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1ccea77e | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
cb72d382 HD |
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> | |
cb72d382 HD |
10 | */ |
11 | ||
12 | /* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 | |
13 | * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015 | |
cb72d382 HD |
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 <asm/unaligned.h> | |
ceba1832 HD |
33 | #include <linux/crc-ccitt.h> |
34 | ||
35 | /* Maximium 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 | /* Maximium 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 | ||
2917f57b HD |
51 | /* Maximium 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) | |
cb72d382 HD |
56 | |
57 | /* List of available DOI definitions */ | |
58 | static DEFINE_SPINLOCK(calipso_doi_list_lock); | |
59 | static LIST_HEAD(calipso_doi_list); | |
60 | ||
4fee5242 HD |
61 | /* Label mapping cache */ |
62 | int calipso_cache_enabled = 1; | |
63 | int 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 | |
67 | struct calipso_map_cache_bkt { | |
68 | spinlock_t lock; | |
69 | u32 size; | |
70 | struct list_head list; | |
71 | }; | |
72 | ||
73 | struct 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 | ||
84 | static struct calipso_map_cache_bkt *calipso_cache; | |
85 | ||
ad5d07f4 PM |
86 | static void calipso_cache_invalidate(void); |
87 | static void calipso_doi_putdef(struct calipso_doi *doi_def); | |
88 | ||
4fee5242 HD |
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 | */ | |
101 | static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry) | |
102 | { | |
103 | if (entry->lsm_data) | |
104 | netlbl_secattr_cache_free(entry->lsm_data); | |
105 | kfree(entry->key); | |
106 | kfree(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 | */ | |
118 | static u32 calipso_map_cache_hash(const unsigned char *key, u32 key_len) | |
119 | { | |
120 | return jhash(key, key_len, 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 | */ | |
132 | static 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(&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 | */ | |
159 | static 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(&calipso_cache[iter].lock); | |
166 | list_for_each_entry_safe(entry, | |
167 | tmp_entry, | |
168 | &calipso_cache[iter].list, list) { | |
169 | list_del(&entry->list); | |
170 | calipso_cache_entry_free(entry); | |
171 | } | |
172 | calipso_cache[iter].size = 0; | |
173 | spin_unlock_bh(&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 | */ | |
199 | static 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(&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; | |
b4217b82 | 219 | refcount_inc(&entry->lsm_data->refcount); |
4fee5242 HD |
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(&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(entry->list.prev, entry->list.next); | |
234 | __list_add(&entry->list, | |
235 | prev_entry->list.prev, | |
236 | &prev_entry->list); | |
237 | } | |
238 | ||
239 | spin_unlock_bh(&calipso_cache[bkt].lock); | |
240 | return 0; | |
241 | } | |
242 | prev_entry = entry; | |
243 | } | |
244 | spin_unlock_bh(&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 | */ | |
264 | static 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(calipso_ptr, calipso_ptr_len); | |
b4217b82 | 288 | refcount_inc(&secattr->cache->refcount); |
4fee5242 HD |
289 | entry->lsm_data = secattr->cache; |
290 | ||
291 | bkt = entry->hash & (CALIPSO_CACHE_BUCKETS - 1); | |
292 | spin_lock_bh(&calipso_cache[bkt].lock); | |
293 | if (calipso_cache[bkt].size < calipso_cache_bucketsize) { | |
294 | list_add(&entry->list, &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(&old_entry->list); | |
300 | list_add(&entry->list, &calipso_cache[bkt].list); | |
301 | calipso_cache_entry_free(old_entry); | |
302 | } | |
303 | spin_unlock_bh(&calipso_cache[bkt].lock); | |
304 | ||
305 | return 0; | |
306 | ||
307 | cache_add_failure: | |
308 | if (entry) | |
309 | calipso_cache_entry_free(entry); | |
310 | return ret_val; | |
311 | } | |
312 | ||
cb72d382 HD |
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 | */ | |
325 | static 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) | |
edcd9270 | 330 | if (iter->doi == doi && refcount_read(&iter->refcount)) |
cb72d382 HD |
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 | */ | |
348 | static 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 | ||
edcd9270 | 362 | refcount_set(&doi_def->refcount, 1); |
cb72d382 HD |
363 | |
364 | spin_lock(&calipso_doi_list_lock); | |
365 | if (calipso_doi_search(doi_def->doi)) { | |
366 | spin_unlock(&calipso_doi_list_lock); | |
367 | ret_val = -EEXIST; | |
368 | goto doi_add_return; | |
369 | } | |
370 | list_add_tail_rcu(&doi_def->list, &calipso_doi_list); | |
371 | spin_unlock(&calipso_doi_list_lock); | |
372 | ret_val = 0; | |
373 | ||
374 | doi_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(audit_buf, | |
387 | " calipso_doi=%u calipso_type=%s res=%u", | |
388 | doi, type_str, ret_val == 0 ? 1 : 0); | |
389 | audit_log_end(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 | */ | |
403 | static void calipso_doi_free(struct calipso_doi *doi_def) | |
404 | { | |
405 | kfree(doi_def); | |
406 | } | |
407 | ||
a5e34490 HD |
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 | */ | |
418 | static 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 | ||
d7cce015 HD |
426 | /** |
427 | * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine | |
428 | * @doi: the DOI value | |
8da1f442 | 429 | * @audit_info: NetLabel audit information |
d7cce015 HD |
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 | */ | |
437 | static 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(&calipso_doi_list_lock); | |
444 | doi_def = calipso_doi_search(doi); | |
445 | if (!doi_def) { | |
446 | spin_unlock(&calipso_doi_list_lock); | |
447 | ret_val = -ENOENT; | |
448 | goto doi_remove_return; | |
449 | } | |
d7cce015 HD |
450 | list_del_rcu(&doi_def->list); |
451 | spin_unlock(&calipso_doi_list_lock); | |
452 | ||
ad5d07f4 | 453 | calipso_doi_putdef(doi_def); |
d7cce015 HD |
454 | ret_val = 0; |
455 | ||
456 | doi_remove_return: | |
457 | audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_DEL, audit_info); | |
458 | if (audit_buf) { | |
459 | audit_log_format(audit_buf, | |
460 | " calipso_doi=%u res=%u", | |
461 | doi, ret_val == 0 ? 1 : 0); | |
462 | audit_log_end(audit_buf); | |
463 | } | |
464 | ||
465 | return ret_val; | |
466 | } | |
467 | ||
a5e34490 HD |
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 | */ | |
478 | static 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; | |
edcd9270 | 486 | if (!refcount_inc_not_zero(&doi_def->refcount)) |
a5e34490 HD |
487 | doi_def = NULL; |
488 | ||
489 | doi_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 | */ | |
502 | static void calipso_doi_putdef(struct calipso_doi *doi_def) | |
503 | { | |
504 | if (!doi_def) | |
505 | return; | |
506 | ||
edcd9270 | 507 | if (!refcount_dec_and_test(&doi_def->refcount)) |
a5e34490 | 508 | return; |
a5e34490 | 509 | |
ad5d07f4 | 510 | calipso_cache_invalidate(); |
a5e34490 HD |
511 | call_rcu(&doi_def->rcu, calipso_doi_free_rcu); |
512 | } | |
513 | ||
e1ce69df HD |
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 | */ | |
527 | static 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) | |
edcd9270 | 538 | if (refcount_read(&iter_doi->refcount) > 0) { |
e1ce69df HD |
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 | ||
548 | doi_walk_return: | |
549 | rcu_read_unlock(); | |
550 | *skip_cnt = doi_cnt; | |
551 | return ret_val; | |
552 | } | |
553 | ||
2e532b70 HD |
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 | */ | |
570 | bool 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(0xffff, option, 8); | |
580 | crc = crc_ccitt(crc, zero, sizeof(zero)); | |
581 | if (len > 10) | |
582 | crc = crc_ccitt(crc, option + 10, 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(get_unaligned_be32(option + 2)); | |
589 | ret_val = !!doi_def; | |
590 | rcu_read_unlock(); | |
591 | ||
592 | return ret_val; | |
593 | } | |
594 | ||
ceba1832 HD |
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 | */ | |
608 | static 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(secattr->attr.mls.cat, | |
619 | spot + 1); | |
620 | if (spot < 0) | |
621 | break; | |
622 | if (spot >= net_clen_bits) | |
623 | return -ENOSPC; | |
624 | netlbl_bitmap_setbit(net_cat, spot, 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 | */ | |
646 | static 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(net_cat, | |
657 | net_clen_bits, | |
658 | spot + 1, | |
659 | 1); | |
660 | if (spot < 0) { | |
661 | if (spot == -2) | |
662 | return -EFAULT; | |
663 | return 0; | |
664 | } | |
665 | ||
666 | ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, | |
667 | spot, | |
668 | GFP_ATOMIC); | |
669 | if (ret_val != 0) | |
670 | return ret_val; | |
671 | } | |
672 | ||
673 | return -EINVAL; | |
674 | } | |
675 | ||
676 | /** | |
677 | * calipso_pad_write - Writes pad bytes in TLV format | |
678 | * @buf: the buffer | |
679 | * @offset: offset from start of buffer to write padding | |
680 | * @count: number of pad bytes to write | |
681 | * | |
682 | * Description: | |
683 | * Write @count bytes of TLV padding into @buffer starting at offset @offset. | |
684 | * @count should be less than 8 - see RFC 4942. | |
685 | * | |
686 | */ | |
687 | static int calipso_pad_write(unsigned char *buf, unsigned int offset, | |
688 | unsigned int count) | |
689 | { | |
690 | if (WARN_ON_ONCE(count >= 8)) | |
691 | return -EINVAL; | |
692 | ||
693 | switch (count) { | |
694 | case 0: | |
695 | break; | |
696 | case 1: | |
697 | buf[offset] = IPV6_TLV_PAD1; | |
698 | break; | |
699 | default: | |
700 | buf[offset] = IPV6_TLV_PADN; | |
701 | buf[offset + 1] = count - 2; | |
702 | if (count > 2) | |
703 | memset(buf + offset + 2, 0, count - 2); | |
704 | break; | |
705 | } | |
706 | return 0; | |
707 | } | |
708 | ||
709 | /** | |
710 | * calipso_genopt - Generate a CALIPSO option | |
711 | * @buf: the option buffer | |
712 | * @start: offset from which to write | |
713 | * @buf_len: the size of opt_buf | |
714 | * @doi_def: the CALIPSO DOI to use | |
715 | * @secattr: the security attributes | |
716 | * | |
717 | * Description: | |
718 | * Generate a CALIPSO option using the DOI definition and security attributes | |
719 | * passed to the function. This also generates upto three bytes of leading | |
720 | * padding that ensures that the option is 4n + 2 aligned. It returns the | |
721 | * number of bytes written (including any initial padding). | |
722 | */ | |
723 | static int calipso_genopt(unsigned char *buf, u32 start, u32 buf_len, | |
724 | const struct calipso_doi *doi_def, | |
725 | const struct netlbl_lsm_secattr *secattr) | |
726 | { | |
727 | int ret_val; | |
728 | u32 len, pad; | |
729 | u16 crc; | |
730 | static const unsigned char padding[4] = {2, 1, 0, 3}; | |
731 | unsigned char *calipso; | |
732 | ||
733 | /* CALIPSO has 4n + 2 alignment */ | |
734 | pad = padding[start & 3]; | |
735 | if (buf_len <= start + pad + CALIPSO_HDR_LEN) | |
736 | return -ENOSPC; | |
737 | ||
738 | if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0) | |
739 | return -EPERM; | |
740 | ||
741 | len = CALIPSO_HDR_LEN; | |
742 | ||
743 | if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { | |
744 | ret_val = calipso_map_cat_hton(doi_def, | |
745 | secattr, | |
746 | buf + start + pad + len, | |
747 | buf_len - start - pad - len); | |
748 | if (ret_val < 0) | |
749 | return ret_val; | |
750 | len += ret_val; | |
751 | } | |
752 | ||
753 | calipso_pad_write(buf, start, pad); | |
754 | calipso = buf + start + pad; | |
755 | ||
756 | calipso[0] = IPV6_TLV_CALIPSO; | |
757 | calipso[1] = len - 2; | |
758 | *(__be32 *)(calipso + 2) = htonl(doi_def->doi); | |
759 | calipso[6] = (len - CALIPSO_HDR_LEN) / 4; | |
6159e963 | 760 | calipso[7] = secattr->attr.mls.lvl; |
ceba1832 HD |
761 | crc = ~crc_ccitt(0xffff, calipso, len); |
762 | calipso[8] = crc & 0xff; | |
763 | calipso[9] = (crc >> 8) & 0xff; | |
764 | return pad + len; | |
765 | } | |
766 | ||
767 | /* Hop-by-hop hdr helper functions | |
768 | */ | |
769 | ||
770 | /** | |
771 | * calipso_opt_update - Replaces socket's hop options with a new set | |
772 | * @sk: the socket | |
773 | * @hop: new hop options | |
774 | * | |
775 | * Description: | |
776 | * Replaces @sk's hop options with @hop. @hop may be NULL to leave | |
777 | * the socket with no hop options. | |
778 | * | |
779 | */ | |
780 | static int calipso_opt_update(struct sock *sk, struct ipv6_opt_hdr *hop) | |
781 | { | |
782 | struct ipv6_txoptions *old = txopt_get(inet6_sk(sk)), *txopts; | |
783 | ||
a9ba23d4 | 784 | txopts = ipv6_renew_options(sk, old, IPV6_HOPOPTS, hop); |
ceba1832 HD |
785 | txopt_put(old); |
786 | if (IS_ERR(txopts)) | |
787 | return PTR_ERR(txopts); | |
788 | ||
789 | txopts = ipv6_update_options(sk, txopts); | |
790 | if (txopts) { | |
791 | atomic_sub(txopts->tot_len, &sk->sk_omem_alloc); | |
792 | txopt_put(txopts); | |
793 | } | |
794 | ||
795 | return 0; | |
796 | } | |
797 | ||
798 | /** | |
799 | * calipso_tlv_len - Returns the length of the TLV | |
800 | * @opt: the option header | |
801 | * @offset: offset of the TLV within the header | |
802 | * | |
803 | * Description: | |
804 | * Returns the length of the TLV option at offset @offset within | |
805 | * the option header @opt. Checks that the entire TLV fits inside | |
806 | * the option header, returns a negative value if this is not the case. | |
807 | */ | |
808 | static int calipso_tlv_len(struct ipv6_opt_hdr *opt, unsigned int offset) | |
809 | { | |
810 | unsigned char *tlv = (unsigned char *)opt; | |
811 | unsigned int opt_len = ipv6_optlen(opt), tlv_len; | |
812 | ||
813 | if (offset < sizeof(*opt) || offset >= opt_len) | |
814 | return -EINVAL; | |
815 | if (tlv[offset] == IPV6_TLV_PAD1) | |
816 | return 1; | |
817 | if (offset + 1 >= opt_len) | |
818 | return -EINVAL; | |
819 | tlv_len = tlv[offset + 1] + 2; | |
820 | if (offset + tlv_len > opt_len) | |
821 | return -EINVAL; | |
822 | return tlv_len; | |
823 | } | |
824 | ||
825 | /** | |
826 | * calipso_opt_find - Finds the CALIPSO option in an IPv6 hop options header | |
827 | * @hop: the hop options header | |
828 | * @start: on return holds the offset of any leading padding | |
829 | * @end: on return holds the offset of the first non-pad TLV after CALIPSO | |
830 | * | |
831 | * Description: | |
832 | * Finds the space occupied by a CALIPSO option (including any leading and | |
833 | * trailing padding). | |
834 | * | |
835 | * If a CALIPSO option exists set @start and @end to the | |
836 | * offsets within @hop of the start of padding before the first | |
837 | * CALIPSO option and the end of padding after the first CALIPSO | |
838 | * option. In this case the function returns 0. | |
839 | * | |
840 | * In the absence of a CALIPSO option, @start and @end will be | |
841 | * set to the start and end of any trailing padding in the header. | |
842 | * This is useful when appending a new option, as the caller may want | |
843 | * to overwrite some of this padding. In this case the function will | |
844 | * return -ENOENT. | |
845 | */ | |
846 | static int calipso_opt_find(struct ipv6_opt_hdr *hop, unsigned int *start, | |
847 | unsigned int *end) | |
848 | { | |
849 | int ret_val = -ENOENT, tlv_len; | |
850 | unsigned int opt_len, offset, offset_s = 0, offset_e = 0; | |
851 | unsigned char *opt = (unsigned char *)hop; | |
852 | ||
853 | opt_len = ipv6_optlen(hop); | |
854 | offset = sizeof(*hop); | |
855 | ||
856 | while (offset < opt_len) { | |
857 | tlv_len = calipso_tlv_len(hop, offset); | |
858 | if (tlv_len < 0) | |
859 | return tlv_len; | |
860 | ||
861 | switch (opt[offset]) { | |
862 | case IPV6_TLV_PAD1: | |
863 | case IPV6_TLV_PADN: | |
864 | if (offset_e) | |
865 | offset_e = offset; | |
866 | break; | |
867 | case IPV6_TLV_CALIPSO: | |
868 | ret_val = 0; | |
869 | offset_e = offset; | |
870 | break; | |
871 | default: | |
872 | if (offset_e == 0) | |
873 | offset_s = offset; | |
874 | else | |
875 | goto out; | |
876 | } | |
877 | offset += tlv_len; | |
878 | } | |
879 | ||
880 | out: | |
881 | if (offset_s) | |
882 | *start = offset_s + calipso_tlv_len(hop, offset_s); | |
883 | else | |
884 | *start = sizeof(*hop); | |
885 | if (offset_e) | |
886 | *end = offset_e + calipso_tlv_len(hop, offset_e); | |
887 | else | |
888 | *end = opt_len; | |
889 | ||
890 | return ret_val; | |
891 | } | |
892 | ||
893 | /** | |
894 | * calipso_opt_insert - Inserts a CALIPSO option into an IPv6 hop opt hdr | |
895 | * @hop: the original hop options header | |
896 | * @doi_def: the CALIPSO DOI to use | |
897 | * @secattr: the specific security attributes of the socket | |
898 | * | |
899 | * Description: | |
900 | * Creates a new hop options header based on @hop with a | |
901 | * CALIPSO option added to it. If @hop already contains a CALIPSO | |
902 | * option this is overwritten, otherwise the new option is appended | |
903 | * after any existing options. If @hop is NULL then the new header | |
904 | * will contain just the CALIPSO option and any needed padding. | |
905 | * | |
906 | */ | |
907 | static struct ipv6_opt_hdr * | |
908 | calipso_opt_insert(struct ipv6_opt_hdr *hop, | |
909 | const struct calipso_doi *doi_def, | |
910 | const struct netlbl_lsm_secattr *secattr) | |
911 | { | |
912 | unsigned int start, end, buf_len, pad, hop_len; | |
913 | struct ipv6_opt_hdr *new; | |
914 | int ret_val; | |
915 | ||
916 | if (hop) { | |
917 | hop_len = ipv6_optlen(hop); | |
918 | ret_val = calipso_opt_find(hop, &start, &end); | |
919 | if (ret_val && ret_val != -ENOENT) | |
920 | return ERR_PTR(ret_val); | |
921 | } else { | |
922 | hop_len = 0; | |
923 | start = sizeof(*hop); | |
924 | end = 0; | |
925 | } | |
926 | ||
927 | buf_len = hop_len + start - end + CALIPSO_OPT_LEN_MAX_WITH_PAD; | |
928 | new = kzalloc(buf_len, GFP_ATOMIC); | |
929 | if (!new) | |
930 | return ERR_PTR(-ENOMEM); | |
931 | ||
932 | if (start > sizeof(*hop)) | |
933 | memcpy(new, hop, start); | |
934 | ret_val = calipso_genopt((unsigned char *)new, start, buf_len, doi_def, | |
935 | secattr); | |
b4c0e0c6 CIK |
936 | if (ret_val < 0) { |
937 | kfree(new); | |
ceba1832 | 938 | return ERR_PTR(ret_val); |
b4c0e0c6 | 939 | } |
ceba1832 HD |
940 | |
941 | buf_len = start + ret_val; | |
942 | /* At this point buf_len aligns to 4n, so (buf_len & 4) pads to 8n */ | |
943 | pad = ((buf_len & 4) + (end & 7)) & 7; | |
944 | calipso_pad_write((unsigned char *)new, buf_len, pad); | |
945 | buf_len += pad; | |
946 | ||
947 | if (end != hop_len) { | |
948 | memcpy((char *)new + buf_len, (char *)hop + end, hop_len - end); | |
949 | buf_len += hop_len - end; | |
950 | } | |
951 | new->nexthdr = 0; | |
952 | new->hdrlen = buf_len / 8 - 1; | |
953 | ||
954 | return new; | |
955 | } | |
956 | ||
957 | /** | |
958 | * calipso_opt_del - Removes the CALIPSO option from an option header | |
959 | * @hop: the original header | |
960 | * @new: the new header | |
961 | * | |
962 | * Description: | |
963 | * Creates a new header based on @hop without any CALIPSO option. If @hop | |
964 | * doesn't contain a CALIPSO option it returns -ENOENT. If @hop contains | |
965 | * no other non-padding options, it returns zero with @new set to NULL. | |
966 | * Otherwise it returns zero, creates a new header without the CALIPSO | |
967 | * option (and removing as much padding as possible) and returns with | |
968 | * @new set to that header. | |
969 | * | |
970 | */ | |
971 | static int calipso_opt_del(struct ipv6_opt_hdr *hop, | |
972 | struct ipv6_opt_hdr **new) | |
973 | { | |
974 | int ret_val; | |
975 | unsigned int start, end, delta, pad, hop_len; | |
976 | ||
977 | ret_val = calipso_opt_find(hop, &start, &end); | |
978 | if (ret_val) | |
979 | return ret_val; | |
980 | ||
981 | hop_len = ipv6_optlen(hop); | |
982 | if (start == sizeof(*hop) && end == hop_len) { | |
983 | /* There's no other option in the header so return NULL */ | |
984 | *new = NULL; | |
985 | return 0; | |
986 | } | |
987 | ||
988 | delta = (end - start) & ~7; | |
989 | *new = kzalloc(hop_len - delta, GFP_ATOMIC); | |
990 | if (!*new) | |
991 | return -ENOMEM; | |
992 | ||
993 | memcpy(*new, hop, start); | |
994 | (*new)->hdrlen -= delta / 8; | |
995 | pad = (end - start) & 7; | |
996 | calipso_pad_write((unsigned char *)*new, start, pad); | |
997 | if (end != hop_len) | |
998 | memcpy((char *)*new + start + pad, (char *)hop + end, | |
999 | hop_len - end); | |
1000 | ||
1001 | return 0; | |
1002 | } | |
1003 | ||
1004 | /** | |
1005 | * calipso_opt_getattr - Get the security attributes from a memory block | |
1006 | * @calipso: the CALIPSO option | |
1007 | * @secattr: the security attributes | |
1008 | * | |
1009 | * Description: | |
1010 | * Inspect @calipso and return the security attributes in @secattr. | |
1011 | * Returns zero on success and negative values on failure. | |
1012 | * | |
1013 | */ | |
1014 | static int calipso_opt_getattr(const unsigned char *calipso, | |
1015 | struct netlbl_lsm_secattr *secattr) | |
1016 | { | |
1017 | int ret_val = -ENOMSG; | |
1018 | u32 doi, len = calipso[1], cat_len = calipso[6] * 4; | |
1019 | struct calipso_doi *doi_def; | |
1020 | ||
1021 | if (cat_len + 8 > len) | |
1022 | return -EINVAL; | |
1023 | ||
4fee5242 HD |
1024 | if (calipso_cache_check(calipso + 2, calipso[1], secattr) == 0) |
1025 | return 0; | |
1026 | ||
ceba1832 HD |
1027 | doi = get_unaligned_be32(calipso + 2); |
1028 | rcu_read_lock(); | |
1029 | doi_def = calipso_doi_search(doi); | |
1030 | if (!doi_def) | |
1031 | goto getattr_return; | |
1032 | ||
1033 | secattr->attr.mls.lvl = calipso[7]; | |
1034 | secattr->flags |= NETLBL_SECATTR_MLS_LVL; | |
1035 | ||
1036 | if (cat_len) { | |
1037 | ret_val = calipso_map_cat_ntoh(doi_def, | |
1038 | calipso + 10, | |
1039 | cat_len, | |
1040 | secattr); | |
1041 | if (ret_val != 0) { | |
1042 | netlbl_catmap_free(secattr->attr.mls.cat); | |
1043 | goto getattr_return; | |
1044 | } | |
1045 | ||
eead1c2e PA |
1046 | if (secattr->attr.mls.cat) |
1047 | secattr->flags |= NETLBL_SECATTR_MLS_CAT; | |
ceba1832 HD |
1048 | } |
1049 | ||
1050 | secattr->type = NETLBL_NLTYPE_CALIPSO; | |
1051 | ||
1052 | getattr_return: | |
1053 | rcu_read_unlock(); | |
1054 | return ret_val; | |
1055 | } | |
1056 | ||
1057 | /* sock functions. | |
1058 | */ | |
1059 | ||
1060 | /** | |
1061 | * calipso_sock_getattr - Get the security attributes from a sock | |
1062 | * @sk: the sock | |
1063 | * @secattr: the security attributes | |
1064 | * | |
1065 | * Description: | |
1066 | * Query @sk to see if there is a CALIPSO option attached to the sock and if | |
1067 | * there is return the CALIPSO security attributes in @secattr. This function | |
1068 | * requires that @sk be locked, or privately held, but it does not do any | |
1069 | * locking itself. Returns zero on success and negative values on failure. | |
1070 | * | |
1071 | */ | |
1072 | static int calipso_sock_getattr(struct sock *sk, | |
1073 | struct netlbl_lsm_secattr *secattr) | |
1074 | { | |
1075 | struct ipv6_opt_hdr *hop; | |
1076 | int opt_len, len, ret_val = -ENOMSG, offset; | |
1077 | unsigned char *opt; | |
1078 | struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk)); | |
1079 | ||
1080 | if (!txopts || !txopts->hopopt) | |
1081 | goto done; | |
1082 | ||
1083 | hop = txopts->hopopt; | |
1084 | opt = (unsigned char *)hop; | |
1085 | opt_len = ipv6_optlen(hop); | |
1086 | offset = sizeof(*hop); | |
1087 | while (offset < opt_len) { | |
1088 | len = calipso_tlv_len(hop, offset); | |
1089 | if (len < 0) { | |
1090 | ret_val = len; | |
1091 | goto done; | |
1092 | } | |
1093 | switch (opt[offset]) { | |
1094 | case IPV6_TLV_CALIPSO: | |
1095 | if (len < CALIPSO_HDR_LEN) | |
1096 | ret_val = -EINVAL; | |
1097 | else | |
1098 | ret_val = calipso_opt_getattr(&opt[offset], | |
1099 | secattr); | |
1100 | goto done; | |
1101 | default: | |
1102 | offset += len; | |
1103 | break; | |
1104 | } | |
1105 | } | |
1106 | done: | |
1107 | txopt_put(txopts); | |
1108 | return ret_val; | |
1109 | } | |
1110 | ||
1111 | /** | |
1112 | * calipso_sock_setattr - Add a CALIPSO option to a socket | |
1113 | * @sk: the socket | |
1114 | * @doi_def: the CALIPSO DOI to use | |
1115 | * @secattr: the specific security attributes of the socket | |
1116 | * | |
1117 | * Description: | |
1118 | * Set the CALIPSO option on the given socket using the DOI definition and | |
1119 | * security attributes passed to the function. This function requires | |
1120 | * exclusive access to @sk, which means it either needs to be in the | |
1121 | * process of being created or locked. Returns zero on success and negative | |
1122 | * values on failure. | |
1123 | * | |
1124 | */ | |
1125 | static int calipso_sock_setattr(struct sock *sk, | |
1126 | const struct calipso_doi *doi_def, | |
1127 | const struct netlbl_lsm_secattr *secattr) | |
1128 | { | |
1129 | int ret_val; | |
1130 | struct ipv6_opt_hdr *old, *new; | |
1131 | struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk)); | |
1132 | ||
1133 | old = NULL; | |
1134 | if (txopts) | |
1135 | old = txopts->hopopt; | |
1136 | ||
1137 | new = calipso_opt_insert(old, doi_def, secattr); | |
1138 | txopt_put(txopts); | |
1139 | if (IS_ERR(new)) | |
1140 | return PTR_ERR(new); | |
1141 | ||
1142 | ret_val = calipso_opt_update(sk, new); | |
1143 | ||
1144 | kfree(new); | |
1145 | return ret_val; | |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * calipso_sock_delattr - Delete the CALIPSO option from a socket | |
1150 | * @sk: the socket | |
1151 | * | |
1152 | * Description: | |
1153 | * Removes the CALIPSO option from a socket, if present. | |
1154 | * | |
1155 | */ | |
1156 | static void calipso_sock_delattr(struct sock *sk) | |
1157 | { | |
1158 | struct ipv6_opt_hdr *new_hop; | |
1159 | struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk)); | |
1160 | ||
1161 | if (!txopts || !txopts->hopopt) | |
1162 | goto done; | |
1163 | ||
1164 | if (calipso_opt_del(txopts->hopopt, &new_hop)) | |
1165 | goto done; | |
1166 | ||
1167 | calipso_opt_update(sk, new_hop); | |
1168 | kfree(new_hop); | |
1169 | ||
1170 | done: | |
1171 | txopt_put(txopts); | |
1172 | } | |
1173 | ||
e1adea92 HD |
1174 | /* request sock functions. |
1175 | */ | |
1176 | ||
1177 | /** | |
1178 | * calipso_req_setattr - Add a CALIPSO option to a connection request socket | |
1179 | * @req: the connection request socket | |
1180 | * @doi_def: the CALIPSO DOI to use | |
1181 | * @secattr: the specific security attributes of the socket | |
1182 | * | |
1183 | * Description: | |
1184 | * Set the CALIPSO option on the given socket using the DOI definition and | |
1185 | * security attributes passed to the function. Returns zero on success and | |
1186 | * negative values on failure. | |
1187 | * | |
1188 | */ | |
1189 | static int calipso_req_setattr(struct request_sock *req, | |
1190 | const struct calipso_doi *doi_def, | |
1191 | const struct netlbl_lsm_secattr *secattr) | |
1192 | { | |
1193 | struct ipv6_txoptions *txopts; | |
1194 | struct inet_request_sock *req_inet = inet_rsk(req); | |
1195 | struct ipv6_opt_hdr *old, *new; | |
1196 | struct sock *sk = sk_to_full_sk(req_to_sk(req)); | |
1197 | ||
1198 | if (req_inet->ipv6_opt && req_inet->ipv6_opt->hopopt) | |
1199 | old = req_inet->ipv6_opt->hopopt; | |
1200 | else | |
1201 | old = NULL; | |
1202 | ||
1203 | new = calipso_opt_insert(old, doi_def, secattr); | |
1204 | if (IS_ERR(new)) | |
1205 | return PTR_ERR(new); | |
1206 | ||
a9ba23d4 | 1207 | txopts = ipv6_renew_options(sk, req_inet->ipv6_opt, IPV6_HOPOPTS, new); |
e1adea92 HD |
1208 | |
1209 | kfree(new); | |
1210 | ||
1211 | if (IS_ERR(txopts)) | |
1212 | return PTR_ERR(txopts); | |
1213 | ||
1214 | txopts = xchg(&req_inet->ipv6_opt, txopts); | |
1215 | if (txopts) { | |
1216 | atomic_sub(txopts->tot_len, &sk->sk_omem_alloc); | |
1217 | txopt_put(txopts); | |
1218 | } | |
1219 | ||
1220 | return 0; | |
1221 | } | |
1222 | ||
1223 | /** | |
1224 | * calipso_req_delattr - Delete the CALIPSO option from a request socket | |
8da1f442 | 1225 | * @req: the request socket |
e1adea92 HD |
1226 | * |
1227 | * Description: | |
1228 | * Removes the CALIPSO option from a request socket, if present. | |
1229 | * | |
1230 | */ | |
1231 | static void calipso_req_delattr(struct request_sock *req) | |
1232 | { | |
1233 | struct inet_request_sock *req_inet = inet_rsk(req); | |
1234 | struct ipv6_opt_hdr *new; | |
1235 | struct ipv6_txoptions *txopts; | |
1236 | struct sock *sk = sk_to_full_sk(req_to_sk(req)); | |
1237 | ||
1238 | if (!req_inet->ipv6_opt || !req_inet->ipv6_opt->hopopt) | |
1239 | return; | |
1240 | ||
1241 | if (calipso_opt_del(req_inet->ipv6_opt->hopopt, &new)) | |
1242 | return; /* Nothing to do */ | |
1243 | ||
a9ba23d4 | 1244 | txopts = ipv6_renew_options(sk, req_inet->ipv6_opt, IPV6_HOPOPTS, new); |
e1adea92 HD |
1245 | |
1246 | if (!IS_ERR(txopts)) { | |
1247 | txopts = xchg(&req_inet->ipv6_opt, txopts); | |
1248 | if (txopts) { | |
1249 | atomic_sub(txopts->tot_len, &sk->sk_omem_alloc); | |
1250 | txopt_put(txopts); | |
1251 | } | |
1252 | } | |
1253 | kfree(new); | |
1254 | } | |
1255 | ||
2917f57b HD |
1256 | /* skbuff functions. |
1257 | */ | |
1258 | ||
1259 | /** | |
1260 | * calipso_skbuff_optptr - Find the CALIPSO option in the packet | |
1261 | * @skb: the packet | |
1262 | * | |
1263 | * Description: | |
1264 | * Parse the packet's IP header looking for a CALIPSO option. Returns a pointer | |
1265 | * to the start of the CALIPSO option on success, NULL if one if not found. | |
1266 | * | |
1267 | */ | |
1268 | static unsigned char *calipso_skbuff_optptr(const struct sk_buff *skb) | |
1269 | { | |
1270 | const struct ipv6hdr *ip6_hdr = ipv6_hdr(skb); | |
1271 | int offset; | |
1272 | ||
1273 | if (ip6_hdr->nexthdr != NEXTHDR_HOP) | |
1274 | return NULL; | |
1275 | ||
1276 | offset = ipv6_find_tlv(skb, sizeof(*ip6_hdr), IPV6_TLV_CALIPSO); | |
1277 | if (offset >= 0) | |
1278 | return (unsigned char *)ip6_hdr + offset; | |
1279 | ||
1280 | return NULL; | |
1281 | } | |
1282 | ||
1283 | /** | |
1284 | * calipso_skbuff_setattr - Set the CALIPSO option on a packet | |
1285 | * @skb: the packet | |
1286 | * @doi_def: the CALIPSO DOI to use | |
1287 | * @secattr: the security attributes | |
1288 | * | |
1289 | * Description: | |
1290 | * Set the CALIPSO option on the given packet based on the security attributes. | |
1291 | * Returns a pointer to the IP header on success and NULL on failure. | |
1292 | * | |
1293 | */ | |
1294 | static int calipso_skbuff_setattr(struct sk_buff *skb, | |
1295 | const struct calipso_doi *doi_def, | |
1296 | const struct netlbl_lsm_secattr *secattr) | |
1297 | { | |
1298 | int ret_val; | |
1299 | struct ipv6hdr *ip6_hdr; | |
1300 | struct ipv6_opt_hdr *hop; | |
1301 | unsigned char buf[CALIPSO_MAX_BUFFER]; | |
e3ebdb20 | 1302 | int len_delta, new_end, pad, payload; |
2917f57b HD |
1303 | unsigned int start, end; |
1304 | ||
1305 | ip6_hdr = ipv6_hdr(skb); | |
1306 | if (ip6_hdr->nexthdr == NEXTHDR_HOP) { | |
1307 | hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1); | |
1308 | ret_val = calipso_opt_find(hop, &start, &end); | |
1309 | if (ret_val && ret_val != -ENOENT) | |
1310 | return ret_val; | |
1311 | } else { | |
1312 | start = 0; | |
1313 | end = 0; | |
1314 | } | |
1315 | ||
1316 | memset(buf, 0, sizeof(buf)); | |
1317 | ret_val = calipso_genopt(buf, start & 3, sizeof(buf), doi_def, secattr); | |
1318 | if (ret_val < 0) | |
1319 | return ret_val; | |
1320 | ||
1321 | new_end = start + ret_val; | |
1322 | /* At this point new_end aligns to 4n, so (new_end & 4) pads to 8n */ | |
1323 | pad = ((new_end & 4) + (end & 7)) & 7; | |
1324 | len_delta = new_end - (int)end + pad; | |
1325 | ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); | |
1326 | if (ret_val < 0) | |
1327 | return ret_val; | |
1328 | ||
e3ebdb20 RH |
1329 | ip6_hdr = ipv6_hdr(skb); /* Reset as skb_cow() may have moved it */ |
1330 | ||
2917f57b HD |
1331 | if (len_delta) { |
1332 | if (len_delta > 0) | |
1333 | skb_push(skb, len_delta); | |
1334 | else | |
1335 | skb_pull(skb, -len_delta); | |
1336 | memmove((char *)ip6_hdr - len_delta, ip6_hdr, | |
1337 | sizeof(*ip6_hdr) + start); | |
1338 | skb_reset_network_header(skb); | |
1339 | ip6_hdr = ipv6_hdr(skb); | |
e3ebdb20 RH |
1340 | payload = ntohs(ip6_hdr->payload_len); |
1341 | ip6_hdr->payload_len = htons(payload + len_delta); | |
2917f57b HD |
1342 | } |
1343 | ||
1344 | hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1); | |
1345 | if (start == 0) { | |
1346 | struct ipv6_opt_hdr *new_hop = (struct ipv6_opt_hdr *)buf; | |
1347 | ||
1348 | new_hop->nexthdr = ip6_hdr->nexthdr; | |
1349 | new_hop->hdrlen = len_delta / 8 - 1; | |
1350 | ip6_hdr->nexthdr = NEXTHDR_HOP; | |
1351 | } else { | |
1352 | hop->hdrlen += len_delta / 8; | |
1353 | } | |
1354 | memcpy((char *)hop + start, buf + (start & 3), new_end - start); | |
1355 | calipso_pad_write((unsigned char *)hop, new_end, pad); | |
1356 | ||
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | /** | |
1361 | * calipso_skbuff_delattr - Delete any CALIPSO options from a packet | |
1362 | * @skb: the packet | |
1363 | * | |
1364 | * Description: | |
1365 | * Removes any and all CALIPSO options from the given packet. Returns zero on | |
1366 | * success, negative values on failure. | |
1367 | * | |
1368 | */ | |
1369 | static int calipso_skbuff_delattr(struct sk_buff *skb) | |
1370 | { | |
1371 | int ret_val; | |
1372 | struct ipv6hdr *ip6_hdr; | |
1373 | struct ipv6_opt_hdr *old_hop; | |
1374 | u32 old_hop_len, start = 0, end = 0, delta, size, pad; | |
1375 | ||
1376 | if (!calipso_skbuff_optptr(skb)) | |
1377 | return 0; | |
1378 | ||
1379 | /* since we are changing the packet we should make a copy */ | |
1380 | ret_val = skb_cow(skb, skb_headroom(skb)); | |
1381 | if (ret_val < 0) | |
1382 | return ret_val; | |
1383 | ||
1384 | ip6_hdr = ipv6_hdr(skb); | |
1385 | old_hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1); | |
1386 | old_hop_len = ipv6_optlen(old_hop); | |
1387 | ||
1388 | ret_val = calipso_opt_find(old_hop, &start, &end); | |
1389 | if (ret_val) | |
1390 | return ret_val; | |
1391 | ||
1392 | if (start == sizeof(*old_hop) && end == old_hop_len) { | |
1393 | /* There's no other option in the header so we delete | |
1394 | * the whole thing. */ | |
1395 | delta = old_hop_len; | |
1396 | size = sizeof(*ip6_hdr); | |
1397 | ip6_hdr->nexthdr = old_hop->nexthdr; | |
1398 | } else { | |
1399 | delta = (end - start) & ~7; | |
1400 | if (delta) | |
1401 | old_hop->hdrlen -= delta / 8; | |
1402 | pad = (end - start) & 7; | |
1403 | size = sizeof(*ip6_hdr) + start + pad; | |
1404 | calipso_pad_write((unsigned char *)old_hop, start, pad); | |
1405 | } | |
1406 | ||
1407 | if (delta) { | |
1408 | skb_pull(skb, delta); | |
1409 | memmove((char *)ip6_hdr + delta, ip6_hdr, size); | |
1410 | skb_reset_network_header(skb); | |
1411 | } | |
1412 | ||
1413 | return 0; | |
1414 | } | |
1415 | ||
cb72d382 HD |
1416 | static const struct netlbl_calipso_ops ops = { |
1417 | .doi_add = calipso_doi_add, | |
1418 | .doi_free = calipso_doi_free, | |
d7cce015 | 1419 | .doi_remove = calipso_doi_remove, |
a5e34490 HD |
1420 | .doi_getdef = calipso_doi_getdef, |
1421 | .doi_putdef = calipso_doi_putdef, | |
e1ce69df | 1422 | .doi_walk = calipso_doi_walk, |
ceba1832 HD |
1423 | .sock_getattr = calipso_sock_getattr, |
1424 | .sock_setattr = calipso_sock_setattr, | |
1425 | .sock_delattr = calipso_sock_delattr, | |
e1adea92 HD |
1426 | .req_setattr = calipso_req_setattr, |
1427 | .req_delattr = calipso_req_delattr, | |
2917f57b HD |
1428 | .opt_getattr = calipso_opt_getattr, |
1429 | .skbuff_optptr = calipso_skbuff_optptr, | |
1430 | .skbuff_setattr = calipso_skbuff_setattr, | |
1431 | .skbuff_delattr = calipso_skbuff_delattr, | |
4fee5242 HD |
1432 | .cache_invalidate = calipso_cache_invalidate, |
1433 | .cache_add = calipso_cache_add | |
cb72d382 HD |
1434 | }; |
1435 | ||
1436 | /** | |
1437 | * calipso_init - Initialize the CALIPSO module | |
1438 | * | |
1439 | * Description: | |
1440 | * Initialize the CALIPSO module and prepare it for use. Returns zero on | |
1441 | * success and negative values on failure. | |
1442 | * | |
1443 | */ | |
1444 | int __init calipso_init(void) | |
1445 | { | |
4fee5242 HD |
1446 | int ret_val; |
1447 | ||
1448 | ret_val = calipso_cache_init(); | |
1449 | if (!ret_val) | |
1450 | netlbl_calipso_ops_register(&ops); | |
1451 | return ret_val; | |
cb72d382 HD |
1452 | } |
1453 | ||
1454 | void calipso_exit(void) | |
1455 | { | |
1456 | netlbl_calipso_ops_register(NULL); | |
4fee5242 HD |
1457 | calipso_cache_invalidate(); |
1458 | kfree(calipso_cache); | |
cb72d382 | 1459 | } |