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d15c345f PM |
1 | /* |
2 | * NetLabel Kernel API | |
3 | * | |
4 | * This file defines the kernel API for the NetLabel system. The NetLabel | |
5 | * system manages static and dynamic label mappings for network protocols such | |
6 | * as CIPSO and RIPSO. | |
7 | * | |
8 | * Author: Paul Moore <paul.moore@hp.com> | |
9 | * | |
10 | */ | |
11 | ||
12 | /* | |
13 | * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or modify | |
16 | * it under the terms of the GNU General Public License as published by | |
17 | * the Free Software Foundation; either version 2 of the License, or | |
18 | * (at your option) any later version. | |
19 | * | |
20 | * This program is distributed in the hope that it will be useful, | |
21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | |
23 | * the GNU General Public License for more details. | |
24 | * | |
25 | * You should have received a copy of the GNU General Public License | |
26 | * along with this program; if not, write to the Free Software | |
27 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
28 | * | |
29 | */ | |
30 | ||
31 | #include <linux/init.h> | |
32 | #include <linux/types.h> | |
33 | #include <net/ip.h> | |
34 | #include <net/netlabel.h> | |
35 | #include <net/cipso_ipv4.h> | |
36 | #include <asm/bug.h> | |
37 | ||
38 | #include "netlabel_domainhash.h" | |
39 | #include "netlabel_unlabeled.h" | |
40 | #include "netlabel_user.h" | |
23bcdc1a | 41 | #include "netlabel_mgmt.h" |
d15c345f | 42 | |
02752760 PM |
43 | /* |
44 | * Security Attribute Functions | |
45 | */ | |
46 | ||
47 | /** | |
48 | * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit | |
49 | * @catmap: the category bitmap | |
50 | * @offset: the offset to start searching at, in bits | |
51 | * | |
52 | * Description: | |
53 | * This function walks a LSM secattr category bitmap starting at @offset and | |
54 | * returns the spot of the first set bit or -ENOENT if no bits are set. | |
55 | * | |
56 | */ | |
57 | int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap, | |
58 | u32 offset) | |
59 | { | |
60 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
61 | u32 node_idx; | |
62 | u32 node_bit; | |
63 | NETLBL_CATMAP_MAPTYPE bitmap; | |
64 | ||
65 | if (offset > iter->startbit) { | |
66 | while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
67 | iter = iter->next; | |
68 | if (iter == NULL) | |
69 | return -ENOENT; | |
70 | } | |
71 | node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
72 | node_bit = offset - iter->startbit - | |
73 | (NETLBL_CATMAP_MAPSIZE * node_idx); | |
74 | } else { | |
75 | node_idx = 0; | |
76 | node_bit = 0; | |
77 | } | |
78 | bitmap = iter->bitmap[node_idx] >> node_bit; | |
79 | ||
80 | for (;;) { | |
81 | if (bitmap != 0) { | |
82 | while ((bitmap & NETLBL_CATMAP_BIT) == 0) { | |
83 | bitmap >>= 1; | |
84 | node_bit++; | |
85 | } | |
86 | return iter->startbit + | |
87 | (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit; | |
88 | } | |
89 | if (++node_idx >= NETLBL_CATMAP_MAPCNT) { | |
90 | if (iter->next != NULL) { | |
91 | iter = iter->next; | |
92 | node_idx = 0; | |
93 | } else | |
94 | return -ENOENT; | |
95 | } | |
96 | bitmap = iter->bitmap[node_idx]; | |
97 | node_bit = 0; | |
98 | } | |
99 | ||
100 | return -ENOENT; | |
101 | } | |
102 | ||
103 | /** | |
104 | * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits | |
105 | * @catmap: the category bitmap | |
106 | * @offset: the offset to start searching at, in bits | |
107 | * | |
108 | * Description: | |
109 | * This function walks a LSM secattr category bitmap starting at @offset and | |
110 | * returns the spot of the first cleared bit or -ENOENT if the offset is past | |
111 | * the end of the bitmap. | |
112 | * | |
113 | */ | |
114 | int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap, | |
115 | u32 offset) | |
116 | { | |
117 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
118 | u32 node_idx; | |
119 | u32 node_bit; | |
120 | NETLBL_CATMAP_MAPTYPE bitmask; | |
121 | NETLBL_CATMAP_MAPTYPE bitmap; | |
122 | ||
123 | if (offset > iter->startbit) { | |
124 | while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
125 | iter = iter->next; | |
126 | if (iter == NULL) | |
127 | return -ENOENT; | |
128 | } | |
129 | node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
130 | node_bit = offset - iter->startbit - | |
131 | (NETLBL_CATMAP_MAPSIZE * node_idx); | |
132 | } else { | |
133 | node_idx = 0; | |
134 | node_bit = 0; | |
135 | } | |
136 | bitmask = NETLBL_CATMAP_BIT << node_bit; | |
137 | ||
138 | for (;;) { | |
139 | bitmap = iter->bitmap[node_idx]; | |
140 | while (bitmask != 0 && (bitmap & bitmask) != 0) { | |
141 | bitmask <<= 1; | |
142 | node_bit++; | |
143 | } | |
144 | ||
145 | if (bitmask != 0) | |
146 | return iter->startbit + | |
147 | (NETLBL_CATMAP_MAPSIZE * node_idx) + | |
148 | node_bit - 1; | |
149 | else if (++node_idx >= NETLBL_CATMAP_MAPCNT) { | |
150 | if (iter->next == NULL) | |
151 | return iter->startbit + NETLBL_CATMAP_SIZE - 1; | |
152 | iter = iter->next; | |
153 | node_idx = 0; | |
154 | } | |
155 | bitmask = NETLBL_CATMAP_BIT; | |
156 | node_bit = 0; | |
157 | } | |
158 | ||
159 | return -ENOENT; | |
160 | } | |
161 | ||
162 | /** | |
163 | * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap | |
164 | * @catmap: the category bitmap | |
165 | * @bit: the bit to set | |
166 | * @flags: memory allocation flags | |
167 | * | |
168 | * Description: | |
169 | * Set the bit specified by @bit in @catmap. Returns zero on success, | |
170 | * negative values on failure. | |
171 | * | |
172 | */ | |
173 | int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap, | |
174 | u32 bit, | |
175 | gfp_t flags) | |
176 | { | |
177 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
178 | u32 node_bit; | |
179 | u32 node_idx; | |
180 | ||
181 | while (iter->next != NULL && | |
182 | bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) | |
183 | iter = iter->next; | |
184 | if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
185 | iter->next = netlbl_secattr_catmap_alloc(flags); | |
186 | if (iter->next == NULL) | |
187 | return -ENOMEM; | |
188 | iter = iter->next; | |
189 | iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1); | |
190 | } | |
191 | ||
192 | /* gcc always rounds to zero when doing integer division */ | |
193 | node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
194 | node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx); | |
195 | iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit; | |
196 | ||
197 | return 0; | |
198 | } | |
199 | ||
200 | /** | |
201 | * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap | |
202 | * @catmap: the category bitmap | |
203 | * @start: the starting bit | |
204 | * @end: the last bit in the string | |
205 | * @flags: memory allocation flags | |
206 | * | |
207 | * Description: | |
208 | * Set a range of bits, starting at @start and ending with @end. Returns zero | |
209 | * on success, negative values on failure. | |
210 | * | |
211 | */ | |
212 | int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap, | |
213 | u32 start, | |
214 | u32 end, | |
215 | gfp_t flags) | |
216 | { | |
217 | int ret_val = 0; | |
218 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
219 | u32 iter_max_spot; | |
220 | u32 spot; | |
221 | ||
222 | /* XXX - This could probably be made a bit faster by combining writes | |
223 | * to the catmap instead of setting a single bit each time, but for | |
224 | * right now skipping to the start of the range in the catmap should | |
225 | * be a nice improvement over calling the individual setbit function | |
226 | * repeatedly from a loop. */ | |
227 | ||
228 | while (iter->next != NULL && | |
229 | start >= (iter->startbit + NETLBL_CATMAP_SIZE)) | |
230 | iter = iter->next; | |
231 | iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; | |
232 | ||
233 | for (spot = start; spot <= end && ret_val == 0; spot++) { | |
234 | if (spot >= iter_max_spot && iter->next != NULL) { | |
235 | iter = iter->next; | |
236 | iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; | |
237 | } | |
238 | ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC); | |
239 | } | |
240 | ||
241 | return ret_val; | |
242 | } | |
243 | ||
d15c345f PM |
244 | /* |
245 | * LSM Functions | |
246 | */ | |
247 | ||
23bcdc1a PM |
248 | /** |
249 | * netlbl_enabled - Determine if the NetLabel subsystem is enabled | |
250 | * | |
251 | * Description: | |
252 | * The LSM can use this function to determine if it should use NetLabel | |
253 | * security attributes in it's enforcement mechanism. Currently, NetLabel is | |
254 | * considered to be enabled when it's configuration contains a valid setup for | |
255 | * at least one labeled protocol (i.e. NetLabel can understand incoming | |
256 | * labeled packets of at least one type); otherwise NetLabel is considered to | |
257 | * be disabled. | |
258 | * | |
259 | */ | |
260 | int netlbl_enabled(void) | |
261 | { | |
262 | /* At some point we probably want to expose this mechanism to the user | |
263 | * as well so that admins can toggle NetLabel regardless of the | |
264 | * configuration */ | |
265 | return (netlbl_mgmt_protocount_value() > 0 ? 1 : 0); | |
266 | } | |
267 | ||
d15c345f PM |
268 | /** |
269 | * netlbl_socket_setattr - Label a socket using the correct protocol | |
ba6ff9f2 | 270 | * @sk: the socket to label |
d15c345f PM |
271 | * @secattr: the security attributes |
272 | * | |
273 | * Description: | |
274 | * Attach the correct label to the given socket using the security attributes | |
ba6ff9f2 PM |
275 | * specified in @secattr. This function requires exclusive access to @sk, |
276 | * which means it either needs to be in the process of being created or locked. | |
277 | * Returns zero on success, negative values on failure. | |
d15c345f PM |
278 | * |
279 | */ | |
ba6ff9f2 PM |
280 | int netlbl_sock_setattr(struct sock *sk, |
281 | const struct netlbl_lsm_secattr *secattr) | |
d15c345f PM |
282 | { |
283 | int ret_val = -ENOENT; | |
284 | struct netlbl_dom_map *dom_entry; | |
285 | ||
286 | rcu_read_lock(); | |
287 | dom_entry = netlbl_domhsh_getentry(secattr->domain); | |
288 | if (dom_entry == NULL) | |
289 | goto socket_setattr_return; | |
290 | switch (dom_entry->type) { | |
291 | case NETLBL_NLTYPE_CIPSOV4: | |
ba6ff9f2 PM |
292 | ret_val = cipso_v4_sock_setattr(sk, |
293 | dom_entry->type_def.cipsov4, | |
294 | secattr); | |
d15c345f PM |
295 | break; |
296 | case NETLBL_NLTYPE_UNLABELED: | |
297 | ret_val = 0; | |
298 | break; | |
299 | default: | |
300 | ret_val = -ENOENT; | |
301 | } | |
302 | ||
303 | socket_setattr_return: | |
304 | rcu_read_unlock(); | |
305 | return ret_val; | |
306 | } | |
307 | ||
14a72f53 PM |
308 | /** |
309 | * netlbl_sock_getattr - Determine the security attributes of a sock | |
310 | * @sk: the sock | |
311 | * @secattr: the security attributes | |
312 | * | |
313 | * Description: | |
314 | * Examines the given sock to see any NetLabel style labeling has been | |
315 | * applied to the sock, if so it parses the socket label and returns the | |
316 | * security attributes in @secattr. Returns zero on success, negative values | |
317 | * on failure. | |
318 | * | |
319 | */ | |
320 | int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) | |
321 | { | |
322 | int ret_val; | |
323 | ||
324 | ret_val = cipso_v4_sock_getattr(sk, secattr); | |
325 | if (ret_val == 0) | |
326 | return 0; | |
327 | ||
328 | return netlbl_unlabel_getattr(secattr); | |
329 | } | |
330 | ||
d15c345f PM |
331 | /** |
332 | * netlbl_skbuff_getattr - Determine the security attributes of a packet | |
333 | * @skb: the packet | |
334 | * @secattr: the security attributes | |
335 | * | |
336 | * Description: | |
337 | * Examines the given packet to see if a recognized form of packet labeling | |
338 | * is present, if so it parses the packet label and returns the security | |
339 | * attributes in @secattr. Returns zero on success, negative values on | |
340 | * failure. | |
341 | * | |
342 | */ | |
343 | int netlbl_skbuff_getattr(const struct sk_buff *skb, | |
344 | struct netlbl_lsm_secattr *secattr) | |
345 | { | |
05e00cbf PM |
346 | if (CIPSO_V4_OPTEXIST(skb) && |
347 | cipso_v4_skbuff_getattr(skb, secattr) == 0) | |
d15c345f PM |
348 | return 0; |
349 | ||
350 | return netlbl_unlabel_getattr(secattr); | |
351 | } | |
352 | ||
353 | /** | |
354 | * netlbl_skbuff_err - Handle a LSM error on a sk_buff | |
355 | * @skb: the packet | |
356 | * @error: the error code | |
357 | * | |
358 | * Description: | |
359 | * Deal with a LSM problem when handling the packet in @skb, typically this is | |
360 | * a permission denied problem (-EACCES). The correct action is determined | |
361 | * according to the packet's labeling protocol. | |
362 | * | |
363 | */ | |
364 | void netlbl_skbuff_err(struct sk_buff *skb, int error) | |
365 | { | |
366 | if (CIPSO_V4_OPTEXIST(skb)) | |
367 | cipso_v4_error(skb, error, 0); | |
368 | } | |
369 | ||
370 | /** | |
371 | * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches | |
372 | * | |
373 | * Description: | |
374 | * For all of the NetLabel protocols that support some form of label mapping | |
375 | * cache, invalidate the cache. Returns zero on success, negative values on | |
376 | * error. | |
377 | * | |
378 | */ | |
379 | void netlbl_cache_invalidate(void) | |
380 | { | |
381 | cipso_v4_cache_invalidate(); | |
382 | } | |
383 | ||
384 | /** | |
385 | * netlbl_cache_add - Add an entry to a NetLabel protocol cache | |
386 | * @skb: the packet | |
387 | * @secattr: the packet's security attributes | |
388 | * | |
389 | * Description: | |
390 | * Add the LSM security attributes for the given packet to the underlying | |
391 | * NetLabel protocol's label mapping cache. Returns zero on success, negative | |
392 | * values on error. | |
393 | * | |
394 | */ | |
395 | int netlbl_cache_add(const struct sk_buff *skb, | |
396 | const struct netlbl_lsm_secattr *secattr) | |
397 | { | |
701a90ba | 398 | if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0) |
d15c345f PM |
399 | return -ENOMSG; |
400 | ||
401 | if (CIPSO_V4_OPTEXIST(skb)) | |
402 | return cipso_v4_cache_add(skb, secattr); | |
403 | ||
404 | return -ENOMSG; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Setup Functions | |
409 | */ | |
410 | ||
411 | /** | |
412 | * netlbl_init - Initialize NetLabel | |
413 | * | |
414 | * Description: | |
415 | * Perform the required NetLabel initialization before first use. | |
416 | * | |
417 | */ | |
418 | static int __init netlbl_init(void) | |
419 | { | |
420 | int ret_val; | |
421 | ||
422 | printk(KERN_INFO "NetLabel: Initializing\n"); | |
423 | printk(KERN_INFO "NetLabel: domain hash size = %u\n", | |
424 | (1 << NETLBL_DOMHSH_BITSIZE)); | |
425 | printk(KERN_INFO "NetLabel: protocols =" | |
426 | " UNLABELED" | |
427 | " CIPSOv4" | |
428 | "\n"); | |
429 | ||
430 | ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE); | |
431 | if (ret_val != 0) | |
432 | goto init_failure; | |
433 | ||
434 | ret_val = netlbl_netlink_init(); | |
435 | if (ret_val != 0) | |
436 | goto init_failure; | |
437 | ||
438 | ret_val = netlbl_unlabel_defconf(); | |
439 | if (ret_val != 0) | |
440 | goto init_failure; | |
441 | printk(KERN_INFO "NetLabel: unlabeled traffic allowed by default\n"); | |
442 | ||
443 | return 0; | |
444 | ||
445 | init_failure: | |
446 | panic("NetLabel: failed to initialize properly (%d)\n", ret_val); | |
447 | } | |
448 | ||
449 | subsys_initcall(netlbl_init); |