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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, 2008
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 <linux/audit.h>
34 #include <linux/in.h>
35 #include <linux/in6.h>
36 #include <net/ip.h>
37 #include <net/ipv6.h>
38 #include <net/netlabel.h>
39 #include <net/cipso_ipv4.h>
40 #include <asm/bug.h>
41 #include <asm/atomic.h>
42 
43 #include "netlabel_domainhash.h"
44 #include "netlabel_unlabeled.h"
45 #include "netlabel_cipso_v4.h"
46 #include "netlabel_user.h"
47 #include "netlabel_mgmt.h"
48 #include "netlabel_addrlist.h"
49 
50 /*
51  * Configuration Functions
52  */
53 
54 /**
55  * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
56  * @domain: the domain mapping to remove
57  * @family: address family
58  * @addr: IP address
59  * @mask: IP address mask
60  * @audit_info: NetLabel audit information
61  *
62  * Description:
63  * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
64  * default domain mapping to be removed.  Returns zero on success, negative
65  * values on failure.
66  *
67  */
netlbl_cfg_map_del(const char * domain,u16 family,const void * addr,const void * mask,struct netlbl_audit * audit_info)68 int netlbl_cfg_map_del(const char *domain,
69 		       u16 family,
70 		       const void *addr,
71 		       const void *mask,
72 		       struct netlbl_audit *audit_info)
73 {
74 	if (addr == NULL && mask == NULL) {
75 		return netlbl_domhsh_remove(domain, audit_info);
76 	} else if (addr != NULL && mask != NULL) {
77 		switch (family) {
78 		case AF_INET:
79 			return netlbl_domhsh_remove_af4(domain, addr, mask,
80 							audit_info);
81 		default:
82 			return -EPFNOSUPPORT;
83 		}
84 	} else
85 		return -EINVAL;
86 }
87 
88 /**
89  * netlbl_cfg_unlbl_map_add - Add a new unlabeled mapping
90  * @domain: the domain mapping to add
91  * @family: address family
92  * @addr: IP address
93  * @mask: IP address mask
94  * @audit_info: NetLabel audit information
95  *
96  * Description:
97  * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
98  * causes a new default domain mapping to be added.  Returns zero on success,
99  * negative values on failure.
100  *
101  */
netlbl_cfg_unlbl_map_add(const char * domain,u16 family,const void * addr,const void * mask,struct netlbl_audit * audit_info)102 int netlbl_cfg_unlbl_map_add(const char *domain,
103 			     u16 family,
104 			     const void *addr,
105 			     const void *mask,
106 			     struct netlbl_audit *audit_info)
107 {
108 	int ret_val = -ENOMEM;
109 	struct netlbl_dom_map *entry;
110 	struct netlbl_domaddr_map *addrmap = NULL;
111 	struct netlbl_domaddr4_map *map4 = NULL;
112 	struct netlbl_domaddr6_map *map6 = NULL;
113 	const struct in_addr *addr4, *mask4;
114 	const struct in6_addr *addr6, *mask6;
115 
116 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
117 	if (entry == NULL)
118 		return -ENOMEM;
119 	if (domain != NULL) {
120 		entry->domain = kstrdup(domain, GFP_ATOMIC);
121 		if (entry->domain == NULL)
122 			goto cfg_unlbl_map_add_failure;
123 	}
124 
125 	if (addr == NULL && mask == NULL)
126 		entry->type = NETLBL_NLTYPE_UNLABELED;
127 	else if (addr != NULL && mask != NULL) {
128 		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
129 		if (addrmap == NULL)
130 			goto cfg_unlbl_map_add_failure;
131 		INIT_LIST_HEAD(&addrmap->list4);
132 		INIT_LIST_HEAD(&addrmap->list6);
133 
134 		switch (family) {
135 		case AF_INET:
136 			addr4 = addr;
137 			mask4 = mask;
138 			map4 = kzalloc(sizeof(*map4), GFP_ATOMIC);
139 			if (map4 == NULL)
140 				goto cfg_unlbl_map_add_failure;
141 			map4->type = NETLBL_NLTYPE_UNLABELED;
142 			map4->list.addr = addr4->s_addr & mask4->s_addr;
143 			map4->list.mask = mask4->s_addr;
144 			map4->list.valid = 1;
145 			ret_val = netlbl_af4list_add(&map4->list,
146 						     &addrmap->list4);
147 			if (ret_val != 0)
148 				goto cfg_unlbl_map_add_failure;
149 			break;
150 		case AF_INET6:
151 			addr6 = addr;
152 			mask6 = mask;
153 			map6 = kzalloc(sizeof(*map6), GFP_ATOMIC);
154 			if (map4 == NULL)
155 				goto cfg_unlbl_map_add_failure;
156 			map6->type = NETLBL_NLTYPE_UNLABELED;
157 			ipv6_addr_copy(&map6->list.addr, addr6);
158 			map6->list.addr.s6_addr32[0] &= mask6->s6_addr32[0];
159 			map6->list.addr.s6_addr32[1] &= mask6->s6_addr32[1];
160 			map6->list.addr.s6_addr32[2] &= mask6->s6_addr32[2];
161 			map6->list.addr.s6_addr32[3] &= mask6->s6_addr32[3];
162 			ipv6_addr_copy(&map6->list.mask, mask6);
163 			map6->list.valid = 1;
164 			ret_val = netlbl_af4list_add(&map4->list,
165 						     &addrmap->list4);
166 			if (ret_val != 0)
167 				goto cfg_unlbl_map_add_failure;
168 			break;
169 		default:
170 			goto cfg_unlbl_map_add_failure;
171 			break;
172 		}
173 
174 		entry->type_def.addrsel = addrmap;
175 		entry->type = NETLBL_NLTYPE_ADDRSELECT;
176 	} else {
177 		ret_val = -EINVAL;
178 		goto cfg_unlbl_map_add_failure;
179 	}
180 
181 	ret_val = netlbl_domhsh_add(entry, audit_info);
182 	if (ret_val != 0)
183 		goto cfg_unlbl_map_add_failure;
184 
185 	return 0;
186 
187 cfg_unlbl_map_add_failure:
188 	if (entry != NULL)
189 		kfree(entry->domain);
190 	kfree(entry);
191 	kfree(addrmap);
192 	kfree(map4);
193 	kfree(map6);
194 	return ret_val;
195 }
196 
197 
198 /**
199  * netlbl_cfg_unlbl_static_add - Adds a new static label
200  * @net: network namespace
201  * @dev_name: interface name
202  * @addr: IP address in network byte order (struct in[6]_addr)
203  * @mask: address mask in network byte order (struct in[6]_addr)
204  * @family: address family
205  * @secid: LSM secid value for the entry
206  * @audit_info: NetLabel audit information
207  *
208  * Description:
209  * Adds a new NetLabel static label to be used when protocol provided labels
210  * are not present on incoming traffic.  If @dev_name is NULL then the default
211  * interface will be used.  Returns zero on success, negative values on failure.
212  *
213  */
netlbl_cfg_unlbl_static_add(struct net * net,const char * dev_name,const void * addr,const void * mask,u16 family,u32 secid,struct netlbl_audit * audit_info)214 int netlbl_cfg_unlbl_static_add(struct net *net,
215 				const char *dev_name,
216 				const void *addr,
217 				const void *mask,
218 				u16 family,
219 				u32 secid,
220 				struct netlbl_audit *audit_info)
221 {
222 	u32 addr_len;
223 
224 	switch (family) {
225 	case AF_INET:
226 		addr_len = sizeof(struct in_addr);
227 		break;
228 	case AF_INET6:
229 		addr_len = sizeof(struct in6_addr);
230 		break;
231 	default:
232 		return -EPFNOSUPPORT;
233 	}
234 
235 	return netlbl_unlhsh_add(net,
236 				 dev_name, addr, mask, addr_len,
237 				 secid, audit_info);
238 }
239 
240 /**
241  * netlbl_cfg_unlbl_static_del - Removes an existing static label
242  * @net: network namespace
243  * @dev_name: interface name
244  * @addr: IP address in network byte order (struct in[6]_addr)
245  * @mask: address mask in network byte order (struct in[6]_addr)
246  * @family: address family
247  * @secid: LSM secid value for the entry
248  * @audit_info: NetLabel audit information
249  *
250  * Description:
251  * Removes an existing NetLabel static label used when protocol provided labels
252  * are not present on incoming traffic.  If @dev_name is NULL then the default
253  * interface will be used.  Returns zero on success, negative values on failure.
254  *
255  */
netlbl_cfg_unlbl_static_del(struct net * net,const char * dev_name,const void * addr,const void * mask,u16 family,struct netlbl_audit * audit_info)256 int netlbl_cfg_unlbl_static_del(struct net *net,
257 				const char *dev_name,
258 				const void *addr,
259 				const void *mask,
260 				u16 family,
261 				struct netlbl_audit *audit_info)
262 {
263 	u32 addr_len;
264 
265 	switch (family) {
266 	case AF_INET:
267 		addr_len = sizeof(struct in_addr);
268 		break;
269 	case AF_INET6:
270 		addr_len = sizeof(struct in6_addr);
271 		break;
272 	default:
273 		return -EPFNOSUPPORT;
274 	}
275 
276 	return netlbl_unlhsh_remove(net,
277 				    dev_name, addr, mask, addr_len,
278 				    audit_info);
279 }
280 
281 /**
282  * netlbl_cfg_cipsov4_add - Add a new CIPSOv4 DOI definition
283  * @doi_def: CIPSO DOI definition
284  * @audit_info: NetLabel audit information
285  *
286  * Description:
287  * Add a new CIPSO DOI definition as defined by @doi_def.  Returns zero on
288  * success and negative values on failure.
289  *
290  */
netlbl_cfg_cipsov4_add(struct cipso_v4_doi * doi_def,struct netlbl_audit * audit_info)291 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
292 			   struct netlbl_audit *audit_info)
293 {
294 	return cipso_v4_doi_add(doi_def, audit_info);
295 }
296 
297 /**
298  * netlbl_cfg_cipsov4_del - Remove an existing CIPSOv4 DOI definition
299  * @doi: CIPSO DOI
300  * @audit_info: NetLabel audit information
301  *
302  * Description:
303  * Remove an existing CIPSO DOI definition matching @doi.  Returns zero on
304  * success and negative values on failure.
305  *
306  */
netlbl_cfg_cipsov4_del(u32 doi,struct netlbl_audit * audit_info)307 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info)
308 {
309 	cipso_v4_doi_remove(doi, audit_info);
310 }
311 
312 /**
313  * netlbl_cfg_cipsov4_map_add - Add a new CIPSOv4 DOI mapping
314  * @doi: the CIPSO DOI
315  * @domain: the domain mapping to add
316  * @addr: IP address
317  * @mask: IP address mask
318  * @audit_info: NetLabel audit information
319  *
320  * Description:
321  * Add a new NetLabel/LSM domain mapping for the given CIPSO DOI to the NetLabel
322  * subsystem.  A @domain value of NULL adds a new default domain mapping.
323  * Returns zero on success, negative values on failure.
324  *
325  */
netlbl_cfg_cipsov4_map_add(u32 doi,const char * domain,const struct in_addr * addr,const struct in_addr * mask,struct netlbl_audit * audit_info)326 int netlbl_cfg_cipsov4_map_add(u32 doi,
327 			       const char *domain,
328 			       const struct in_addr *addr,
329 			       const struct in_addr *mask,
330 			       struct netlbl_audit *audit_info)
331 {
332 	int ret_val = -ENOMEM;
333 	struct cipso_v4_doi *doi_def;
334 	struct netlbl_dom_map *entry;
335 	struct netlbl_domaddr_map *addrmap = NULL;
336 	struct netlbl_domaddr4_map *addrinfo = NULL;
337 
338 	doi_def = cipso_v4_doi_getdef(doi);
339 	if (doi_def == NULL)
340 		return -ENOENT;
341 
342 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
343 	if (entry == NULL)
344 		return -ENOMEM;
345 	if (domain != NULL) {
346 		entry->domain = kstrdup(domain, GFP_ATOMIC);
347 		if (entry->domain == NULL)
348 			goto cfg_cipsov4_map_add_failure;
349 	}
350 
351 	if (addr == NULL && mask == NULL) {
352 		entry->type_def.cipsov4 = doi_def;
353 		entry->type = NETLBL_NLTYPE_CIPSOV4;
354 	} else if (addr != NULL && mask != NULL) {
355 		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
356 		if (addrmap == NULL)
357 			goto cfg_cipsov4_map_add_failure;
358 		INIT_LIST_HEAD(&addrmap->list4);
359 		INIT_LIST_HEAD(&addrmap->list6);
360 
361 		addrinfo = kzalloc(sizeof(*addrinfo), GFP_ATOMIC);
362 		if (addrinfo == NULL)
363 			goto cfg_cipsov4_map_add_failure;
364 		addrinfo->type_def.cipsov4 = doi_def;
365 		addrinfo->type = NETLBL_NLTYPE_CIPSOV4;
366 		addrinfo->list.addr = addr->s_addr & mask->s_addr;
367 		addrinfo->list.mask = mask->s_addr;
368 		addrinfo->list.valid = 1;
369 		ret_val = netlbl_af4list_add(&addrinfo->list, &addrmap->list4);
370 		if (ret_val != 0)
371 			goto cfg_cipsov4_map_add_failure;
372 
373 		entry->type_def.addrsel = addrmap;
374 		entry->type = NETLBL_NLTYPE_ADDRSELECT;
375 	} else {
376 		ret_val = -EINVAL;
377 		goto cfg_cipsov4_map_add_failure;
378 	}
379 
380 	ret_val = netlbl_domhsh_add(entry, audit_info);
381 	if (ret_val != 0)
382 		goto cfg_cipsov4_map_add_failure;
383 
384 	return 0;
385 
386 cfg_cipsov4_map_add_failure:
387 	cipso_v4_doi_putdef(doi_def);
388 	if (entry != NULL)
389 		kfree(entry->domain);
390 	kfree(entry);
391 	kfree(addrmap);
392 	kfree(addrinfo);
393 	return ret_val;
394 }
395 
396 /*
397  * Security Attribute Functions
398  */
399 
400 /**
401  * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
402  * @catmap: the category bitmap
403  * @offset: the offset to start searching at, in bits
404  *
405  * Description:
406  * This function walks a LSM secattr category bitmap starting at @offset and
407  * returns the spot of the first set bit or -ENOENT if no bits are set.
408  *
409  */
netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap * catmap,u32 offset)410 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
411 			       u32 offset)
412 {
413 	struct netlbl_lsm_secattr_catmap *iter = catmap;
414 	u32 node_idx;
415 	u32 node_bit;
416 	NETLBL_CATMAP_MAPTYPE bitmap;
417 
418 	if (offset > iter->startbit) {
419 		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
420 			iter = iter->next;
421 			if (iter == NULL)
422 				return -ENOENT;
423 		}
424 		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
425 		node_bit = offset - iter->startbit -
426 			   (NETLBL_CATMAP_MAPSIZE * node_idx);
427 	} else {
428 		node_idx = 0;
429 		node_bit = 0;
430 	}
431 	bitmap = iter->bitmap[node_idx] >> node_bit;
432 
433 	for (;;) {
434 		if (bitmap != 0) {
435 			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
436 				bitmap >>= 1;
437 				node_bit++;
438 			}
439 			return iter->startbit +
440 				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
441 		}
442 		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
443 			if (iter->next != NULL) {
444 				iter = iter->next;
445 				node_idx = 0;
446 			} else
447 				return -ENOENT;
448 		}
449 		bitmap = iter->bitmap[node_idx];
450 		node_bit = 0;
451 	}
452 
453 	return -ENOENT;
454 }
455 
456 /**
457  * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
458  * @catmap: the category bitmap
459  * @offset: the offset to start searching at, in bits
460  *
461  * Description:
462  * This function walks a LSM secattr category bitmap starting at @offset and
463  * returns the spot of the first cleared bit or -ENOENT if the offset is past
464  * the end of the bitmap.
465  *
466  */
netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap * catmap,u32 offset)467 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
468 				   u32 offset)
469 {
470 	struct netlbl_lsm_secattr_catmap *iter = catmap;
471 	u32 node_idx;
472 	u32 node_bit;
473 	NETLBL_CATMAP_MAPTYPE bitmask;
474 	NETLBL_CATMAP_MAPTYPE bitmap;
475 
476 	if (offset > iter->startbit) {
477 		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
478 			iter = iter->next;
479 			if (iter == NULL)
480 				return -ENOENT;
481 		}
482 		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
483 		node_bit = offset - iter->startbit -
484 			   (NETLBL_CATMAP_MAPSIZE * node_idx);
485 	} else {
486 		node_idx = 0;
487 		node_bit = 0;
488 	}
489 	bitmask = NETLBL_CATMAP_BIT << node_bit;
490 
491 	for (;;) {
492 		bitmap = iter->bitmap[node_idx];
493 		while (bitmask != 0 && (bitmap & bitmask) != 0) {
494 			bitmask <<= 1;
495 			node_bit++;
496 		}
497 
498 		if (bitmask != 0)
499 			return iter->startbit +
500 				(NETLBL_CATMAP_MAPSIZE * node_idx) +
501 				node_bit - 1;
502 		else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
503 			if (iter->next == NULL)
504 				return iter->startbit +	NETLBL_CATMAP_SIZE - 1;
505 			iter = iter->next;
506 			node_idx = 0;
507 		}
508 		bitmask = NETLBL_CATMAP_BIT;
509 		node_bit = 0;
510 	}
511 
512 	return -ENOENT;
513 }
514 
515 /**
516  * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
517  * @catmap: the category bitmap
518  * @bit: the bit to set
519  * @flags: memory allocation flags
520  *
521  * Description:
522  * Set the bit specified by @bit in @catmap.  Returns zero on success,
523  * negative values on failure.
524  *
525  */
netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap * catmap,u32 bit,gfp_t flags)526 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
527 				 u32 bit,
528 				 gfp_t flags)
529 {
530 	struct netlbl_lsm_secattr_catmap *iter = catmap;
531 	u32 node_bit;
532 	u32 node_idx;
533 
534 	while (iter->next != NULL &&
535 	       bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
536 		iter = iter->next;
537 	if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
538 		iter->next = netlbl_secattr_catmap_alloc(flags);
539 		if (iter->next == NULL)
540 			return -ENOMEM;
541 		iter = iter->next;
542 		iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
543 	}
544 
545 	/* gcc always rounds to zero when doing integer division */
546 	node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
547 	node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
548 	iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;
549 
550 	return 0;
551 }
552 
553 /**
554  * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
555  * @catmap: the category bitmap
556  * @start: the starting bit
557  * @end: the last bit in the string
558  * @flags: memory allocation flags
559  *
560  * Description:
561  * Set a range of bits, starting at @start and ending with @end.  Returns zero
562  * on success, negative values on failure.
563  *
564  */
netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap * catmap,u32 start,u32 end,gfp_t flags)565 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
566 				 u32 start,
567 				 u32 end,
568 				 gfp_t flags)
569 {
570 	int ret_val = 0;
571 	struct netlbl_lsm_secattr_catmap *iter = catmap;
572 	u32 iter_max_spot;
573 	u32 spot;
574 
575 	/* XXX - This could probably be made a bit faster by combining writes
576 	 * to the catmap instead of setting a single bit each time, but for
577 	 * right now skipping to the start of the range in the catmap should
578 	 * be a nice improvement over calling the individual setbit function
579 	 * repeatedly from a loop. */
580 
581 	while (iter->next != NULL &&
582 	       start >= (iter->startbit + NETLBL_CATMAP_SIZE))
583 		iter = iter->next;
584 	iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
585 
586 	for (spot = start; spot <= end && ret_val == 0; spot++) {
587 		if (spot >= iter_max_spot && iter->next != NULL) {
588 			iter = iter->next;
589 			iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
590 		}
591 		ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC);
592 	}
593 
594 	return ret_val;
595 }
596 
597 /*
598  * LSM Functions
599  */
600 
601 /**
602  * netlbl_enabled - Determine if the NetLabel subsystem is enabled
603  *
604  * Description:
605  * The LSM can use this function to determine if it should use NetLabel
606  * security attributes in it's enforcement mechanism.  Currently, NetLabel is
607  * considered to be enabled when it's configuration contains a valid setup for
608  * at least one labeled protocol (i.e. NetLabel can understand incoming
609  * labeled packets of at least one type); otherwise NetLabel is considered to
610  * be disabled.
611  *
612  */
netlbl_enabled(void)613 int netlbl_enabled(void)
614 {
615 	/* At some point we probably want to expose this mechanism to the user
616 	 * as well so that admins can toggle NetLabel regardless of the
617 	 * configuration */
618 	return (atomic_read(&netlabel_mgmt_protocount) > 0);
619 }
620 
621 /**
622  * netlbl_socket_setattr - Label a socket using the correct protocol
623  * @sk: the socket to label
624  * @secattr: the security attributes
625  *
626  * Description:
627  * Attach the correct label to the given socket using the security attributes
628  * specified in @secattr.  This function requires exclusive access to @sk,
629  * which means it either needs to be in the process of being created or locked.
630  * Returns zero on success, -EDESTADDRREQ if the domain is configured to use
631  * network address selectors (can't blindly label the socket), and negative
632  * values on all other failures.
633  *
634  */
netlbl_sock_setattr(struct sock * sk,const struct netlbl_lsm_secattr * secattr)635 int netlbl_sock_setattr(struct sock *sk,
636 			const struct netlbl_lsm_secattr *secattr)
637 {
638 	int ret_val = -ENOENT;
639 	struct netlbl_dom_map *dom_entry;
640 
641 	rcu_read_lock();
642 	dom_entry = netlbl_domhsh_getentry(secattr->domain);
643 	if (dom_entry == NULL)
644 		goto socket_setattr_return;
645 	switch (dom_entry->type) {
646 	case NETLBL_NLTYPE_ADDRSELECT:
647 		ret_val = -EDESTADDRREQ;
648 		break;
649 	case NETLBL_NLTYPE_CIPSOV4:
650 		ret_val = cipso_v4_sock_setattr(sk,
651 						dom_entry->type_def.cipsov4,
652 						secattr);
653 		break;
654 	case NETLBL_NLTYPE_UNLABELED:
655 		ret_val = 0;
656 		break;
657 	default:
658 		ret_val = -ENOENT;
659 	}
660 
661 socket_setattr_return:
662 	rcu_read_unlock();
663 	return ret_val;
664 }
665 
666 /**
667  * netlbl_sock_delattr - Delete all the NetLabel labels on a socket
668  * @sk: the socket
669  *
670  * Description:
671  * Remove all the NetLabel labeling from @sk.  The caller is responsible for
672  * ensuring that @sk is locked.
673  *
674  */
netlbl_sock_delattr(struct sock * sk)675 void netlbl_sock_delattr(struct sock *sk)
676 {
677 	cipso_v4_sock_delattr(sk);
678 }
679 
680 /**
681  * netlbl_sock_getattr - Determine the security attributes of a sock
682  * @sk: the sock
683  * @secattr: the security attributes
684  *
685  * Description:
686  * Examines the given sock to see if any NetLabel style labeling has been
687  * applied to the sock, if so it parses the socket label and returns the
688  * security attributes in @secattr.  Returns zero on success, negative values
689  * on failure.
690  *
691  */
netlbl_sock_getattr(struct sock * sk,struct netlbl_lsm_secattr * secattr)692 int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
693 {
694 	return cipso_v4_sock_getattr(sk, secattr);
695 }
696 
697 /**
698  * netlbl_conn_setattr - Label a connected socket using the correct protocol
699  * @sk: the socket to label
700  * @addr: the destination address
701  * @secattr: the security attributes
702  *
703  * Description:
704  * Attach the correct label to the given connected socket using the security
705  * attributes specified in @secattr.  The caller is responsible for ensuring
706  * that @sk is locked.  Returns zero on success, negative values on failure.
707  *
708  */
netlbl_conn_setattr(struct sock * sk,struct sockaddr * addr,const struct netlbl_lsm_secattr * secattr)709 int netlbl_conn_setattr(struct sock *sk,
710 			struct sockaddr *addr,
711 			const struct netlbl_lsm_secattr *secattr)
712 {
713 	int ret_val;
714 	struct sockaddr_in *addr4;
715 	struct netlbl_domaddr4_map *af4_entry;
716 
717 	rcu_read_lock();
718 	switch (addr->sa_family) {
719 	case AF_INET:
720 		addr4 = (struct sockaddr_in *)addr;
721 		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
722 						       addr4->sin_addr.s_addr);
723 		if (af4_entry == NULL) {
724 			ret_val = -ENOENT;
725 			goto conn_setattr_return;
726 		}
727 		switch (af4_entry->type) {
728 		case NETLBL_NLTYPE_CIPSOV4:
729 			ret_val = cipso_v4_sock_setattr(sk,
730 						   af4_entry->type_def.cipsov4,
731 						   secattr);
732 			break;
733 		case NETLBL_NLTYPE_UNLABELED:
734 			/* just delete the protocols we support for right now
735 			 * but we could remove other protocols if needed */
736 			cipso_v4_sock_delattr(sk);
737 			ret_val = 0;
738 			break;
739 		default:
740 			ret_val = -ENOENT;
741 		}
742 		break;
743 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
744 	case AF_INET6:
745 		/* since we don't support any IPv6 labeling protocols right
746 		 * now we can optimize everything away until we do */
747 		ret_val = 0;
748 		break;
749 #endif /* IPv6 */
750 	default:
751 		ret_val = 0;
752 	}
753 
754 conn_setattr_return:
755 	rcu_read_unlock();
756 	return ret_val;
757 }
758 
759 /**
760  * netlbl_skbuff_setattr - Label a packet using the correct protocol
761  * @skb: the packet
762  * @family: protocol family
763  * @secattr: the security attributes
764  *
765  * Description:
766  * Attach the correct label to the given packet using the security attributes
767  * specified in @secattr.  Returns zero on success, negative values on failure.
768  *
769  */
netlbl_skbuff_setattr(struct sk_buff * skb,u16 family,const struct netlbl_lsm_secattr * secattr)770 int netlbl_skbuff_setattr(struct sk_buff *skb,
771 			  u16 family,
772 			  const struct netlbl_lsm_secattr *secattr)
773 {
774 	int ret_val;
775 	struct iphdr *hdr4;
776 	struct netlbl_domaddr4_map *af4_entry;
777 
778 	rcu_read_lock();
779 	switch (family) {
780 	case AF_INET:
781 		hdr4 = ip_hdr(skb);
782 		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
783 						       hdr4->daddr);
784 		if (af4_entry == NULL) {
785 			ret_val = -ENOENT;
786 			goto skbuff_setattr_return;
787 		}
788 		switch (af4_entry->type) {
789 		case NETLBL_NLTYPE_CIPSOV4:
790 			ret_val = cipso_v4_skbuff_setattr(skb,
791 						   af4_entry->type_def.cipsov4,
792 						   secattr);
793 			break;
794 		case NETLBL_NLTYPE_UNLABELED:
795 			/* just delete the protocols we support for right now
796 			 * but we could remove other protocols if needed */
797 			ret_val = cipso_v4_skbuff_delattr(skb);
798 			break;
799 		default:
800 			ret_val = -ENOENT;
801 		}
802 		break;
803 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
804 	case AF_INET6:
805 		/* since we don't support any IPv6 labeling protocols right
806 		 * now we can optimize everything away until we do */
807 		ret_val = 0;
808 		break;
809 #endif /* IPv6 */
810 	default:
811 		ret_val = 0;
812 	}
813 
814 skbuff_setattr_return:
815 	rcu_read_unlock();
816 	return ret_val;
817 }
818 
819 /**
820  * netlbl_skbuff_getattr - Determine the security attributes of a packet
821  * @skb: the packet
822  * @family: protocol family
823  * @secattr: the security attributes
824  *
825  * Description:
826  * Examines the given packet to see if a recognized form of packet labeling
827  * is present, if so it parses the packet label and returns the security
828  * attributes in @secattr.  Returns zero on success, negative values on
829  * failure.
830  *
831  */
netlbl_skbuff_getattr(const struct sk_buff * skb,u16 family,struct netlbl_lsm_secattr * secattr)832 int netlbl_skbuff_getattr(const struct sk_buff *skb,
833 			  u16 family,
834 			  struct netlbl_lsm_secattr *secattr)
835 {
836 	if (CIPSO_V4_OPTEXIST(skb) &&
837 	    cipso_v4_skbuff_getattr(skb, secattr) == 0)
838 		return 0;
839 
840 	return netlbl_unlabel_getattr(skb, family, secattr);
841 }
842 
843 /**
844  * netlbl_skbuff_err - Handle a LSM error on a sk_buff
845  * @skb: the packet
846  * @error: the error code
847  * @gateway: true if host is acting as a gateway, false otherwise
848  *
849  * Description:
850  * Deal with a LSM problem when handling the packet in @skb, typically this is
851  * a permission denied problem (-EACCES).  The correct action is determined
852  * according to the packet's labeling protocol.
853  *
854  */
netlbl_skbuff_err(struct sk_buff * skb,int error,int gateway)855 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway)
856 {
857 	if (CIPSO_V4_OPTEXIST(skb))
858 		cipso_v4_error(skb, error, gateway);
859 }
860 
861 /**
862  * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
863  *
864  * Description:
865  * For all of the NetLabel protocols that support some form of label mapping
866  * cache, invalidate the cache.  Returns zero on success, negative values on
867  * error.
868  *
869  */
netlbl_cache_invalidate(void)870 void netlbl_cache_invalidate(void)
871 {
872 	cipso_v4_cache_invalidate();
873 }
874 
875 /**
876  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
877  * @skb: the packet
878  * @secattr: the packet's security attributes
879  *
880  * Description:
881  * Add the LSM security attributes for the given packet to the underlying
882  * NetLabel protocol's label mapping cache.  Returns zero on success, negative
883  * values on error.
884  *
885  */
netlbl_cache_add(const struct sk_buff * skb,const struct netlbl_lsm_secattr * secattr)886 int netlbl_cache_add(const struct sk_buff *skb,
887 		     const struct netlbl_lsm_secattr *secattr)
888 {
889 	if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
890 		return -ENOMSG;
891 
892 	if (CIPSO_V4_OPTEXIST(skb))
893 		return cipso_v4_cache_add(skb, secattr);
894 
895 	return -ENOMSG;
896 }
897 
898 /*
899  * Protocol Engine Functions
900  */
901 
902 /**
903  * netlbl_audit_start - Start an audit message
904  * @type: audit message type
905  * @audit_info: NetLabel audit information
906  *
907  * Description:
908  * Start an audit message using the type specified in @type and fill the audit
909  * message with some fields common to all NetLabel audit messages.  This
910  * function should only be used by protocol engines, not LSMs.  Returns a
911  * pointer to the audit buffer on success, NULL on failure.
912  *
913  */
netlbl_audit_start(int type,struct netlbl_audit * audit_info)914 struct audit_buffer *netlbl_audit_start(int type,
915 					struct netlbl_audit *audit_info)
916 {
917 	return netlbl_audit_start_common(type, audit_info);
918 }
919 
920 /*
921  * Setup Functions
922  */
923 
924 /**
925  * netlbl_init - Initialize NetLabel
926  *
927  * Description:
928  * Perform the required NetLabel initialization before first use.
929  *
930  */
netlbl_init(void)931 static int __init netlbl_init(void)
932 {
933 	int ret_val;
934 
935 	printk(KERN_INFO "NetLabel: Initializing\n");
936 	printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
937 	       (1 << NETLBL_DOMHSH_BITSIZE));
938 	printk(KERN_INFO "NetLabel:  protocols ="
939 	       " UNLABELED"
940 	       " CIPSOv4"
941 	       "\n");
942 
943 	ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
944 	if (ret_val != 0)
945 		goto init_failure;
946 
947 	ret_val = netlbl_unlabel_init(NETLBL_UNLHSH_BITSIZE);
948 	if (ret_val != 0)
949 		goto init_failure;
950 
951 	ret_val = netlbl_netlink_init();
952 	if (ret_val != 0)
953 		goto init_failure;
954 
955 	ret_val = netlbl_unlabel_defconf();
956 	if (ret_val != 0)
957 		goto init_failure;
958 	printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
959 
960 	return 0;
961 
962 init_failure:
963 	panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
964 }
965 
966 subsys_initcall(netlbl_init);
967