Commit | Line | Data |
---|---|---|
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> | |
c783f1ce | 37 | #include <asm/atomic.h> |
d15c345f PM |
38 | |
39 | #include "netlabel_domainhash.h" | |
40 | #include "netlabel_unlabeled.h" | |
41 | #include "netlabel_user.h" | |
23bcdc1a | 42 | #include "netlabel_mgmt.h" |
d15c345f | 43 | |
02752760 PM |
44 | /* |
45 | * Security Attribute Functions | |
46 | */ | |
47 | ||
48 | /** | |
49 | * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit | |
50 | * @catmap: the category bitmap | |
51 | * @offset: the offset to start searching at, in bits | |
52 | * | |
53 | * Description: | |
54 | * This function walks a LSM secattr category bitmap starting at @offset and | |
55 | * returns the spot of the first set bit or -ENOENT if no bits are set. | |
56 | * | |
57 | */ | |
58 | int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap, | |
59 | u32 offset) | |
60 | { | |
61 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
62 | u32 node_idx; | |
63 | u32 node_bit; | |
64 | NETLBL_CATMAP_MAPTYPE bitmap; | |
65 | ||
66 | if (offset > iter->startbit) { | |
67 | while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
68 | iter = iter->next; | |
69 | if (iter == NULL) | |
70 | return -ENOENT; | |
71 | } | |
72 | node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
73 | node_bit = offset - iter->startbit - | |
74 | (NETLBL_CATMAP_MAPSIZE * node_idx); | |
75 | } else { | |
76 | node_idx = 0; | |
77 | node_bit = 0; | |
78 | } | |
79 | bitmap = iter->bitmap[node_idx] >> node_bit; | |
80 | ||
81 | for (;;) { | |
82 | if (bitmap != 0) { | |
83 | while ((bitmap & NETLBL_CATMAP_BIT) == 0) { | |
84 | bitmap >>= 1; | |
85 | node_bit++; | |
86 | } | |
87 | return iter->startbit + | |
88 | (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit; | |
89 | } | |
90 | if (++node_idx >= NETLBL_CATMAP_MAPCNT) { | |
91 | if (iter->next != NULL) { | |
92 | iter = iter->next; | |
93 | node_idx = 0; | |
94 | } else | |
95 | return -ENOENT; | |
96 | } | |
97 | bitmap = iter->bitmap[node_idx]; | |
98 | node_bit = 0; | |
99 | } | |
100 | ||
101 | return -ENOENT; | |
102 | } | |
103 | ||
104 | /** | |
105 | * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits | |
106 | * @catmap: the category bitmap | |
107 | * @offset: the offset to start searching at, in bits | |
108 | * | |
109 | * Description: | |
110 | * This function walks a LSM secattr category bitmap starting at @offset and | |
111 | * returns the spot of the first cleared bit or -ENOENT if the offset is past | |
112 | * the end of the bitmap. | |
113 | * | |
114 | */ | |
115 | int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap, | |
116 | u32 offset) | |
117 | { | |
118 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
119 | u32 node_idx; | |
120 | u32 node_bit; | |
121 | NETLBL_CATMAP_MAPTYPE bitmask; | |
122 | NETLBL_CATMAP_MAPTYPE bitmap; | |
123 | ||
124 | if (offset > iter->startbit) { | |
125 | while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
126 | iter = iter->next; | |
127 | if (iter == NULL) | |
128 | return -ENOENT; | |
129 | } | |
130 | node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
131 | node_bit = offset - iter->startbit - | |
132 | (NETLBL_CATMAP_MAPSIZE * node_idx); | |
133 | } else { | |
134 | node_idx = 0; | |
135 | node_bit = 0; | |
136 | } | |
137 | bitmask = NETLBL_CATMAP_BIT << node_bit; | |
138 | ||
139 | for (;;) { | |
140 | bitmap = iter->bitmap[node_idx]; | |
141 | while (bitmask != 0 && (bitmap & bitmask) != 0) { | |
142 | bitmask <<= 1; | |
143 | node_bit++; | |
144 | } | |
145 | ||
146 | if (bitmask != 0) | |
147 | return iter->startbit + | |
148 | (NETLBL_CATMAP_MAPSIZE * node_idx) + | |
149 | node_bit - 1; | |
150 | else if (++node_idx >= NETLBL_CATMAP_MAPCNT) { | |
151 | if (iter->next == NULL) | |
152 | return iter->startbit + NETLBL_CATMAP_SIZE - 1; | |
153 | iter = iter->next; | |
154 | node_idx = 0; | |
155 | } | |
156 | bitmask = NETLBL_CATMAP_BIT; | |
157 | node_bit = 0; | |
158 | } | |
159 | ||
160 | return -ENOENT; | |
161 | } | |
162 | ||
163 | /** | |
164 | * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap | |
165 | * @catmap: the category bitmap | |
166 | * @bit: the bit to set | |
167 | * @flags: memory allocation flags | |
168 | * | |
169 | * Description: | |
170 | * Set the bit specified by @bit in @catmap. Returns zero on success, | |
171 | * negative values on failure. | |
172 | * | |
173 | */ | |
174 | int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap, | |
175 | u32 bit, | |
176 | gfp_t flags) | |
177 | { | |
178 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
179 | u32 node_bit; | |
180 | u32 node_idx; | |
181 | ||
182 | while (iter->next != NULL && | |
183 | bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) | |
184 | iter = iter->next; | |
185 | if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) { | |
186 | iter->next = netlbl_secattr_catmap_alloc(flags); | |
187 | if (iter->next == NULL) | |
188 | return -ENOMEM; | |
189 | iter = iter->next; | |
190 | iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1); | |
191 | } | |
192 | ||
193 | /* gcc always rounds to zero when doing integer division */ | |
194 | node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE; | |
195 | node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx); | |
196 | iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit; | |
197 | ||
198 | return 0; | |
199 | } | |
200 | ||
201 | /** | |
202 | * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap | |
203 | * @catmap: the category bitmap | |
204 | * @start: the starting bit | |
205 | * @end: the last bit in the string | |
206 | * @flags: memory allocation flags | |
207 | * | |
208 | * Description: | |
209 | * Set a range of bits, starting at @start and ending with @end. Returns zero | |
210 | * on success, negative values on failure. | |
211 | * | |
212 | */ | |
213 | int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap, | |
214 | u32 start, | |
215 | u32 end, | |
216 | gfp_t flags) | |
217 | { | |
218 | int ret_val = 0; | |
219 | struct netlbl_lsm_secattr_catmap *iter = catmap; | |
220 | u32 iter_max_spot; | |
221 | u32 spot; | |
222 | ||
223 | /* XXX - This could probably be made a bit faster by combining writes | |
224 | * to the catmap instead of setting a single bit each time, but for | |
225 | * right now skipping to the start of the range in the catmap should | |
226 | * be a nice improvement over calling the individual setbit function | |
227 | * repeatedly from a loop. */ | |
228 | ||
229 | while (iter->next != NULL && | |
230 | start >= (iter->startbit + NETLBL_CATMAP_SIZE)) | |
231 | iter = iter->next; | |
232 | iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; | |
233 | ||
234 | for (spot = start; spot <= end && ret_val == 0; spot++) { | |
235 | if (spot >= iter_max_spot && iter->next != NULL) { | |
236 | iter = iter->next; | |
237 | iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; | |
238 | } | |
239 | ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC); | |
240 | } | |
241 | ||
242 | return ret_val; | |
243 | } | |
244 | ||
d15c345f PM |
245 | /* |
246 | * LSM Functions | |
247 | */ | |
248 | ||
23bcdc1a PM |
249 | /** |
250 | * netlbl_enabled - Determine if the NetLabel subsystem is enabled | |
251 | * | |
252 | * Description: | |
253 | * The LSM can use this function to determine if it should use NetLabel | |
254 | * security attributes in it's enforcement mechanism. Currently, NetLabel is | |
255 | * considered to be enabled when it's configuration contains a valid setup for | |
256 | * at least one labeled protocol (i.e. NetLabel can understand incoming | |
257 | * labeled packets of at least one type); otherwise NetLabel is considered to | |
258 | * be disabled. | |
259 | * | |
260 | */ | |
261 | int netlbl_enabled(void) | |
262 | { | |
263 | /* At some point we probably want to expose this mechanism to the user | |
264 | * as well so that admins can toggle NetLabel regardless of the | |
265 | * configuration */ | |
c783f1ce | 266 | return (atomic_read(&netlabel_mgmt_protocount) > 0); |
23bcdc1a PM |
267 | } |
268 | ||
d15c345f PM |
269 | /** |
270 | * netlbl_socket_setattr - Label a socket using the correct protocol | |
ba6ff9f2 | 271 | * @sk: the socket to label |
d15c345f PM |
272 | * @secattr: the security attributes |
273 | * | |
274 | * Description: | |
275 | * Attach the correct label to the given socket using the security attributes | |
ba6ff9f2 PM |
276 | * specified in @secattr. This function requires exclusive access to @sk, |
277 | * which means it either needs to be in the process of being created or locked. | |
278 | * Returns zero on success, negative values on failure. | |
d15c345f PM |
279 | * |
280 | */ | |
ba6ff9f2 PM |
281 | int netlbl_sock_setattr(struct sock *sk, |
282 | const struct netlbl_lsm_secattr *secattr) | |
d15c345f PM |
283 | { |
284 | int ret_val = -ENOENT; | |
285 | struct netlbl_dom_map *dom_entry; | |
286 | ||
287 | rcu_read_lock(); | |
288 | dom_entry = netlbl_domhsh_getentry(secattr->domain); | |
289 | if (dom_entry == NULL) | |
290 | goto socket_setattr_return; | |
291 | switch (dom_entry->type) { | |
292 | case NETLBL_NLTYPE_CIPSOV4: | |
ba6ff9f2 PM |
293 | ret_val = cipso_v4_sock_setattr(sk, |
294 | dom_entry->type_def.cipsov4, | |
295 | secattr); | |
d15c345f PM |
296 | break; |
297 | case NETLBL_NLTYPE_UNLABELED: | |
298 | ret_val = 0; | |
299 | break; | |
300 | default: | |
301 | ret_val = -ENOENT; | |
302 | } | |
303 | ||
304 | socket_setattr_return: | |
305 | rcu_read_unlock(); | |
306 | return ret_val; | |
307 | } | |
308 | ||
14a72f53 PM |
309 | /** |
310 | * netlbl_sock_getattr - Determine the security attributes of a sock | |
311 | * @sk: the sock | |
312 | * @secattr: the security attributes | |
313 | * | |
314 | * Description: | |
315 | * Examines the given sock to see any NetLabel style labeling has been | |
316 | * applied to the sock, if so it parses the socket label and returns the | |
317 | * security attributes in @secattr. Returns zero on success, negative values | |
318 | * on failure. | |
319 | * | |
320 | */ | |
321 | int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) | |
322 | { | |
323 | int ret_val; | |
324 | ||
325 | ret_val = cipso_v4_sock_getattr(sk, secattr); | |
326 | if (ret_val == 0) | |
327 | return 0; | |
328 | ||
329 | return netlbl_unlabel_getattr(secattr); | |
330 | } | |
331 | ||
d15c345f PM |
332 | /** |
333 | * netlbl_skbuff_getattr - Determine the security attributes of a packet | |
334 | * @skb: the packet | |
335 | * @secattr: the security attributes | |
336 | * | |
337 | * Description: | |
338 | * Examines the given packet to see if a recognized form of packet labeling | |
339 | * is present, if so it parses the packet label and returns the security | |
340 | * attributes in @secattr. Returns zero on success, negative values on | |
341 | * failure. | |
342 | * | |
343 | */ | |
344 | int netlbl_skbuff_getattr(const struct sk_buff *skb, | |
345 | struct netlbl_lsm_secattr *secattr) | |
346 | { | |
05e00cbf PM |
347 | if (CIPSO_V4_OPTEXIST(skb) && |
348 | cipso_v4_skbuff_getattr(skb, secattr) == 0) | |
d15c345f PM |
349 | return 0; |
350 | ||
351 | return netlbl_unlabel_getattr(secattr); | |
352 | } | |
353 | ||
354 | /** | |
355 | * netlbl_skbuff_err - Handle a LSM error on a sk_buff | |
356 | * @skb: the packet | |
357 | * @error: the error code | |
358 | * | |
359 | * Description: | |
360 | * Deal with a LSM problem when handling the packet in @skb, typically this is | |
361 | * a permission denied problem (-EACCES). The correct action is determined | |
362 | * according to the packet's labeling protocol. | |
363 | * | |
364 | */ | |
365 | void netlbl_skbuff_err(struct sk_buff *skb, int error) | |
366 | { | |
367 | if (CIPSO_V4_OPTEXIST(skb)) | |
368 | cipso_v4_error(skb, error, 0); | |
369 | } | |
370 | ||
371 | /** | |
372 | * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches | |
373 | * | |
374 | * Description: | |
375 | * For all of the NetLabel protocols that support some form of label mapping | |
376 | * cache, invalidate the cache. Returns zero on success, negative values on | |
377 | * error. | |
378 | * | |
379 | */ | |
380 | void netlbl_cache_invalidate(void) | |
381 | { | |
382 | cipso_v4_cache_invalidate(); | |
383 | } | |
384 | ||
385 | /** | |
386 | * netlbl_cache_add - Add an entry to a NetLabel protocol cache | |
387 | * @skb: the packet | |
388 | * @secattr: the packet's security attributes | |
389 | * | |
390 | * Description: | |
391 | * Add the LSM security attributes for the given packet to the underlying | |
392 | * NetLabel protocol's label mapping cache. Returns zero on success, negative | |
393 | * values on error. | |
394 | * | |
395 | */ | |
396 | int netlbl_cache_add(const struct sk_buff *skb, | |
397 | const struct netlbl_lsm_secattr *secattr) | |
398 | { | |
701a90ba | 399 | if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0) |
d15c345f PM |
400 | return -ENOMSG; |
401 | ||
402 | if (CIPSO_V4_OPTEXIST(skb)) | |
403 | return cipso_v4_cache_add(skb, secattr); | |
404 | ||
405 | return -ENOMSG; | |
406 | } | |
407 | ||
408 | /* | |
409 | * Setup Functions | |
410 | */ | |
411 | ||
412 | /** | |
413 | * netlbl_init - Initialize NetLabel | |
414 | * | |
415 | * Description: | |
416 | * Perform the required NetLabel initialization before first use. | |
417 | * | |
418 | */ | |
419 | static int __init netlbl_init(void) | |
420 | { | |
421 | int ret_val; | |
422 | ||
423 | printk(KERN_INFO "NetLabel: Initializing\n"); | |
424 | printk(KERN_INFO "NetLabel: domain hash size = %u\n", | |
425 | (1 << NETLBL_DOMHSH_BITSIZE)); | |
426 | printk(KERN_INFO "NetLabel: protocols =" | |
427 | " UNLABELED" | |
428 | " CIPSOv4" | |
429 | "\n"); | |
430 | ||
431 | ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE); | |
432 | if (ret_val != 0) | |
433 | goto init_failure; | |
434 | ||
435 | ret_val = netlbl_netlink_init(); | |
436 | if (ret_val != 0) | |
437 | goto init_failure; | |
438 | ||
439 | ret_val = netlbl_unlabel_defconf(); | |
440 | if (ret_val != 0) | |
441 | goto init_failure; | |
442 | printk(KERN_INFO "NetLabel: unlabeled traffic allowed by default\n"); | |
443 | ||
444 | return 0; | |
445 | ||
446 | init_failure: | |
447 | panic("NetLabel: failed to initialize properly (%d)\n", ret_val); | |
448 | } | |
449 | ||
450 | subsys_initcall(netlbl_init); |