattr)
849{
850 int ret_val;
851 int net_spot = -1;
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;
856
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;
860 }
861
862 for (;;) {
863 net_spot = netlbl_bitmap_walk(bitmap: net_cat,
864 bitmap_len: net_clen_bits,
865 offset: net_spot + 1,
866 state: 1);
867 if (net_spot < 0)
868 return 0;
869
870 switch (doi_def->type) {
871 case CIPSO_V4_MAP_PASS:
872 host_spot = net_spot;
873 break;
874 case CIPSO_V4_MAP_TRANS:
875 if (net_spot >= net_cat_size)
876 return -EPERM;
877 host_spot = net_cat_array[net_spot];
878 if (host_spot >= CIPSO_V4_INV_CAT)
879 return -EPERM;
880 break;
881 }
882 ret_val = netlbl_catmap_setbit(catmap: &secattr->attr.mls.cat,
883 bit: host_spot,
884 GFP_ATOMIC);
885 if (ret_val != 0)
886 return ret_val;
887 }
888
889 return -EINVAL;
890}
891
892/**
893 * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
894 * @doi_def: the DOI definition
895 * @enumcat: category list
896 * @enumcat_len: length of the category list in bytes
897 *
898 * Description:
899 * Checks the given categories against the given DOI definition and returns a
900 * negative value if any of the categories do not have a valid mapping and a
901 * zero value if all of the categories are valid.
902 *
903 */
904static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
905 const unsigned char *enumcat,
906 u32 enumcat_len)
907{
908 u16 cat;
909 int cat_prev = -1;
910 u32 iter;
911
912 if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
913 return -EFAULT;
914
915 for (iter = 0; iter < enumcat_len; iter += 2) {
916 cat = get_unaligned_be16(p: &enumcat[iter]);
917 if (cat <= cat_prev)
918 return -EFAULT;
919 cat_prev = cat;
920 }
921
922 return 0;
923}
924
925/**
926 * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
927 * @doi_def: the DOI definition
928 * @secattr: the security attributes
929 * @net_cat: the zero'd out category list in network/CIPSO format
930 * @net_cat_len: the length of the CIPSO category list in bytes
931 *
932 * Description:
933 * Perform a label mapping to translate a local MLS category bitmap to the
934 * correct CIPSO category list using the given DOI definition. Returns the
935 * size in bytes of the network category bitmap on success, negative values
936 * otherwise.
937 *
938 */
939static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
940 const struct netlbl_lsm_secattr *secattr,
941 unsigned char *net_cat,
942 u32 net_cat_len)
943{
944 int cat = -1;
945 u32 cat_iter = 0;
946
947 for (;;) {
948 cat = netlbl_catmap_walk(catmap: secattr->attr.mls.cat, offset: cat + 1);
949 if (cat < 0)
950 break;
951 if ((cat_iter + 2) > net_cat_len)
952 return -ENOSPC;
953
954 *((__be16 *)&net_cat[cat_iter]) = htons(cat);
955 cat_iter += 2;
956 }
957
958 return cat_iter;
959}
960
961/**
962 * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
963 * @doi_def: the DOI definition
964 * @net_cat: the category list in network/CIPSO format
965 * @net_cat_len: the length of the CIPSO bitmap in bytes
966 * @secattr: the security attributes
967 *
968 * Description:
969 * Perform a label mapping to translate a CIPSO category list to the correct
970 * local MLS category bitmap using the given DOI definition. Returns zero on
971 * success, negative values on failure.
972 *
973 */
974static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
975 const unsigned char *net_cat,
976 u32 net_cat_len,
977 struct netlbl_lsm_secattr *secattr)
978{
979 int ret_val;
980 u32 iter;
981
982 for (iter = 0; iter < net_cat_len; iter += 2) {
983 ret_val = netlbl_catmap_setbit(catmap: &secattr->attr.mls.cat,
984 bit: get_unaligned_be16(p: &net_cat[iter]),
985 GFP_ATOMIC);
986 if (ret_val != 0)
987 return ret_val;
988 }
989
990 return 0;
991}
992
993/**
994 * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
995 * @doi_def: the DOI definition
996 * @rngcat: category list
997 * @rngcat_len: length of the category list in bytes
998 *
999 * Description:
1000 * Checks the given categories against the given DOI definition and returns a
1001 * negative value if any of the categories do not have a valid mapping and a
1002 * zero value if all of the categories are valid.
1003 *
1004 */
1005static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
1006 const unsigned char *rngcat,
1007 u32 rngcat_len)
1008{
1009 u16 cat_high;
1010 u16 cat_low;
1011 u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
1012 u32 iter;
1013
1014 if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
1015 return -EFAULT;
1016
1017 for (iter = 0; iter < rngcat_len; iter += 4) {
1018 cat_high = get_unaligned_be16(p: &rngcat[iter]);
1019 if ((iter + 4) <= rngcat_len)
1020 cat_low = get_unaligned_be16(p: &rngcat[iter + 2]);
1021 else
1022 cat_low = 0;
1023
1024 if (cat_high > cat_prev)
1025 return -EFAULT;
1026
1027 cat_prev = cat_low;
1028 }
1029
1030 return 0;
1031}
1032
1033/**
1034 * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
1035 * @doi_def: the DOI definition
1036 * @secattr: the security attributes
1037 * @net_cat: the zero'd out category list in network/CIPSO format
1038 * @net_cat_len: the length of the CIPSO category list in bytes
1039 *
1040 * Description:
1041 * Perform a label mapping to translate a local MLS category bitmap to the
1042 * correct CIPSO category list using the given DOI definition. Returns the
1043 * size in bytes of the network category bitmap on success, negative values
1044 * otherwise.
1045 *
1046 */
1047static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
1048 const struct netlbl_lsm_secattr *secattr,
1049 unsigned char *net_cat,
1050 u32 net_cat_len)
1051{
1052 int iter = -1;
1053 u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
1054 u32 array_cnt = 0;
1055 u32 cat_size = 0;
1056
1057 /* make sure we don't overflow the 'array[]' variable */
1058 if (net_cat_len >
1059 (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
1060 return -ENOSPC;
1061
1062 for (;;) {
1063 iter = netlbl_catmap_walk(catmap: secattr->attr.mls.cat, offset: iter + 1);
1064 if (iter < 0)
1065 break;
1066 cat_size += (iter == 0 ? 0 : sizeof(u16));
1067 if (cat_size > net_cat_len)
1068 return -ENOSPC;
1069 array[array_cnt++] = iter;
1070
1071 iter = netlbl_catmap_walkrng(catmap: secattr->attr.mls.cat, offset: iter);
1072 if (iter < 0)
1073 return -EFAULT;
1074 cat_size += sizeof(u16);
1075 if (cat_size > net_cat_len)
1076 return -ENOSPC;
1077 array[array_cnt++] = iter;
1078 }
1079
1080 for (iter = 0; array_cnt > 0;) {
1081 *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
1082 iter += 2;
1083 array_cnt--;
1084 if (array[array_cnt] != 0) {
1085 *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
1086 iter += 2;
1087 }
1088 }
1089
1090 return cat_size;
1091}
1092
1093/**
1094 * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
1095 * @doi_def: the DOI definition
1096 * @net_cat: the category list in network/CIPSO format
1097 * @net_cat_len: the length of the CIPSO bitmap in bytes
1098 * @secattr: the security attributes
1099 *
1100 * Description:
1101 * Perform a label mapping to translate a CIPSO category list to the correct
1102 * local MLS category bitmap using the given DOI definition. Returns zero on
1103 * success, negative values on failure.
1104 *
1105 */
1106static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
1107 const unsigned char *net_cat,
1108 u32 net_cat_len,
1109 struct netlbl_lsm_secattr *secattr)
1110{
1111 int ret_val;
1112 u32 net_iter;
1113 u16 cat_low;
1114 u16 cat_high;
1115
1116 for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
1117 cat_high = get_unaligned_be16(p: &net_cat[net_iter]);
1118 if ((net_iter + 4) <= net_cat_len)
1119 cat_low = get_unaligned_be16(p: &net_cat[net_iter + 2]);
1120 else
1121 cat_low = 0;
1122
1123 ret_val = netlbl_catmap_setrng(catmap: &secattr->attr.mls.cat,
1124 start: cat_low,
1125 end: cat_high,
1126 GFP_ATOMIC);
1127 if (ret_val != 0)
1128 return ret_val;
1129 }
1130
1131 return 0;
1132}
1133
1134/*
1135 * Protocol Handling Functions
1136 */
1137
1138/**
1139 * cipso_v4_gentag_hdr - Generate a CIPSO option header
1140 * @doi_def: the DOI definition
1141 * @len: the total tag length in bytes, not including this header
1142 * @buf: the CIPSO option buffer
1143 *
1144 * Description:
1145 * Write a CIPSO header into the beginning of @buffer.
1146 *
1147 */
1148static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
1149 unsigned char *buf,
1150 u32 len)
1151{
1152 buf[0] = IPOPT_CIPSO;
1153 buf[1] = CIPSO_V4_HDR_LEN + len;
1154 put_unaligned_be32(val: doi_def->doi, p: &buf[2]);
1155}
1156
1157/**
1158 * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
1159 * @doi_def: the DOI definition
1160 * @secattr: the security attributes
1161 * @buffer: the option buffer
1162 * @buffer_len: length of buffer in bytes
1163 *
1164 * Description:
1165 * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The
1166 * actual buffer length may be larger than the indicated size due to
1167 * translation between host and network category bitmaps. Returns the size of
1168 * the tag on success, negative values on failure.
1169 *
1170 */
1171static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
1172 const struct netlbl_lsm_secattr *secattr,
1173 unsigned char *buffer,
1174 u32 buffer_len)
1175{
1176 int ret_val;
1177 u32 tag_len;
1178 u32 level;
1179
1180 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
1181 return -EPERM;
1182
1183 ret_val = cipso_v4_map_lvl_hton(doi_def,
1184 host_lvl: secattr->attr.mls.lvl,
1185 net_lvl: &level);
1186 if (ret_val != 0)
1187 return ret_val;
1188
1189 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1190 ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
1191 secattr,
1192 net_cat: &buffer[4],
1193 net_cat_len: buffer_len - 4);
1194 if (ret_val < 0)
1195 return ret_val;
1196
1197 /* This will send packets using the "optimized" format when
1198 * possible as specified in section 3.4.2.6 of the
1199 * CIPSO draft. */
1200 if (READ_ONCE(cipso_v4_rbm_optfmt) && ret_val > 0 &&
1201 ret_val <= 10)
1202 tag_len = 14;
1203 else
1204 tag_len = 4 + ret_val;
1205 } else
1206 tag_len = 4;
1207
1208 buffer[0] = CIPSO_V4_TAG_RBITMAP;
1209 buffer[1] = tag_len;
1210 buffer[3] = level;
1211
1212 return tag_len;
1213}
1214
1215/**
1216 * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
1217 * @doi_def: the DOI definition
1218 * @tag: the CIPSO tag
1219 * @secattr: the security attributes
1220 *
1221 * Description:
1222 * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
1223 * attributes in @secattr. Return zero on success, negatives values on
1224 * failure.
1225 *
1226 */
1227static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
1228 const unsigned char *tag,
1229 struct netlbl_lsm_secattr *secattr)
1230{
1231 int ret_val;
1232 u8 tag_len = tag[1];
1233 u32 level;
1234
1235 ret_val = cipso_v4_map_lvl_ntoh(doi_def, net_lvl: tag[3], host_lvl: &level);
1236 if (ret_val != 0)
1237 return ret_val;
1238 secattr->attr.mls.lvl = level;
1239 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1240
1241 if (tag_len > 4) {
1242 ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
1243 net_cat: &tag[4],
1244 net_cat_len: tag_len - 4,
1245 secattr);
1246 if (ret_val != 0) {
1247 netlbl_catmap_free(catmap: secattr->attr.mls.cat);
1248 return ret_val;
1249 }
1250
1251 if (secattr->attr.mls.cat)
1252 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1253 }
1254
1255 return 0;
1256}
1257
1258/**
1259 * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
1260 * @doi_def: the DOI definition
1261 * @secattr: the security attributes
1262 * @buffer: the option buffer
1263 * @buffer_len: length of buffer in bytes
1264 *
1265 * Description:
1266 * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the
1267 * size of the tag on success, negative values on failure.
1268 *
1269 */
1270static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
1271 const struct netlbl_lsm_secattr *secattr,
1272 unsigned char *buffer,
1273 u32 buffer_len)
1274{
1275 int ret_val;
1276 u32 tag_len;
1277 u32 level;
1278
1279 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1280 return -EPERM;
1281
1282 ret_val = cipso_v4_map_lvl_hton(doi_def,
1283 host_lvl: secattr->attr.mls.lvl,
1284 net_lvl: &level);
1285 if (ret_val != 0)
1286 return ret_val;
1287
1288 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1289 ret_val = cipso_v4_map_cat_enum_hton(doi_def,
1290 secattr,
1291 net_cat: &buffer[4],
1292 net_cat_len: buffer_len - 4);
1293 if (ret_val < 0)
1294 return ret_val;
1295
1296 tag_len = 4 + ret_val;
1297 } else
1298 tag_len = 4;
1299
1300 buffer[0] = CIPSO_V4_TAG_ENUM;
1301 buffer[1] = tag_len;
1302 buffer[3] = level;
1303
1304 return tag_len;
1305}
1306
1307/**
1308 * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
1309 * @doi_def: the DOI definition
1310 * @tag: the CIPSO tag
1311 * @secattr: the security attributes
1312 *
1313 * Description:
1314 * Parse a CIPSO enumerated tag (tag type #2) and return the security
1315 * attributes in @secattr. Return zero on success, negatives values on
1316 * failure.
1317 *
1318 */
1319static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
1320 const unsigned char *tag,
1321 struct netlbl_lsm_secattr *secattr)
1322{
1323 int ret_val;
1324 u8 tag_len = tag[1];
1325 u32 level;
1326
1327 ret_val = cipso_v4_map_lvl_ntoh(doi_def, net_lvl: tag[3], host_lvl: &level);
1328 if (ret_val != 0)
1329 return ret_val;
1330 secattr->attr.mls.lvl = level;
1331 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1332
1333 if (tag_len > 4) {
1334 ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
1335 net_cat: &tag[4],
1336 net_cat_len: tag_len - 4,
1337 secattr);
1338 if (ret_val != 0) {
1339 netlbl_catmap_free(catmap: secattr->attr.mls.cat);
1340 return ret_val;
1341 }
1342
1343 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1344 }
1345
1346 return 0;
1347}
1348
1349/**
1350 * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
1351 * @doi_def: the DOI definition
1352 * @secattr: the security attributes
1353 * @buffer: the option buffer
1354 * @buffer_len: length of buffer in bytes
1355 *
1356 * Description:
1357 * Generate a CIPSO option using the ranged tag, tag type #5. Returns the
1358 * size of the tag on success, negative values on failure.
1359 *
1360 */
1361static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
1362 const struct netlbl_lsm_secattr *secattr,
1363 unsigned char *buffer,
1364 u32 buffer_len)
1365{
1366 int ret_val;
1367 u32 tag_len;
1368 u32 level;
1369
1370 if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
1371 return -EPERM;
1372
1373 ret_val = cipso_v4_map_lvl_hton(doi_def,
1374 host_lvl: secattr->attr.mls.lvl,
1375 net_lvl: &level);
1376 if (ret_val != 0)
1377 return ret_val;
1378
1379 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
1380 ret_val = cipso_v4_map_cat_rng_hton(doi_def,
1381 secattr,
1382 net_cat: &buffer[4],
1383 net_cat_len: buffer_len - 4);
1384 if (ret_val < 0)
1385 return ret_val;
1386
1387 tag_len = 4 + ret_val;
1388 } else
1389 tag_len = 4;
1390
1391 buffer[0] = CIPSO_V4_TAG_RANGE;
1392 buffer[1] = tag_len;
1393 buffer[3] = level;
1394
1395 return tag_len;
1396}
1397
1398/**
1399 * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
1400 * @doi_def: the DOI definition
1401 * @tag: the CIPSO tag
1402 * @secattr: the security attributes
1403 *
1404 * Description:
1405 * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
1406 * in @secattr. Return zero on success, negatives values on failure.
1407 *
1408 */
1409static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
1410 const unsigned char *tag,
1411 struct netlbl_lsm_secattr *secattr)
1412{
1413 int ret_val;
1414 u8 tag_len = tag[1];
1415 u32 level;
1416
1417 ret_val = cipso_v4_map_lvl_ntoh(doi_def, net_lvl: tag[3], host_lvl: &level);
1418 if (ret_val != 0)
1419 return ret_val;
1420 secattr->attr.mls.lvl = level;
1421 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1422
1423 if (tag_len > 4) {
1424 ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
1425 net_cat: &tag[4],
1426 net_cat_len: tag_len - 4,
1427 secattr);
1428 if (ret_val != 0) {
1429 netlbl_catmap_free(catmap: secattr->attr.mls.cat);
1430 return ret_val;
1431 }
1432
1433 if (secattr->attr.mls.cat)
1434 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1435 }
1436
1437 return 0;
1438}
1439
1440/**
1441 * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
1442 * @doi_def: the DOI definition
1443 * @secattr: the security attributes
1444 * @buffer: the option buffer
1445 * @buffer_len: length of buffer in bytes
1446 *
1447 * Description:
1448 * Generate a CIPSO option using the local tag. Returns the size of the tag
1449 * on success, negative values on failure.
1450 *
1451 */
1452static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
1453 const struct netlbl_lsm_secattr *secattr,
1454 unsigned char *buffer,
1455 u32 buffer_len)
1456{
1457 if (!(secattr->flags & NETLBL_SECATTR_SECID))
1458 return -EPERM;
1459
1460 buffer[0] = CIPSO_V4_TAG_LOCAL;
1461 buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
1462 *(u32 *)&buffer[2] = secattr->attr.secid;
1463
1464 return CIPSO_V4_TAG_LOC_BLEN;
1465}
1466
1467/**
1468 * cipso_v4_parsetag_loc - Parse a CIPSO local tag
1469 * @doi_def: the DOI definition
1470 * @tag: the CIPSO tag
1471 * @secattr: the security attributes
1472 *
1473 * Description:
1474 * Parse a CIPSO local tag and return the security attributes in @secattr.
1475 * Return zero on success, negatives values on failure.
1476 *
1477 */
1478static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
1479 const unsigned char *tag,
1480 struct netlbl_lsm_secattr *secattr)
1481{
1482 secattr->attr.secid = *(u32 *)&tag[2];
1483 secattr->flags |= NETLBL_SECATTR_SECID;
1484
1485 return 0;
1486}
1487
1488/**
1489 * cipso_v4_optptr - Find the CIPSO option in the packet
1490 * @skb: the packet
1491 *
1492 * Description:
1493 * Parse the packet's IP header looking for a CIPSO option. Returns a pointer
1494 * to the start of the CIPSO option on success, NULL if one is not found.
1495 *
1496 */
1497unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
1498{
1499 const struct iphdr *iph = ip_hdr(skb);
1500 unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]);
1501 int optlen;
1502 int taglen;
1503
1504 for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
1505 switch (optptr[0]) {
1506 case IPOPT_END:
1507 return NULL;
1508 case IPOPT_NOOP:
1509 taglen = 1;
1510 break;
1511 default:
1512 taglen = optptr[1];
1513 }
1514 if (!taglen || taglen > optlen)
1515 return NULL;
1516 if (optptr[0] == IPOPT_CIPSO)
1517 return optptr;
1518
1519 optlen -= taglen;
1520 optptr += taglen;
1521 }
1522
1523 return NULL;
1524}
1525
1526/**
1527 * cipso_v4_validate - Validate a CIPSO option
1528 * @skb: the packet
1529 * @option: the start of the option, on error it is set to point to the error
1530 *
1531 * Description:
1532 * This routine is called to validate a CIPSO option, it checks all of the
1533 * fields to ensure that they are at least valid, see the draft snippet below
1534 * for details. If the option is valid then a zero value is returned and
1535 * the value of @option is unchanged. If the option is invalid then a
1536 * non-zero value is returned and @option is adjusted to point to the
1537 * offending portion of the option. From the IETF draft ...
1538 *
1539 * "If any field within the CIPSO options, such as the DOI identifier, is not
1540 * recognized the IP datagram is discarded and an ICMP 'parameter problem'
1541 * (type 12) is generated and returned. The ICMP code field is set to 'bad
1542 * parameter' (code 0) and the pointer is set to the start of the CIPSO field
1543 * that is unrecognized."
1544 *
1545 */
1546int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
1547{
1548 unsigned char *opt = *option;
1549 unsigned char *tag;
1550 unsigned char opt_iter;
1551 unsigned char err_offset = 0;
1552 u8 opt_len;
1553 u8 tag_len;
1554 struct cipso_v4_doi *doi_def = NULL;
1555 u32 tag_iter;
1556
1557 /* caller already checks for length values that are too large */
1558 opt_len = opt[1];
1559 if (opt_len < 8) {
1560 err_offset = 1;
1561 goto validate_return;
1562 }
1563
1564 rcu_read_lock();
1565 doi_def = cipso_v4_doi_search(doi: get_unaligned_be32(p: &opt[2]));
1566 if (!doi_def) {
1567 err_offset = 2;
1568 goto validate_return_locked;
1569 }
1570
1571 opt_iter = CIPSO_V4_HDR_LEN;
1572 tag = opt + opt_iter;
1573 while (opt_iter < opt_len) {
1574 for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
1575 if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
1576 ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
1577 err_offset = opt_iter;
1578 goto validate_return_locked;
1579 }
1580
1581 if (opt_iter + 1 == opt_len) {
1582 err_offset = opt_iter;
1583 goto validate_return_locked;
1584 }
1585 tag_len = tag[1];
1586 if (tag_len > (opt_len - opt_iter)) {
1587 err_offset = opt_iter + 1;
1588 goto validate_return_locked;
1589 }
1590
1591 switch (tag[0]) {
1592 case CIPSO_V4_TAG_RBITMAP:
1593 if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
1594 err_offset = opt_iter + 1;
1595 goto validate_return_locked;
1596 }
1597
1598 /* We are already going to do all the verification
1599 * necessary at the socket layer so from our point of
1600 * view it is safe to turn these checks off (and less
1601 * work), however, the CIPSO draft says we should do
1602 * all the CIPSO validations here but it doesn't
1603 * really specify _exactly_ what we need to validate
1604 * ... so, just make it a sysctl tunable. */
1605 if (READ_ONCE(cipso_v4_rbm_strictvalid)) {
1606 if (cipso_v4_map_lvl_valid(doi_def,
1607 level: tag[3]) < 0) {
1608 err_offset = opt_iter + 3;
1609 goto validate_return_locked;
1610 }
1611 if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
1612 cipso_v4_map_cat_rbm_valid(doi_def,
1613 bitmap: &tag[4],
1614 bitmap_len: tag_len - 4) < 0) {
1615 err_offset = opt_iter + 4;
1616 goto validate_return_locked;
1617 }
1618 }
1619 break;
1620 case CIPSO_V4_TAG_ENUM:
1621 if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
1622 err_offset = opt_iter + 1;
1623 goto validate_return_locked;
1624 }
1625
1626 if (cipso_v4_map_lvl_valid(doi_def,
1627 level: tag[3]) < 0) {
1628 err_offset = opt_iter + 3;
1629 goto validate_return_locked;
1630 }
1631 if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
1632 cipso_v4_map_cat_enum_valid(doi_def,
1633 enumcat: &tag[4],
1634 enumcat_len: tag_len - 4) < 0) {
1635 err_offset = opt_iter + 4;
1636 goto validate_return_locked;
1637 }
1638 break;
1639 case CIPSO_V4_TAG_RANGE:
1640 if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
1641 err_offset = opt_iter + 1;
1642 goto validate_return_locked;
1643 }
1644
1645 if (cipso_v4_map_lvl_valid(doi_def,
1646 level: tag[3]) < 0) {
1647 err_offset = opt_iter + 3;
1648 goto validate_return_locked;
1649 }
1650 if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
1651 cipso_v4_map_cat_rng_valid(doi_def,
1652 rngcat: &tag[4],
1653 rngcat_len: tag_len - 4) < 0) {
1654 err_offset = opt_iter + 4;
1655 goto validate_return_locked;
1656 }
1657 break;
1658 case CIPSO_V4_TAG_LOCAL:
1659 /* This is a non-standard tag that we only allow for
1660 * local connections, so if the incoming interface is
1661 * not the loopback device drop the packet. Further,
1662 * there is no legitimate reason for setting this from
1663 * userspace so reject it if skb is NULL. */
1664 if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) {
1665 err_offset = opt_iter;
1666 goto validate_return_locked;
1667 }
1668 if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
1669 err_offset = opt_iter + 1;
1670 goto validate_return_locked;
1671 }
1672 break;
1673 default:
1674 err_offset = opt_iter;
1675 goto validate_return_locked;
1676 }
1677
1678 tag += tag_len;
1679 opt_iter += tag_len;
1680 }
1681
1682validate_return_locked:
1683 rcu_read_unlock();
1684validate_return:
1685 *option = opt + err_offset;
1686 return err_offset;
1687}
1688
1689/**
1690 * cipso_v4_error - Send the correct response for a bad packet
1691 * @skb: the packet
1692 * @error: the error code
1693 * @gateway: CIPSO gateway flag
1694 *
1695 * Description:
1696 * Based on the error code given in @error, send an ICMP error message back to
1697 * the originating host. From the IETF draft ...
1698 *
1699 * "If the contents of the CIPSO [option] are valid but the security label is
1700 * outside of the configured host or port label range, the datagram is
1701 * discarded and an ICMP 'destination unreachable' (type 3) is generated and
1702 * returned. The code field of the ICMP is set to 'communication with
1703 * destination network administratively prohibited' (code 9) or to
1704 * 'communication with destination host administratively prohibited'
1705 * (code 10). The value of the code is dependent on whether the originator
1706 * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The
1707 * recipient of the ICMP message MUST be able to handle either value. The
1708 * same procedure is performed if a CIPSO [option] can not be added to an
1709 * IP packet because it is too large to fit in the IP options area."
1710 *
1711 * "If the error is triggered by receipt of an ICMP message, the message is
1712 * discarded and no response is permitted (consistent with general ICMP
1713 * processing rules)."
1714 *
1715 */
1716void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
1717{
1718 struct inet_skb_parm parm;
1719 int res;
1720
1721 if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
1722 return;
1723
1724 /*
1725 * We might be called above the IP layer,
1726 * so we can not use icmp_send and IPCB here.
1727 */
1728
1729 memset(s: &parm, c: 0, n: sizeof(parm));
1730 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1731 rcu_read_lock();
1732 res = __ip_options_compile(net: dev_net(dev: skb->dev), opt: &parm.opt, skb, NULL);
1733 rcu_read_unlock();
1734
1735 if (res)
1736 return;
1737
1738 if (gateway)
1739 __icmp_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, info: 0, parm: &parm);
1740 else
1741 __icmp_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, info: 0, parm: &parm);
1742}
1743
1744/**
1745 * cipso_v4_genopt - Generate a CIPSO option
1746 * @buf: the option buffer
1747 * @buf_len: the size of opt_buf
1748 * @doi_def: the CIPSO DOI to use
1749 * @secattr: the security attributes
1750 *
1751 * Description:
1752 * Generate a CIPSO option using the DOI definition and security attributes
1753 * passed to the function. Returns the length of the option on success and
1754 * negative values on failure.
1755 *
1756 */
1757static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
1758 const struct cipso_v4_doi *doi_def,
1759 const struct netlbl_lsm_secattr *secattr)
1760{
1761 int ret_val;
1762 u32 iter;
1763
1764 if (buf_len <= CIPSO_V4_HDR_LEN)
1765 return -ENOSPC;
1766
1767 /* XXX - This code assumes only one tag per CIPSO option which isn't
1768 * really a good assumption to make but since we only support the MAC
1769 * tags right now it is a safe assumption. */
1770 iter = 0;
1771 do {
1772 memset(s: buf, c: 0, n: buf_len);
1773 switch (doi_def->tags[iter]) {
1774 case CIPSO_V4_TAG_RBITMAP:
1775 ret_val = cipso_v4_gentag_rbm(doi_def,
1776 secattr,
1777 buffer: &buf[CIPSO_V4_HDR_LEN],
1778 buffer_len: buf_len - CIPSO_V4_HDR_LEN);
1779 break;
1780 case CIPSO_V4_TAG_ENUM:
1781 ret_val = cipso_v4_gentag_enum(doi_def,
1782 secattr,
1783 buffer: &buf[CIPSO_V4_HDR_LEN],
1784 buffer_len: buf_len - CIPSO_V4_HDR_LEN);
1785 break;
1786 case CIPSO_V4_TAG_RANGE:
1787 ret_val = cipso_v4_gentag_rng(doi_def,
1788 secattr,
1789 buffer: &buf[CIPSO_V4_HDR_LEN],
1790 buffer_len: buf_len - CIPSO_V4_HDR_LEN);
1791 break;
1792 case CIPSO_V4_TAG_LOCAL:
1793 ret_val = cipso_v4_gentag_loc(doi_def,
1794 secattr,
1795 buffer: &buf[CIPSO_V4_HDR_LEN],
1796 buffer_len: buf_len - CIPSO_V4_HDR_LEN);
1797 break;
1798 default:
1799 return -EPERM;
1800 }
1801
1802 iter++;
1803 } while (ret_val < 0 &&
1804 iter < CIPSO_V4_TAG_MAXCNT &&
1805 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
1806 if (ret_val < 0)
1807 return ret_val;
1808 cipso_v4_gentag_hdr(doi_def, buf, len: ret_val);
1809 return CIPSO_V4_HDR_LEN + ret_val;
1810}
1811
1812static int cipso_v4_get_actual_opt_len(const unsigned char *data, int len)
1813{
1814 int iter = 0, optlen = 0;
1815
1816 /* determining the new total option length is tricky because of
1817 * the padding necessary, the only thing i can think to do at
1818 * this point is walk the options one-by-one, skipping the
1819 * padding at the end to determine the actual option size and
1820 * from there we can determine the new total option length
1821 */
1822 while (iter < len) {
1823 if (data[iter] == IPOPT_END) {
1824 break;
1825 } else if (data[iter] == IPOPT_NOP) {
1826 iter++;
1827 } else {
1828 iter += data[iter + 1];
1829 optlen = iter;
1830 }
1831 }
1832 return optlen;
1833}
1834
1835/**
1836 * cipso_v4_sock_setattr - Add a CIPSO option to a socket
1837 * @sk: the socket
1838 * @doi_def: the CIPSO DOI to use
1839 * @secattr: the specific security attributes of the socket
1840 * @sk_locked: true if caller holds the socket lock
1841 *
1842 * Description:
1843 * Set the CIPSO option on the given socket using the DOI definition and
1844 * security attributes passed to the function. This function requires
1845 * exclusive access to @sk, which means it either needs to be in the
1846 * process of being created or locked. Returns zero on success and negative
1847 * values on failure.
1848 *
1849 */
1850int cipso_v4_sock_setattr(struct sock *sk,
1851 const struct cipso_v4_doi *doi_def,
1852 const struct netlbl_lsm_secattr *secattr,
1853 bool sk_locked)
1854{
1855 int ret_val = -EPERM;
1856 unsigned char *buf = NULL;
1857 u32 buf_len;
1858 u32 opt_len;
1859 struct ip_options_rcu *old, *opt = NULL;
1860 struct inet_sock *sk_inet;
1861 struct inet_connection_sock *sk_conn;
1862
1863 /* In the case of sock_create_lite(), the sock->sk field is not
1864 * defined yet but it is not a problem as the only users of these
1865 * "lite" PF_INET sockets are functions which do an accept() call
1866 * afterwards so we will label the socket as part of the accept(). */
1867 if (!sk)
1868 return 0;
1869
1870 /* We allocate the maximum CIPSO option size here so we are probably
1871 * being a little wasteful, but it makes our life _much_ easier later
1872 * on and after all we are only talking about 40 bytes. */
1873 buf_len = CIPSO_V4_OPT_LEN_MAX;
1874 buf = kmalloc(buf_len, GFP_ATOMIC);
1875 if (!buf) {
1876 ret_val = -ENOMEM;
1877 goto socket_setattr_failure;
1878 }
1879
1880 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1881 if (ret_val < 0)
1882 goto socket_setattr_failure;
1883 buf_len = ret_val;
1884
1885 /* We can't use ip_options_get() directly because it makes a call to
1886 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1887 * we won't always have CAP_NET_RAW even though we _always_ want to
1888 * set the IPOPT_CIPSO option. */
1889 opt_len = (buf_len + 3) & ~3;
1890 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1891 if (!opt) {
1892 ret_val = -ENOMEM;
1893 goto socket_setattr_failure;
1894 }
1895 memcpy(to: opt->opt.__data, from: buf, len: buf_len);
1896 opt->opt.optlen = opt_len;
1897 opt->opt.cipso = sizeof(struct iphdr);
1898 kfree(objp: buf);
1899 buf = NULL;
1900
1901 sk_inet = inet_sk(sk);
1902
1903 old = rcu_dereference_protected(sk_inet->inet_opt, sk_locked);
1904 if (inet_test_bit(IS_ICSK, sk)) {
1905 sk_conn = inet_csk(sk);
1906 if (old)
1907 sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
1908 sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
1909 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
1910 }
1911 rcu_assign_pointer(sk_inet->inet_opt, opt);
1912 if (old)
1913 kfree_rcu(old, rcu);
1914
1915 return 0;
1916
1917socket_setattr_failure:
1918 kfree(objp: buf);
1919 kfree(objp: opt);
1920 return ret_val;
1921}
1922
1923/**
1924 * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket
1925 * @req: the connection request socket
1926 * @doi_def: the CIPSO DOI to use
1927 * @secattr: the specific security attributes of the socket
1928 *
1929 * Description:
1930 * Set the CIPSO option on the given socket using the DOI definition and
1931 * security attributes passed to the function. Returns zero on success and
1932 * negative values on failure.
1933 *
1934 */
1935int cipso_v4_req_setattr(struct request_sock *req,
1936 const struct cipso_v4_doi *doi_def,
1937 const struct netlbl_lsm_secattr *secattr)
1938{
1939 int ret_val = -EPERM;
1940 unsigned char *buf = NULL;
1941 u32 buf_len;
1942 u32 opt_len;
1943 struct ip_options_rcu *opt = NULL;
1944 struct inet_request_sock *req_inet;
1945
1946 /* We allocate the maximum CIPSO option size here so we are probably
1947 * being a little wasteful, but it makes our life _much_ easier later
1948 * on and after all we are only talking about 40 bytes. */
1949 buf_len = CIPSO_V4_OPT_LEN_MAX;
1950 buf = kmalloc(buf_len, GFP_ATOMIC);
1951 if (!buf) {
1952 ret_val = -ENOMEM;
1953 goto req_setattr_failure;
1954 }
1955
1956 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
1957 if (ret_val < 0)
1958 goto req_setattr_failure;
1959 buf_len = ret_val;
1960
1961 /* We can't use ip_options_get() directly because it makes a call to
1962 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
1963 * we won't always have CAP_NET_RAW even though we _always_ want to
1964 * set the IPOPT_CIPSO option. */
1965 opt_len = (buf_len + 3) & ~3;
1966 opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
1967 if (!opt) {
1968 ret_val = -ENOMEM;
1969 goto req_setattr_failure;
1970 }
1971 memcpy(to: opt->opt.__data, from: buf, len: buf_len);
1972 opt->opt.optlen = opt_len;
1973 opt->opt.cipso = sizeof(struct iphdr);
1974 kfree(objp: buf);
1975 buf = NULL;
1976
1977 req_inet = inet_rsk(sk: req);
1978 opt = unrcu_pointer(xchg(&req_inet->ireq_opt, RCU_INITIALIZER(opt)));
1979 if (opt)
1980 kfree_rcu(opt, rcu);
1981
1982 return 0;
1983
1984req_setattr_failure:
1985 kfree(objp: buf);
1986 kfree(objp: opt);
1987 return ret_val;
1988}
1989
1990/**
1991 * cipso_v4_delopt - Delete the CIPSO option from a set of IP options
1992 * @opt_ptr: IP option pointer
1993 *
1994 * Description:
1995 * Deletes the CIPSO IP option from a set of IP options and makes the necessary
1996 * adjustments to the IP option structure. Returns zero on success, negative
1997 * values on failure.
1998 *
1999 */
2000static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr)
2001{
2002 struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1);
2003 int hdr_delta = 0;
2004
2005 if (!opt || opt->opt.cipso == 0)
2006 return 0;
2007 if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
2008 u8 cipso_len;
2009 u8 cipso_off;
2010 unsigned char *cipso_ptr;
2011 int optlen_new;
2012
2013 cipso_off = opt->opt.cipso - sizeof(struct iphdr);
2014 cipso_ptr = &opt->opt.__data[cipso_off];
2015 cipso_len = cipso_ptr[1];
2016
2017 if (opt->opt.srr > opt->opt.cipso)
2018 opt->opt.srr -= cipso_len;
2019 if (opt->opt.rr > opt->opt.cipso)
2020 opt->opt.rr -= cipso_len;
2021 if (opt->opt.ts > opt->opt.cipso)
2022 opt->opt.ts -= cipso_len;
2023 if (opt->opt.router_alert > opt->opt.cipso)
2024 opt->opt.router_alert -= cipso_len;
2025 opt->opt.cipso = 0;
2026
2027 memmove(dest: cipso_ptr, src: cipso_ptr + cipso_len,
2028 count: opt->opt.optlen - cipso_off - cipso_len);
2029
2030 optlen_new = cipso_v4_get_actual_opt_len(data: opt->opt.__data,
2031 len: opt->opt.optlen);
2032 hdr_delta = opt->opt.optlen;
2033 opt->opt.optlen = (optlen_new + 3) & ~3;
2034 hdr_delta -= opt->opt.optlen;
2035 } else {
2036 /* only the cipso option was present on the socket so we can
2037 * remove the entire option struct */
2038 *opt_ptr = NULL;
2039 hdr_delta = opt->opt.optlen;
2040 kfree_rcu(opt, rcu);
2041 }
2042
2043 return hdr_delta;
2044}
2045
2046/**
2047 * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
2048 * @sk: the socket
2049 *
2050 * Description:
2051 * Removes the CIPSO option from a socket, if present.
2052 *
2053 */
2054void cipso_v4_sock_delattr(struct sock *sk)
2055{
2056 struct inet_sock *sk_inet;
2057 int hdr_delta;
2058
2059 sk_inet = inet_sk(sk);
2060
2061 hdr_delta = cipso_v4_delopt(opt_ptr: &sk_inet->inet_opt);
2062 if (inet_test_bit(IS_ICSK, sk) && hdr_delta > 0) {
2063 struct inet_connection_sock *sk_conn = inet_csk(sk);
2064 sk_conn->icsk_ext_hdr_len -= hdr_delta;
2065 sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
2066 }
2067}
2068
2069/**
2070 * cipso_v4_req_delattr - Delete the CIPSO option from a request socket
2071 * @req: the request socket
2072 *
2073 * Description:
2074 * Removes the CIPSO option from a request socket, if present.
2075 *
2076 */
2077void cipso_v4_req_delattr(struct request_sock *req)
2078{
2079 cipso_v4_delopt(opt_ptr: &inet_rsk(sk: req)->ireq_opt);
2080}
2081
2082/**
2083 * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
2084 * @cipso: the CIPSO v4 option
2085 * @secattr: the security attributes
2086 *
2087 * Description:
2088 * Inspect @cipso and return the security attributes in @secattr. Returns zero
2089 * on success and negative values on failure.
2090 *
2091 */
2092int cipso_v4_getattr(const unsigned char *cipso,
2093 struct netlbl_lsm_secattr *secattr)
2094{
2095 int ret_val = -ENOMSG;
2096 u32 doi;
2097 struct cipso_v4_doi *doi_def;
2098
2099 if (cipso_v4_cache_check(key: cipso, key_len: cipso[1], secattr) == 0)
2100 return 0;
2101
2102 doi = get_unaligned_be32(p: &cipso[2]);
2103 rcu_read_lock();
2104 doi_def = cipso_v4_doi_search(doi);
2105 if (!doi_def)
2106 goto getattr_return;
2107 /* XXX - This code assumes only one tag per CIPSO option which isn't
2108 * really a good assumption to make but since we only support the MAC
2109 * tags right now it is a safe assumption. */
2110 switch (cipso[6]) {
2111 case CIPSO_V4_TAG_RBITMAP:
2112 ret_val = cipso_v4_parsetag_rbm(doi_def, tag: &cipso[6], secattr);
2113 break;
2114 case CIPSO_V4_TAG_ENUM:
2115 ret_val = cipso_v4_parsetag_enum(doi_def, tag: &cipso[6], secattr);
2116 break;
2117 case CIPSO_V4_TAG_RANGE:
2118 ret_val = cipso_v4_parsetag_rng(doi_def, tag: &cipso[6], secattr);
2119 break;
2120 case CIPSO_V4_TAG_LOCAL:
2121 ret_val = cipso_v4_parsetag_loc(doi_def, tag: &cipso[6], secattr);
2122 break;
2123 }
2124 if (ret_val == 0)
2125 secattr->type = NETLBL_NLTYPE_CIPSOV4;
2126
2127getattr_return:
2128 rcu_read_unlock();
2129 return ret_val;
2130}
2131
2132/**
2133 * cipso_v4_sock_getattr - Get the security attributes from a sock
2134 * @sk: the sock
2135 * @secattr: the security attributes
2136 *
2137 * Description:
2138 * Query @sk to see if there is a CIPSO option attached to the sock and if
2139 * there is return the CIPSO security attributes in @secattr. This function
2140 * requires that @sk be locked, or privately held, but it does not do any
2141 * locking itself. Returns zero on success and negative values on failure.
2142 *
2143 */
2144int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
2145{
2146 struct ip_options_rcu *opt;
2147 int res = -ENOMSG;
2148
2149 rcu_read_lock();
2150 opt = rcu_dereference(inet_sk(sk)->inet_opt);
2151 if (opt && opt->opt.cipso)
2152 res = cipso_v4_getattr(cipso: opt->opt.__data +
2153 opt->opt.cipso -
2154 sizeof(struct iphdr),
2155 secattr);
2156 rcu_read_unlock();
2157 return res;
2158}
2159
2160/**
2161 * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
2162 * @skb: the packet
2163 * @doi_def: the DOI structure
2164 * @secattr: the security attributes
2165 *
2166 * Description:
2167 * Set the CIPSO option on the given packet based on the security attributes.
2168 * Returns a pointer to the IP header on success and NULL on failure.
2169 *
2170 */
2171int cipso_v4_skbuff_setattr(struct sk_buff *skb,
2172 const struct cipso_v4_doi *doi_def,
2173 const struct netlbl_lsm_secattr *secattr)
2174{
2175 int ret_val;
2176 struct iphdr *iph;
2177 struct ip_options *opt = &IPCB(skb)->opt;
2178 unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
2179 u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
2180 u32 opt_len;
2181 int len_delta;
2182
2183 ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
2184 if (ret_val < 0)
2185 return ret_val;
2186 buf_len = ret_val;
2187 opt_len = (buf_len + 3) & ~3;
2188
2189 /* we overwrite any existing options to ensure that we have enough
2190 * room for the CIPSO option, the reason is that we _need_ to guarantee
2191 * that the security label is applied to the packet - we do the same
2192 * thing when using the socket options and it hasn't caused a problem,
2193 * if we need to we can always revisit this choice later */
2194
2195 len_delta = opt_len - opt->optlen;
2196 /* if we don't ensure enough headroom we could panic on the skb_push()
2197 * call below so make sure we have enough, we are also "mangling" the
2198 * packet so we should probably do a copy-on-write call anyway */
2199 ret_val = skb_cow(skb, headroom: skb_headroom(skb) + len_delta);
2200 if (ret_val < 0)
2201 return ret_val;
2202
2203 if (len_delta > 0) {
2204 /* we assume that the header + opt->optlen have already been
2205 * "pushed" in ip_options_build() or similar */
2206 iph = ip_hdr(skb);
2207 skb_push(skb, len: len_delta);
2208 memmove(dest: (char *)iph - len_delta, src: iph, count: iph->ihl << 2);
2209 skb_reset_network_header(skb);
2210 iph = ip_hdr(skb);
2211 } else if (len_delta < 0) {
2212 iph = ip_hdr(skb);
2213 memset(s: iph + 1, IPOPT_NOP, n: opt->optlen);
2214 } else
2215 iph = ip_hdr(skb);
2216
2217 if (opt->optlen > 0)
2218 memset(s: opt, c: 0, n: sizeof(*opt));
2219 opt->optlen = opt_len;
2220 opt->cipso = sizeof(struct iphdr);
2221 opt->is_changed = 1;
2222
2223 /* we have to do the following because we are being called from a
2224 * netfilter hook which means the packet already has had the header
2225 * fields populated and the checksum calculated - yes this means we
2226 * are doing more work than needed but we do it to keep the core
2227 * stack clean and tidy */
2228 memcpy(to: iph + 1, from: buf, len: buf_len);
2229 if (opt_len > buf_len)
2230 memset(s: (char *)(iph + 1) + buf_len, c: 0, n: opt_len - buf_len);
2231 if (len_delta != 0) {
2232 iph->ihl = 5 + (opt_len >> 2);
2233 iph_set_totlen(iph, len: skb->len);
2234 }
2235 ip_send_check(ip: iph);
2236
2237 return 0;
2238}
2239
2240/**
2241 * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
2242 * @skb: the packet
2243 *
2244 * Description:
2245 * Removes any and all CIPSO options from the given packet. Returns zero on
2246 * success, negative values on failure.
2247 *
2248 */
2249int cipso_v4_skbuff_delattr(struct sk_buff *skb)
2250{
2251 int ret_val, cipso_len, hdr_len_actual, new_hdr_len_actual, new_hdr_len,
2252 hdr_len_delta;
2253 struct iphdr *iph;
2254 struct ip_options *opt = &IPCB(skb)->opt;
2255 unsigned char *cipso_ptr;
2256
2257 if (opt->cipso == 0)
2258 return 0;
2259
2260 /* since we are changing the packet we should make a copy */
2261 ret_val = skb_cow(skb, headroom: skb_headroom(skb));
2262 if (ret_val < 0)
2263 return ret_val;
2264
2265 iph = ip_hdr(skb);
2266 cipso_ptr = (unsigned char *)iph + opt->cipso;
2267 cipso_len = cipso_ptr[1];
2268
2269 hdr_len_actual = sizeof(struct iphdr) +
2270 cipso_v4_get_actual_opt_len(data: (unsigned char *)(iph + 1),
2271 len: opt->optlen);
2272 new_hdr_len_actual = hdr_len_actual - cipso_len;
2273 new_hdr_len = (new_hdr_len_actual + 3) & ~3;
2274 hdr_len_delta = (iph->ihl << 2) - new_hdr_len;
2275
2276 /* 1. shift any options after CIPSO to the left */
2277 memmove(dest: cipso_ptr, src: cipso_ptr + cipso_len,
2278 count: new_hdr_len_actual - opt->cipso);
2279 /* 2. move the whole IP header to its new place */
2280 memmove(dest: (unsigned char *)iph + hdr_len_delta, src: iph, count: new_hdr_len_actual);
2281 /* 3. adjust the skb layout */
2282 skb_pull(skb, len: hdr_len_delta);
2283 skb_reset_network_header(skb);
2284 iph = ip_hdr(skb);
2285 /* 4. re-fill new padding with IPOPT_END (may now be longer) */
2286 memset(s: (unsigned char *)iph + new_hdr_len_actual, IPOPT_END,
2287 n: new_hdr_len - new_hdr_len_actual);
2288
2289 opt->optlen -= hdr_len_delta;
2290 opt->cipso = 0;
2291 opt->is_changed = 1;
2292 if (hdr_len_delta != 0) {
2293 iph->ihl = new_hdr_len >> 2;
2294 iph_set_totlen(iph, len: skb->len);
2295 }
2296 ip_send_check(ip: iph);
2297
2298 return 0;
2299}
2300
2301/*
2302 * Setup Functions
2303 */
2304
2305/**
2306 * cipso_v4_init - Initialize the CIPSO module
2307 *
2308 * Description:
2309 * Initialize the CIPSO module and prepare it for use. Returns zero on success
2310 * and negative values on failure.
2311 *
2312 */
2313static int __init cipso_v4_init(void)
2314{
2315 int ret_val;
2316
2317 ret_val = cipso_v4_cache_init();
2318 if (ret_val != 0)
2319 panic(fmt: "Failed to initialize the CIPSO/IPv4 cache (%d)\n",
2320 ret_val);
2321
2322 return 0;
2323}
2324
2325subsys_initcall(cipso_v4_init);
2326