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Paul Moored15c3452006-08-03 16:48:37 -07001/*
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"
41
42/*
Paul Moore02752762006-11-29 13:18:18 -050043 * Security Attribute Functions
44 */
45
46/**
47 * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
48 * @catmap: the category bitmap
49 * @offset: the offset to start searching at, in bits
50 *
51 * Description:
52 * This function walks a LSM secattr category bitmap starting at @offset and
53 * returns the spot of the first set bit or -ENOENT if no bits are set.
54 *
55 */
56int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
57 u32 offset)
58{
59 struct netlbl_lsm_secattr_catmap *iter = catmap;
60 u32 node_idx;
61 u32 node_bit;
62 NETLBL_CATMAP_MAPTYPE bitmap;
63
64 if (offset > iter->startbit) {
65 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
66 iter = iter->next;
67 if (iter == NULL)
68 return -ENOENT;
69 }
70 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
71 node_bit = offset - iter->startbit -
72 (NETLBL_CATMAP_MAPSIZE * node_idx);
73 } else {
74 node_idx = 0;
75 node_bit = 0;
76 }
77 bitmap = iter->bitmap[node_idx] >> node_bit;
78
79 for (;;) {
80 if (bitmap != 0) {
81 while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
82 bitmap >>= 1;
83 node_bit++;
84 }
85 return iter->startbit +
86 (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
87 }
88 if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
89 if (iter->next != NULL) {
90 iter = iter->next;
91 node_idx = 0;
92 } else
93 return -ENOENT;
94 }
95 bitmap = iter->bitmap[node_idx];
96 node_bit = 0;
97 }
98
99 return -ENOENT;
100}
101
102/**
103 * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
104 * @catmap: the category bitmap
105 * @offset: the offset to start searching at, in bits
106 *
107 * Description:
108 * This function walks a LSM secattr category bitmap starting at @offset and
109 * returns the spot of the first cleared bit or -ENOENT if the offset is past
110 * the end of the bitmap.
111 *
112 */
113int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
114 u32 offset)
115{
116 struct netlbl_lsm_secattr_catmap *iter = catmap;
117 u32 node_idx;
118 u32 node_bit;
119 NETLBL_CATMAP_MAPTYPE bitmask;
120 NETLBL_CATMAP_MAPTYPE bitmap;
121
122 if (offset > iter->startbit) {
123 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
124 iter = iter->next;
125 if (iter == NULL)
126 return -ENOENT;
127 }
128 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
129 node_bit = offset - iter->startbit -
130 (NETLBL_CATMAP_MAPSIZE * node_idx);
131 } else {
132 node_idx = 0;
133 node_bit = 0;
134 }
135 bitmask = NETLBL_CATMAP_BIT << node_bit;
136
137 for (;;) {
138 bitmap = iter->bitmap[node_idx];
139 while (bitmask != 0 && (bitmap & bitmask) != 0) {
140 bitmask <<= 1;
141 node_bit++;
142 }
143
144 if (bitmask != 0)
145 return iter->startbit +
146 (NETLBL_CATMAP_MAPSIZE * node_idx) +
147 node_bit - 1;
148 else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
149 if (iter->next == NULL)
150 return iter->startbit + NETLBL_CATMAP_SIZE - 1;
151 iter = iter->next;
152 node_idx = 0;
153 }
154 bitmask = NETLBL_CATMAP_BIT;
155 node_bit = 0;
156 }
157
158 return -ENOENT;
159}
160
161/**
162 * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
163 * @catmap: the category bitmap
164 * @bit: the bit to set
165 * @flags: memory allocation flags
166 *
167 * Description:
168 * Set the bit specified by @bit in @catmap. Returns zero on success,
169 * negative values on failure.
170 *
171 */
172int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
173 u32 bit,
174 gfp_t flags)
175{
176 struct netlbl_lsm_secattr_catmap *iter = catmap;
177 u32 node_bit;
178 u32 node_idx;
179
180 while (iter->next != NULL &&
181 bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
182 iter = iter->next;
183 if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
184 iter->next = netlbl_secattr_catmap_alloc(flags);
185 if (iter->next == NULL)
186 return -ENOMEM;
187 iter = iter->next;
188 iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
189 }
190
191 /* gcc always rounds to zero when doing integer division */
192 node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
193 node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
194 iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;
195
196 return 0;
197}
198
199/**
200 * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
201 * @catmap: the category bitmap
202 * @start: the starting bit
203 * @end: the last bit in the string
204 * @flags: memory allocation flags
205 *
206 * Description:
207 * Set a range of bits, starting at @start and ending with @end. Returns zero
208 * on success, negative values on failure.
209 *
210 */
211int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
212 u32 start,
213 u32 end,
214 gfp_t flags)
215{
216 int ret_val = 0;
217 struct netlbl_lsm_secattr_catmap *iter = catmap;
218 u32 iter_max_spot;
219 u32 spot;
220
221 /* XXX - This could probably be made a bit faster by combining writes
222 * to the catmap instead of setting a single bit each time, but for
223 * right now skipping to the start of the range in the catmap should
224 * be a nice improvement over calling the individual setbit function
225 * repeatedly from a loop. */
226
227 while (iter->next != NULL &&
228 start >= (iter->startbit + NETLBL_CATMAP_SIZE))
229 iter = iter->next;
230 iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
231
232 for (spot = start; spot <= end && ret_val == 0; spot++) {
233 if (spot >= iter_max_spot && iter->next != NULL) {
234 iter = iter->next;
235 iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
236 }
237 ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC);
238 }
239
240 return ret_val;
241}
242
243/*
Paul Moored15c3452006-08-03 16:48:37 -0700244 * LSM Functions
245 */
246
247/**
248 * netlbl_socket_setattr - Label a socket using the correct protocol
249 * @sock: the socket to label
250 * @secattr: the security attributes
251 *
252 * Description:
253 * Attach the correct label to the given socket using the security attributes
254 * specified in @secattr. This function requires exclusive access to
255 * @sock->sk, which means it either needs to be in the process of being
256 * created or locked via lock_sock(sock->sk). Returns zero on success,
257 * negative values on failure.
258 *
259 */
260int netlbl_socket_setattr(const struct socket *sock,
261 const struct netlbl_lsm_secattr *secattr)
262{
263 int ret_val = -ENOENT;
264 struct netlbl_dom_map *dom_entry;
265
Paul Moore701a90b2006-11-17 17:38:46 -0500266 if ((secattr->flags & NETLBL_SECATTR_DOMAIN) == 0)
267 return -ENOENT;
268
Paul Moored15c3452006-08-03 16:48:37 -0700269 rcu_read_lock();
270 dom_entry = netlbl_domhsh_getentry(secattr->domain);
271 if (dom_entry == NULL)
272 goto socket_setattr_return;
273 switch (dom_entry->type) {
274 case NETLBL_NLTYPE_CIPSOV4:
275 ret_val = cipso_v4_socket_setattr(sock,
276 dom_entry->type_def.cipsov4,
277 secattr);
278 break;
279 case NETLBL_NLTYPE_UNLABELED:
280 ret_val = 0;
281 break;
282 default:
283 ret_val = -ENOENT;
284 }
285
286socket_setattr_return:
287 rcu_read_unlock();
288 return ret_val;
289}
290
291/**
Paul Moore14a72f52006-09-25 15:52:01 -0700292 * netlbl_sock_getattr - Determine the security attributes of a sock
293 * @sk: the sock
294 * @secattr: the security attributes
295 *
296 * Description:
297 * Examines the given sock to see any NetLabel style labeling has been
298 * applied to the sock, if so it parses the socket label and returns the
299 * security attributes in @secattr. Returns zero on success, negative values
300 * on failure.
301 *
302 */
303int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
304{
305 int ret_val;
306
307 ret_val = cipso_v4_sock_getattr(sk, secattr);
308 if (ret_val == 0)
309 return 0;
310
311 return netlbl_unlabel_getattr(secattr);
312}
313
314/**
Paul Moored15c3452006-08-03 16:48:37 -0700315 * netlbl_socket_getattr - Determine the security attributes of a socket
316 * @sock: the socket
317 * @secattr: the security attributes
318 *
319 * Description:
320 * Examines the given socket to see any NetLabel style labeling has been
321 * applied to the socket, if so it parses the socket label and returns the
322 * security attributes in @secattr. Returns zero on success, negative values
323 * on failure.
324 *
325 */
326int netlbl_socket_getattr(const struct socket *sock,
327 struct netlbl_lsm_secattr *secattr)
328{
329 int ret_val;
330
331 ret_val = cipso_v4_socket_getattr(sock, secattr);
332 if (ret_val == 0)
333 return 0;
334
335 return netlbl_unlabel_getattr(secattr);
336}
337
338/**
339 * netlbl_skbuff_getattr - Determine the security attributes of a packet
340 * @skb: the packet
341 * @secattr: the security attributes
342 *
343 * Description:
344 * Examines the given packet to see if a recognized form of packet labeling
345 * is present, if so it parses the packet label and returns the security
346 * attributes in @secattr. Returns zero on success, negative values on
347 * failure.
348 *
349 */
350int netlbl_skbuff_getattr(const struct sk_buff *skb,
351 struct netlbl_lsm_secattr *secattr)
352{
Paul Moore05e00cb2006-11-17 17:38:47 -0500353 if (CIPSO_V4_OPTEXIST(skb) &&
354 cipso_v4_skbuff_getattr(skb, secattr) == 0)
Paul Moored15c3452006-08-03 16:48:37 -0700355 return 0;
356
357 return netlbl_unlabel_getattr(secattr);
358}
359
360/**
361 * netlbl_skbuff_err - Handle a LSM error on a sk_buff
362 * @skb: the packet
363 * @error: the error code
364 *
365 * Description:
366 * Deal with a LSM problem when handling the packet in @skb, typically this is
367 * a permission denied problem (-EACCES). The correct action is determined
368 * according to the packet's labeling protocol.
369 *
370 */
371void netlbl_skbuff_err(struct sk_buff *skb, int error)
372{
373 if (CIPSO_V4_OPTEXIST(skb))
374 cipso_v4_error(skb, error, 0);
375}
376
377/**
378 * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
379 *
380 * Description:
381 * For all of the NetLabel protocols that support some form of label mapping
382 * cache, invalidate the cache. Returns zero on success, negative values on
383 * error.
384 *
385 */
386void netlbl_cache_invalidate(void)
387{
388 cipso_v4_cache_invalidate();
389}
390
391/**
392 * netlbl_cache_add - Add an entry to a NetLabel protocol cache
393 * @skb: the packet
394 * @secattr: the packet's security attributes
395 *
396 * Description:
397 * Add the LSM security attributes for the given packet to the underlying
398 * NetLabel protocol's label mapping cache. Returns zero on success, negative
399 * values on error.
400 *
401 */
402int netlbl_cache_add(const struct sk_buff *skb,
403 const struct netlbl_lsm_secattr *secattr)
404{
Paul Moore701a90b2006-11-17 17:38:46 -0500405 if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
Paul Moored15c3452006-08-03 16:48:37 -0700406 return -ENOMSG;
407
408 if (CIPSO_V4_OPTEXIST(skb))
409 return cipso_v4_cache_add(skb, secattr);
410
411 return -ENOMSG;
412}
413
414/*
415 * Setup Functions
416 */
417
418/**
419 * netlbl_init - Initialize NetLabel
420 *
421 * Description:
422 * Perform the required NetLabel initialization before first use.
423 *
424 */
425static int __init netlbl_init(void)
426{
427 int ret_val;
428
429 printk(KERN_INFO "NetLabel: Initializing\n");
430 printk(KERN_INFO "NetLabel: domain hash size = %u\n",
431 (1 << NETLBL_DOMHSH_BITSIZE));
432 printk(KERN_INFO "NetLabel: protocols ="
433 " UNLABELED"
434 " CIPSOv4"
435 "\n");
436
437 ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
438 if (ret_val != 0)
439 goto init_failure;
440
441 ret_val = netlbl_netlink_init();
442 if (ret_val != 0)
443 goto init_failure;
444
445 ret_val = netlbl_unlabel_defconf();
446 if (ret_val != 0)
447 goto init_failure;
448 printk(KERN_INFO "NetLabel: unlabeled traffic allowed by default\n");
449
450 return 0;
451
452init_failure:
453 panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
454}
455
456subsys_initcall(netlbl_init);