1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CALIPSO - Common Architecture Label IPv6 Security Option
4 *
5 * This is an implementation of the CALIPSO protocol as specified in
6 * RFC 5570.
7 *
8 * Authors: Paul Moore <paul.moore@hp.com>
9 * Huw Davies <huw@codeweavers.com>
10 */
11
12/* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
13 * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015
14 */
15
16#include <linux/init.h>
17#include <linux/types.h>
18#include <linux/rcupdate.h>
19#include <linux/list.h>
20#include <linux/spinlock.h>
21#include <linux/string.h>
22#include <linux/jhash.h>
23#include <linux/audit.h>
24#include <linux/slab.h>
25#include <net/ip.h>
26#include <net/icmp.h>
27#include <net/tcp.h>
28#include <net/netlabel.h>
29#include <net/calipso.h>
30#include <linux/atomic.h>
31#include <linux/bug.h>
32#include <linux/unaligned.h>
33#include <linux/crc-ccitt.h>
34
35/* Maximum size of the calipso option including
36 * the two-byte TLV header.
37 */
38#define CALIPSO_OPT_LEN_MAX (2 + 252)
39
40/* Size of the minimum calipso option including
41 * the two-byte TLV header.
42 */
43#define CALIPSO_HDR_LEN (2 + 8)
44
45/* Maximum size of the calipso option including
46 * the two-byte TLV header and upto 3 bytes of
47 * leading pad and 7 bytes of trailing pad.
48 */
49#define CALIPSO_OPT_LEN_MAX_WITH_PAD (3 + CALIPSO_OPT_LEN_MAX + 7)
50
51 /* Maximum size of u32 aligned buffer required to hold calipso
52 * option. Max of 3 initial pad bytes starting from buffer + 3.
53 * i.e. the worst case is when the previous tlv finishes on 4n + 3.
54 */
55#define CALIPSO_MAX_BUFFER (6 + CALIPSO_OPT_LEN_MAX)
56
57/* List of available DOI definitions */
58static DEFINE_SPINLOCK(calipso_doi_list_lock);
59static LIST_HEAD(calipso_doi_list);
60
61/* Label mapping cache */
62int calipso_cache_enabled = 1;
63int calipso_cache_bucketsize = 10;
64#define CALIPSO_CACHE_BUCKETBITS 7
65#define CALIPSO_CACHE_BUCKETS BIT(CALIPSO_CACHE_BUCKETBITS)
66#define CALIPSO_CACHE_REORDERLIMIT 10
67struct calipso_map_cache_bkt {
68 spinlock_t lock;
69 u32 size;
70 struct list_head list;
71};
72
73struct calipso_map_cache_entry {
74 u32 hash;
75 unsigned char *key;
76 size_t key_len;
77
78 struct netlbl_lsm_cache *lsm_data;
79
80 u32 activity;
81 struct list_head list;
82};
83
84static struct calipso_map_cache_bkt *calipso_cache;
85
86static void calipso_cache_invalidate(void);
87static void calipso_doi_putdef(struct calipso_doi *doi_def);
88
89/* Label Mapping Cache Functions
90 */
91
92/**
93 * calipso_cache_entry_free - Frees a cache entry
94 * @entry: the entry to free
95 *
96 * Description:
97 * This function frees the memory associated with a cache entry including the
98 * LSM cache data if there are no longer any users, i.e. reference count == 0.
99 *
100 */
101static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry)
102{
103 if (entry->lsm_data)
104 netlbl_secattr_cache_free(cache: entry->lsm_data);
105 kfree(objp: entry->key);
106 kfree(objp: entry);
107}
108
109/**
110 * calipso_map_cache_hash - Hashing function for the CALIPSO cache
111 * @key: the hash key
112 * @key_len: the length of the key in bytes
113 *
114 * Description:
115 * The CALIPSO tag hashing function. Returns a 32-bit hash value.
116 *
117 */
118static u32 calipso_map_cache_hash(const unsigned char *key, u32 key_len)
119{
120 return jhash(key, length: key_len, initval: 0);
121}
122
123/**
124 * calipso_cache_init - Initialize the CALIPSO cache
125 *
126 * Description:
127 * Initializes the CALIPSO label mapping cache, this function should be called
128 * before any of the other functions defined in this file. Returns zero on
129 * success, negative values on error.
130 *
131 */
132static int __init calipso_cache_init(void)
133{
134 u32 iter;
135
136 calipso_cache = kcalloc(CALIPSO_CACHE_BUCKETS,
137 sizeof(struct calipso_map_cache_bkt),
138 GFP_KERNEL);
139 if (!calipso_cache)
140 return -ENOMEM;
141
142 for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
143 spin_lock_init(&calipso_cache[iter].lock);
144 calipso_cache[iter].size = 0;
145 INIT_LIST_HEAD(list: &calipso_cache[iter].list);
146 }
147
148 return 0;
149}
150
151/**
152 * calipso_cache_invalidate - Invalidates the current CALIPSO cache
153 *
154 * Description:
155 * Invalidates and frees any entries in the CALIPSO cache. Returns zero on
156 * success and negative values on failure.
157 *
158 */
159static void calipso_cache_invalidate(void)
160{
161 struct calipso_map_cache_entry *entry, *tmp_entry;
162 u32 iter;
163
164 for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
165 spin_lock_bh(lock: &calipso_cache[iter].lock);
166 list_for_each_entry_safe(entry,
167 tmp_entry,
168 &calipso_cache[iter].list, list) {
169 list_del(entry: &entry->list);
170 calipso_cache_entry_free(entry);
171 }
172 calipso_cache[iter].size = 0;
173 spin_unlock_bh(lock: &calipso_cache[iter].lock);
174 }
175}
176
177/**
178 * calipso_cache_check - Check the CALIPSO cache for a label mapping
179 * @key: the buffer to check
180 * @key_len: buffer length in bytes
181 * @secattr: the security attribute struct to use
182 *
183 * Description:
184 * This function checks the cache to see if a label mapping already exists for
185 * the given key. If there is a match then the cache is adjusted and the
186 * @secattr struct is populated with the correct LSM security attributes. The
187 * cache is adjusted in the following manner if the entry is not already the
188 * first in the cache bucket:
189 *
190 * 1. The cache entry's activity counter is incremented
191 * 2. The previous (higher ranking) entry's activity counter is decremented
192 * 3. If the difference between the two activity counters is geater than
193 * CALIPSO_CACHE_REORDERLIMIT the two entries are swapped
194 *
195 * Returns zero on success, -ENOENT for a cache miss, and other negative values
196 * on error.
197 *
198 */
199static int calipso_cache_check(const unsigned char *key,
200 u32 key_len,
201 struct netlbl_lsm_secattr *secattr)
202{
203 u32 bkt;
204 struct calipso_map_cache_entry *entry;
205 struct calipso_map_cache_entry *prev_entry = NULL;
206 u32 hash;
207
208 if (!calipso_cache_enabled)
209 return -ENOENT;
210
211 hash = calipso_map_cache_hash(key, key_len);
212 bkt = hash & (CALIPSO_CACHE_BUCKETS - 1);
213 spin_lock_bh(lock: &calipso_cache[bkt].lock);
214 list_for_each_entry(entry, &calipso_cache[bkt].list, list) {
215 if (entry->hash == hash &&
216 entry->key_len == key_len &&
217 memcmp(entry->key, key, key_len) == 0) {
218 entry->activity += 1;
219 refcount_inc(r: &entry->lsm_data->refcount);
220 secattr->cache = entry->lsm_data;
221 secattr->flags |= NETLBL_SECATTR_CACHE;
222 secattr->type = NETLBL_NLTYPE_CALIPSO;
223 if (!prev_entry) {
224 spin_unlock_bh(lock: &calipso_cache[bkt].lock);
225 return 0;
226 }
227
228 if (prev_entry->activity > 0)
229 prev_entry->activity -= 1;
230 if (entry->activity > prev_entry->activity &&
231 entry->activity - prev_entry->activity >
232 CALIPSO_CACHE_REORDERLIMIT) {
233 __list_del(prev: entry->list.prev, next: entry->list.next);
234 __list_add(new: &entry->list,
235 prev: prev_entry->list.prev,
236 next: &prev_entry->list);
237 }
238
239 spin_unlock_bh(lock: &calipso_cache[bkt].lock);
240 return 0;
241 }
242 prev_entry = entry;
243 }
244 spin_unlock_bh(lock: &calipso_cache[bkt].lock);
245
246 return -ENOENT;
247}
248
249/**
250 * calipso_cache_add - Add an entry to the CALIPSO cache
251 * @calipso_ptr: the CALIPSO option
252 * @secattr: the packet's security attributes
253 *
254 * Description:
255 * Add a new entry into the CALIPSO label mapping cache. Add the new entry to
256 * head of the cache bucket's list, if the cache bucket is out of room remove
257 * the last entry in the list first. It is important to note that there is
258 * currently no checking for duplicate keys. Returns zero on success,
259 * negative values on failure. The key stored starts at calipso_ptr + 2,
260 * i.e. the type and length bytes are not stored, this corresponds to
261 * calipso_ptr[1] bytes of data.
262 *
263 */
264static int calipso_cache_add(const unsigned char *calipso_ptr,
265 const struct netlbl_lsm_secattr *secattr)
266{
267 int ret_val = -EPERM;
268 u32 bkt;
269 struct calipso_map_cache_entry *entry = NULL;
270 struct calipso_map_cache_entry *old_entry = NULL;
271 u32 calipso_ptr_len;
272
273 if (!calipso_cache_enabled || calipso_cache_bucketsize <= 0)
274 return 0;
275
276 calipso_ptr_len = calipso_ptr[1];
277
278 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
279 if (!entry)
280 return -ENOMEM;
281 entry->key = kmemdup(calipso_ptr + 2, calipso_ptr_len, GFP_ATOMIC);
282 if (!entry->key) {
283 ret_val = -ENOMEM;
284 goto cache_add_failure;
285 }
286 entry->key_len = calipso_ptr_len;
287 entry->hash = calipso_map_cache_hash(key: calipso_ptr, key_len: calipso_ptr_len);
288 refcount_inc(r: &secattr->cache->refcount);
289 entry->lsm_data = secattr->cache;
290
291 bkt = entry->hash & (CALIPSO_CACHE_BUCKETS - 1);
292 spin_lock_bh(lock: &calipso_cache[bkt].lock);
293 if (calipso_cache[bkt].size < calipso_cache_bucketsize) {
294 list_add(new: &entry->list, head: &calipso_cache[bkt].list);
295 calipso_cache[bkt].size += 1;
296 } else {
297 old_entry = list_entry(calipso_cache[bkt].list.prev,
298 struct calipso_map_cache_entry, list);
299 list_del(entry: &old_entry->list);
300 list_add(new: &entry->list, head: &calipso_cache[bkt].list);
301 calipso_cache_entry_free(entry: old_entry);
302 }
303 spin_unlock_bh(lock: &calipso_cache[bkt].lock);
304
305 return 0;
306
307cache_add_failure:
308 if (entry)
309 calipso_cache_entry_free(entry);
310 return ret_val;
311}
312
313/* DOI List Functions
314 */
315
316/**
317 * calipso_doi_search - Searches for a DOI definition
318 * @doi: the DOI to search for
319 *
320 * Description:
321 * Search the DOI definition list for a DOI definition with a DOI value that
322 * matches @doi. The caller is responsible for calling rcu_read_[un]lock().
323 * Returns a pointer to the DOI definition on success and NULL on failure.
324 */
325static struct calipso_doi *calipso_doi_search(u32 doi)
326{
327 struct calipso_doi *iter;
328
329 list_for_each_entry_rcu(iter, &calipso_doi_list, list)
330 if (iter->doi == doi && refcount_read(r: &iter->refcount))
331 return iter;
332 return NULL;
333}
334
335/**
336 * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine
337 * @doi_def: the DOI structure
338 * @audit_info: NetLabel audit information
339 *
340 * Description:
341 * The caller defines a new DOI for use by the CALIPSO engine and calls this
342 * function to add it to the list of acceptable domains. The caller must
343 * ensure that the mapping table specified in @doi_def->map meets all of the
344 * requirements of the mapping type (see calipso.h for details). Returns
345 * zero on success and non-zero on failure.
346 *
347 */
348static int calipso_doi_add(struct calipso_doi *doi_def,
349 struct netlbl_audit *audit_info)
350{
351 int ret_val = -EINVAL;
352 u32 doi;
353 u32 doi_type;
354 struct audit_buffer *audit_buf;
355
356 doi = doi_def->doi;
357 doi_type = doi_def->type;
358
359 if (doi_def->doi == CALIPSO_DOI_UNKNOWN)
360 goto doi_add_return;
361
362 refcount_set(r: &doi_def->refcount, n: 1);
363
364 spin_lock(lock: &calipso_doi_list_lock);
365 if (calipso_doi_search(doi: doi_def->doi)) {
366 spin_unlock(lock: &calipso_doi_list_lock);
367 ret_val = -EEXIST;
368 goto doi_add_return;
369 }
370 list_add_tail_rcu(new: &doi_def->list, head: &calipso_doi_list);
371 spin_unlock(lock: &calipso_doi_list_lock);
372 ret_val = 0;
373
374doi_add_return:
375 audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_ADD, audit_info);
376 if (audit_buf) {
377 const char *type_str;
378
379 switch (doi_type) {
380 case CALIPSO_MAP_PASS:
381 type_str = "pass";
382 break;
383 default:
384 type_str = "(unknown)";
385 }
386 audit_log_format(ab: audit_buf,
387 fmt: " calipso_doi=%u calipso_type=%s res=%u",
388 doi, type_str, ret_val == 0 ? 1 : 0);
389 audit_log_end(ab: audit_buf);
390 }
391
392 return ret_val;
393}
394
395/**
396 * calipso_doi_free - Frees a DOI definition
397 * @doi_def: the DOI definition
398 *
399 * Description:
400 * This function frees all of the memory associated with a DOI definition.
401 *
402 */
403static void calipso_doi_free(struct calipso_doi *doi_def)
404{
405 kfree(objp: doi_def);
406}
407
408/**
409 * calipso_doi_free_rcu - Frees a DOI definition via the RCU pointer
410 * @entry: the entry's RCU field
411 *
412 * Description:
413 * This function is designed to be used as a callback to the call_rcu()
414 * function so that the memory allocated to the DOI definition can be released
415 * safely.
416 *
417 */
418static void calipso_doi_free_rcu(struct rcu_head *entry)
419{
420 struct calipso_doi *doi_def;
421
422 doi_def = container_of(entry, struct calipso_doi, rcu);
423 calipso_doi_free(doi_def);
424}
425
426/**
427 * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine
428 * @doi: the DOI value
429 * @audit_info: NetLabel audit information
430 *
431 * Description:
432 * Removes a DOI definition from the CALIPSO engine. The NetLabel routines will
433 * be called to release their own LSM domain mappings as well as our own
434 * domain list. Returns zero on success and negative values on failure.
435 *
436 */
437static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info)
438{
439 int ret_val;
440 struct calipso_doi *doi_def;
441 struct audit_buffer *audit_buf;
442
443 spin_lock(lock: &calipso_doi_list_lock);
444 doi_def = calipso_doi_search(doi);
445 if (!doi_def) {
446 spin_unlock(lock: &calipso_doi_list_lock);
447 ret_val = -ENOENT;
448 goto doi_remove_return;
449 }
450 list_del_rcu(entry: &doi_def->list);
451 spin_unlock(lock: &calipso_doi_list_lock);
452
453 calipso_doi_putdef(doi_def);
454 ret_val = 0;
455
456doi_remove_return:
457 audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_DEL, audit_info);
458 if (audit_buf) {
459 audit_log_format(ab: audit_buf,
460 fmt: " calipso_doi=%u res=%u",
461 doi, ret_val == 0 ? 1 : 0);
462 audit_log_end(ab: audit_buf);
463 }
464
465 return ret_val;
466}
467
468/**
469 * calipso_doi_getdef - Returns a reference to a valid DOI definition
470 * @doi: the DOI value
471 *
472 * Description:
473 * Searches for a valid DOI definition and if one is found it is returned to
474 * the caller. Otherwise NULL is returned. The caller must ensure that
475 * calipso_doi_putdef() is called when the caller is done.
476 *
477 */
478static struct calipso_doi *calipso_doi_getdef(u32 doi)
479{
480 struct calipso_doi *doi_def;
481
482 rcu_read_lock();
483 doi_def = calipso_doi_search(doi);
484 if (!doi_def)
485 goto doi_getdef_return;
486 if (!refcount_inc_not_zero(r: &doi_def->refcount))
487 doi_def = NULL;
488
489doi_getdef_return:
490 rcu_read_unlock();
491 return doi_def;
492}
493
494/**
495 * calipso_doi_putdef - Releases a reference for the given DOI definition
496 * @doi_def: the DOI definition
497 *
498 * Description:
499 * Releases a DOI definition reference obtained from calipso_doi_getdef().
500 *
501 */
502static void calipso_doi_putdef(struct calipso_doi *doi_def)
503{
504 if (!doi_def)
505 return;
506
507 if (!refcount_dec_and_test(r: &doi_def->refcount))
508 return;
509
510 calipso_cache_invalidate();
511 call_rcu(head: &doi_def->rcu, func: calipso_doi_free_rcu);
512}
513
514/**
515 * calipso_doi_walk - Iterate through the DOI definitions
516 * @skip_cnt: skip past this number of DOI definitions, updated
517 * @callback: callback for each DOI definition
518 * @cb_arg: argument for the callback function
519 *
520 * Description:
521 * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
522 * For each entry call @callback, if @callback returns a negative value stop
523 * 'walking' through the list and return. Updates the value in @skip_cnt upon
524 * return. Returns zero on success, negative values on failure.
525 *
526 */
527static int calipso_doi_walk(u32 *skip_cnt,
528 int (*callback)(struct calipso_doi *doi_def,
529 void *arg),
530 void *cb_arg)
531{
532 int ret_val = -ENOENT;
533 u32 doi_cnt = 0;
534 struct calipso_doi *iter_doi;
535
536 rcu_read_lock();
537 list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list)
538 if (refcount_read(r: &iter_doi->refcount) > 0) {
539 if (doi_cnt++ < *skip_cnt)
540 continue;
541 ret_val = callback(iter_doi, cb_arg);
542 if (ret_val < 0) {
543 doi_cnt--;
544 goto doi_walk_return;
545 }
546 }
547
548doi_walk_return:
549 rcu_read_unlock();
550 *skip_cnt = doi_cnt;
551 return ret_val;
552}
553
554/**
555 * calipso_validate - Validate a CALIPSO option
556 * @skb: the packet
557 * @option: the start of the option
558 *
559 * Description:
560 * This routine is called to validate a CALIPSO option.
561 * If the option is valid then %true is returned, otherwise
562 * %false is returned.
563 *
564 * The caller should have already checked that the length of the
565 * option (including the TLV header) is >= 10 and that the catmap
566 * length is consistent with the option length.
567 *
568 * We leave checks on the level and categories to the socket layer.
569 */
570bool calipso_validate(const struct sk_buff *skb, const unsigned char *option)
571{
572 struct calipso_doi *doi_def;
573 bool ret_val;
574 u16 crc, len = option[1] + 2;
575 static const u8 zero[2];
576
577 /* The original CRC runs over the option including the TLV header
578 * with the CRC-16 field (at offset 8) zeroed out. */
579 crc = crc_ccitt(crc: 0xffff, buffer: option, len: 8);
580 crc = crc_ccitt(crc, buffer: zero, len: sizeof(zero));
581 if (len > 10)
582 crc = crc_ccitt(crc, buffer: option + 10, len: len - 10);
583 crc = ~crc;
584 if (option[8] != (crc & 0xff) || option[9] != ((crc >> 8) & 0xff))
585 return false;
586
587 rcu_read_lock();
588 doi_def = calipso_doi_search(doi: get_unaligned_be32(p: option + 2));
589 ret_val = !!doi_def;
590 rcu_read_unlock();
591
592 return ret_val;
593}
594
595/**
596 * calipso_map_cat_hton - Perform a category mapping from host to network
597 * @doi_def: the DOI definition
598 * @secattr: the security attributes
599 * @net_cat: the zero'd out category bitmap in network/CALIPSO format
600 * @net_cat_len: the length of the CALIPSO bitmap in bytes
601 *
602 * Description:
603 * Perform a label mapping to translate a local MLS category bitmap to the
604 * correct CALIPSO bitmap using the given DOI definition. Returns the minimum
605 * size in bytes of the network bitmap on success, negative values otherwise.
606 *
607 */
608static int calipso_map_cat_hton(const struct calipso_doi *doi_def,
609 const struct netlbl_lsm_secattr *secattr,
610 unsigned char *net_cat,
611 u32 net_cat_len)
612{
613 int spot = -1;
614 u32 net_spot_max = 0;
615 u32 net_clen_bits = net_cat_len * 8;
616
617 for (;;) {
618 spot = netlbl_catmap_walk(catmap: secattr->attr.mls.cat,
619 offset: spot + 1);
620 if (spot < 0)
621 break;
622 if (spot >= net_clen_bits)
623 return -ENOSPC;
624 netlbl_bitmap_setbit(bitmap: net_cat, bit: spot, state: 1);
625
626 if (spot > net_spot_max)
627 net_spot_max = spot;
628 }
629
630 return (net_spot_max / 32 + 1) * 4;
631}
632
633/**
634 * calipso_map_cat_ntoh - Perform a category mapping from network to host
635 * @doi_def: the DOI definition
636 * @net_cat: the category bitmap in network/CALIPSO format
637 * @net_cat_len: the length of the CALIPSO bitmap in bytes
638 * @secattr: the security attributes
639 *
640 * Description:
641 * Perform a label mapping to translate a CALIPSO bitmap to the correct local
642 * MLS category bitmap using the given DOI definition. Returns zero on
643 * success, negative values on failure.
644 *
645 */
646static int calipso_map_cat_ntoh(const struct calipso_doi *doi_def,
647 const unsigned char *net_cat,
648 u32 net_cat_len,
649 struct netlbl_lsm_secattr *secattr)
650{
651 int ret_val;
652 int spot = -1;
653 u32 net_clen_bits = net_cat_len * 8;
654
655 for (;;) {
656 spot = netlbl_bitmap_walk(bitmap: net_cat,
657 bitmap_len: net_clen_bits,
658 offset: spot + 1,
659 state: 1);
660 if (spot < 0)
661 return 0;
662
663 ret_val = netlbl_catmap_setbit(catmap: &secattr->attr.mls.cat,
664 bit: spot,
665 GFP_ATOMIC);
666 if (ret_val != 0)
667 return ret_val;
668 }
669
670 return -EINVAL;
671}
672
673/**
674 * calipso_pad_write - Writes pad bytes in TLV format
675 * @buf: the buffer
676 * @offset: offset from start of buffer to write padding
677 * @count: number of pad bytes to write
678 *
679 * Description:
680 * Write @count bytes of TLV padding into @buffer starting at offset @offset.
681 * @count should be less than 8 - see RFC 4942.
682 *
683 */
684static int calipso_pad_write(unsigned char *buf, unsigned int offset,
685 unsigned int count)
686{
687 if (WARN_ON_ONCE(count >= 8))
688 return -EINVAL;
689
690 switch (count) {
691 case 0:
692 break;
693 case 1:
694 buf[offset] = IPV6_TLV_PAD1;
695 break;
696 default:
697 buf[offset] = IPV6_TLV_PADN;
698 buf[offset + 1] = count - 2;
699 if (count > 2)
700 memset(s: buf + offset + 2, c: 0, n: count - 2);
701 break;
702 }
703 return 0;
704}
705
706/**
707 * calipso_genopt - Generate a CALIPSO option
708 * @buf: the option buffer
709 * @start: offset from which to write
710 * @buf_len: the size of opt_buf
711 * @doi_def: the CALIPSO DOI to use
712 * @secattr: the security attributes
713 *
714 * Description:
715 * Generate a CALIPSO option using the DOI definition and security attributes
716 * passed to the function. This also generates upto three bytes of leading
717 * padding that ensures that the option is 4n + 2 aligned. It returns the
718 * number of bytes written (including any initial padding).
719 */
720static int calipso_genopt(unsigned char *buf, u32 start, u32 buf_len,
721 const struct calipso_doi *doi_def,
722 const struct netlbl_lsm_secattr *secattr)
723{
724 int ret_val;
725 u32 len, pad;
726 u16 crc;
727 static const unsigned char padding[4] = {2, 1, 0, 3};
728 unsigned char *calipso;
729
730 /* CALIPSO has 4n + 2 alignment */
731 pad = padding[start & 3];
732 if (buf_len <= start + pad + CALIPSO_HDR_LEN)
733 return -ENOSPC;
734
735 if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
736 return -EPERM;
737
738 len = CALIPSO_HDR_LEN;
739
740 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
741 ret_val = calipso_map_cat_hton(doi_def,
742 secattr,
743 net_cat: buf + start + pad + len,
744 net_cat_len: buf_len - start - pad - len);
745 if (ret_val < 0)
746 return ret_val;
747 len += ret_val;
748 }
749
750 calipso_pad_write(buf, offset: start, count: pad);
751 calipso = buf + start + pad;
752
753 calipso[0] = IPV6_TLV_CALIPSO;
754 calipso[1] = len - 2;
755 *(__be32 *)(calipso + 2) = htonl(doi_def->doi);
756 calipso[6] = (len - CALIPSO_HDR_LEN) / 4;
757 calipso[7] = secattr->attr.mls.lvl;
758 crc = ~crc_ccitt(crc: 0xffff, buffer: calipso, len);
759 calipso[8] = crc & 0xff;
760 calipso[9] = (crc >> 8) & 0xff;
761 return pad + len;
762}
763
764/* Hop-by-hop hdr helper functions
765 */
766
767/**
768 * calipso_opt_update - Replaces socket's hop options with a new set
769 * @sk: the socket
770 * @hop: new hop options
771 *
772 * Description:
773 * Replaces @sk's hop options with @hop. @hop may be NULL to leave
774 * the socket with no hop options.
775 *
776 */
777static int calipso_opt_update(struct sock *sk, struct ipv6_opt_hdr *hop)
778{
779 struct ipv6_txoptions *old = txopt_get(np: inet6_sk(sk: sk)), *txopts;
780
781 txopts = ipv6_renew_options(sk, opt: old, IPV6_HOPOPTS, newopt: hop);
782 txopt_put(opt: old);
783 if (IS_ERR(ptr: txopts))
784 return PTR_ERR(ptr: txopts);
785
786 txopts = ipv6_update_options(sk, opt: txopts);
787 if (txopts) {
788 atomic_sub(i: txopts->tot_len, v: &sk->sk_omem_alloc);
789 txopt_put(opt: txopts);
790 }
791
792 return 0;
793}
794
795/**
796 * calipso_tlv_len - Returns the length of the TLV
797 * @opt: the option header
798 * @offset: offset of the TLV within the header
799 *
800 * Description:
801 * Returns the length of the TLV option at offset @offset within
802 * the option header @opt. Checks that the entire TLV fits inside
803 * the option header, returns a negative value if this is not the case.
804 */
805static int calipso_tlv_len(struct ipv6_opt_hdr *opt, unsigned int offset)
806{
807 unsigned char *tlv = (unsigned char *)opt;
808 unsigned int opt_len = ipv6_optlen(opt), tlv_len;
809
810 if (offset < sizeof(*opt) || offset >= opt_len)
811 return -EINVAL;
812 if (tlv[offset] == IPV6_TLV_PAD1)
813 return 1;
814 if (offset + 1 >= opt_len)
815 return -EINVAL;
816 tlv_len = tlv[offset + 1] + 2;
817 if (offset + tlv_len > opt_len)
818 return -EINVAL;
819 return tlv_len;
820}
821
822/**
823 * calipso_opt_find - Finds the CALIPSO option in an IPv6 hop options header
824 * @hop: the hop options header
825 * @start: on return holds the offset of any leading padding
826 * @end: on return holds the offset of the first non-pad TLV after CALIPSO
827 *
828 * Description:
829 * Finds the space occupied by a CALIPSO option (including any leading and
830 * trailing padding).
831 *
832 * If a CALIPSO option exists set @start and @end to the
833 * offsets within @hop of the start of padding before the first
834 * CALIPSO option and the end of padding after the first CALIPSO
835 * option. In this case the function returns 0.
836 *
837 * In the absence of a CALIPSO option, @start and @end will be
838 * set to the start and end of any trailing padding in the header.
839 * This is useful when appending a new option, as the caller may want
840 * to overwrite some of this padding. In this case the function will
841 * return -ENOENT.
842 */
843static int calipso_opt_find(struct ipv6_opt_hdr *hop, unsigned int *start,
844 unsigned int *end)
845{
846 int ret_val = -ENOENT, tlv_len;
847 unsigned int opt_len, offset, offset_s = 0, offset_e = 0;
848 unsigned char *opt = (unsigned char *)hop;
849
850 opt_len = ipv6_optlen(hop);
851 offset = sizeof(*hop);
852
853 while (offset < opt_len) {
854 tlv_len = calipso_tlv_len(opt: hop, offset);
855 if (tlv_len < 0)
856 return tlv_len;
857
858 switch (opt[offset]) {
859 case IPV6_TLV_PAD1:
860 case IPV6_TLV_PADN:
861 if (offset_e)
862 offset_e = offset;
863 break;
864 case IPV6_TLV_CALIPSO:
865 ret_val = 0;
866 offset_e = offset;
867 break;
868 default:
869 if (offset_e == 0)
870 offset_s = offset;
871 else
872 goto out;
873 }
874 offset += tlv_len;
875 }
876
877out:
878 if (offset_s)
879 *start = offset_s + calipso_tlv_len(opt: hop, offset: offset_s);
880 else
881 *start = sizeof(*hop);
882 if (offset_e)
883 *end = offset_e + calipso_tlv_len(opt: hop, offset: offset_e);
884 else
885 *end = opt_len;
886
887 return ret_val;
888}
889
890/**
891 * calipso_opt_insert - Inserts a CALIPSO option into an IPv6 hop opt hdr
892 * @hop: the original hop options header
893 * @doi_def: the CALIPSO DOI to use
894 * @secattr: the specific security attributes of the socket
895 *
896 * Description:
897 * Creates a new hop options header based on @hop with a
898 * CALIPSO option added to it. If @hop already contains a CALIPSO
899 * option this is overwritten, otherwise the new option is appended
900 * after any existing options. If @hop is NULL then the new header
901 * will contain just the CALIPSO option and any needed padding.
902 *
903 */
904static struct ipv6_opt_hdr *
905calipso_opt_insert(struct ipv6_opt_hdr *hop,
906 const struct calipso_doi *doi_def,
907 const struct netlbl_lsm_secattr *secattr)
908{
909 unsigned int start, end, buf_len, pad, hop_len;
910 struct ipv6_opt_hdr *new;
911 int ret_val;
912
913 if (hop) {
914 hop_len = ipv6_optlen(hop);
915 ret_val = calipso_opt_find(hop, start: &start, end: &end);
916 if (ret_val && ret_val != -ENOENT)
917 return ERR_PTR(error: ret_val);
918 } else {
919 hop_len = 0;
920 start = sizeof(*hop);
921 end = 0;
922 }
923
924 buf_len = hop_len + start - end + CALIPSO_OPT_LEN_MAX_WITH_PAD;
925 new = kzalloc(buf_len, GFP_ATOMIC);
926 if (!new)
927 return ERR_PTR(error: -ENOMEM);
928
929 if (start > sizeof(*hop))
930 memcpy(to: new, from: hop, len: start);
931 ret_val = calipso_genopt(buf: (unsigned char *)new, start, buf_len, doi_def,
932 secattr);
933 if (ret_val < 0) {
934 kfree(objp: new);
935 return ERR_PTR(error: ret_val);
936 }
937
938 buf_len = start + ret_val;
939 /* At this point buf_len aligns to 4n, so (buf_len & 4) pads to 8n */
940 pad = ((buf_len & 4) + (end & 7)) & 7;
941 calipso_pad_write(buf: (unsigned char *)new, offset: buf_len, count: pad);
942 buf_len += pad;
943
944 if (end != hop_len) {
945 memcpy(to: (char *)new + buf_len, from: (char *)hop + end, len: hop_len - end);
946 buf_len += hop_len - end;
947 }
948 new->nexthdr = 0;
949 new->hdrlen = buf_len / 8 - 1;
950
951 return new;
952}
953
954/**
955 * calipso_opt_del - Removes the CALIPSO option from an option header
956 * @hop: the original header
957 * @new: the new header
958 *
959 * Description:
960 * Creates a new header based on @hop without any CALIPSO option. If @hop
961 * doesn't contain a CALIPSO option it returns -ENOENT. If @hop contains
962 * no other non-padding options, it returns zero with @new set to NULL.
963 * Otherwise it returns zero, creates a new header without the CALIPSO
964 * option (and removing as much padding as possible) and returns with
965 * @new set to that header.
966 *
967 */
968static int calipso_opt_del(struct ipv6_opt_hdr *hop,
969 struct ipv6_opt_hdr **new)
970{
971 int ret_val;
972 unsigned int start, end, delta, pad, hop_len;
973
974 ret_val = calipso_opt_find(hop, start: &start, end: &end);
975 if (ret_val)
976 return ret_val;
977
978 hop_len = ipv6_optlen(hop);
979 if (start == sizeof(*hop) && end == hop_len) {
980 /* There's no other option in the header so return NULL */
981 *new = NULL;
982 return 0;
983 }
984
985 delta = (end - start) & ~7;
986 *new = kzalloc(hop_len - delta, GFP_ATOMIC);
987 if (!*new)
988 return -ENOMEM;
989
990 memcpy(to: *new, from: hop, len: start);
991 (*new)->hdrlen -= delta / 8;
992 pad = (end - start) & 7;
993 calipso_pad_write(buf: (unsigned char *)*new, offset: start, count: pad);
994 if (end != hop_len)
995 memcpy(to: (char *)*new + start + pad, from: (char *)hop + end,
996 len: hop_len - end);
997
998 return 0;
999}
1000
1001/**
1002 * calipso_opt_getattr - Get the security attributes from a memory block
1003 * @calipso: the CALIPSO option
1004 * @secattr: the security attributes
1005 *
1006 * Description:
1007 * Inspect @calipso and return the security attributes in @secattr.
1008 * Returns zero on success and negative values on failure.
1009 *
1010 */
1011static int calipso_opt_getattr(const unsigned char *calipso,
1012 struct netlbl_lsm_secattr *secattr)
1013{
1014 int ret_val = -ENOMSG;
1015 u32 doi, len = calipso[1], cat_len = calipso[6] * 4;
1016 struct calipso_doi *doi_def;
1017
1018 if (cat_len + 8 > len)
1019 return -EINVAL;
1020
1021 if (calipso_cache_check(key: calipso + 2, key_len: calipso[1], secattr) == 0)
1022 return 0;
1023
1024 doi = get_unaligned_be32(p: calipso + 2);
1025 rcu_read_lock();
1026 doi_def = calipso_doi_search(doi);
1027 if (!doi_def)
1028 goto getattr_return;
1029
1030 secattr->attr.mls.lvl = calipso[7];
1031 secattr->flags |= NETLBL_SECATTR_MLS_LVL;
1032
1033 if (cat_len) {
1034 ret_val = calipso_map_cat_ntoh(doi_def,
1035 net_cat: calipso + 10,
1036 net_cat_len: cat_len,
1037 secattr);
1038 if (ret_val != 0) {
1039 netlbl_catmap_free(catmap: secattr->attr.mls.cat);
1040 goto getattr_return;
1041 }
1042
1043 if (secattr->attr.mls.cat)
1044 secattr->flags |= NETLBL_SECATTR_MLS_CAT;
1045 }
1046
1047 secattr->type = NETLBL_NLTYPE_CALIPSO;
1048
1049getattr_return:
1050 rcu_read_unlock();
1051 return ret_val;
1052}
1053
1054/* sock functions.
1055 */
1056
1057/**
1058 * calipso_sock_getattr - Get the security attributes from a sock
1059 * @sk: the sock
1060 * @secattr: the security attributes
1061 *
1062 * Description:
1063 * Query @sk to see if there is a CALIPSO option attached to the sock and if
1064 * there is return the CALIPSO security attributes in @secattr. This function
1065 * requires that @sk be locked, or privately held, but it does not do any
1066 * locking itself. Returns zero on success and negative values on failure.
1067 *
1068 */
1069static int calipso_sock_getattr(struct sock *sk,
1070 struct netlbl_lsm_secattr *secattr)
1071{
1072 struct ipv6_opt_hdr *hop;
1073 int opt_len, len, ret_val = -ENOMSG, offset;
1074 unsigned char *opt;
1075 struct ipv6_pinfo *pinfo = inet6_sk(sk: sk);
1076 struct ipv6_txoptions *txopts;
1077
1078 if (!pinfo)
1079 return -EAFNOSUPPORT;
1080
1081 txopts = txopt_get(np: pinfo);
1082 if (!txopts || !txopts->hopopt)
1083 goto done;
1084
1085 hop = txopts->hopopt;
1086 opt = (unsigned char *)hop;
1087 opt_len = ipv6_optlen(hop);
1088 offset = sizeof(*hop);
1089 while (offset < opt_len) {
1090 len = calipso_tlv_len(opt: hop, offset);
1091 if (len < 0) {
1092 ret_val = len;
1093 goto done;
1094 }
1095 switch (opt[offset]) {
1096 case IPV6_TLV_CALIPSO:
1097 if (len < CALIPSO_HDR_LEN)
1098 ret_val = -EINVAL;
1099 else
1100 ret_val = calipso_opt_getattr(calipso: &opt[offset],
1101 secattr);
1102 goto done;
1103 default:
1104 offset += len;
1105 break;
1106 }
1107 }
1108done:
1109 txopt_put(opt: txopts);
1110 return ret_val;
1111}
1112
1113/**
1114 * calipso_sock_setattr - Add a CALIPSO option to a socket
1115 * @sk: the socket
1116 * @doi_def: the CALIPSO DOI to use
1117 * @secattr: the specific security attributes of the socket
1118 *
1119 * Description:
1120 * Set the CALIPSO option on the given socket using the DOI definition and
1121 * security attributes passed to the function. This function requires
1122 * exclusive access to @sk, which means it either needs to be in the
1123 * process of being created or locked. Returns zero on success and negative
1124 * values on failure.
1125 *
1126 */
1127static int calipso_sock_setattr(struct sock *sk,
1128 const struct calipso_doi *doi_def,
1129 const struct netlbl_lsm_secattr *secattr)
1130{
1131 int ret_val;
1132 struct ipv6_opt_hdr *old, *new;
1133 struct ipv6_pinfo *pinfo = inet6_sk(sk: sk);
1134 struct ipv6_txoptions *txopts;
1135
1136 if (!pinfo)
1137 return -EAFNOSUPPORT;
1138
1139 txopts = txopt_get(np: pinfo);
1140 old = NULL;
1141 if (txopts)
1142 old = txopts->hopopt;
1143
1144 new = calipso_opt_insert(hop: old, doi_def, secattr);
1145 txopt_put(opt: txopts);
1146 if (IS_ERR(ptr: new))
1147 return PTR_ERR(ptr: new);
1148
1149 ret_val = calipso_opt_update(sk, hop: new);
1150
1151 kfree(objp: new);
1152 return ret_val;
1153}
1154
1155/**
1156 * calipso_sock_delattr - Delete the CALIPSO option from a socket
1157 * @sk: the socket
1158 *
1159 * Description:
1160 * Removes the CALIPSO option from a socket, if present.
1161 *
1162 */
1163static void calipso_sock_delattr(struct sock *sk)
1164{
1165 struct ipv6_opt_hdr *new_hop;
1166 struct ipv6_pinfo *pinfo = inet6_sk(sk: sk);
1167 struct ipv6_txoptions *txopts;
1168
1169 if (!pinfo)
1170 return;
1171
1172 txopts = txopt_get(np: pinfo);
1173 if (!txopts || !txopts->hopopt)
1174 goto done;
1175
1176 if (calipso_opt_del(hop: txopts->hopopt, new: &new_hop))
1177 goto done;
1178
1179 calipso_opt_update(sk, hop: new_hop);
1180 kfree(objp: new_hop);
1181
1182done:
1183 txopt_put(opt: txopts);
1184}
1185
1186/* request sock functions.
1187 */
1188
1189/**
1190 * calipso_req_setattr - Add a CALIPSO option to a connection request socket
1191 * @req: the connection request socket
1192 * @doi_def: the CALIPSO DOI to use
1193 * @secattr: the specific security attributes of the socket
1194 *
1195 * Description:
1196 * Set the CALIPSO option on the given socket using the DOI definition and
1197 * security attributes passed to the function. Returns zero on success and
1198 * negative values on failure.
1199 *
1200 */
1201static int calipso_req_setattr(struct request_sock *req,
1202 const struct calipso_doi *doi_def,
1203 const struct netlbl_lsm_secattr *secattr)
1204{
1205 struct ipv6_txoptions *txopts;
1206 struct inet_request_sock *req_inet = inet_rsk(sk: req);
1207 struct ipv6_opt_hdr *old, *new;
1208 struct sock *sk = sk_to_full_sk(sk: req_to_sk(req));
1209
1210 /* sk is NULL for SYN+ACK w/ SYN Cookie */
1211 if (!sk)
1212 return -ENOMEM;
1213
1214 if (req_inet->ipv6_opt && req_inet->ipv6_opt->hopopt)
1215 old = req_inet->ipv6_opt->hopopt;
1216 else
1217 old = NULL;
1218
1219 new = calipso_opt_insert(hop: old, doi_def, secattr);
1220 if (IS_ERR(ptr: new))
1221 return PTR_ERR(ptr: new);
1222
1223 txopts = ipv6_renew_options(sk, opt: req_inet->ipv6_opt, IPV6_HOPOPTS, newopt: new);
1224
1225 kfree(objp: new);
1226
1227 if (IS_ERR(ptr: txopts))
1228 return PTR_ERR(ptr: txopts);
1229
1230 txopts = xchg(&req_inet->ipv6_opt, txopts);
1231 if (txopts) {
1232 atomic_sub(i: txopts->tot_len, v: &sk->sk_omem_alloc);
1233 txopt_put(opt: txopts);
1234 }
1235
1236 return 0;
1237}
1238
1239/**
1240 * calipso_req_delattr - Delete the CALIPSO option from a request socket
1241 * @req: the request socket
1242 *
1243 * Description:
1244 * Removes the CALIPSO option from a request socket, if present.
1245 *
1246 */
1247static void calipso_req_delattr(struct request_sock *req)
1248{
1249 struct inet_request_sock *req_inet = inet_rsk(sk: req);
1250 struct ipv6_opt_hdr *new;
1251 struct ipv6_txoptions *txopts;
1252 struct sock *sk = sk_to_full_sk(sk: req_to_sk(req));
1253
1254 /* sk is NULL for SYN+ACK w/ SYN Cookie */
1255 if (!sk)
1256 return;
1257
1258 if (!req_inet->ipv6_opt || !req_inet->ipv6_opt->hopopt)
1259 return;
1260
1261 if (calipso_opt_del(hop: req_inet->ipv6_opt->hopopt, new: &new))
1262 return; /* Nothing to do */
1263
1264 txopts = ipv6_renew_options(sk, opt: req_inet->ipv6_opt, IPV6_HOPOPTS, newopt: new);
1265
1266 if (!IS_ERR(ptr: txopts)) {
1267 txopts = xchg(&req_inet->ipv6_opt, txopts);
1268 if (txopts) {
1269 atomic_sub(i: txopts->tot_len, v: &sk->sk_omem_alloc);
1270 txopt_put(opt: txopts);
1271 }
1272 }
1273 kfree(objp: new);
1274}
1275
1276/* skbuff functions.
1277 */
1278
1279/**
1280 * calipso_skbuff_optptr - Find the CALIPSO option in the packet
1281 * @skb: the packet
1282 *
1283 * Description:
1284 * Parse the packet's IP header looking for a CALIPSO option. Returns a pointer
1285 * to the start of the CALIPSO option on success, NULL if one if not found.
1286 *
1287 */
1288static unsigned char *calipso_skbuff_optptr(const struct sk_buff *skb)
1289{
1290 const struct ipv6hdr *ip6_hdr = ipv6_hdr(skb);
1291 int offset;
1292
1293 if (ip6_hdr->nexthdr != NEXTHDR_HOP)
1294 return NULL;
1295
1296 offset = ipv6_find_tlv(skb, offset: sizeof(*ip6_hdr), IPV6_TLV_CALIPSO);
1297 if (offset >= 0)
1298 return (unsigned char *)ip6_hdr + offset;
1299
1300 return NULL;
1301}
1302
1303/**
1304 * calipso_skbuff_setattr - Set the CALIPSO option on a packet
1305 * @skb: the packet
1306 * @doi_def: the CALIPSO DOI to use
1307 * @secattr: the security attributes
1308 *
1309 * Description:
1310 * Set the CALIPSO option on the given packet based on the security attributes.
1311 * Returns a pointer to the IP header on success and NULL on failure.
1312 *
1313 */
1314static int calipso_skbuff_setattr(struct sk_buff *skb,
1315 const struct calipso_doi *doi_def,
1316 const struct netlbl_lsm_secattr *secattr)
1317{
1318 int ret_val;
1319 struct ipv6hdr *ip6_hdr;
1320 struct ipv6_opt_hdr *hop;
1321 unsigned char buf[CALIPSO_MAX_BUFFER];
1322 int len_delta, new_end, pad, payload;
1323 unsigned int start, end;
1324
1325 ip6_hdr = ipv6_hdr(skb);
1326 if (ip6_hdr->nexthdr == NEXTHDR_HOP) {
1327 hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
1328 ret_val = calipso_opt_find(hop, start: &start, end: &end);
1329 if (ret_val && ret_val != -ENOENT)
1330 return ret_val;
1331 } else {
1332 start = 0;
1333 end = 0;
1334 }
1335
1336 memset(s: buf, c: 0, n: sizeof(buf));
1337 ret_val = calipso_genopt(buf, start: start & 3, buf_len: sizeof(buf), doi_def, secattr);
1338 if (ret_val < 0)
1339 return ret_val;
1340
1341 new_end = start + ret_val;
1342 /* At this point new_end aligns to 4n, so (new_end & 4) pads to 8n */
1343 pad = ((new_end & 4) + (end & 7)) & 7;
1344 len_delta = new_end - (int)end + pad;
1345 ret_val = skb_cow(skb, headroom: skb_headroom(skb) + len_delta);
1346 if (ret_val < 0)
1347 return ret_val;
1348
1349 ip6_hdr = ipv6_hdr(skb); /* Reset as skb_cow() may have moved it */
1350
1351 if (len_delta) {
1352 if (len_delta > 0)
1353 skb_push(skb, len: len_delta);
1354 else
1355 skb_pull(skb, len: -len_delta);
1356 memmove(dest: (char *)ip6_hdr - len_delta, src: ip6_hdr,
1357 count: sizeof(*ip6_hdr) + start);
1358 skb_reset_network_header(skb);
1359 ip6_hdr = ipv6_hdr(skb);
1360 payload = ntohs(ip6_hdr->payload_len);
1361 ip6_hdr->payload_len = htons(payload + len_delta);
1362 }
1363
1364 hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
1365 if (start == 0) {
1366 struct ipv6_opt_hdr *new_hop = (struct ipv6_opt_hdr *)buf;
1367
1368 new_hop->nexthdr = ip6_hdr->nexthdr;
1369 new_hop->hdrlen = len_delta / 8 - 1;
1370 ip6_hdr->nexthdr = NEXTHDR_HOP;
1371 } else {
1372 hop->hdrlen += len_delta / 8;
1373 }
1374 memcpy(to: (char *)hop + start, from: buf + (start & 3), len: new_end - start);
1375 calipso_pad_write(buf: (unsigned char *)hop, offset: new_end, count: pad);
1376
1377 return 0;
1378}
1379
1380/**
1381 * calipso_skbuff_delattr - Delete any CALIPSO options from a packet
1382 * @skb: the packet
1383 *
1384 * Description:
1385 * Removes any and all CALIPSO options from the given packet. Returns zero on
1386 * success, negative values on failure.
1387 *
1388 */
1389static int calipso_skbuff_delattr(struct sk_buff *skb)
1390{
1391 int ret_val;
1392 struct ipv6hdr *ip6_hdr;
1393 struct ipv6_opt_hdr *old_hop;
1394 u32 old_hop_len, start = 0, end = 0, delta, size, pad;
1395
1396 if (!calipso_skbuff_optptr(skb))
1397 return 0;
1398
1399 /* since we are changing the packet we should make a copy */
1400 ret_val = skb_cow(skb, headroom: skb_headroom(skb));
1401 if (ret_val < 0)
1402 return ret_val;
1403
1404 ip6_hdr = ipv6_hdr(skb);
1405 old_hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
1406 old_hop_len = ipv6_optlen(old_hop);
1407
1408 ret_val = calipso_opt_find(hop: old_hop, start: &start, end: &end);
1409 if (ret_val)
1410 return ret_val;
1411
1412 if (start == sizeof(*old_hop) && end == old_hop_len) {
1413 /* There's no other option in the header so we delete
1414 * the whole thing. */
1415 delta = old_hop_len;
1416 size = sizeof(*ip6_hdr);
1417 ip6_hdr->nexthdr = old_hop->nexthdr;
1418 } else {
1419 delta = (end - start) & ~7;
1420 if (delta)
1421 old_hop->hdrlen -= delta / 8;
1422 pad = (end - start) & 7;
1423 size = sizeof(*ip6_hdr) + start + pad;
1424 calipso_pad_write(buf: (unsigned char *)old_hop, offset: start, count: pad);
1425 }
1426
1427 if (delta) {
1428 skb_pull(skb, len: delta);
1429 memmove(dest: (char *)ip6_hdr + delta, src: ip6_hdr, count: size);
1430 skb_reset_network_header(skb);
1431 }
1432
1433 return 0;
1434}
1435
1436static const struct netlbl_calipso_ops ops = {
1437 .doi_add = calipso_doi_add,
1438 .doi_free = calipso_doi_free,
1439 .doi_remove = calipso_doi_remove,
1440 .doi_getdef = calipso_doi_getdef,
1441 .doi_putdef = calipso_doi_putdef,
1442 .doi_walk = calipso_doi_walk,
1443 .sock_getattr = calipso_sock_getattr,
1444 .sock_setattr = calipso_sock_setattr,
1445 .sock_delattr = calipso_sock_delattr,
1446 .req_setattr = calipso_req_setattr,
1447 .req_delattr = calipso_req_delattr,
1448 .opt_getattr = calipso_opt_getattr,
1449 .skbuff_optptr = calipso_skbuff_optptr,
1450 .skbuff_setattr = calipso_skbuff_setattr,
1451 .skbuff_delattr = calipso_skbuff_delattr,
1452 .cache_invalidate = calipso_cache_invalidate,
1453 .cache_add = calipso_cache_add
1454};
1455
1456/**
1457 * calipso_init - Initialize the CALIPSO module
1458 *
1459 * Description:
1460 * Initialize the CALIPSO module and prepare it for use. Returns zero on
1461 * success and negative values on failure.
1462 *
1463 */
1464int __init calipso_init(void)
1465{
1466 int ret_val;
1467
1468 ret_val = calipso_cache_init();
1469 if (!ret_val)
1470 netlbl_calipso_ops_register(ops: &ops);
1471 return ret_val;
1472}
1473
1474void calipso_exit(void)
1475{
1476 netlbl_calipso_ops_register(NULL);
1477 calipso_cache_invalidate();
1478 kfree(objp: calipso_cache);
1479}
1480